High-Resolution Time-of-Flight Magnetic Resonance Angiography with a Volume Rendering Algorithm for Detection of Unruptured Aneurysms: Correlations with Digital Subtraction Angiography

Objective@#We investigated the diagnostic accuracy of high-resolution magnetic resonance angiography (HR-MRA) with volume rendering (VR) post-processing techniques for the detection of cerebral aneurysms compared with conventional MRA (C-MRA) using digital subtraction angiography (DSA) as the gold standard. @*Methods@#HR-MRA was performed for 51 possible aneurysms of 38 patients on C-MRA. For each possible aneurysm, readers recorded their level of confidence on a 5-point scale. All patients underwent DSA, which was used as the standard of reference. Receiver-operating characteristic (ROC) analysis and the area under the ROC curves (AUC) were used to determine the effectiveness of C-MRA and HR-MRA in detecting cerebral aneurysm with and without VR algorithm. The increased discriminative value was examined by calculation of Net Reclassification Index (NRI) and Integrated Discrimination Improvement (IDI) index. @*Results@#DSA revealed 37 aneurysms in 26 patients. In aneurysm-based analysis, HR-MRA showed higher diagnostic accuracy than C-MRA, and increased diagnostic accuracy on adding VR (C-MRA vs. HR-MRA, P< 0.01; C-MRA with VR vs. HR-MRA with VR, P< 0.01, respectively). The differences in AUC, IDI (19.38%, Z= 3.18, P< 0.01) and NRI (46.3%, Z= 6.32, P< 0.01), on adding VR to the HR-MRA, were also statistically significant. The application of HR-MRA with VR increased the detection rate of aneurysms less than 3 mm. @*Conclusion@#The application of HR-MRA with VR algorithm improves diagnostic performance for the detection of intracranial aneurysms, especially when the aneurysm is less than 3 mm. Clinically, HR-MRA with VR algorithm could facilitate the accurate differentiation of aneurysms from infundibula and prevent unnecessary, invasive procedure before aneurysmal rupture.

An MRI-Based Quantification for Correlation of Imaging Biomarker and Clinical Performance in Chronic Phase of Carbon Monoxide Poisoning

PURPOSE: The purpose of this study was to determine the relation between quantitative magnetic resonance imaging biomarkers, and clinical performances in chronic phase of carbon monoxide intoxication. MATERIALS AND METHODS: Eighteen magnetic resonance scans and cognitive evaluations were performed, on patients with carbon monoxide intoxication in chronic phase. Apparent diffusion coefficient (ADC) ratios of affected versus unaffected centrum semiovale, and corpus callosum were obtained. Signal intensity (SI) ratios between affected centrum semiovale, and normal pons in T2-FLAIR (fluid-attenuated inversion recovery) images were obtained. The Mini-Mental State Exam, and clinical outcome scores were assessed. Correlation coefficients were calculated, between MRI and clinical markers. Patients were further classified into poor-outcome and good-outcome groups based on clinical performance, and imaging parameters were compared. T2-SI ratio of centrum semiovale was compared, with that of 18 sex-matched and age-matched controls. RESULTS: T2-SI ratio of centrum semiovale was significantly higher in the poor-outcome group, than that in the good-outcome group and was strongly inversely correlated, with results from the Mini-Mental State Exam. ADC ratios of centrum semiovale were significantly lower in the poor outcome group than in the good outcome group, and were moderately correlated with the Mini-Mental State Exam score. CONCLUSION: A higher T2-SI and a lower ratio of ADC values in the centrum semiovale, may indicate presence of more severe white matter injury and clinical impairment. T2-SI ratio and ADC values in the centrum semiovale, are useful quantitative imaging biomarkers for correlation with clinical performance in individuals with carbon monoxide intoxication.

Sixth Cranial Nerve Palsy Caused by Gastric Adenocarcinoma Metastasis to the Clivus

Tumors of the clivus and metastases to the clivus are very rare. Metastasis involving the clivus has previously been described in only two case reports. In skull metastasis, the breast and prostate are the most common primary foci, while metastasis from gastric carcinoma is extremely rare. A review of the English literature revealed only one published case of clivus metastases from gastric adenocarcinoma. There is no literature thoroughly explaining the differential diagnosis between chordoma and metastasis. Here we report a rare case of metastasis to the clivus from a gastric adenocarcinoma in a 42-year-old female patient with sudden blurry vision, presenting as bilateral cranial nerve VI palsy.

