- Spiral T1 Spin-Echo for Routine Postcontrast Brain MRI Exams: A Multicenter Multireader Clinical Evaluation
The authors report a multicenter multireader study that was designed to compare spiral with standard-of-care Cartesian postcontrast structural brain MR imaging on the basis of relative performance in 10 metrics of image quality, artifact prevalence, and diagnostic benefit. Seven clinical sites acquired 88 total subjects. For each subject, sites acquired 2 postcontrast MR imaging scans: a spiral 2D T1 spin-echo, and 1 of 4 routine Cartesian 2D T1 spin-echo/TSE scans. Nine neuroradiologists independently reviewed each subject, with the matching pair of spiral and Cartesian scans compared side-by-side, and scored the subject on 10 image-quality metrics. Spiral was superior to Cartesian in 7 of 10 metrics (flow artifact mitigation, SNR, GM/WM contrast, image sharpness, lesion conspicuity, preference for diagnosing abnormal enhancement, and overall intracranial image quality), comparable in 1 of 10 metrics (motion artifacts), and inferior in 2 of 10 metrics (susceptibility artifacts, overall extracranial image quality). Spiral 2D T1 spin-echo for routine structural brain MR imaging is feasible in the clinic with conventional scanners and was preferred by neuroradiologists for overall postcontrast intracranial evaluation.
- Renal Excretion of Contrast on CT Myelography: A Specific Marker of CSF Leak
The authors performed a retrospective review of postmyelographic CT scans from 49 consecutive patients seen between January 2009 and August 2018 with imaging and/or clinical findings related to intracranial hypotension. Each scan was evaluated by both a neuroradiology fellow and a board-certified neuroradiologist for the presence of contrast in the renal excretory system. A similar assessment was also performed on 90 consecutive control subjects who underwent CT myelography for alternative indications. Among the 49 patients with suspected CSF leak, 21 (43%) had an overt CSF leak on postmyelographic CT (group 1) and 28 (57%) did not (group 2). Overall, renal contrast was identified in 7/49 patients (14.3%): 5 (24%) patients in group 1, and 2 (7%) patients in group 2. Renal contrast was not seen in any of the 90 controls on postmyelographic CT. Renal contrast was exclusively seen in patients with a clinically or radiographically suspected CSF leak. Identification of this finding should prompt a second look for subtle myelographic contrast extravasation or an underlying CSF-venous fistula.