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Angiographic and Isotope Pool Circulation Study of the Cerebral Hemispheres After Internal Carotid Artery Occlusion
Angiographic and Isotope Pool Circulation Study of the Cerebral Hemispheres After Internal Carotid Artery Occlusion ERICH
K.
LANG, M.D., F.C.C.P. AND E.
CARL
HANN, M.D.
Indianapolis, Indiana
T
However, an accurate determination of cerebral blood flow would be desirable for a better clinico-pathologic correlation of occlusive arterial disease. Measurements of flow rates and pressures following arterial occlusion have been carried out and plastic models allowing detailed measurements at various points have been constructed.... The most expeditious estimation of circulation in several organs of the body is derived by monitoring the passage of radio-isotopes in the bloodstream with external counting techniques. From an anatomic point of view, the cerebral hemispheres would appear to be particularly suited for such a study. The topographic separation of the head from the rest of the body allows easy shielding and collimation of the counting apparatus against the blood pool in other areas. The essentially symmetrical hemispheres with normally equal blood supply permit easy comparison and base line. However, it should be noted that, commonly, there is asymmetry in the venous flow with durovenous sinuses draining to one side more than the other.l0.l~17 An intravenous injection of radioactive iodinated serum albumin (RISA) with external monitoring and recording has produced consistent and reproduceable results. II.I4-17 The method is felt to be superior to circulation studies depending upon the radioisotope injection into the carotid artery and recovery of the isotope from the jugular vein; mainly because of the relative ease of intravenous injection as compared to the traumatic multiple arterial and venous punctures necessary with the other technique.····· Moreover, any change in intracranial contents and irritation of the arterial system may easily result in exaggerated and false vaiues because of resulting spasm of the intracranial arterial system.
HE BRAIN, WITH A PRE-EXISTING COL-
lateral system, has a unique position in regard to its vascular supply. Willis first recognized the importance of the circle which bears his name in the collateral circulation to the brain. s ,u He demonstrated that, in case of obstruction of one of the carotid arteries, the con t r a I ate r a I brain hemisphere could be successfully supplied via the pre-existing communications of the circle of Willis from the contralateral side. However, apart from all important interconnected canal system of the circle of Willis, multiple other anastomotic pathways have been recognized in the recent past.II.llI.lI-n En d-t o-e n d ana.~tomoses between the distal branches of the anterior, middle and posterior cerebral arteries have been demonstrated angiographically. Anastomotic channels between the external and internal carotid arteries, namely the angular artery, the superficial temporal artery, the pterygopalatine artery, the inferior orbital artery, the ophthalmic artery, and particularly the mid meningeal and middle cerebral artery are likewise readily demonstrable angiographically.I:I.Io.1I Particularly the direct analitomotic branch between the mid meningeal artery of the external carotid and mid meningeal group of the mid cerebral artery often refillli the siphon portion of the internal carotid in cases of complete occlusion of the internal carotid in the neck area. The rete-~{irabile, consisting of small anastomotic branches between the meningeal arteries and the dura likewise serve as a major anastomotic group." These vessels may extend through the bone and anastomose with the arteries of the scalp. The angiographic examination by arterial injection of radiopaq ue media gives an adequate anatomic demonstration of the main arteries and collateral systems.'
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A~r;rO(;RAPHIC
A:-;n ISOTOPE POOr. CIRCl:LATlO:-; STl:OY
TECH~IQUE
Forty to 100 microcuries of radioactive iodinated serum albumin RIS..\ arc injected intravenously, The right and left hemispheres are "seen" by a crystal adequately collimated and shielded to allow exposure of the crystal by only the respective hemisphere or part of the respecti"e hemisphere. It is admitted that the contribution to the count rate in anteroposterior projection is greatly influenced by the geometric proximity of the frontal lobe in contrast to the geometrically distant occipital lohe, ~lore over, in ,'iew of the sc,'ere collimation onh' a portion of the respectin frontal lobe and a greater portion of the occipital lobe are "seen" by the crystal. Nonetheless. the accrued error should be the same on the right and left side. ao;suming that the geometr;.' of source, recipient scintillation cr;.'stal and interposed material arc maintained. It is conceded that selective thrombosis of the anterior cerebral group or the postf'riur cer-
ebral group could be reflected by markedly exaggerated "alues in this data presentatiun since the geometric factor and im'erse square law may considerably influence the count rates under these conditions. The time constant of the rate meter must not exceed one second since the rapidly changin,g rate of counts has to be recorded accurately to present the data in a proper curve, The impubes received via scintillation cr;.'stal are recorded on a count rate meter preferahly in a graphic curn demonstration, The first flat portion of the cun'e represents the arm-ta-brain circulation time. The rapidly ascending part of the cun'e is initialh' due to the arterial flow into the hemisphere; the upper one-third of the steeply rising slope is due to a combination of arterial flow. capillary pool, and venous return, The final plateau of the eun'e is proportional to the isotope volume in the cerebral vascular system after equal distribution throughout the body.
FIGURE I: Note the excellent refilling of the siphon segment of the carotid artery via the ophthalmic and hugely dilated midmeningeal branches of the external carotid system, (Reproduced from Radiolog)·, 83:
632, 1964).
Diseases of the Chest
LANG AND HANN
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The slope of the sharply ascending curve is affected by the amount of radio-isotope injected, the rate of blood flow, the sensitivity of the apparatus, and its integration time, and lastly the intactness of the bolus of the isotope. If one excludes the possibility of systemic left-to-right or right-to-Ieft shunts, all these factors will cancel out and only a difference in the rate of blood flow will cause a disparity and difference in the slopes. Thus, it can be safely assumed that a change in the slope reflects the overall arterial flow and the status of the arterial system. RESULTS
Fifty-eight patients with known thrombosis of one or both of the internal carotid arteries were subjected to serial carotid arteriograms and serial radio-isotope flow studies. Eighteen of the patientl\ were examined on at least two occasions with an adequate interval between the two examinations to allow fonnation of collateral supply after the acute arterial thrombosis.
These cases classically demonstrated not only a change in the arteriographic pattern with fonnation of dilated and prominent collateral channels, par tic u Ia rIy via the ophthalmic artery, the mid meningeal group, and the pterygopalatine artery with resulting re-opacification of the siphon segment of the affected carotid artery, but showed also a considerable improvement in the isotope pool curve over the affected hemisphere. While the slope would never quite equal the nonnal side in steepness of ascent, the peak of the arterial and venous maximum isotope pool would equal that of the nonnal side in several instances. Progressive narrowing of the base of the curve reflects improving and increasing collateral supply, resulting in rapid delivery of the isotope bolus. Delayed descent to the plateau level appears to reflect sluggish venous circulation and prolonged pooling in the capillary bed. It was of particular interest to note a significant correlation to the clinical picture.
