Yuh-Feng Tsai

Utility of source images of three-dimensional time-of-flight magnetic resonance angiography in the diagnosis of indirect carotid-cavernous sinus fistulas.

Background: We sought to assess the relative contribution of magnetic resonance imaging (MRI), maximum intensity projection (MIP), and source images of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) to the diagnosis of indirect (dural) carotid-cavernous sinus fistulas (CCFs). Methods: MRI and 3D TOF MRA were obtained in eight consecutive patients with indirect CCFs confirmed by conventional catheter angiography. Two radiologists masked to the angiographic results reviewed images retrospectively to evaluate the efficacy of MRI and 3D TOF MRA source and MIP images in the diagnosis of CCF. Results: MRI disclosed CCF in five of eight cases; MIP images of TOF MRA disclosed CCF in four cases; source images of TOF MRA disclosed all eight CCF cases. Conclusions: The MRA source images are indispensable for a confirmatory diagnosis of indirect (dural) CCF. Underdiagnosis may occur by relying on MRI or 3D TOF MIP images alone.

Emphysematous pyelonephritis in a renal allograft.

A 46-year-old man presented to the Emergency Department after having fever and chills for 2 days. He had a history of renal transplantation for diabetic nephropathy. After renal transplantation he regularly received immunosuppressive therapy, including tacrolimus, mycophenolatemofetil, and prednisolone, for 1 year before presentation. On arrival, his blood pressure was 68/40 mm Hg, with a heart rate of 110 beats/min and a respiratory rate of 30 breaths/min. The physical examination showed a temperature of 40 C (104 F), a distended abdomen, and hypoactive bowel sounds; with mild tenderness in the right lower quadrants. The laboratory evaluation revealed a white blood cell (WBC) count of 16,800/mm with 85% segmented neutrophils, C-reactive protein of 38 mg/L, glucose 240mg/dL, serum urea nitrogen 80mg/dL, serum creatinine 2.8 mg/dL, sodium 138 mEq/L, potassium 6.7 mEq/L, and hemoglobin 9.8 gm/dL. Arterial blood gas on room air revealed pH 7.12, PCO2 28 mm Hg, PO2 62 mm Hg, and HCO3 12.4 mmol/L. Urine analysis

Hyperdense Basilar Sign: An Early Computed Tomography Finding of Acute Ischemia

A 58-year-old woman, who had recently been treated for hypertension and atrial fibrillation, was brought to our hospital due to sudden onset of vertigo with cold sweating of 4 h duration before presentation to our Emergency Department. On examination, she was responsive to painful stimuli, her left pupil was dilatated with sluggish reaction to light, and there were bilateral pyramidal signs. There was no seizure at onset. A non-contrast computed tomography (CT) scan of the brain was performed; it showed hyperdense thrombus in the basilar artery (hyperdense basilar artery sign) with bilateral cerebellar hemispheres infarcts (Figure 1). The diagnoses of basilar artery occlusion and ischemic stroke were made. She was intubated, admitted to the intensive care unit, and given antiplatelet agents. The patient was not a candidate for anti-thrombolytic agents due to the time window. A palliative care consultation was obtained. The family agreed to a transition to comfort care. The follow-up CT scan revealed acute infarct areas in the bilateral cerebellar hemispheres (Figure 2). By day 3 of her hospitalization, she died.