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BACKGROUND AND PURPOSE: Early and accurate detection of global cerebral anoxia is important for determination of prognosis and further management. We evaluated whether accuracy in early detection of global cerebral anoxia was improved by high-b-value diffusion-weighted imaging (DWI) with long echo time (TE). METHODS: Routine DWI (b = 1000 s/mm(2); TE = 139 ms), high-b-value DWI (b = 3000 s/mm(2); TE = 190 ms), T2-weighted imaging (T2WI), and fluid-attenuated inversion recovery (FLAIR) imaging were acquired in six patients who experienced cardiopulmonary arrest within 24 hours and six volunteers. Region of interest–based analysis was performed. Regions of interest of patients showing significant decrease in apparent diffusion coefficient (ADC) values than volunteers were considered abnormal. Three neuroradiologists independently assessed images of the patients for conspicuity of hyperintensity within regions of interest. Receiver operating characteristic (ROC) analysis was performed, and the area under the curve (Az) was compared among sequences and observers. Average contrast and contrast-to-noise ratios between abnormal regions of interest and regions of interest of normal surrounding parenchyma were calculated. RESULTS: For all observers, high-b-value DWIs achieved the largest Az, and FLAIR imaging the lowest Az. Az of routine DWI and T2WI were between these values. High-b-value DWI and FLAIR imaging showed no significant interobserver variation in Az, whereas routine DWI and T2WI did. High-b-value DWI also achieved the largest contrast and contrast-to-noise ratios. CONCLUSION: High-b-value DWI with long TE improved accuracy in early detection of global cerebral anoxia. Application of the sequence would facilitate early diagnosis.

Summary: We describe radiologic findings of germinoma involving bilateral basal ganglia and cerebral white matter. In the early stage, T1-weighted MR images showed hyperintense areas in the bilateral globi pallidi. Later, T2-weighted images showed hyperintense areas involving bilateral white matter. The MR imaging findings reported here could help facilitate the early diagnosis of germ cell tumors in young patients.

BACKGROUND AND PURPOSE: Blood flow of the internal jugular vein and intracranial venous sinuses is affected by respiratory state. The purpose of this study was to clarify the changes in flow velocity and direction and signal intensities of sigmoid sinuses on phase-contrast (PC) MR images obtained with regular breathing and with deep inspiratory breath holding. METHODS: One hundred seven subjects without venous sinus abnormality were studied. Coronal 2D PC MR venography and axial 2D PC images with peripheral pulse gating were acquired with a 1.5-T MR unit, during regular breathing and deep inspiratory breath holding. The signal intensity changes of bilateral sigmoid sinuses on MR venograms and the changes of flow velocity and direction on the axial 2D PC images were analyzed. RESULTS: Breath holding decreased signal intensities of the right and left sigmoid sinuses on MR venograms in 57 (53.3%) and 36 (33.6%) subjects, respectively. Increased signal intensity was observed in 12 (11.2%) and 33 (30.8%) subjects, respectively. In the flow analysis, retrograde flow was detected at the left sigmoid sinus in four subjects (3.7%) during regular breathing, which was normalized by breath holding. Flow velocities of the right and left sigmoid sinuses decreased during breath holding in 92 (86.0%) and 70 (65.4%) subjects, and increased in 15 (14.0%) and 37 (34.6%) subjects, respectively. CONCLUSION: The signal intensities of sigmoid sinuses were affected by breath holding in about 2/3 of the subjects. Breath-holding maneuver can be used to increase blood flow and signal intensities of dural venous sinuses on PC MR venograms.

BACKGROUND AND PURPOSE: Our purpose was to evaluate the visualization of the artery of Adamkiewicz (AKA) and the anterior spinal artery (ASA) by using multi-detector row CT. Preoperative detection of the AKA and ASA is important for prevention of ischemic complications of thoracoabdominal aortic surgery. METHODS: Data from contrast-enhanced CT of the abdomen of 19 consecutive patients with known or suspected liver disease were evaluated. The scanning range was set from the level of the diaphragm to the lower edge of the liver. After bolus injection of contrast material (100 mL of iohexol, 350 mgI/mL, 5 mL/s), arterial phase scans were obtained by using a four-channel multi-detector row CT scanner. The scanning parameters included a detector row configuration of 4 × 2 mm, a pitch of 5:1, a gantry rotation speed of 0.5 s, 120 kVp, and 150 mAs. Arterial phase coronal multiplanar reconstruction scans obtained parallel to the spinal cord were evaluated by two neuroradiologists. The detectability of ASA and AKA was analyzed. RESULTS: The AKA was visualized on the scans of 13 of 19 patients (68%). The segmental level of AKA origin ranged from T10 to L2. The AKA originated from the left side in nine patients (69%) and the right side in four patients (31%). The ASA was visualized on the scans of all patients (100%). For 16 of the 19 patients, the ASA was detected in its full length from the cranial edge of the scan range. However, the ascending branch of the ASA distal to the junction of the AKA was not detected for the remaining three patients. CONCLUSION: The AKA and ASA can be visualized by using multi-detector row CT with the use of IV administered contrast material. Multi-detector row CT could be a useful tool in the evaluation of spinal vascular structures.