TABLE I-CORJlELATION OF THE ARTERTOORAPHICALLY DEMONSTRATED LESION TO THE IsOTOPE CURVE ApPEARANCE (58 PATIENTS) Total Number Patients 58
Acute Thrombosis Old Thrombosis a. With collateral supply via anterior communicator b. With collateral supply via posterior communicator and vertebral arteries c. With collateral supply the external carotid system d. Collateral supply by r~canalization
e. Combination of a and of c f. Combination of c and of d Thrombosis of both Carotid Arteries a. Collateral supply via the vertebral arteries b. Collateral supply via the external carotid system c. Collateral supply by recanalization d. Combination of a, b and of c
11 39
Appearance of Radio-Isotope Curve; Peak Height, Width of Base of Curve and Ascent of Slope Nonnal Flat Ascent Ascent Near of the of Nonnal Lowered Nonnal Broad Slope Base Curve Peak Base Peak 11 11 11
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A:"GIOGRAPHIC A:"D ISOTOPE POOl. CIRCULATIO:" STUOY
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TABLE 2-PATIE:-TS SUBJECTED TO MULTIPLE EXAMINATIONS AT ABOUT SIX MO:-TH INTERVALS·
Total Patients in This Group
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Acute Thrombosis With increased external collateral supply b. Recanalizations c. Collateral supply over th(' circle of Willis d. Combination of a and b e. Combination of a and c
Old Thrombosis a. With incrl'ase of the ('xternal collateral supply b. Recanalization c. Collaterals over th(' circle of Willis d. Combinalion of a and b e. Combination of a and c
Appearance of the Radio-Isotope Curve Steepening of Narrowing of the Ascent of the Increase of the Base of Slope of the the Peak the Curve Count Rate Curve
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·Reproduced from Radi%g)·, 83: 632, 1964.
FIGllRE 2: Note complete obstruction of the internal carotid at the level of the bifurcation and refilling of the siphon segment of the interal carotid predominantly via the markedly dilated ophthalmic artery.
LA:".. A:"n HA:":"
Patients who failed to show any permanent neurologic deficit would usually present an isotope pool curve resembling the normal side in steepness of ascent and width of base, as well as height of the arterial and venous maximum peak. Conversely, subacute thrombosis cases with only poor collateral formation would show an extremely flat ascent of the slope of the isotope pool cur..-e reflecting a delayed and reduced flow of blood to this hemisphere. The most effective collateral delivery of blood to the affected hemisphere is \'ia the anterior communicator branch and the circle of Willis. The isotope pool CUf\'es in these patients showed a fairly steep ascent of the slope, but a somewhat lowered peak, The phenomenon, however, is explained on a technicaJ basis since the cf\'stal is unable to see the entire area supplied by the anterior cerebral group but integrates all of the counts of the occipital region. Hence. the
Disease's of the Ch."
contribution, in spite of the inverse square law, from the anterior cerebral group is less because of the limited amount of area seen by the crystal. Of II patients in this group, eight revealed a near normal isotope cun·e. :\part from a slight delay in the ascent of the curve, there was no substantiaJ difference to the normal side with the exception of a slight decrease in the peak height. In contrast to the patients supplied predominantly via a collateral system, the angle of the ascent slope is not significantly changed in comparison with normal values. However. a narrow base of the CUf\'e reflect~ best the prompt delivery of the isotope in form of a bolus. Com'ersely, patients with thrombosis of both carotid arteries and ma<;.<;ive collateral supply via the external carotid. the vertebral and posterior communicator arteries showed considerable widening of the base, a less steep ascent. but ultimately a higher
FIGURE 3: Demonstration of excellent cross circulation over the anterior communicator arteries of the circle of Willis with complete filling of the contralateral anterior and midcerebral group.
Volume 48, !'\o..\ SC'rtembc-r I yC,c.,
A:-.:r.IOGRAPHIC A:'\D ISOTOPE POOL CIRCULATIO:-': STUDY
peak. This again is partially caused by geometric factors determining the data presentation. The area of the posterior cerebral artery is completely seen by the crystal whereas the poorer supplied anterior and midcerebral region is only partial1y integrated by the crystal. In five patients with thrombosis of both carotid arteries, a dominant supply over col1aterals of the external system and the posterior communicator arteries was noted, The considerable broadening of the base of the cun'c reflects also a sluggish venous and capillary circulation with slow dissipation of thc bolus. Analysis of the isotope curves reveal that the integral area below the cun'e reflccts the total amount of isotope entering the brain blood pool. However, the clinically significant factor is related to the blood flow per unit time. Hence, the adequacy of collateral supply is best a."<;essed by the steepness in the ascent of the slope of the cun'e and the relative width of the cun'e rather than overall volume area or peak of the cun'e. The most frequently encountered collateral supply way is between thc external and internal carotid system. Particularly the
FIGURE 4: The affected hemisphere shows a 3 second delay in the sharp ascent of the slope, However, the steepness of the angle of the ascent slope n-f1ects excellent collateral circulation via large collateral vessels. The width of the base of the curve is near double that of the normal size. This is probably Ihe most sensitive indicator for assessment of a sluggish capillary and venous circulation and stasis in the brain blood pool.
ophthalmic, palpebral, and midmeningeal arteries wil1 readily dilate and contribute to collateral supply as demonstrated on serial arteriograms. The pterygopalatine branch can likewise contribute to the collateral blood flow. Of a group of 28 patients, 14showed a normal base of their radioisotope curve. Eighteen showed near normal ascent of the slope reflecting rapid blood flow via thc col1ateral system. However, in 15 patients, broadening of the base, flatness in the ascent of the isotope cun'e or both were present. This reflected presence of collatcral flow, but definite decrea.<;e in flow volume per unit time. It wa.s of interest to note that in many of these patients, the peak of the isotope cun'e would be near normal..\ combination of supply via collateral vesseL'i and \·ia the anterior communicators of the circle of Willis as well as recanalized segment of the thrombosed artery are obsen'ed, but did not significantly alter the overall blood flow. SUMMARY
Fifty-eight patients with known occlusive disease of the internal carotid artery were examined by arteriograms and radio-iso
FIGt'RE 5: Note the incre~d width of the b~ of both the right and left hemispheres. The steepness in ascent is better on the left side reflecting the intactness of the isotope bolus. On the right side, an ascent deflection precedes the left side by almost 2 seconds. This reflects dilatation of the external carotid system often seen in more acute cases of carotid artery thrombosis. A n-lative flatness in the ascent of the slope reflects the relatively poor development of a collateral system.
