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Rapid imaging of abdominal aortic disease
ABSTRACTS T H E R O L E OF G A D O L I N I U M D T P A IN MRI: T H E B R I S T O L EXPERIENCE R. U B E R O I , B. B R O W N and P. G O D D A R D
Department o['Radiology, Frenchay Hospital, Bristol M R I with Gadolinium D T P A enhancement has become an important technique for craniospinal imaging which is becoming ever more widely used. In this paper we review the use of Gadolinium D T P A in our department since June 1989, A total of 451 M R I scans were performed with Gadolinium DTPA, of which we reviewed 295 scans. We divided these broadly into brain, spine, orbit and internal auditory canals. The patterns of enhancement for lesions were noted and the value of contrast enhancement assessed. A total of 41.8 % of the brain M RI scans, 21.9 % of the IACs, 36.7 % of the spines and 23.8 % of the orbit group benefited from enhancement with intravenous contrast (55.5%, 36.7%, 49.2% and 26.3% respectively of the pathological scans are considered). In 12.9% of brains, in 11.1% of IACs, in 1.5"/,, of spines and 5 % o f orbits unsuspected lesions are demonstrated in the abnormal scans, not seen precontrast. In a single case, enhancement made the lesion invisible on the post-contrast scan and therefore was detrimental. We discuss areas of most benefit, with some possible pitfalls and review the literature. We conclude that intravenous Gadolinium D T P A enhancement increases sensitivity and helps lesion categorization. It is safe and useful if the possible pitfalls are appreciated.
R A P I D I M A G I N G OF A B D O M I N A L A O R T I C DISEASE A. R. M O O D Y , B. J. NEILSON, P. E M B E R T O N , S. C. B O L T O N and G. R. C H E R R Y M A N
Unit:ersity Departnwnt of Radiology, Leicester Royal Infirmary, Leicester Purpose: We describe an M R protocol that allows accurate demonstration of aortic disease in less than 1 min. Materials and Methods': Scanning was performed on a Siemens 1.0 T lmager. TI coronal magnetization prepared rapid acquisition gradient echo images were obtained before and after Gadopentetate Dimeglumine (0.05 mmot/kg) with suspended respiration if possible. Processing involved MIP. Patients included admissions for elective aneurysm surgery and aortic occlusive disease. All images were compared with surgery. Results: This method was highly accurate in demonstrating the neck of abdominal aortic aneurysms in relation to the renal arteries. While some detail was lost on the MIP images these were felt to be useful in surgical planning. Similar high accuracy was demonstrated in aortic occlusion with the benefit of demonstrating reconstituted distal vessels. Acquisition of single, sub-second images removed unwanted movement and ghosting artefact. Breathless patients could be imaged without breath holding and the first pass effect allowed better visualization of the right renal artery due to lack of contrast within the IVC. Conclusion: The method described allows rapid imaging of the abdominal aorta and delineation of sites of disease, in less than 1 rain. The images are suitable for surgical planning and provide a high level of diagnostic accuracy. T H E R O L E O F C O M P U T E D T O M O G R A P H Y AND V E N O U S S A M P L I N G IN T H E INVESTIGATION OF HYPERALDOSTERONISM (CONN'S SYNDROME) J. G O L D I N , R. SHEAVES, R. H. R E Z N E K , J. E. DACIE, A. G R O S S M A N and G. M. BESSER
Department of Radiology, St Bartholomew's Hospital, London Hyperaldosteronism can result from a unilateral adrenal cortical adenoma, treated surgically or bilateral adrenal hyperplasia, managed medically. This study assesses the role of CT and selective venous sampling in distinguishing these two causes. The CT scans and results of venous sampling on 23 patients with biochemically proven hyperaldosteronism were reviewed retrospectively. The findings were compared with pathology (16 patients) and clinical outcome (seven patients). Venous sampling was successful in 17 patients. The CT appearances of adenomata and hyperplasia will be illustrated, in the demonstration of adenomata, C T had a sensitivity of 100%, positive predictive value of 83% and accuracy of 81%; venous sampling showed sensitivity of 70%, positive predictive value of 79% and accuracy of 68 %. When combined, the two tests had a positive predictive value of 94%, and accuracy of 92%. The causes of false positive and negative results in both investigations will be illustrated and discussed.
