Partially thrombosed giant basilar artery aneurysm with attenuated contrast enhancement of the intraluminal thrombus on vessel wall MRI after flow diversion treatment: illustrative case.

BACKGROUND: The effect of vessel wall magnetic resonance imaging (VW-MRI) enhancement in partially thrombosed aneurysms has previously indicated aneurysmal instability and a rupture risk. However, whether the contrast effect of the wall changes before or after flow diversion treatment is still under investigation. OBSERVATIONS: The authors report a case of a partially thrombosed basilar artery aneurysm that increased in size over a short period, worsened brainstem compression symptoms, and was treated with a flow diverter stent with good results. In this case, VW-MRI after surgery showed a reduced contrast effect on the intraluminal thrombus within the aneurysm. The aneurysm thrombosed and markedly regressed over the next 5 months, with remarkable improvement in the brainstem compression symptoms. LESSONS: This finding on VW-MRI may indicate an attenuation of neovascularization in the thrombus wall and be a sign of aneurysm stabilization.

A human T-lymphotropic virus-1 carrier who developed progressive multifocal leukoencephalopathy following immunotherapy for sarcoidosis: a case report.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disorder of the central nervous system caused by opportunistic infection of the JC virus (JCV). CASE PRESENTATION: A 58-year-old Japanese woman was admitted to our hospital for aphasia. She had a 5-year history of untreated sarcoidosis and was a human T cell lymphotropic virus-1 (HTLV-1) carrier. Serum angiotensin-converting enzyme, soluble interleukin-2 receptor, lysozyme, and calcium levels were elevated. JCV-DNA was not detected in cerebrospinal fluid by PCR testing. Skin biopsy revealed noncaseating granuloma formation. Bilateral multiple nodular lesions were present on chest X-ray. Brain magnetic resonance imaging showed left frontal and temporal lesions without gadolinium enhancement. As we suspected that systemic sarcoidosis had developed into neurosarcoidosis, we started steroid and infliximab administration. After treatment, the chest X-ray and serum abnormalities ameliorated, but the neurological deficits remained. At 1 month after immunotherapy, she developed right hemiparesis. Cerebrospinal fluid was positive for prototype (PML-type) JCV on repeated PCR testing. Brain biopsy revealed demyelinating lesions with macrophage infiltration, atypical astrocytes, and JCV antigen-positive cells. We diagnosed her with PML and started mefloquine, leading to partial remission. CONCLUSIONS: Sarcoidosis and HTLV-1 infection both affect T cell function, especially CD4+ T cells, and may developped the patient's PML. The comorbidity of sarcoidosis, PML, and HTLV-1 infection has not been reported, and this is the world's first report of PML associated with HTLV-1 infection and sarcoidosis.

Ultrashort Echo Time Magnetic Resonance Angiography as an Alternative Tool to Digital Subtraction Angiography in the Follow-up of Stent-Assisted Coil Embolization Outcomes.

BACKGROUND: Follow-up of aneurysms treated with stent-assisted coil embolization has been performed using digital subtraction angiography (DSA) because in time-of-flight magnetic resonance angiography, metal artifacts from the stent often affect visualization. OBJECTIVE: To confirm whether ultrashort echo time (TE) MRA may be an alternative for DSA during follow-up. METHODS: Patients with unruptured aneurysms initially treated with stent-assisted coil embolization between April 2019 and March 2021 were enrolled. After 3 months of treatment, follow-up DSA and ultrashort TE MRA were performed. All images were independently reviewed by neurosurgeons to evaluate in-stent flow and rated from 1 (not visible) to 4 (excellent). Aneurysmal embolization status was assessed as complete obliteration, residual neck, or residual aneurysm. Ultrashort TE MRA findings were classified as evaluative or nonevaluative state based on the presence of metal artifacts. We investigated the types of aneurysms that were evaluative and the agreement between ultrashort TE and DSA. RESULTS: Overall, 89 aneurysms were examined, of which 74% (n = 66) were classified as evaluative on ultrashort TE. Significant differences were observed in size and stent type. Evaluative cases had an aneurysm size of <7 mm ( P = .0007) and a higher rate of Neuroform Atlas ( P = .0006). The rate of agreement between ultrashort TE with evaluative state and DSA was 95%. CONCLUSION: Ultrashort TE MRA could evaluate an embolization status treated with stenting, and the findings are in excellent agreement with those of DSA. Aneurysms measuring <7 mm and treated with Neuroform Atlas are evaluative on ultrashort TE, and DSA might not be necessary.