Di~a~s 01
LANG ANn HANN
tope flow studies. The arteriograms offered an excellent demonstration of collateral pathways, particularly via the ophthalmic, pterygopalatine and midmeningeal branches of the external system. The patency and presence of anterior or posteriorly communicator arteries are likewise readily assessed by this method. Radio-isotope flow studies were particularly useful for finite assessment of blood flow per unit time to the affected hemisphere. The angle of the ascending slope of the isotope curve, the width of the base, and the angle of the descending slope give a reliable picture of the overall flow rate per unit time to the affected hemisphere. The width of the slope more or less corresponding to the brain pool transit time is the most sensitive indicator. A mean nonnal brain pool transit time is five to nine seconds. \\'ith significant occlusive disease, the transit time may be prolonged 14 to 26 seconds. The angle and steepness of the ascending slope are likewise a sensitive indicator for the intactness of the isotope bolus and rapidity of delivery of blood to the affected area. The overall volume entering the affected hemisphere reflected by the area below the entire curve is the least sensitive and appropriate measurement. The height of the peak of the curve is likewise of secondary clinical significance since sluggishness of the circulation and increased brain pool transit time may actually result in increased height of the peak. An excellent correlation between the clinical picture and the appearance of the isotope curve, as well as the arteriogram was noted in this series. The change in the width of the curve and the width of the base of the curve appeared to bear a most significant correlation to the clinical improvement of the patient and his potential for ultimate recovery. RESUMEN
Cincuenta y ocho sujetos con oclusion patologica manifesta de la carotida intema fueron estudiados mediante arteriogramas y determinaciones radio-isotopicas del flu jo sanguineo. Los arteriogramas proporcionaron una demostracion excelente de la circulacion colateral, particularmente via la rama oftal mica. pteriogo-palatina
the Chest
y meningeas medios del sistema externo. La presencia y permeabilidad de comunicantes anteriores y posteriores son susceptibles tambien de demostracion por este metodo. Los radioisotopos fueron particularmente {niles para la determinacion del flujo sanguineo por unidad de tiempo en el hemisferio afectado. EI angulo de la rama ascendente de la curva isotopica, la latitud de su base y el declive de su rama descendente reflejan fielmente el volumen del flujo total por unidad de tiempo en el hemisferio afectado. La latitud de la grafica, que corresponde aproximadamente con el tiempo de transito por el reservorio sanguineo encefalico, es el indicador de mayor sensibilidad. EI promedio normal del tiempo de transito es de cinco a nueve segundos. En las alteraciones patologicas oclusivas de importancia este tiempo puede aumentar hasta de 14 a 26 segundos. EI angulo y el gradiente de la rama ascendente de la curva es tambien un indicador sensible de la integridad del bolo isotopico y de la rapidez del aporte sanguineo a la parte afectada. EI area bajo la cun'a, como expresion del volumen total de sangre que entra en el hemisferio afectado. es el indice menos apropriado y exacto en este tipo de investigacion. La altura de la curva es asi mismo de importancia clinica secundaria. En nuestra serie observamos una correlacion excelente entre el cuadro clinico. la curva isotopica y el arteriograma. Los cambios en la latitud de la curva y en la de la base de la curva presentan una correlacion muy significativa con la mejoria clinica y las posibilidades de recuperacion definitiva. RESUME
Cinquante huit malades ayant une maladie occlusive connue de I'arthe carotide interne, ont ete examines par des etudes arteriographiques et de circulation de radio-isotopes. Des arteriographies ont donne une excellente preuve des \'oies collaterales, en particulier a travers les branches ophtalmiques, pterygo-pa lat ines et meningees moyennes du syst~me exteme. La permeabilite et la presence de communiquantes anterieures ou posterieures sont facilement demontrees par celte methode. Les etudes de circulation de radio-isotopes ont ete particuli~rement utiles pour la determination definie du flot sanguin par unite de temps a I'hemisphhe interesse. L'angle de la pente ascendante de la courbe d'isotopes, la largeur de la base, et l'angle de la courbe descendante, donnent une image fid~le du flot sanguin total par unite de temps a I'hemisphhe considere. La largeur de la pente correspondant plus ou moins au temps de traversee de la reserve cerebrale est I'indicateur Ie plus sensible. Un temps moyen normal de traversee cerebra Ie varie de 5 a 9 secondes. Avec une maladie occlusive
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ANGIOGRAPHIC AND ISOTOPE POOL CIRCULATION STUDY
significative, Ie temps de traversee peut etre prolonge de 14 a 26 secondes. L'angle et la rapidite d'ascension de la couroe est de meme un indicateur sensible pour I'integrite du hoi isotope, et pour la rapidite d'apport du sang a la region considere. Le volume total penetrant dans I'hemisphere considere, traduit par la surface se trouvant sur la couroe entiere, est la mesure la moins sensible et appropriee. La hauteur du pic de la courbe, a de meme une signification clinique secondaire, etant donne que Ie ralentissement de la circulation et l'augmentation du temps de traversee de la reserve cerebrale peuvent entrainer une augmentation de la hauteur du pic. Une excel? lente correlation entre Ie tableu clinique et l'apparition de la courbe d'isotope aussi bien que I'arteriographie a ete notee dans cette serie. us changements dans la largeur de la combe et la largeur de la base de la courhe semblent presenter une correlation significative avec l'amelioration clinique du malade et sa possibilite de guerison ulterieure. ZUSAMMF:NF.O\SSUNG Untersuchung liher 58 Patienten mit hekannter Verschlu13krankheit der art. carotis int. mit Untersuchungen durch Arteriogramme und RadioIsotopen. Die Arteriogramme liefem einen ausgezeichneten Nachweis der kollateralen Vebindungen, hesonders auf den \Vege liber die vasa ophtalmico, vasa pterygopalatina und menigea media als Asten des Systems de art, carotis extema. Die Durchgangigkeit und das VVorliegen von anterioren bzw. posterioren Verbindungswegen Uil3t sich ebenfalls leicht auf diesen Wege feststellen. Durchstrorungsstudien mit Radio-Isotopen waren von hesonderem Wert zu einer ganauen Ermittlung der Durchstromung bezogen auf die Zeiteinheit und die betroffene Hirnhemisphare. Der Winkel des aufsteigenden Astes der IsotopenKurve, die lichte Weite der Basis und der Winkel des absteigenden Schenkels gehen ein zuverlassiges Bild der gesamten Durchstromung-bezogen auf die Zeiteinheit fUr die betroffene Hemisphare. Die lichte Weite der Kurve, mehr oder weniger in Obereinstimmung mit der zusammengefa13ten Gesamtdurchstromungszeit des Gehims ist der meist f'mpfindliche Indikator. Die mittlere normale Gesamtgehirndurchstromungszeit betrigt 5 9 Sek. Bei wesentlicher Verschlul3krankheit bnn die Durchstromungzeit auf 14 - 26 Sek, verlangert sein. Ded Winkel und die Steilheit des aufsteigenden Kurvenastes ist ebenfalls ein empfindlicher Indikator fUr die Glite des Isotopenstiicks und die Geschwindigkeit der Blutzufuhr fUr das befallene Gebiet. Das Gesamtvolumen, das in die betreffende Hemisphare eintritt und dmch den Bereich unterhalb der gesamten Kurve dargestellt wird, ist der wenigst empfindliche und geeignete Gradmesser. Die Gipfelhohe der Kurve ist in
gleicher Weise nur von sekundarer klinischer Bedeutung, da die Verzogerung der Zirkulation und die erhohte Gesamtgehirndurchstromungszeit in einer hoheren Gipfelkurve zum Ausdruck kommen kann. Eine ausgezeichnte Korrelation zwischen dem klinischen Bild und dem Erscheinungsbild der Isotopen-Kurve ebenso dem Arteriogramm wurde bei diesem Krankengut festgestellt. Der Wandel in der Kurvenbreite und das Ausma13 der Basiswerte der Kurve dlirften die besonders signifikante Korrelation enthalten, bezogen auf die klinische Besserung des Patienten und sein Vermogen fUr eine schliessliche Erholung.
