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Neuroradiological findings in perinatally HIV-infected children (In German)
222
CLINICAL IMAGING VOL. 19, NO. 3
ABSTRACTS
INTRACRANIAL MAGNETIC RESONANCE ANGIOGRAPHY (In German) Ftirst G, Hofer M, Mijdder U (Institut fiir Diagnostische Radiologie der Universitiit, Moorenstrasse 5, D-40225 Diisseldorf, Germany). Radiologe 1994;34:437-446. Magnetic resonance angiography (MRA) is gaining wide acceptance as a screening modality for the intracranial vasculature. Previous reports have demonstrated that MRA is capable of accurately depicting the normal vascular anatomy and anatomic variants. To date, various techniques have been applied in evaluating vaso-occlusive disease, aneurysms, arteriovenous malformations, and venous sinus thrombosis. Recent technical developments have significantly improved spatial resolution and vascular contrast and will further enhance its routine clinical use. This essay summarizes the technical approaches, clinical role, and limitations of MI&Aas they apply to the intracranial circulation. Authors’ Summary
MRA OF THE CAROTID SYSTEM (In German) Bongartz G, Behrendt J, Schuierer G, et al. (Institut fiir Klinische Radiologie der Universittit, Albert-Schweitzer-Strasse 33, D-48129, Berlin, Germany) Radiologe 1994;34:430-436. Magnetic resonance angiography (MRA) of the carotid system was found readily applicable due to the laminar and fast-flow conditions in the supra-aortic arteries. Time-of-flight methods are superior to phase-contrast measurements for investigation of atherosclerotic lesions. Recent developments in sequence design enable improvement of the MRA results with respect to correct staging of stenotic alterations. Two-dimensional acquisitions are preferred in slow-flow conditions, with the disadvantage of decreased resolution, inplane saturation effects, and poststenotic signal voids. In 3D MFtA the major advantage is improved resolution, although the saturation effects within the measurement volume must be compensated for by either sequential acquisition of multiple thin volumes or the application of asymmetric excitation pulses. In a prospective trial with 50 patients, the advantages of a new type of if-pulse (TONE) are demonstrated. Authors’ Summary
IUEURORADIOIx)GICAL FINDINGS IN PERINATALLY HIVINFECI’ED CHILDREN I?n German) Spreer J, Enekel-Stoodt S, Funk M, et al. (Institut ftir Radiologische Diagnostik der Unversitit zu Kijln, Joseph-Stelzmann-Strasse 9, D-50931 Cologne, Germany). Forts&r Rijntgenstr 1994;161:106-112. The neuroradiological studies by computed tomography, magnetic resonance imaging, and angiography in 21 children with perinatal HIV infection were reviewed retrospectively. No patient showed an intracranial mass lesion; after intravenous contrast medium application there was no case with disturbed blood-brain barrier. Common non specific findings were atrophy and delayed myelination. In 7 cases, atrophy was combined with multifocal nearly symmetric white matter lesions, which characteristically spared the U-fibers. Further findings included an intramedullary ring-shaped structure in the cervical cord, an AIDS-associated vasculopathy, and symmetric calcifications in the basal ganglia. The spectrum of neuroradiological findings in pediatric AIDS patients differs from that in adults, Knowledge of these age-specific findings is important because the number of HIV-infectedchildren is rising. Authors’ Summary
TIME-OF-FLIGHT MRA OF CEREBRAL ARTERIOVENOUS MALFORMATIONS BEFORE AND AFTER RADIOTHERAPY (In German). Schlemmer HP, Hess T, Debus J, et al. (Deutches Krebsforschungszentrum, Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany). Radiologe 1994;34:447-453. Intracerebral arteriovenous malformations represent congenital anomalies with an arteriovenous shunt (nidus). The therapeutic goal is to eliminate the risk of bleeding and to improve the clinical symptoms. The exact localization of the nidus and the identification of the feeding arteries are critical for therapy planning. Until now, conventional brain angiograms have been used for treatment planning and for assessing therapy response. We studied whether 3D time-of-flight (TOF) magnetic resonance angiography (MRA) can be used for therapy planning and monitoring. MRI and TOF-MRA studies of 28 patients undergoing radiotherapy were evaluated. They were compared with con-
