Magnetic resonance angiography in reversible cerebral vasoconstriction syndromes.

OBJECTIVE: To investigate the evolution and clinical significance of vasoconstriction on magnetic resonance angiography (MRA) in patients with reversible cerebral vasoconstriction syndromes (RCVS). METHODS: Patients with RCVS were recruited and followed up with MRA examinations until normalization of vasoconstriction or for 6 months. The vasoconstriction severity of the major cerebral arterial segments (M1, M2, A1, A2, P1, P2, and basilar artery) was scored on a 5-point scale: 0 (0-<10%), 1 (10-<25%), 2 (25-<50%), 3 (50-<75%), and 4 (> or =75%). Subjects with at least 1 segment with a vasoconstriction score > or =2 were eligible for the study. Initial mean scores of single or combined arterial segments were used to predict ischemic complications. RESULTS: Seventy-seven patients with RCVS (8 men/69 women; average age 47.7 +/- 11.6 years) finished the study with a total of 225 MRAs performed. The mean number of arterial segments involved was 5.3 +/- 3.0 in the initial MRA. Vasoconstriction scores reached their maximum 16.3 +/- 10.2 days after headache onset, close to the average timing of headache resolution (16.7 +/- 8.6 days). Vasoconstriction evolved in a parallel trend among different arterial segments. Seven (9.1%) patients developed posterior reversible encephalopathy syndromes (PRES). Six (7.8%) patients had ischemic stroke. A logistic regression model demonstrated that the M1-P2 combined score was associated with highest risk of PRES (odds ratio [OR], 11.6, p = 0.005) and ischemic stroke (OR, 3.4; p = 0.026). INTERPRETATION: MRA evaluation in patients with RCVS is valid. Vasoconstriction was pervasive and outlasted headache resolution. Vasoconstrictions in M1 and P2 are important determinants for PRES and ischemic stroke.

Characteristics of cranial aneurysmal bone cyst on computed tomography and magnetic resonance imaging.

Aneurysmal bone cysts are benign bone tumors that most commonly occur in people younger than 30 years. The cysts are most often found in the metaphyses of long bones and rarely affect the skull. We present a 54-year-old woman with a rapidly enlarging mass in the left occipital region that caused tenderness for 2 weeks. Computed tomography (CT) revealed an expansile, osteolytic lesion with characteristic soap-bubble appearance and fluid-fluid levels. Magnetic resonance images showed a dark rim surrounding the lesion, as well as multilocular spaces with fluid-fluid levels. The tumor was soft, fragile, and pulsatile during surgery. The patient was treated with en bloc resection of the tumor with cranioplasty. Follow-up CT 5 months later showed no evidence of recurrence.

Financial assessment of a picture archiving and communication system implemented all at once.

The objective of this study was to determine the differential cost between film-based radiology and a hospital-wide picture archiving and communication system (PACS) implemented all at once. The cash flow and running costs of PACS and film-based operation were measured over an 8-year time horizon. When the hospital-wide PACS was implemented over a short period, there was instant conversion into digital film and archives. The net present value (NPV) for PACS operation is US $1,598,698, whereas the NPV for film-based operation is US $2,083,856, indicating a net saving of US $485,157. The payback period is 4 years. The costs of computed radiography and image plates account for 40% of the initial capital expenditure in PACS implementation, followed by computer hardware (30%) and software (9%) costs. Our experience shows that implementation of hospital-wide PACS all at once can produce cost savings. For hospitals intending to go filmless, this study offers a model for financial evaluation of PACS to help in decision making.