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REFERENCES AVMAN, N. AND BEllINO, E. A.: "A Plastic Model for the Study of Pressure Changes in the Circle of Willis and Major Cerebral Arteries Following Arterial Occlusion," }. Neurosurg., 18: 361, 1961. BAKAY, L. AND SWEEK, W. H.: "Intra-arterial Pressures in the Neck and Brain-Late Changes After Carotid Closure, Acute Measurements After Vertebral Closure," }. Neurosur,., 10: 353, 1953. BEEVER, C. E.: "The Cerebral Arterial Supply," Brain, 30:403, 1907. BELL, R. F. AND HERTSCR, G. T.: "The Detennination of Cerebral Circulation Time," }. Nucl. Med., 3:399, 1962. ELSCHNIO, A.: "Die Folgen der Carotisunterbindung fuer das Centralgefaessystem der Retina," Med. Klin., 7: 1943, 1911. FAZIO, C. AND FEISCHI, C.: "Evaluation of Cerebral Hemydynamics With Radioactive Isotopes," Minerva Nucleare, 4: 324, 1960. FISHER, A. G. T.: "A Case of Complete Absence of Both Internal Carotid Arteries, With a Preliminary Note on the Development History of the Strapedial Artery," }. Anat., 48:37, 1913. GREITZ, T.: "A Radiologic Study of the Brain Circulation by Rapid Angiography of The Carotid Artery," Acta Radial. Suppl., 140: 123, 1956. KETY, S. S. AND SCHlKIDT, C. F.: "The Nitrous Oxide Method for the Quantitative Determination of Cerebral Blood Flow in Man; Theory, Procedure and Normal Values," }. Clin. Invest., 27: 476, 1948. LANO, E. K., HANN, E. C. AND LURos, T. J.: "Arteriographic Demonstration of External-Internal Carotid Anastomoses and Their Correlation to RISA Circulation Studies," Radiology, 71:768,1964. LoWREY, L. G.: "Anomaly in The Circle of Willis, Due to Absence of the Right Internal Carotid Artery," Anat. Rec., 10:221, 1916. MOUNT, L. A. AND TAVERAS, J. M.: "A Study of the Collateral Circulation of the Brain Following Ligation of the Internal Carotid Artery," Tr. Am. Neural. A., 78:47, 1953. MOUNT, L. A. AND TAVERAS, J. M.: "Arteriagraphic Demonstration of the Collateral Circulation of the Cerebral Hemispheres," AMA A rd. N eurol. and Psychiat., 78: 235, 1957. OLDun>ORF, W. H.: "Measurement of the Mean Transit Time of Cerebral Circulation by
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External Detection of an Intravenously Injected Radio-Isotope," ]. Nucl. Med., 3: 382, 1962. OLDENDORF, W. H., CRANDALL, P. M., NORDYKE, R. A. AND ROSE, A. S.: "A Comparison of the Arrival in the Cerebral Hemispheres of Intravenously Injected Radio-Isotope," ]. Neurol., 10: 223, 1960. OLDENDORF, W. H. AND CRANDALL, P. M.: "Bilateral Cerebral Circulation Curves Obtained by Intravenous Injection of Radio-Isotopes," ]. N eurosurg., 19: 195, 1961. OLDENDORF, W. H. AND KITANO, M.: "Measurement of Brain Circulation Time by an Intravenous Radio-Isotope Technique," Unpub. Data~oc. Nucl. M ed., June 17-20, 1964, Berkeley. SACHS, E., JR.: "Arteriographic Demonstration of Collateral Circulation Through the Ophthalmic Artery in Internal Carotid Artery Thrombosis; Report of Two Cases," ]. Neurosurg., 11 :405, 1954. SEAMAN, W. B., PAGE, W. R. AND GERMAN. W. J.: "Arteriographic Findings in Brain Ar-
HANN
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Diseases of the Chest
terial Occlusion," Tr. Am. Neurol. Asm., 74: 55, 1949. TAVERAS, J. M., MOUNT, L. A. AND FRIEDENBERG, R. M.: "Arteriographic Demonstration of External-Internal Carotid Anastomoses Through the Ophthalmic Arteries," Radiology, 63: 525, 1954. TORKILDSEN, A. AND KOPPANG, K.: "Notes on the Collateral Cerebral Circulation as Demonstrated by Carotid Angiography," ]. Neurosurg., 8: 269, 1951. WELCH, K., STEPHENS, J., HUBER, W. AND INGERSOLL, C.: "The CoUateral Circulation Following Middle Cerebral Branch Occlusion," ]. NeMrosurg., 12:361, 1955. WILLIS, T.: Two Discourses Concerning the Soul of Brutes, in his Practice of Physick, Be-
ing the Whole Works of That Renouned and Famous Physician, Containing These Eleven Several Treatises, London, T. Dring. C. Harper, and J. Leigh, 1684. For reprints, please write: Dr. Lang, Methodist Hospital. Indianapolis.
PROGNOSIS OF COAL-MINERS WITH LUNG CANCER A retrospective survey was conducted on 746 hospital patients from South Wales. of whom 172 had been miners and 518 non-miners. During the first five years of fol1owup. there was no appreciable difference In survival rates between the two occupational groups, whether they were treated surglcal1y or otherwise, and the rate of surgical resection was similar In each group. However, an analysis of the miners' experience In relation to the presence and extent of coincidental pneumoconiosis showed a con-
slstent association. survival Increasing with a rise In the radiographic category of simple pneumoconiosis. The highest two-year survival rates In the series were in the small proportion of miners with categories 2 and 3 pneumoconiosis. This association would be expected If the spread of lung cancer in miners' lungs were Impeded by coal-dust. GOLDMAN, K. P.: "Prognosis of Coal-miners with Cancer of the Lung," Tho,tlx, 20:170, 19M.
EXTERNAL RESPIRATORY FUNCTION IN MYOCARDIAL INFARCTION External respiration In :I) patients :I) to 60 days after acute myocardial infarction. and In 20 patients at periods ranging from six to 12 months was Investigated. In patients at different periods after myocardial Infarction. functional disturbances 01 the external respiration were manifested by an Increased minute ventlJatlon, decreased vital capacity. reduced maximum breathing capacity, reserve all' and coefficient of oxygen consumption, decreased oX)'gen absorption per minute. In 93 per cent of patients exam-
Ined :I) to 60 days after acute myocardial Infarction, the author noted respiratory insu"'clency. Investigations performed 6 to 12 months later disclosed respiratory Insufflclency In 80 per cent of cases. The author attributes functional disturbances of the external respiration to latent right ventricular Insufflclency. NECHAEV, S. I.: "The Functional State of the Apparatus of External Respiration in Patients After Sustained Myocardial Infarction," Sor;tt MtlJ.• 28:B, 196'.
