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Of 3769 included radiologists ever subspecialty certified, 84.1% are currently subspecialty certified. Of 1777/3769 radiologists ever subspecialty-certified and with lifetime primary certificates, only 66.6% are currently subspecialty certified. Of 3341 included most-practice neuroradiologists (>50% clinical work effort in neuroradiology based on work relative value unit–weighted national Medicare claims), 73.0% were ever subspecialty certified; of these, 89.1% are currently subspecialty certified. More than one-quarter of most-practice neuroradiologists never obtained neuroradiology subspecialty certification. Even when initially obtained, that certification is commonly not maintained, particularly by lifetime primary certificate diplomates and those in nonacademic and smaller practices.

Forty-seven patients with high-grade gliomas (primarily glioblastoma) with recurrent contrast-enhancing lesions on DSC-MR imaging were retrospectively evaluated after surgical sampling. Histopathologic examination defined treatment effect versus tumor. Normalized relative CBV thresholds of 1.0 and 1.75 were used to define low, intermediate, and high fractional tumor burden classes in each histopathologically defined group. Performance was assessed with an area under the receiver operating characteristic curve. Mean low fractional tumor burden, high fractional tumor burden, and relative CBV of the contrast-enhancing volume were significantly different between treatment effect and tumor with tumor having significantly higher fractional tumor burden and relative CBV and lower fractional tumor burden. High fractional tumor burden and low fractional tumor burden define fractions of the contrast-enhancing lesion volume with high a nd low blood volume, respectively, and can differentiate treatment effect from tumor in recurrent glioblastomas. Fractional tumor burden maps can also help to inform clinical decision-making.

This was a single-center, retrospective study of 205 consecutive patients who were referred for vessel wall MR imaging to clarify the etiology of an ischemic stroke or TIA. An expert panel classified stroke etiology before and after incorporating vessel wall MR imaging results using a modified Trial of Org 10172 in Acute Stroke Treatment system. Vessel wall MR imaging altered the etiologic classification in 55% (112/205) of patients. The proportion of patients classified as having intracranial arteriopathy not otherwise specified decreased from 31% to 4% (64/205 versus 9/205) and the proportion classified as having intracranial atherosclerotic disease increased from 23% to 57%. When vessel wall MR imaging is performed to clarify the etiology of a stroke or TIA, it frequently alters the etiologic classification, which is the basis for therapeutic decision-making.

Twenty-six participants underwent conventional imaging methods followed by 2 randomized black-blood thrombus imaging scans, with a preoptimized DANTE preparation switched on and off, respectively. The signal intensity of residual blood, thrombus, brain parenchyma, normal lumen, and noise on black-blood thrombus images were measured. The thrombus volume, SNR of residual blood, and contrast-to-noise ratio for residual blood versus normal lumen, thrombus versus residual blood, and brain parenchyma versus normal lumen were compared between the 2 black-blood thrombus imaging techniques. The new black-blood thrombus imaging technique provided higher thrombus-to-residual blood contrast-to-noise ratio, significantly lower thrombus volume, and substantially improved diagnostic specificity and agreement with conventional imaging methods.

Twenty-one consecutive patients with ruptured brain AVMs who underwent transvenous embolization were prospectively followed between November 2016 and November 2018. Complete AVM nidus obliteration was shown in 16 (84%) of 19 patients. One (5%) patient with a small residual nidus after treatment showed complete obliteration at 13-month follow-up. There were 5 hemorrhages and 1 infarction; 4 patients' symptoms improved gradually. Transvenous embolization can be performed only in highly selected hemorrhagic brain AVMs with high complete obliteration rates, but it should not be considered as a first-line treatment.

Ten patients with clinically suspected facetogenic low back pain were prospectively recruited with a designation of specific facet joints implicated clinically. Subsequently, patients underwent an FDG-PET/MR imaging examination with gadolinium. Each facet joint was graded for perifacet signal change on MR imaging and FDG activity. The frequency and correlation of MR imaging, FDG-PET, and clinical findings were determined. There was low concordance of perifacet signal change and FDG activity with clinically implicated facet joints. This could indicate either the potential to change patient management or a lack of biomarker accuracy.

