Neuroimaging Findings of Hospitalized Covid-19 Patients: A Canadian Retrospective Observational Study.

PURPOSE: Coronavirus disease (COVID-19) has been associated with neurologic sequelae and neuroimaging abnormalities in several case series previously. In this study, the neuroimaging findings and clinical course of adult patients admitted with COVID-19 to a tertiary care hospital network in Canada were characterized. METHODS: This is a retrospective observational study conducted at a tertiary hospital network in Ontario, Canada. All adult patients with PCR-confirmed COVID-19 admitted from February 1, 2020 to July 22, 2020 who received neuroimaging related to their COVID-19 admission were included. CT and MR images were reviewed and categorized by fellowship-trained neuroradiologists. Demographic and clinical data were collected and correlated with imaging findings. RESULTS: We identified 422 patients admitted with COVID-19 during the study period. 103 (24.4%) met the inclusion criteria and were included: 30 ICU patients (29.1%) and 73 non-ICU patients (70.9%). A total of 198 neuroimaging studies were performed: 177 CTs and 21 MRIs. 17 out of 103 imaged patients (16.8%) had acute abnormalities on neuroimaging: 10 had macrohemorrhages (58.8%), 9 had acute ischemia (52.9%), 4 had SWI abnormalities (23.5%), and 1 had asymmetric sulcal effacement suggesting possible focal encephalitis (5.8%). ICU patients were more likely to have positive neuroimaging findings, more specifically acute ischemia and macrohemorrhages (P < 0.05). Macrohemorrhages were associated with increased mortality (P < 0.05). CONCLUSION: Macrohemorrhages, acute ischemia and SWI abnormalities were the main neuroimaging abnormalities in our cohort of hospitalized COVID-19 patients. Acute ischemia and hemorrhage were associated with worse clinical status.

MRI Findings of Two Patients With Hashimoto Encephalopathy.

Hashimoto encephalopathy (HE), also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a rare type of autoimmune encephalitis that typically presents with cognitive and neuropsychiatric symptoms that resolve with steroids. Positive neuroimaging findings of HE are rarely reported in the literature. We present two cases of HE with abnormal MRI findings, including signal abnormalities in the claustrum, cerebral white matter, and mesial temporal lobes. HE and other forms of autoimmune encephalopathies can often be misdiagnosed as viral encephalopathies. As such detection of subtle neuroimaging findings in the context of suspicious clinical history should prompt further investigations to ensure accurate and timely diagnosis.

Pseudo fat-saturated appearance of magnetic resonance head and neck images in 2 cachectic patients.

Cachexia is a significant contributor to cancer mortality as it is responsible for up to 30% of cancer deaths. Magnetic resonance imaging offers a noninvasive approach to detect features of cachexia. T1-weighted images of cachectic patients have a "pseudo fat-saturated" appearance secondary to disappearance of subcutaneous and fascial fat throughout the body, as well as fat in the bone marrow. Orbital fat remains preserved until late disease. We present 2 cases with these classic imaging findings of cancer cachexia in the subcutaneous tissues of the head, neck, and spine. This imaging phenomenon is often misinterpreted by radiologists and may lead to delayed diagnosis or unnecessary repeat imaging.

Refractive Laser-Assisted Cataract Surgery versus Conventional Manual Surgery: Comparing Efficacy and Safety in 3144 Eyes.

PURPOSE: To report on outcomes of the efficacy and safety in 1 of the largest series of eyes undergoing either conventional manual cataract surgery (MCS) or refractive femtosecond laser-assisted cataract surgery (ReLACS). DESIGN: Retrospective, consecutive, interventional comparative case series. METHODS: This study included 3144 consecutive eyes, of which 1580 were treated via MCS, and 1564 were treated via ReLACS at Uptown Surgical Centre in Vaughan, Ontario, Canada. Preoperative characteristics, best corrected visual acuity (BCVA), mean absolute spherical error (MAE), rates of intraoperative posterior capsular rupture, and postoperative complications were evaluated. RESULTS: Across all eyes, ReLACS was superior to MCS for reducing surgical time (MCS: 7.7 ± 0.1 min vs ReLACS: 6.8 ± 0.1 min, P < 0.001); was less commonly associated with postoperative cystoid macular edema (OR = 0.36, 95% CI: 0.14-0.91, P = 0.031) and more commonly reduced MAE (MCS: 0.60 ± 0.02 diopters (D) vs ReLACS: 0.54 ± 0.02 D, P = 0.02). There were no differences in rates of posterior capsular rupture (P = 0.918), overall postoperative complications (P = 0.088) or final BCVA (P = 0.881). When analyzing a subgroup of more difficult cases (n = 833), ReLACS was superior to MCS for: 1) being more likely to yield an improvement of more than 0.1 logarithm of the minimum angle of resolution BCVA (OR = 1.80, 95% CI: 1.15-2.74, P = 0.01); 2) reducing MAE (MCS: 0.73 ± 0.3 D vs ReLACS: 0.60 ± 0.27 D, P = 0.04); and 3) being more likely to yield an MAE within 0.5 D (OR = 1.61, 95% CI: 1.11-2.33, P = 0.012). CONCLUSIONS: Across all eyes, our results support that ReLACS and MCS yield similar outcomes. However, our results show trends toward a more pronounced benefit of ReLACS compared to MCS when treating more difficult eyes.