K.
LANG, M.D., F.C.C.P. AND E.
CARL
HANN, M.D.
Indianapolis, Indiana
T
However, an accurate determination of cerebral blood flow would be desirable for a better clinico-pathologic correlation of occlusive arterial disease. Measurements of flow rates and pressures following arterial occlusion have been carried out and plastic models allowing detailed measurements at various points have been constructed.... The most expeditious estimation of circulation in several organs of the body is derived by monitoring the passage of radio-isotopes in the bloodstream with external counting techniques. From an anatomic point of view, the cerebral hemispheres would appear to be particularly suited for such a study. The topographic separation of the head from the rest of the body allows easy shielding and collimation of the counting apparatus against the blood pool in other areas. The essentially symmetrical hemispheres with normally equal blood supply permit easy comparison and base line. However, it should be noted that, commonly, there is asymmetry in the venous flow with durovenous sinuses draining to one side more than the other.l0.l~17 An intravenous injection of radioactive iodinated serum albumin (RISA) with external monitoring and recording has produced consistent and reproduceable results. II.I4-17 The method is felt to be superior to circulation studies depending upon the radioisotope injection into the carotid artery and recovery of the isotope from the jugular vein; mainly because of the relative ease of intravenous injection as compared to the traumatic multiple arterial and venous punctures necessary with the other technique.····· Moreover, any change in intracranial contents and irritation of the arterial system may easily result in exaggerated and false vaiues because of resulting spasm of the intracranial arterial system.
HE BRAIN, WITH A PRE-EXISTING COL-
lateral system, has a unique position in regard to its vascular supply. Willis first recognized the importance of the circle which bears his name in the collateral circulation to the brain. s ,u He demonstrated that, in case of obstruction of one of the carotid arteries, the con t r a I ate r a I brain hemisphere could be successfully supplied via the pre-existing communications of the circle of Willis from the contralateral side. However, apart from all important interconnected canal system of the circle of Willis, multiple other anastomotic pathways have been recognized in the recent past.II.llI.lI-n En d-t o-e n d ana.~tomoses between the distal branches of the anterior, middle and posterior cerebral arteries have been demonstrated angiographically. Anastomotic channels between the external and internal carotid arteries, namely the angular artery, the superficial temporal artery, the pterygopalatine artery, the inferior orbital artery, the ophthalmic artery, and particularly the mid meningeal and middle cerebral artery are likewise readily demonstrable angiographically.I:I.Io.1I Particularly the direct analitomotic branch between the mid meningeal artery of the external carotid and mid meningeal group of the mid cerebral artery often refillli the siphon portion of the internal carotid in cases of complete occlusion of the internal carotid in the neck area. The rete-~{irabile, consisting of small anastomotic branches between the meningeal arteries and the dura likewise serve as a major anastomotic group." These vessels may extend through the bone and anastomose with the arteries of the scalp. The angiographic examination by arterial injection of radiopaq ue media gives an adequate anatomic demonstration of the main arteries and collateral systems.'
278
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Volum~iH.
Sertt'm~r
A~r;rO(;RAPHIC
A:-;n ISOTOPE POOr. CIRCl:LATlO:-; STl:OY
TECH~IQUE
Forty to 100 microcuries of radioactive iodinated serum albumin RIS..\ arc injected intravenously, The right and left hemispheres are "seen" by a crystal adequately collimated and shielded to allow exposure of the crystal by only the respective hemisphere or part of the respecti"e hemisphere. It is admitted that the contribution to the count rate in anteroposterior projection is greatly influenced by the geometric proximity of the frontal lobe in contrast to the geometrically distant occipital lohe, ~lore over, in ,'iew of the sc,'ere collimation onh' a portion of the respectin frontal lobe and a greater portion of the occipital lobe are "seen" by the crystal. Nonetheless. the accrued error should be the same on the right and left side. ao;suming that the geometr;.' of source, recipient scintillation cr;.'stal and interposed material arc maintained. It is conceded that selective thrombosis of the anterior cerebral group or the postf'riur cer-
ebral group could be reflected by markedly exaggerated "alues in this data presentatiun since the geometric factor and im'erse square law may considerably influence the count rates under these conditions. The time constant of the rate meter must not exceed one second since the rapidly changin,g rate of counts has to be recorded accurately to present the data in a proper curve, The impubes received via scintillation cr;.'stal are recorded on a count rate meter preferahly in a graphic curn demonstration, The first flat portion of the cun'e represents the arm-ta-brain circulation time. The rapidly ascending part of the cun'e is initialh' due to the arterial flow into the hemisphere; the upper one-third of the steeply rising slope is due to a combination of arterial flow. capillary pool, and venous return, The final plateau of the eun'e is proportional to the isotope volume in the cerebral vascular system after equal distribution throughout the body.
FIGURE I: Note the excellent refilling of the siphon segment of the carotid artery via the ophthalmic and hugely dilated midmeningeal branches of the external carotid system, (Reproduced from Radiolog)·, 83:
632, 1964).
Diseases of the Chest
LANG AND HANN
280
The slope of the sharply ascending curve is affected by the amount of radio-isotope injected, the rate of blood flow, the sensitivity of the apparatus, and its integration time, and lastly the intactness of the bolus of the isotope. If one excludes the possibility of systemic left-to-right or right-to-Ieft shunts, all these factors will cancel out and only a difference in the rate of blood flow will cause a disparity and difference in the slopes. Thus, it can be safely assumed that a change in the slope reflects the overall arterial flow and the status of the arterial system. RESULTS
Fifty-eight patients with known thrombosis of one or both of the internal carotid arteries were subjected to serial carotid arteriograms and serial radio-isotope flow studies. Eighteen of the patientl\ were examined on at least two occasions with an adequate interval between the two examinations to allow fonnation of collateral supply after the acute arterial thrombosis.
These cases classically demonstrated not only a change in the arteriographic pattern with fonnation of dilated and prominent collateral channels, par tic u Ia rIy via the ophthalmic artery, the mid meningeal group, and the pterygopalatine artery with resulting re-opacification of the siphon segment of the affected carotid artery, but showed also a considerable improvement in the isotope pool curve over the affected hemisphere. While the slope would never quite equal the nonnal side in steepness of ascent, the peak of the arterial and venous maximum isotope pool would equal that of the nonnal side in several instances. Progressive narrowing of the base of the curve reflects improving and increasing collateral supply, resulting in rapid delivery of the isotope bolus. Delayed descent to the plateau level appears to reflect sluggish venous circulation and prolonged pooling in the capillary bed. It was of particular interest to note a significant correlation to the clinical picture.
