This review presents up-to-date imaging applications in the substantia nigra and its related structures used in Parkinson disease and other parkinsonian syndromes, assesses their usefulness, and di... Parkinson disease is characterized by dopaminergic cell loss in the substantia nigra of the midbrain. There are various imaging markers for Parkinson disease. Recent advances in MRI have enabled el...

Intracranial atherosclerosis is associated with frequent stroke recurrence. High resolution vessel wall magnetic resonance imaging (HRMRI) can provide atheroma information related to its vulnerability. We performed HRMRI in stroke patients with intracranial atherosclerosis to determine whether plaque characteristics from vessel wall imaging can predict future stroke recurrence. Between July 2011 and June 2013, acute stroke patients with symptomatic intracranial atherosclerosis were prospectively enrolled and 3-tesla HRMRI was performed on the relevant artery. The plaque enhancement was visually determined from T1 post-gadolinium enhancement image. Stroke recurrence was monitored after index event and multivariate Cox proportional hazards model was constructed to identify factors related to future stroke recurrence. A total of 138 patients were included with a median follow-up of 18 months. There were 39 stroke recurrences. Plaque enhancement was detected in 108 patients (78.3%), and 37 of them experienced stroke recurrence. Among 30 stroke patients without plaque enhancement, two patients experienced stroke recurrence. Kaplan–Meier curves demonstrated a significant difference in event free survival between the patients with plaque enhancement and those patients without plaque enhancement (event rates at year 1: 30.3% vs. 6.8%, log-rank test, p = 0.004). Multivariate Cox-regression analysis showed that the plaque enhancement from HRMRI was independently associated with stroke recurrence (hazard ratio: 7.42, 95% confidence interval: 1.74–31.75, p = 0.007). Intracranial plaque enhancement from HRMRI is associated with stroke recurrence among the patients with symptomatic intracranial atherosclerosis.

Contrast-enhanced MRI T1 mapping of the brain suggested that sleep was associated with greater brain clearance of gadolinium-based contrast agent, potentially due to greater glymphatic clearance. Background Evaluation of the glymphatic system with intrathecal contrast material injection has limited clinical use. Purpose To investigate the feasibility of using serial intravenous contrast-enh...

Pak E, et al. Korean J Radiol. 2021 Sep;22(9):1514-1524. https://doi.org/10.3348/kjr.2020.1433

Objective: We aimed to evaluate the impact of underlying mechanism of basilar artery (BA) occlusion on the outcomes after endovascular therapy (EVT) for reperfusion and the outcome factors associated with each mechanism, and to identify radiologic parameters enabling to distinguish the underlying mechanism.Methods: From a registry database, 194 consecutive patients with acute BA occlusion who underwent EVT were analyzed. Stroke mechanism, classified into in situ atherosclerotic thrombosis (ISAT) and embolism, clot sign location profiles in pre‐angiography magnetic resonance image (MRI), parameters of angiography and EVT, and reperfusion were assessed. Poor outcome was defined as a modified Rankin‐Scale score at 90 days of 3–6.Results: The mean age was 68.8±11.8 years (range 21–92 years) and seventy‐eight (40.2%) were female patients. 102 (52.6%) patients were classified into an embolism mechanism and 92 (47.4%) into an ISAT mechanism. Overall, ISAT mechanism compared with embolism was significantly associated with poor outcomes (P = 0.002), along with the NIHSS scores, reperfusion status, and collateral status. In the embolism group, reperfusion (P = 0.001), NIHSS scores (P < 0.001), and onset‐to‐treatment time (P = 0.030) were significant outcome factors. However, in the ISAT group, baseline collateral status (P = 0.001) and NIHSS scores (P < 0.001) were significant outcome factors. A clot sign at the distal BA segment on pre‐angiography MRI was strongly associated with embolism mechanism (P < 0.001).Interpretation: Stroke mechanism has a major influence on outcomes, and outcome predictors differ according to the underlying mechanism in acute BA occlusion with EVT. Clot sign profile on pre‐angiography MRI might be useful to determine the underlying mechanism.