CLINICAL IMAGING VOL. 19, NO. 3
ABSTRACTS
INTRACRANIAL MAGNETIC RESONANCE ANGIOGRAPHY (In German) Ftirst G, Hofer M, Mijdder U (Institut fiir Diagnostische Radiologie der Universitiit, Moorenstrasse 5, D-40225 Diisseldorf, Germany). Radiologe 1994;34:437-446. Magnetic resonance angiography (MRA) is gaining wide acceptance as a screening modality for the intracranial vasculature. Previous reports have demonstrated that MRA is capable of accurately depicting the normal vascular anatomy and anatomic variants. To date, various techniques have been applied in evaluating vaso-occlusive disease, aneurysms, arteriovenous malformations, and venous sinus thrombosis. Recent technical developments have significantly improved spatial resolution and vascular contrast and will further enhance its routine clinical use. This essay summarizes the technical approaches, clinical role, and limitations of MI&Aas they apply to the intracranial circulation. Authors’ Summary
MRA OF THE CAROTID SYSTEM (In German) Bongartz G, Behrendt J, Schuierer G, et al. (Institut fiir Klinische Radiologie der Universittit, Albert-Schweitzer-Strasse 33, D-48129, Berlin, Germany) Radiologe 1994;34:430-436. Magnetic resonance angiography (MRA) of the carotid system was found readily applicable due to the laminar and fast-flow conditions in the supra-aortic arteries. Time-of-flight methods are superior to phase-contrast measurements for investigation of atherosclerotic lesions. Recent developments in sequence design enable improvement of the MRA results with respect to correct staging of stenotic alterations. Two-dimensional acquisitions are preferred in slow-flow conditions, with the disadvantage of decreased resolution, inplane saturation effects, and poststenotic signal voids. In 3D MFtA the major advantage is improved resolution, although the saturation effects within the measurement volume must be compensated for by either sequential acquisition of multiple thin volumes or the application of asymmetric excitation pulses. In a prospective trial with 50 patients, the advantages of a new type of if-pulse (TONE) are demonstrated. Authors’ Summary
IUEURORADIOIx)GICAL FINDINGS IN PERINATALLY HIVINFECI’ED CHILDREN I?n German) Spreer J, Enekel-Stoodt S, Funk M, et al. (Institut ftir Radiologische Diagnostik der Unversitit zu Kijln, Joseph-Stelzmann-Strasse 9, D-50931 Cologne, Germany). Forts&r Rijntgenstr 1994;161:106-112. The neuroradiological studies by computed tomography, magnetic resonance imaging, and angiography in 21 children with perinatal HIV infection were reviewed retrospectively. No patient showed an intracranial mass lesion; after intravenous contrast medium application there was no case with disturbed blood-brain barrier. Common non specific findings were atrophy and delayed myelination. In 7 cases, atrophy was combined with multifocal nearly symmetric white matter lesions, which characteristically spared the U-fibers. Further findings included an intramedullary ring-shaped structure in the cervical cord, an AIDS-associated vasculopathy, and symmetric calcifications in the basal ganglia. The spectrum of neuroradiological findings in pediatric AIDS patients differs from that in adults, Knowledge of these age-specific findings is important because the number of HIV-infectedchildren is rising. Authors’ Summary
TIME-OF-FLIGHT MRA OF CEREBRAL ARTERIOVENOUS MALFORMATIONS BEFORE AND AFTER RADIOTHERAPY (In German). Schlemmer HP, Hess T, Debus J, et al. (Deutches Krebsforschungszentrum, Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany). Radiologe 1994;34:447-453. Intracerebral arteriovenous malformations represent congenital anomalies with an arteriovenous shunt (nidus). The therapeutic goal is to eliminate the risk of bleeding and to improve the clinical symptoms. The exact localization of the nidus and the identification of the feeding arteries are critical for therapy planning. Until now, conventional brain angiograms have been used for treatment planning and for assessing therapy response. We studied whether 3D time-of-flight (TOF) magnetic resonance angiography (MRA) can be used for therapy planning and monitoring. MRI and TOF-MRA studies of 28 patients undergoing radiotherapy were evaluated. They were compared with con-