357
These results show that neither CT nor selective venous sampling alone is sufficiently accurate in diagnosing an adrenal adenoma in patients with C o n n ' s syndrome but a combination of the two studies is usually required. A strategy for the investigation of these patients will be proposed.
C O L O U R F L O W INTENSITY O F T H E P E R I P H E R A L Z O N E O F T H E P R O S T A T E - C O R R E L A T I O N W I T H H I S T O L O G Y AND INFLAMMATORY CELL INFILTRATION U. P A T E L and D. R I C K A R D S
Department of Radiology, The Middlesex Hospital, London Assessment of prostatic blood flow by colour flow imaging (CF) may help to increase accuracy o f sonographic diagnosis of prostatic disease and guided biopsy. Flow abnormality of the peripheral zone is reported to be most frequent with carcinoma but it is not clear how reliable intensity of CF of the peripheral zone is in diagnosis. The results of 232 biopsies of the peripheral zone with detailed C F correlation were reviewed. C F intensity was graded 0 3, and histology was classified as normal prostate, cancer or inflammation. Inflammation was subgraded as inflammatory cell infiltrate (ICI) on a 3 point scale. Of 13 samples with grade 3 flow, seven showed cancer and six had inflammation (mean grade of ICI - 2 . 6 ) . With grade 2 flow (24 samples), 11 had cancer, seven inflammation (mean ICI = 1.32) and six normal prostate. For grade 1 (49 samples) and grade 0 (146 samples) flows the figures were 17,15 (mean ICI = 1.27), 17; and 12,26 (Mean ICI = 1.136), 108 respectively. In conclusion, in the peripheral zone of the prostate: (1) the most intense C F is only seen with abnormal prostatic tissue, either cancer or inflammation. These two cannot be separated on C F intensity alone; (2) intermediate CF change is not diagnostically reliable, although in patients without cancer it appears to reflect degree of inflammatory cell infiltration.
C O N T R A S T M O D I F I C A T I O N OF 3D P R O S T A T E S C A N S BY INTRODUCTION OF MTC C. E. H U T C H I N S O N , X. P. Z H U , J. M. H A W N A U R and I. I S H E R W O O D
Department of Diagnostic Radiology, University of Manchester, Manchester A 3D-volume acquisition technique has been developed for volume segmentation of the prostate to facilitate semi-automated radiotherapy treatment planning techniques from M R images. The commercially available 3D-Gradient Recalled Echo (3D-GRE) sequences with low flip angle and relatively long TE result in a T2*-weighted (T2*W) image but provide intrinsically poor contrast between prostate and pelvic floor muscles. We have modified the 3 D - G R E sequence by incorporating a pulsed saturation transfer technique ( 12 I-MTC pulse). The effects of the Magnetization Transfer Contrast (MTC) have been assessed. Images were obtained in the body coil using a 0.5 T Vectra scanner (General Electric). A T2*W 3 D - G R E sequence, T R - 8 0 ms, TE = 30 ms, flip angle cr of 25 '~, and 30 50 partitions of 2 m m thickness were obtained through the prostate. The 3 D - G R E sequence was then modified by the 121 M T C pulse introduced before each cr pulse. The signal intensity (SI) was measured in a region of interest (ROI = 90 pixels) for prostate, fat and muscle. Image contrast was determined using the formula: C = (Sl-S2/Sj + $2) where Sl + 82 w e r e the SI to be compared. Significant improvement of image contrast was obtained between prostate, muscle and fat (P < 0.001). Incorporation of the 121 M T C pulse improved contrast between prostate and muscle due to the differences in M T in different structures. The increased contrast facilitates segmentation of the prostate by increasing the signal difference at tissue boundaries. Clinical 3D prostate images are now routinely obtained using this sequence. This work was supported by the Cancer Research Campaign.
F A L L O P I A N T U B E C A N N U L A T I O N IN T H E T R E A T M E N T O F INFERTILITY M. E. C R O F T O N and J. C. D A N I N
Department of Radiology, Samaritan Hospital for Women, London Fallopian tube catheterization and recannalization of proximal occlusions is an accepted form of treatment in the USA with reported pregnancy rates of up to 45 %. To date, the technique has received scant attention in the U K .
