Chung Ping Lo

Brain Injury After Acute Carbon Monoxide Poisoning: Early and Late Complications

OBJECTIVE The purposes of this article are to illustrate the variable CT and MRI features of carbon monoxide-induced brain injury and to discuss the underlying pathogenesis. CONCLUSION Carbon monoxide can produce different patterns of brain injury in the acute and delayed stages. CT and MRI are valuable in the delineation of disease extent and helpful for understanding the pathophysiologic mechanisms.

MRI features of spongiform leukoencephalopathy following heroin inhalation

A 26-year-old man with a history of heroin inhalation presented with impaired motor, speech, and cognitive functions, reduced muscle strength, hyperactive deep tendon reflexes, and intact light-tough, vibration, and pinprick sensitivity. T2-weighted MRI revealed symmetric hyperintensity in white matter tracts, consistent with spongiform degeneration and demyelination (figure 1).1 Involvement of …

Are the Local Blood Oxygen Level–Dependent (BOLD) Signals Caused by Neural Stimulation Response Dependent on Global BOLD Signals Induced by Hypercapnia in the Functional MR Imaging Experiment? Experiments of Long-Duration Hypercapnia and Multilevel Carbon Dioxide Concentration

BACKGROUND AND PURPOSE: The relationship between the local blood oxygen level–dependent (BOLD) signals caused by neural stimulation (fBOLD) and the global BOLD signals induced by hypercapnia (hBOLD) has not been fully investigated. In this study, we examine whether fBOLD is modulated by hBOLD signals, by means of experiments using a relatively wide range of inhaled carbon dioxide (CO2) for a long duration of 5 minutes. MATERIALS AND METHODS: Ten healthy volunteers were recruited, each undergoing 6 separate experiments by inhaling gas mixtures with different fractions of CO2 (room air, 3%–7%). Each experiment contained 3 phases, prehypercapnic, hypercapnic, and posthypercapnic, during which boxcar visual stimulus was given. The local fBOLD signals were measured from areas showing activation patterns highly correlated with the visual stimulus paradigm, whereas the global hBOLD signals were measured from areas showing no visual activations. Percentage changes in fBOLD during transient-state hypercapnia and steady-state hypercapnia were both investigated in response to varying degrees of hypercapnic perturbations. RESULTS: The hBOLD signals increased with increase of inhaled CO2 fractions. The duration for the hBOLD signals to reach steady state prolonged with increase of inhaled CO2 fractions. Normalized fBOLD ratio was inversely related to the inhaled CO2 during steady-state hypercapnia but showed positive association with hBOLD during transient-state hypercapnia. CONCLUSION: Our study concludes that the steady-state fBOLD signal intensity is dependent on and inversely related to the hBOLD signals. Previous reports documenting independent and additive relationships between hBOLD and fBOLD may likely be due to transient-state observations.

Parasellar solitary fibrous tumor of meninges: magnetic resonance imaging features with pathologic correlation.

Solitary fibrous tumor (SFT) is a benign mensenchymal neoplasm of spindle-cell origin. The authors report the case of a 50-year-old man with SFT arising from the meninges of the left parasellar region with cavernous sinus involvement. The tumor was demonstrated isointense on T1-weighted and heterogeneously hypointense on T2-weighted magnetic resonance imaging (MRI) with strong contrast enhancement. The preoperative MRI diagnosis was meningioma or hemangiopericytoma. Pathological study revealed an SFT that stained positive immunohistochemically for CD34 and vimentin.

Computed tomographic features of circulatory arrest.

Although computed tomography (CT) is used widely in evaluating injuries from various kinds of trauma, the CT features of circulatory events are rarely reported. Recognizing these features is crucial to proper emergency management of patients when circulatory events occur during CT examination. We report two trauma patients who developed circulatory arrest during CT. Both patients had similar CT features of contrast distribution over the dependent portion of the right-sided venous system, a finding that has been previously reported only in patients with cardiac arrest. The quick paddle look feature may be useful to identify the condition and initiate proper resuscitation of patients without electrocardiographic monitoring in CT rooms.

Diffusion-Weighted Magnetic Resonance Imaging of Spontaneous Venous Infarction and Cortical Hemorrhage Complicating Dural Arteriovenous Fistula

Dural arteriovenous fistula (DAVF) is an abnormal arteriovenous shunt that occurs in the dura matter within or near a dural sinus. The clinical manifestations vary. The authors report herein a rare case of type III DAVF presenting with coexisting intracranial hemorrhage (ICH) and venous infarction evidenced by computed tomography (CT) and diffusion‐weighted magnetic resonance imaging. Conventional angiography proved that the right middle meningeal artery and the occipital artery supplied the DAVF, with direct drainage into the cortical veins and superior sagittal sinus.

Cystic Schmorl’s Node: An Unusual Cause of Lower Back Pain

A 40-year-old man was admitted to our hospital with symptoms of acute back pain without sciatica. He had a 1-month history of progressive lower back pain and the painful sensation was persistent. He reported no history of trauma or spinal injuries. The neurologic examination and laboratory results were normal. Plain radiographs of the lumbar spine showed a faint osteolytic lesion of the L5 vertebral body, suggesting an inflammatory reaction or benign spinal tumor. Initial magnetic resonance imaging (MRI) revealed an area of low signal intensity in the L5 vertebral body with a small cleft at the superior endplate on the…

Diffuse cerebral vasculopathy in a HIV-positive patient with recurrent strokes

The causes of ischemic stroke in the young adult are diverse. Human immunodeficiency virus (HIV) infection-related vasculopathy is usually not included in the list of differential diagnoses. HIV-positive patients may present with acute neurologic dysfunction of different causes, among which cerebral infarction is an uncommon one. Herein, we report a HIV-infected young man who suffered from recurrent ischemic strokes with evidence of cerebral vasculopathy on serial magnetic resonance images.

Typical meningioma with atypical MR imaging features masquerading malignancy. A case report

Meningiomas are the most common extraaxial tumors of intracranial neoplasms. They are usually benign with characteristic pathologic and imaging features. However, a histologically typical meningioma can have unusual or misleading imaging features that may not be suggestive of meningioma. Unusual imaging features such as large meningeal cysts, ring enhancement, and various metaplastic changes can be particularly misleading. Here we present a fibrous meningioma with atypical magnetic resonance (MR) imaging features in a 76-year-old woman.