TABLE I-CORJlELATION OF THE ARTERTOORAPHICALLY DEMONSTRATED LESION TO THE IsOTOPE CURVE ApPEARANCE (58 PATIENTS) Total Number Patients 58
Acute Thrombosis Old Thrombosis a. With collateral supply via anterior communicator b. With collateral supply via posterior communicator and vertebral arteries c. With collateral supply the external carotid system d. Collateral supply by r~canalization
e. Combination of a and of c f. Combination of c and of d Thrombosis of both Carotid Arteries a. Collateral supply via the vertebral arteries b. Collateral supply via the external carotid system c. Collateral supply by recanalization d. Combination of a, b and of c
11 39
Appearance of Radio-Isotope Curve; Peak Height, Width of Base of Curve and Ascent of Slope Nonnal Flat Ascent Ascent Near of the of Nonnal Lowered Nonnal Broad Slope Base Curve Peak Base Peak 11 11 11
II
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A:"GIOGRAPHIC A:"D ISOTOPE POOl. CIRCULATIO:" STUOY
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TABLE 2-PATIE:-TS SUBJECTED TO MULTIPLE EXAMINATIONS AT ABOUT SIX MO:-TH INTERVALS·
Total Patients in This Group
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Acute Thrombosis With increased external collateral supply b. Recanalizations c. Collateral supply over th(' circle of Willis d. Combination of a and b e. Combination of a and c
Old Thrombosis a. With incrl'ase of the ('xternal collateral supply b. Recanalization c. Collaterals over th(' circle of Willis d. Combinalion of a and b e. Combination of a and c
Appearance of the Radio-Isotope Curve Steepening of Narrowing of the Ascent of the Increase of the Base of Slope of the the Peak the Curve Count Rate Curve
~- -~~-~~~-
8
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-------
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:;
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'l
8 I
8
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·Reproduced from Radi%g)·, 83: 632, 1964.
FIGllRE 2: Note complete obstruction of the internal carotid at the level of the bifurcation and refilling of the siphon segment of the interal carotid predominantly via the markedly dilated ophthalmic artery.
LA:".. A:"n HA:":"
Patients who failed to show any permanent neurologic deficit would usually present an isotope pool curve resembling the normal side in steepness of ascent and width of base, as well as height of the arterial and venous maximum peak. Conversely, subacute thrombosis cases with only poor collateral formation would show an extremely flat ascent of the slope of the isotope pool cur..-e reflecting a delayed and reduced flow of blood to this hemisphere. The most effective collateral delivery of blood to the affected hemisphere is \'ia the anterior communicator branch and the circle of Willis. The isotope pool CUf\'es in these patients showed a fairly steep ascent of the slope, but a somewhat lowered peak, The phenomenon, however, is explained on a technicaJ basis since the cf\'stal is unable to see the entire area supplied by the anterior cerebral group but integrates all of the counts of the occipital region. Hence. the
Disease's of the Ch."
contribution, in spite of the inverse square law, from the anterior cerebral group is less because of the limited amount of area seen by the crystal. Of II patients in this group, eight revealed a near normal isotope cun·e. :\part from a slight delay in the ascent of the curve, there was no substantiaJ difference to the normal side with the exception of a slight decrease in the peak height. In contrast to the patients supplied predominantly via a collateral system, the angle of the ascent slope is not significantly changed in comparison with normal values. However. a narrow base of the CUf\'e reflect~ best the prompt delivery of the isotope in form of a bolus. Com'ersely, patients with thrombosis of both carotid arteries and ma<;.<;ive collateral supply via the external carotid. the vertebral and posterior communicator arteries showed considerable widening of the base, a less steep ascent. but ultimately a higher
FIGURE 3: Demonstration of excellent cross circulation over the anterior communicator arteries of the circle of Willis with complete filling of the contralateral anterior and midcerebral group.
Volume 48, !'\o..\ SC'rtembc-r I yC,c.,
A:-.:r.IOGRAPHIC A:'\D ISOTOPE POOL CIRCULATIO:-': STUDY
peak. This again is partially caused by geometric factors determining the data presentation. The area of the posterior cerebral artery is completely seen by the crystal whereas the poorer supplied anterior and midcerebral region is only partial1y integrated by the crystal. In five patients with thrombosis of both carotid arteries, a dominant supply over col1aterals of the external system and the posterior communicator arteries was noted, The considerable broadening of the base of the cun'c reflects also a sluggish venous and capillary circulation with slow dissipation of thc bolus. Analysis of the isotope curves reveal that the integral area below the cun'e reflccts the total amount of isotope entering the brain blood pool. However, the clinically significant factor is related to the blood flow per unit time. Hence, the adequacy of collateral supply is best a."<;essed by the steepness in the ascent of the slope of the cun'e and the relative width of the cun'e rather than overall volume area or peak of the cun'e. The most frequently encountered collateral supply way is between thc external and internal carotid system. Particularly the
FIGURE 4: The affected hemisphere shows a 3 second delay in the sharp ascent of the slope, However, the steepness of the angle of the ascent slope n-f1ects excellent collateral circulation via large collateral vessels. The width of the base of the curve is near double that of the normal size. This is probably Ihe most sensitive indicator for assessment of a sluggish capillary and venous circulation and stasis in the brain blood pool.
ophthalmic, palpebral, and midmeningeal arteries wil1 readily dilate and contribute to collateral supply as demonstrated on serial arteriograms. The pterygopalatine branch can likewise contribute to the collateral blood flow. Of a group of 28 patients, 14showed a normal base of their radioisotope curve. Eighteen showed near normal ascent of the slope reflecting rapid blood flow via thc col1ateral system. However, in 15 patients, broadening of the base, flatness in the ascent of the isotope cun'e or both were present. This reflected presence of collatcral flow, but definite decrea.<;e in flow volume per unit time. It wa.s of interest to note that in many of these patients, the peak of the isotope cun'e would be near normal..\ combination of supply via collateral vesseL'i and \·ia the anterior communicators of the circle of Willis as well as recanalized segment of the thrombosed artery are obsen'ed, but did not significantly alter the overall blood flow. SUMMARY
Fifty-eight patients with known occlusive disease of the internal carotid artery were examined by arteriograms and radio-iso
FIGt'RE 5: Note the incre~d width of the b~ of both the right and left hemispheres. The steepness in ascent is better on the left side reflecting the intactness of the isotope bolus. On the right side, an ascent deflection precedes the left side by almost 2 seconds. This reflects dilatation of the external carotid system often seen in more acute cases of carotid artery thrombosis. A n-lative flatness in the ascent of the slope reflects the relatively poor development of a collateral system.