Department o['Radiology, Frenchay Hospital, Bristol M R I with Gadolinium D T P A enhancement has become an important technique for craniospinal imaging which is becoming ever more widely used. In this paper we review the use of Gadolinium D T P A in our department since June 1989, A total of 451 M R I scans were performed with Gadolinium DTPA, of which we reviewed 295 scans. We divided these broadly into brain, spine, orbit and internal auditory canals. The patterns of enhancement for lesions were noted and the value of contrast enhancement assessed. A total of 41.8 % of the brain M RI scans, 21.9 % of the IACs, 36.7 % of the spines and 23.8 % of the orbit group benefited from enhancement with intravenous contrast (55.5%, 36.7%, 49.2% and 26.3% respectively of the pathological scans are considered). In 12.9% of brains, in 11.1% of IACs, in 1.5"/,, of spines and 5 % o f orbits unsuspected lesions are demonstrated in the abnormal scans, not seen precontrast. In a single case, enhancement made the lesion invisible on the post-contrast scan and therefore was detrimental. We discuss areas of most benefit, with some possible pitfalls and review the literature. We conclude that intravenous Gadolinium D T P A enhancement increases sensitivity and helps lesion categorization. It is safe and useful if the possible pitfalls are appreciated.
R A P I D I M A G I N G OF A B D O M I N A L A O R T I C DISEASE A. R. M O O D Y , B. J. NEILSON, P. E M B E R T O N , S. C. B O L T O N and G. R. C H E R R Y M A N
Unit:ersity Departnwnt of Radiology, Leicester Royal Infirmary, Leicester Purpose: We describe an M R protocol that allows accurate demonstration of aortic disease in less than 1 min. Materials and Methods': Scanning was performed on a Siemens 1.0 T lmager. TI coronal magnetization prepared rapid acquisition gradient echo images were obtained before and after Gadopentetate Dimeglumine (0.05 mmot/kg) with suspended respiration if possible. Processing involved MIP. Patients included admissions for elective aneurysm surgery and aortic occlusive disease. All images were compared with surgery. Results: This method was highly accurate in demonstrating the neck of abdominal aortic aneurysms in relation to the renal arteries. While some detail was lost on the MIP images these were felt to be useful in surgical planning. Similar high accuracy was demonstrated in aortic occlusion with the benefit of demonstrating reconstituted distal vessels. Acquisition of single, sub-second images removed unwanted movement and ghosting artefact. Breathless patients could be imaged without breath holding and the first pass effect allowed better visualization of the right renal artery due to lack of contrast within the IVC. Conclusion: The method described allows rapid imaging of the abdominal aorta and delineation of sites of disease, in less than 1 rain. The images are suitable for surgical planning and provide a high level of diagnostic accuracy. T H E R O L E O F C O M P U T E D T O M O G R A P H Y AND V E N O U S S A M P L I N G IN T H E INVESTIGATION OF HYPERALDOSTERONISM (CONN'S SYNDROME) J. G O L D I N , R. SHEAVES, R. H. R E Z N E K , J. E. DACIE, A. G R O S S M A N and G. M. BESSER
Department of Radiology, St Bartholomew's Hospital, London Hyperaldosteronism can result from a unilateral adrenal cortical adenoma, treated surgically or bilateral adrenal hyperplasia, managed medically. This study assesses the role of CT and selective venous sampling in distinguishing these two causes. The CT scans and results of venous sampling on 23 patients with biochemically proven hyperaldosteronism were reviewed retrospectively. The findings were compared with pathology (16 patients) and clinical outcome (seven patients). Venous sampling was successful in 17 patients. The CT appearances of adenomata and hyperplasia will be illustrated, in the demonstration of adenomata, C T had a sensitivity of 100%, positive predictive value of 83% and accuracy of 81%; venous sampling showed sensitivity of 70%, positive predictive value of 79% and accuracy of 68 %. When combined, the two tests had a positive predictive value of 94%, and accuracy of 92%. The causes of false positive and negative results in both investigations will be illustrated and discussed.