Chordoid Glioma Originating in the Intrasellar and Suprasellar Regions: Case Report

Chordoid glioma is a rare, low-grade brain neoplasm typically located in the third ventricle. Herein, we report an unusual case of histologically confirmed chordoid glioma located in the pituitary fossa and suprasellar region, not attached to the third ventricle. A 57-year-old woman presented with a 2-month history of headache and visual disturbance. Magnetic resonance imaging revealed an ovoid mass in the pituitary fossa and suprasellar region, compressing the optic chiasm without involvement of the third ventricle. The tumor showed low signal intensity on T1-weighted images and iso- to high signal intensity on T2-weighted images, with strong and homogenous contrast enhancement. Subtotal resection was performed via the transcranial approach, and the patient subsequently received adjuvant gamma knife radiosurgery. However, the residual mass showed disease progression 5 months after the initial surgery.

Cerebral Fat Embolism after Intramedullary Nailing for Femur and Tibia Fractures: A Case Report / 대한신경손상학회지

We are to report a case of cerebral fat embolism for presenting with unconsciousness without any respiratory dysfunction after intramedullary nailing for femur and tibia fractures. A sixteen-year-old boy was involved in motorcycle accident. His consciousness was alert. He had closed shaft fractures of left femur and left tibia and underwent standard femoral and tibial nail insertions. During the operation, there was no change of vital signs and saturation of oxygen. The consciousness was stuporous after the surgery. The brain CT was normal, but multiple high-signal intensity lesions in T2-weighted and diffusion-weighted images were found at bilateral cerebral hemispheres, corpus callosum, and pons. He woke up on postoperative day 12 and recovered to speak fluently without any neurological deficits at 3 months later. MR image should be recommended if the patient is not neurologically stable after the surgery for lone-bone fractures.

Cerebral Fat Embolism after Intramedullary Nailing for Femur and Tibia Fractures: A Case Report / 대한신경손상학회지

We are to report a case of cerebral fat embolism for presenting with unconsciousness without any respiratory dysfunction after intramedullary nailing for femur and tibia fractures. A sixteen-year-old boy was involved in motorcycle accident. His consciousness was alert. He had closed shaft fractures of left femur and left tibia and underwent standard femoral and tibial nail insertions. During the operation, there was no change of vital signs and saturation of oxygen. The consciousness was stuporous after the surgery. The brain CT was normal, but multiple high-signal intensity lesions in T2-weighted and diffusion-weighted images were found at bilateral cerebral hemispheres, corpus callosum, and pons. He woke up on postoperative day 12 and recovered to speak fluently without any neurological deficits at 3 months later. MR image should be recommended if the patient is not neurologically stable after the surgery for lone-bone fractures.

Nocardia Brain Abscess Mimicking a Metastatic Brain Tumor: A Severe CNS Infection Requiring Aggressive Management

Nocardiosis is an uncommon Gram-positive bacterial infection caused by aerobic actinomycetes in the genus Nocardia. Nocardia spp. have the ability to cause localized or systemic suppurative disease in humans and animals. Nocardiosis is typically regarded as an opportunistic infection, but approximately one-third of infected patients are immunocompetent. We report a rare case of pulmonary nocardiosis and a brain abscess caused by Nocardia asteroides in an elderly woman with a history of Crohn's disease. Radiographic imaging revealed a contrast-enhancing lesion with perilesional parenchymal edema that was preoperatively thought to be a neoplasm. The patient experienced aggressive disease progression simulating a metastatic brain tumor. Early diagnosis of norcadiosis, the absence of underlying disease, and the administration of appropriate antibiotics has a positive impact on prognosis. Familiarity with the magnetic resonance and computed tomography findings associated with CNS nocardiosis, such as those presented here, is essential for making an early diagnosis.