Distinguishing hantavirus pulmonary syndrome from acute respiratory distress syndrome by chest radiography: are there different radiographic manifestations of increased alveolar permeability?

Hantavirus infection may cause diffuse air space disease, termed hantavirus pulmonary syndrome (HPS). The authors sought to determine if chest radiographs could differentiate HPS from typical acute respiratory distress syndrome (ARDS). The authors identified patients with either HPS (n = 11) or acute ARDS (n = 32) and selected the earliest chest radiograph showing diffuse airspace disease, and a chest radiograph taken 24 to 48 hours previously. Thoracic and general radiologists first viewed the chest radiograph showing diffuse air space disease, and ranked the likelihood that each case represented HPS versus ARDS. Afterward, readers viewed earlier chest radiographs and rescored each case. Receiver operating characteristic (ROC) curves from both scoring sessions were generated. The mean areas under the ROC curves for the entire group was 0.83 +/- 0.12 initially, and improved to 0.87 +/- 0.09 (p < 0.05) after viewing prior chest radiographs. Receiver operating characteristic curves of thoracic radiologists described greater areas than those of general radiologists both before and after viewing prior chest radiographs; 0.95 +/- 0.01 versus 0.78 +/- 0.08 (p < 0.05) and 96 +/- 0.02 versus 0.80 +/- 0.05 (p < 0.05). The mean sensitivity and specificity of chest radiograph interpretation for HPS was 86 +/- 13% and 74 +/- 11%, respectively. Chest radiographs can differentiate HPS from ARDS. Accuracy is improved by the use of serial radiographs and more highly trained readers. The chest radiograph findings may represent differences in the extent of alveolar epithelial damage seen in HPS and ARDS.

Granulomatous amebic encephalitis caused by acanthamoeba.

Infections arising from free-living amebae are rare. They generally cause recognizable disease only in chronically ill, debilitated patients who are immune suppressed. Only about 70 cases of granulomatous amebic encephalitis have been reported. We present an unusual case of granulomatous encephalitis in a 35-year-old man. Neurologic examination and laboratory tests were inconclusive. CT demonstrated bilateral low-density areas with mild mass effect in the cortex and subcortical white matter, which showed increased signal on T2-weighted MRI. Craniotomy and brain biopsy revealed granulomatous encephalitis with acanthamoeba organisms. Though non-specific, imaging can support the diagnosis of amebic encephalitis and direct biopsy.

Hemangiopericytoma: a rare pineal mass.

We describe a hemangiopericytoma of the pineal region in a young woman. The striking radiologic features were intense, homogeneous contrast enhancement on MRI and a dense blush on angiography.

Performance of radiologic and nuclear medicine examinations in the 6 months before death.

PURPOSE: To determine the rate of use and type of radiologic and nuclear medicine examinations performed prior to the death of an individual. MATERIALS AND METHODS: Radiologic and nuclear medicine examination data from the University of New Mexico Hospital were analyzed and correlated with death records from the New Mexico Department of Vital Statistics. The study cohort included 558 patients who were treated between July 1992 and June 1993 and died within 6 months. The records for the 558 patients were analyzed according to the type and number of examinations performed within 30 days and 6 months prior to death. RESULTS: Of 26,067 patients examined during the year, 558 (2%) underwent a radiographic or nuclear medicine examination in the 6 months prior to death. That group of patients underwent a total of 6,196 radiographic or nuclear medicine examinations (4.6%) out of a total of 134,892 examinations that were performed in that year. The rate of use was highest in those patients who were younger than 1 year at death. CONCLUSION: Approximately 5% or fewer radiologic and nuclear medicine examinations were performed during the final 6 months of an illness.

Epithelioid hemangioendothelioma of bone.

Neoplasms of bone can arise from any of the cellular elements that constitute osseous tissues. Although tumors of vascular origin are not uncommon, the vast majority are benign. A rare malignant vascular tumor--epithelioid hemangioendothelioma of bone--classifically affects young males and produces osteolytic lesions involving the cortex and cancellous bone of the lower extremities. We present a case with these findings, as well as such unusual findings as cervical spine instability and lesions affecting no fewer than 45 different bones. We conclude that epithelioid hemangioendothelioma should be investigated by skeletal survey because (1) osteolytic lesions involving more that 50% of the cortex present a serious risk for pathologic fracture and (2) the natural history of multicentric epithelioid hemangioendothelioma is more indolent than its solitary counterparts.

Angiographic pattern change in fibromuscular dysplasia. A case report.

Fibromuscular dysplasia (FMD) is an angiopathy that commonly affects the renal arteries but may affect other medium to large arteries, including the carotid artery. It has a variety of angiography appearances, the most common of which is a string-of-beads pattern consisting of a segment of alternating stenoses and dilatations. This case documents that these patterns are not necessarily fixed. An initial angiogram in a patient with neurologic symptoms shows a string-of-beads pattern in the carotid artery. Later, this pattern is seen to convert to a smooth tubular form on follow-up arteriography. FMD may present angiographically as a dynamic process.

Rotational vertebrobasilar insufficiency as a component of thoracic outlet syndrome resulting in transient blindness. Case report.

Cases of unilateral vertebral artery compression associated with thoracic outlet syndrome infrequently result in symptoms and, of those that do, most involve the brain stem. Reports of transient blindness resulting from this condition are even more rare. The authors describe the case of a middle-aged woman who presented with transient blindness when she turned her head excessively to the left. She also exhibited other less severe brainstem symptoms. Arteriography demonstrated occlusion of the left vertebral artery only when her head was rotated to the left. Surgical exploration revealed entrapment of the left vertebral artery by a tight anterior scalene muscle, release of which resulted in complete resolution of her symptoms. Both neurosurgeons and radiologists need to be aware that extrinsic compression of the vertebral artery precipitated by head rotation may sometimes result in transient cortical blindness.

Arteriography with portable DSA equipment.

Fifty-one arteriograms were obtained outside of the radiology department with portable digital subtraction angiographic equipment. Thirty-five studies were performed in the emergency room, 12 in the operating room, and four in the intensive care unit. There was a significant decrease in the time interval from arrival in the emergency room to arteriogram completion for examinations performed in the emergency room with portable equipment, compared with those performed in the radiology department. One of the 51 examinations yielded questionable results and was repeated with the conventional screen-film technique. Accurate angiographic diagnoses can be obtained by means of portable equipment in a variety of hospital locations.