This study assesses the accuracy of combined velocity-selective arterial spin-labeling and traditional pulsed arterial spin-labeling CBF measurements in pediatric Moyamoya disease, with comparison with blood flow patterns on conventional angiography. Twenty-two neurologically stable pediatric patients with Moyamoya disease and 5 asymptomatic siblings without frank Moyamoya disease were imaged with velocity-selective arterial spin-labeling, pulsed arterial spin-labeling, and DSA (patients). Qualitatively, velocity-selective arterial spin-labeling perfusion maps reflect the DSA parenchymal phase, regardless of postinjection timing. Conversely, pulsed arterial spin-labeling maps reflect the DSA appearance at postinjection times closer to pulsed arterial spin-labeling postlabeling delay, regardless of vascular phase. ASPECTS comparison showed excellent agreement between arterial spin-labeling and DSA, suggesting velocity-selecti ve arterial spin-labeling and pulsed arterial spin-labeling capture key perfusion and transit delay information, respectively. Velocity-selective arterial spin-labeling offers a powerful approach to image perfusion in pediatric Moyamoya disease due to transit delay insensitivity.

Projection data from 83 patients undergoing unenhanced spiral head CT for suspected neurologic deficits were collected. A routine dose was obtained using 250 effective mAs and iterative reconstruction. Lower-dose configurations were reconstructed (25-effective mAs iterative reconstruction, 50-effective mAs filtered back-projection and iterative reconstruction, 100-effective mAs filtered back-projection and iterative reconstruction, 200-effective mAs filtered back-projection). Three neuroradiologists circled findings, indicating diagnosis, confidence, and image quality. The routine-dose jackknife alternative free-response receiver operating characteristic figure of merit was 0.87. Noninferiority was shown for 100-effective mAs iterative reconstruction and 200-effective mAs filtered back-projection, but not for100-effective mAs filtered back-projection. The authors conclude that substantial opportunity exists for dose reductio n using spiral nonenhanced head CT and that the dose level might potentially be reduced to 40% of routine dose levels or a volume CT dose index of approximately 15mGy if slight decreases in performance are acceptable. The beneficial effect of iterative reconstrution was most pronounced at this 15-mGy dose level.

Brain MR imaging scans of National Aeronautics and Space Administration astronauts were retrospectively analyzed to quantify pre- to postflight changes in brain structure. Local structural changes were assessed using the Jacobian determinant. Structural changes were compared with clinical findings and cognitive and motor function. Long-duration spaceflights aboard the International Space Station, but not short-duration Space Shuttle flights, resulted in a significant increase in the percentage of total ventricular volume change (10.7% versus 0%). The percentage of total ventricular volume change was significantly associated with mission duration but negatively associated with age. Pre- to postflight structural changes of the left caudate correlated significantly with poor postural control, and the right primary motor area/midcingulate correlated significantly with a complex motor task completion time. These findings suggest that brain structural changes are associated with changes in cognitive and motor test scores and with the development of spaceflight-associated neuro-optic syndrome.

The authors enrolled 10 patients with intracranial aneurysms, treated with flow diverters between September 2014 and December 2018, who experienced postoperative aneurysm rupture. They matched these subjects 1:2 with 20 with postoperative unruptured intracranial aneurysms based on clinical and morphologic factors. Using computational fluid dynamics, they assessed hemodynamic changes pre- and posttreatment between the 2 groups on a number of qualitative and quantitative parameters. Compared with pretreatment, unstable flow pattern and higher energy loss after Pipeline Embolization Device placement for intracranial aneurysm may be the important hemodynamic risk factors related to delayed aneurysm rupture.

This study assesses the results of armed kyphoplasty using vertebral body stents or the SpineJack in traumatic, osteoporotic, and neoplastic burst fractures with respect to vertebral body height restoration and correction of posterior wall retropulsion. The authors performed a retrospective assessment of 53 burst fractures with posterior wall retropulsion and no neurologic deficit in 51 consecutive patients treated with armed kyphoplasty. Posterior wall retropulsion and vertebral body height were measured on pre- and postprocedural CT. Armed kyphoplasty was performed as a stand-alone treatment in 43 patients, combined with posterior instrumentation in 8 and laminectomy in 4. Pre-armed kyphoplasty and post-armed kyphoplasty mean posterior wall retropulsion was 5.8 and 4.5 mm, respectively, and mean vertebral body height was 10.8 and 16.7 mm, respectively. They conclude that in the treatment of burst fractures with posterior w all retropulsion and no neurologic deficit, armed kyphoplastyyields fracture reduction, internal fixation, and indirect central canal decompression.