Differential Subsampling with Cartesian Ordering-MRA for Classifying Residual Treated Aneurysms.

BACKGROUND AND PURPOSE: Differential Subsampling with Cartesian Ordering (DISCO), an ultrafast high-spatial-resolution head MRA, has been introduced. We aimed to determine the diagnostic performance of DISCO-MRA in grading residual aneurysm in comparison with TOF-MRA in patients with treated intracranial aneurysms. MATERIALS AND METHODS: Patients with endovascular treatment and having undergone DISCO-MRA, TOF-MRA, and DSA were included for review. The voxel size and acquisition time were 0.75 × 0.75 × 1 mm3/6 seconds for DISCO-MRA and 0.6 × 0.6 × 1 mm3/6 minutes for TOF-MRA. Residual aneurysms were determined using the Modified Raymond-Roy Classification on TOF-MRA and DISCO-MRA by 2 neuroradiologists independently and were compared against DSA as the reference standard. Statistical analysis was performed using the κ statistic and the χ2 test. RESULTS: Sixty-eight treated intracranial aneurysms were included. The intermodality agreement was κ = 0.82 (95% CI, 0.67-0.97) between DISCO and DSA and 0.44 (95% CI, 0.28-0.61) between TOF and DSA. Modified Raymond-Roy Classification scores matched DSA scores in 60/68 cases (88%; χ2 = 144.4, P < .001 for DISCO and 46/68 cases (68%; χ2 = 65.0, P < .001) for TOF. The diagnostic accuracy for the detection of aneurysm remnants was higher for DISCO (0.96; 95% CI, 0.88-0.99) than for TOF (0.79; 95% CI, 0.68-0.88). CONCLUSIONS: In patients with endovascularly treated intracranial aneurysms, DISCO-MRA provides superior diagnostic performance in comparison with TOF-MRA in delineating residual aneurysms in a fraction of the time.

Imaging Features of Acute Encephalopathy in Patients with COVID-19: A Case Series.

Coronavirus disease 2019 was declared a global pandemic by the World Health Organization on March 11, 2020. There is a scarcity of data on coronavirus disease 2019-related brain imaging features. We present 5 cases that illustrate varying imaging presentations of acute encephalopathy in patients with coronavirus disease 2019. MR features include leukoencephalopathy, diffusion restriction that involves the GM and WM, microhemorrhages, and leptomeningitis. We believe it is important for radiologists to be familiar with the neuroradiologic imaging spectrum of acute encephalopathy in the coronavirus disease 2019 population.

COVID-19 Is an Independent Risk Factor for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Coronavirus disease 2019 (COVID-19) is an active worldwide pandemic with diverse complications. Stroke as a presentation has not been strongly associated with COVID-19. The authors aimed to retrospectively review a link between COVID-19 and acute stroke. MATERIALS AND METHODS: We conducted a retrospective case-control study of 41 cases and 82 control subjects matched by age, sex, and risk factors. Cases were patients who underwent stroke alert imaging with confirmed acute stroke on imaging between March 16 and April 5, 2020, at 6 hospitals across New York City. Control subjects were those who underwent stroke alertimaging during the same timeframe without imaging evidence of acute infarction. Data pertaining to diagnosis of COVID-19 infection, patient demographics, and risk factors were collected. A univariate analysis was performed to assess the covariate effect of risk factors and COVID-19 status on stroke imaging with positive findings. RESULTS: The mean age for cases and controls was 65.5 ± 15.3 years and 68.8 ± 13.2 years, respectively. Of patients with acute ischemic stroke, 46.3% had COVID-19 infection compared with 18.3% of controls (P = .001). After adjusting for age, sex, and risk factors, COVID-19 infection had a significant independent association with acute ischemic stroke compared with control subjects (OR, 3.9; 95% CI, 1.7-8.9; P = .001). CONCLUSIONS: We demonstrated that COVID-19 infection is significantly associated with imaging confirmation of acute ischemic stroke, and patients with COVID-19 should undergo more aggressive monitoring for stroke.

Early MRI Characteristics after MRI-Guided Laser-Assisted Cingulotomy for Intractable Pain Control.

BACKGROUND AND PURPOSE: Cingulotomy is a well-accepted stereotactic procedure in the treatment of debilitating pain syndromes. At our institution, we used a 980-nm diode laser to perform MR imaging-guided laser-assisted cingulotomy. We report the early MR imaging changes associated with this technique. MATERIALS AND METHODS: In this retrospective analysis, MR imaging-guided laser-assisted cingulotomy was performed in 4 patients with intractable pain secondary to metastatic disease. Patients were imaged at various time points postprocedure, with visual analysis of MR imaging changes in the cingulate gyri during that timeframe. RESULTS: Twenty-four hours postablation, 4 distinct zones of concentric rings reminiscent of an "owl eye" shape were noted in the cingulate gyri. Extrapolating from the imaging characteristics of the rings, we defined each zone as follows: The central zone (zone 1) represents a laser probe void with fluid, zones 2 and 3 have signal characteristics that represent hemorrhage and leaked protein, and zone 4 has a peripheral ring of acute infarction, enhancement, and surrounding edema. One patient with 1-year follow-up showed persistent concentric rings with resolution of enhancement and edema. CONCLUSIONS: Post-MR imaging-guided laser-assisted cingulotomy rings appear to represent a continuum of injury created by the laser probe and thermal injury. The imaging changes are similar to those described for laser ablation of tumor-infiltrated brain with a 1064-nm laser. This is the first study to characterize early MR imaging changes after MR imaging-guided laser-assisted cingulotomy by using a 980-nm laser. It is important for neuroradiologists and neurosurgeons to understand expected imaging findings as laser ablation cingulotomy re-emerges to treat intractable pain.