Di~a~s 01
LANG ANn HANN
tope flow studies. The arteriograms offered an excellent demonstration of collateral pathways, particularly via the ophthalmic, pterygopalatine and midmeningeal branches of the external system. The patency and presence of anterior or posteriorly communicator arteries are likewise readily assessed by this method. Radio-isotope flow studies were particularly useful for finite assessment of blood flow per unit time to the affected hemisphere. The angle of the ascending slope of the isotope curve, the width of the base, and the angle of the descending slope give a reliable picture of the overall flow rate per unit time to the affected hemisphere. The width of the slope more or less corresponding to the brain pool transit time is the most sensitive indicator. A mean nonnal brain pool transit time is five to nine seconds. \\'ith significant occlusive disease, the transit time may be prolonged 14 to 26 seconds. The angle and steepness of the ascending slope are likewise a sensitive indicator for the intactness of the isotope bolus and rapidity of delivery of blood to the affected area. The overall volume entering the affected hemisphere reflected by the area below the entire curve is the least sensitive and appropriate measurement. The height of the peak of the curve is likewise of secondary clinical significance since sluggishness of the circulation and increased brain pool transit time may actually result in increased height of the peak. An excellent correlation between the clinical picture and the appearance of the isotope curve, as well as the arteriogram was noted in this series. The change in the width of the curve and the width of the base of the curve appeared to bear a most significant correlation to the clinical improvement of the patient and his potential for ultimate recovery. RESUMEN
Cincuenta y ocho sujetos con oclusion patologica manifesta de la carotida intema fueron estudiados mediante arteriogramas y determinaciones radio-isotopicas del flu jo sanguineo. Los arteriogramas proporcionaron una demostracion excelente de la circulacion colateral, particularmente via la rama oftal mica. pteriogo-palatina
the Chest
y meningeas medios del sistema externo. La presencia y permeabilidad de comunicantes anteriores y posteriores son susceptibles tambien de demostracion por este metodo. Los radioisotopos fueron particularmente {niles para la determinacion del flujo sanguineo por unidad de tiempo en el hemisferio afectado. EI angulo de la rama ascendente de la curva isotopica, la latitud de su base y el declive de su rama descendente reflejan fielmente el volumen del flujo total por unidad de tiempo en el hemisferio afectado. La latitud de la grafica, que corresponde aproximadamente con el tiempo de transito por el reservorio sanguineo encefalico, es el indicador de mayor sensibilidad. EI promedio normal del tiempo de transito es de cinco a nueve segundos. En las alteraciones patologicas oclusivas de importancia este tiempo puede aumentar hasta de 14 a 26 segundos. EI angulo y el gradiente de la rama ascendente de la curva es tambien un indicador sensible de la integridad del bolo isotopico y de la rapidez del aporte sanguineo a la parte afectada. EI area bajo la cun'a, como expresion del volumen total de sangre que entra en el hemisferio afectado. es el indice menos apropriado y exacto en este tipo de investigacion. La altura de la curva es asi mismo de importancia clinica secundaria. En nuestra serie observamos una correlacion excelente entre el cuadro clinico. la curva isotopica y el arteriograma. Los cambios en la latitud de la curva y en la de la base de la curva presentan una correlacion muy significativa con la mejoria clinica y las posibilidades de recuperacion definitiva. RESUME
Cinquante huit malades ayant une maladie occlusive connue de I'arthe carotide interne, ont ete examines par des etudes arteriographiques et de circulation de radio-isotopes. Des arteriographies ont donne une excellente preuve des \'oies collaterales, en particulier a travers les branches ophtalmiques, pterygo-pa lat ines et meningees moyennes du syst~me exteme. La permeabilite et la presence de communiquantes anterieures ou posterieures sont facilement demontrees par celte methode. Les etudes de circulation de radio-isotopes ont ete particuli~rement utiles pour la determination definie du flot sanguin par unite de temps a I'hemisphhe interesse. L'angle de la pente ascendante de la courbe d'isotopes, la largeur de la base, et l'angle de la courbe descendante, donnent une image fid~le du flot sanguin total par unite de temps a I'hemisphhe considere. La largeur de la pente correspondant plus ou moins au temps de traversee de la reserve cerebrale est I'indicateur Ie plus sensible. Un temps moyen normal de traversee cerebra Ie varie de 5 a 9 secondes. Avec une maladie occlusive
Volume 48, No. September 196'1
~
ANGIOGRAPHIC AND ISOTOPE POOL CIRCULATION STUDY
significative, Ie temps de traversee peut etre prolonge de 14 a 26 secondes. L'angle et la rapidite d'ascension de la couroe est de meme un indicateur sensible pour I'integrite du hoi isotope, et pour la rapidite d'apport du sang a la region considere. Le volume total penetrant dans I'hemisphere considere, traduit par la surface se trouvant sur la couroe entiere, est la mesure la moins sensible et appropriee. La hauteur du pic de la courbe, a de meme une signification clinique secondaire, etant donne que Ie ralentissement de la circulation et l'augmentation du temps de traversee de la reserve cerebrale peuvent entrainer une augmentation de la hauteur du pic. Une excel? lente correlation entre Ie tableu clinique et l'apparition de la courbe d'isotope aussi bien que I'arteriographie a ete notee dans cette serie. us changements dans la largeur de la combe et la largeur de la base de la courhe semblent presenter une correlation significative avec l'amelioration clinique du malade et sa possibilite de guerison ulterieure. ZUSAMMF:NF.O\SSUNG Untersuchung liher 58 Patienten mit hekannter Verschlu13krankheit der art. carotis int. mit Untersuchungen durch Arteriogramme und RadioIsotopen. Die Arteriogramme liefem einen ausgezeichneten Nachweis der kollateralen Vebindungen, hesonders auf den \Vege liber die vasa ophtalmico, vasa pterygopalatina und menigea media als Asten des Systems de art, carotis extema. Die Durchgangigkeit und das VVorliegen von anterioren bzw. posterioren Verbindungswegen Uil3t sich ebenfalls leicht auf diesen Wege feststellen. Durchstrorungsstudien mit Radio-Isotopen waren von hesonderem Wert zu einer ganauen Ermittlung der Durchstromung bezogen auf die Zeiteinheit und die betroffene Hirnhemisphare. Der Winkel des aufsteigenden Astes der IsotopenKurve, die lichte Weite der Basis und der Winkel des absteigenden Schenkels gehen ein zuverlassiges Bild der gesamten Durchstromung-bezogen auf die Zeiteinheit fUr die betroffene Hemisphare. Die lichte Weite der Kurve, mehr oder weniger in Obereinstimmung mit der zusammengefa13ten Gesamtdurchstromungszeit des Gehims ist der meist f'mpfindliche Indikator. Die mittlere normale Gesamtgehirndurchstromungszeit betrigt 5 9 Sek. Bei wesentlicher Verschlul3krankheit bnn die Durchstromungzeit auf 14 - 26 Sek, verlangert sein. Ded Winkel und die Steilheit des aufsteigenden Kurvenastes ist ebenfalls ein empfindlicher Indikator fUr die Glite des Isotopenstiicks und die Geschwindigkeit der Blutzufuhr fUr das befallene Gebiet. Das Gesamtvolumen, das in die betreffende Hemisphare eintritt und dmch den Bereich unterhalb der gesamten Kurve dargestellt wird, ist der wenigst empfindliche und geeignete Gradmesser. Die Gipfelhohe der Kurve ist in
gleicher Weise nur von sekundarer klinischer Bedeutung, da die Verzogerung der Zirkulation und die erhohte Gesamtgehirndurchstromungszeit in einer hoheren Gipfelkurve zum Ausdruck kommen kann. Eine ausgezeichnte Korrelation zwischen dem klinischen Bild und dem Erscheinungsbild der Isotopen-Kurve ebenso dem Arteriogramm wurde bei diesem Krankengut festgestellt. Der Wandel in der Kurvenbreite und das Ausma13 der Basiswerte der Kurve dlirften die besonders signifikante Korrelation enthalten, bezogen auf die klinische Besserung des Patienten und sein Vermogen fUr eine schliessliche Erholung.