357
These results show that neither CT nor selective venous sampling alone is sufficiently accurate in diagnosing an adrenal adenoma in patients with C o n n ' s syndrome but a combination of the two studies is usually required. A strategy for the investigation of these patients will be proposed.
C O L O U R F L O W INTENSITY O F T H E P E R I P H E R A L Z O N E O F T H E P R O S T A T E - C O R R E L A T I O N W I T H H I S T O L O G Y AND INFLAMMATORY CELL INFILTRATION U. P A T E L and D. R I C K A R D S
Department of Radiology, The Middlesex Hospital, London Assessment of prostatic blood flow by colour flow imaging (CF) may help to increase accuracy o f sonographic diagnosis of prostatic disease and guided biopsy. Flow abnormality of the peripheral zone is reported to be most frequent with carcinoma but it is not clear how reliable intensity of CF of the peripheral zone is in diagnosis. The results of 232 biopsies of the peripheral zone with detailed C F correlation were reviewed. C F intensity was graded 0 3, and histology was classified as normal prostate, cancer or inflammation. Inflammation was subgraded as inflammatory cell infiltrate (ICI) on a 3 point scale. Of 13 samples with grade 3 flow, seven showed cancer and six had inflammation (mean grade of ICI - 2 . 6 ) . With grade 2 flow (24 samples), 11 had cancer, seven inflammation (mean ICI = 1.32) and six normal prostate. For grade 1 (49 samples) and grade 0 (146 samples) flows the figures were 17,15 (mean ICI = 1.27), 17; and 12,26 (Mean ICI = 1.136), 108 respectively. In conclusion, in the peripheral zone of the prostate: (1) the most intense C F is only seen with abnormal prostatic tissue, either cancer or inflammation. These two cannot be separated on C F intensity alone; (2) intermediate CF change is not diagnostically reliable, although in patients without cancer it appears to reflect degree of inflammatory cell infiltration.
C O N T R A S T M O D I F I C A T I O N OF 3D P R O S T A T E S C A N S BY INTRODUCTION OF MTC C. E. H U T C H I N S O N , X. P. Z H U , J. M. H A W N A U R and I. I S H E R W O O D
Department of Diagnostic Radiology, University of Manchester, Manchester A 3D-volume acquisition technique has been developed for volume segmentation of the prostate to facilitate semi-automated radiotherapy treatment planning techniques from M R images. The commercially available 3D-Gradient Recalled Echo (3D-GRE) sequences with low flip angle and relatively long TE result in a T2*-weighted (T2*W) image but provide intrinsically poor contrast between prostate and pelvic floor muscles. We have modified the 3 D - G R E sequence by incorporating a pulsed saturation transfer technique ( 12 I-MTC pulse). The effects of the Magnetization Transfer Contrast (MTC) have been assessed. Images were obtained in the body coil using a 0.5 T Vectra scanner (General Electric). A T2*W 3 D - G R E sequence, T R - 8 0 ms, TE = 30 ms, flip angle cr of 25 '~, and 30 50 partitions of 2 m m thickness were obtained through the prostate. The 3 D - G R E sequence was then modified by the 121 M T C pulse introduced before each cr pulse. The signal intensity (SI) was measured in a region of interest (ROI = 90 pixels) for prostate, fat and muscle. Image contrast was determined using the formula: C = (Sl-S2/Sj + $2) where Sl + 82 w e r e the SI to be compared. Significant improvement of image contrast was obtained between prostate, muscle and fat (P < 0.001). Incorporation of the 121 M T C pulse improved contrast between prostate and muscle due to the differences in M T in different structures. The increased contrast facilitates segmentation of the prostate by increasing the signal difference at tissue boundaries. Clinical 3D prostate images are now routinely obtained using this sequence. This work was supported by the Cancer Research Campaign.
F A L L O P I A N T U B E C A N N U L A T I O N IN T H E T R E A T M E N T O F INFERTILITY M. E. C R O F T O N and J. C. D A N I N
Department of Radiology, Samaritan Hospital for Women, London Fallopian tube catheterization and recannalization of proximal occlusions is an accepted form of treatment in the USA with reported pregnancy rates of up to 45 %. To date, the technique has received scant attention in the U K .