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REFERENCES AVMAN, N. AND BEllINO, E. A.: "A Plastic Model for the Study of Pressure Changes in the Circle of Willis and Major Cerebral Arteries Following Arterial Occlusion," }. Neurosurg., 18: 361, 1961. BAKAY, L. AND SWEEK, W. H.: "Intra-arterial Pressures in the Neck and Brain-Late Changes After Carotid Closure, Acute Measurements After Vertebral Closure," }. Neurosur,., 10: 353, 1953. BEEVER, C. E.: "The Cerebral Arterial Supply," Brain, 30:403, 1907. BELL, R. F. AND HERTSCR, G. T.: "The Detennination of Cerebral Circulation Time," }. Nucl. Med., 3:399, 1962. ELSCHNIO, A.: "Die Folgen der Carotisunterbindung fuer das Centralgefaessystem der Retina," Med. Klin., 7: 1943, 1911. FAZIO, C. AND FEISCHI, C.: "Evaluation of Cerebral Hemydynamics With Radioactive Isotopes," Minerva Nucleare, 4: 324, 1960. FISHER, A. G. T.: "A Case of Complete Absence of Both Internal Carotid Arteries, With a Preliminary Note on the Development History of the Strapedial Artery," }. Anat., 48:37, 1913. GREITZ, T.: "A Radiologic Study of the Brain Circulation by Rapid Angiography of The Carotid Artery," Acta Radial. Suppl., 140: 123, 1956. KETY, S. S. AND SCHlKIDT, C. F.: "The Nitrous Oxide Method for the Quantitative Determination of Cerebral Blood Flow in Man; Theory, Procedure and Normal Values," }. Clin. Invest., 27: 476, 1948. LANO, E. K., HANN, E. C. AND LURos, T. J.: "Arteriographic Demonstration of External-Internal Carotid Anastomoses and Their Correlation to RISA Circulation Studies," Radiology, 71:768,1964. LoWREY, L. G.: "Anomaly in The Circle of Willis, Due to Absence of the Right Internal Carotid Artery," Anat. Rec., 10:221, 1916. MOUNT, L. A. AND TAVERAS, J. M.: "A Study of the Collateral Circulation of the Brain Following Ligation of the Internal Carotid Artery," Tr. Am. Neural. A., 78:47, 1953. MOUNT, L. A. AND TAVERAS, J. M.: "Arteriagraphic Demonstration of the Collateral Circulation of the Cerebral Hemispheres," AMA A rd. N eurol. and Psychiat., 78: 235, 1957. OLDun>ORF, W. H.: "Measurement of the Mean Transit Time of Cerebral Circulation by
286 15
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17
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19
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External Detection of an Intravenously Injected Radio-Isotope," ]. Nucl. Med., 3: 382, 1962. OLDENDORF, W. H., CRANDALL, P. M., NORDYKE, R. A. AND ROSE, A. S.: "A Comparison of the Arrival in the Cerebral Hemispheres of Intravenously Injected Radio-Isotope," ]. Neurol., 10: 223, 1960. OLDENDORF, W. H. AND CRANDALL, P. M.: "Bilateral Cerebral Circulation Curves Obtained by Intravenous Injection of Radio-Isotopes," ]. N eurosurg., 19: 195, 1961. OLDENDORF, W. H. AND KITANO, M.: "Measurement of Brain Circulation Time by an Intravenous Radio-Isotope Technique," Unpub. Data~oc. Nucl. M ed., June 17-20, 1964, Berkeley. SACHS, E., JR.: "Arteriographic Demonstration of Collateral Circulation Through the Ophthalmic Artery in Internal Carotid Artery Thrombosis; Report of Two Cases," ]. Neurosurg., 11 :405, 1954. SEAMAN, W. B., PAGE, W. R. AND GERMAN. W. J.: "Arteriographic Findings in Brain Ar-
HANN
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terial Occlusion," Tr. Am. Neurol. Asm., 74: 55, 1949. TAVERAS, J. M., MOUNT, L. A. AND FRIEDENBERG, R. M.: "Arteriographic Demonstration of External-Internal Carotid Anastomoses Through the Ophthalmic Arteries," Radiology, 63: 525, 1954. TORKILDSEN, A. AND KOPPANG, K.: "Notes on the Collateral Cerebral Circulation as Demonstrated by Carotid Angiography," ]. Neurosurg., 8: 269, 1951. WELCH, K., STEPHENS, J., HUBER, W. AND INGERSOLL, C.: "The CoUateral Circulation Following Middle Cerebral Branch Occlusion," ]. NeMrosurg., 12:361, 1955. WILLIS, T.: Two Discourses Concerning the Soul of Brutes, in his Practice of Physick, Be-
ing the Whole Works of That Renouned and Famous Physician, Containing These Eleven Several Treatises, London, T. Dring. C. Harper, and J. Leigh, 1684. For reprints, please write: Dr. Lang, Methodist Hospital. Indianapolis.
PROGNOSIS OF COAL-MINERS WITH LUNG CANCER A retrospective survey was conducted on 746 hospital patients from South Wales. of whom 172 had been miners and 518 non-miners. During the first five years of fol1owup. there was no appreciable difference In survival rates between the two occupational groups, whether they were treated surglcal1y or otherwise, and the rate of surgical resection was similar In each group. However, an analysis of the miners' experience In relation to the presence and extent of coincidental pneumoconiosis showed a con-
slstent association. survival Increasing with a rise In the radiographic category of simple pneumoconiosis. The highest two-year survival rates In the series were in the small proportion of miners with categories 2 and 3 pneumoconiosis. This association would be expected If the spread of lung cancer in miners' lungs were Impeded by coal-dust. GOLDMAN, K. P.: "Prognosis of Coal-miners with Cancer of the Lung," Tho,tlx, 20:170, 19M.
EXTERNAL RESPIRATORY FUNCTION IN MYOCARDIAL INFARCTION External respiration In :I) patients :I) to 60 days after acute myocardial infarction. and In 20 patients at periods ranging from six to 12 months was Investigated. In patients at different periods after myocardial Infarction. functional disturbances 01 the external respiration were manifested by an Increased minute ventlJatlon, decreased vital capacity. reduced maximum breathing capacity, reserve all' and coefficient of oxygen consumption, decreased oX)'gen absorption per minute. In 93 per cent of patients exam-
Ined :I) to 60 days after acute myocardial Infarction, the author noted respiratory insu"'clency. Investigations performed 6 to 12 months later disclosed respiratory Insufflclency In 80 per cent of cases. The author attributes functional disturbances of the external respiration to latent right ventricular Insufflclency. NECHAEV, S. I.: "The Functional State of the Apparatus of External Respiration in Patients After Sustained Myocardial Infarction," Sor;tt MtlJ.• 28:B, 196'.