Neurologic complications of the tryptophan-associated eosinophilia-myalgia syndrome.

A case of tryptophan-associated eosinophilia, central nervous system complications, and multiple white matter lesions by magnetic resonance imaging is presented. Eosinophilia regardless of its cause should be included within the differential of patients exhibiting periventricular white matter lesions.

Aortic and renal atherosclerotic calcifications seen on computed tomography of the spine. A positive predictor of hypertension.

RATIONALE AND OBJECTIVES: This study was undertaken to determine if there is an association between hypertension and aortic or renal atherosclerotic calcifications seen on computed tomography (CT) of the spine. METHODS: The lumbar CTs of 93 sequential patients were evaluated without knowledge of their blood pressures. Aortic and renal atherosclerosis was graded on a scale of 0-3. The patients' charts were reviewed for the presence of hypertension and diseases that might cause hypertension. RESULTS: Sixty-five patients had atherosclerotic calcifications. Forty-four of these were hypertensive. Logistic regression analysis revealed that calcifications in the left renal artery (P = .003), the right renal artery (P = .010) and the abdominal aorta (P = .001) are statistically significant positive predictors of hypertension. Renal artery calcifications are better predictors of hypertension than aortic calcifications. CONCLUSIONS: Renal and abdominal aortic calcifications are significant radiographic findings in lumbar spine CT examinations and their presence should be routinely included in the radiographic report.

Diagnostic performance of teleradiology in cervical spine fracture detection.

This study was done to assess the diagnostic accuracy of high-resolution (5 lp/mm) teleradiology for detecting cervical spine fractures. Single radiographs from 25 patients with and 25 patients without cervical spine fractures were transmitted between two units of our teleradiology system (Dupont DTR 2000) located 5 miles apart. Each image was examined by four readers. Fracture detection accuracy was assessed by generating receiver operating characteristic (ROC) curves and comparing the areas under each reader's curves for original and transmitted images. Two readers had statistically significant better fracture detection using nontransmitted images, whereas two had no significant differences in accuracy. The authors conclude that high resolution in and of itself is not adequate for fracture detection, and that issues concerning image contrast manipulation also will have to be addressed before teleradiology systems can be used for clinical cervical spine fracture screening.

Detection of breast abnormalities on teleradiology transmitted mammograms.

The authors conducted an observer performance study to compare breast lesion detection of conventional mammography (CM) with teleradiology (TE) transmitted mammograms. One hundred four abnormal, single-projection mammographic images were transmitted by teleradiology. Abnormalities included 11 cases with skin thickening or retraction, 48 cases with microcalcifications, and 52 with parenchymal masses. The CM and TE images were reviewed by four mammographers who indicated the type and location of abnormalities and a level of confidence for their diagnostic decisions. For each of three detection tasks--skin and nipple abnormalities, microcalcifications, and masses--receiver operating characteristic curve analysis was performed for individual readers and all readers as a group. For detecting skin and nipple abnormalities, readers performed significantly better with CM than with TE (z = 2.05, P = less than 0.04). However, no significant differences were found among readers for detection of either microcalcifications or masses. Further improvements in hardware and imaging parameters may improve detection of soft tissue abnormalities. Further evaluation is necessary to determine whether teleradiology might be applicable to breast cancer screening.

Pleomorphic xanthoastrocytoma.

We report two cases of pleomorphic astrocytoma, a rare primary brain tumor with an unusually good prognosis. These lesions typically are peripherally located, partially cystic, temporal lobe masses. Dural attachment is frequent, calcifications are not. Angiography usually shows a hypovascular mass, although blood supply from the external carotid artery may be seen.

Metallic postoperative artifacts on cervical MR.

Spectroscopy of cervical diskectomy specimens obtained from sheep demonstrated that metallic susceptibility artifacts are produced by microscopic amounts of nickel, copper, and zinc. Sufficient quantities of metals to produce artifacts are deposited only by contact of metal drill bits and suction tips. If these instruments do not come in contact during surgery, susceptibility artifacts are not observed.

Conventional vs computed radiography: evaluation of myelography.

A prospective study was performed to compare the diagnostic efficacy of conventional film-screen (FS) imaging with computed radiography (CR) in myelography. Forty examinations were done with both methods. Digital myelography was found to have diagnostic accuracy equal to that of conventional film-screen examinations.

Marchiafava-Bignami disease. Premortem diagnosis of an acute case utilizing magnetic resonance imaging.

Marchiafava-Bignami disease is a rare demyelinating disease involving the corpus callosum and other central white matter tracts. In the patient described here, the disease produced extensive demyelination of the corpus callosum and deep cerebral white matter. This widespread demyelination, confirmed pathologically, was associated with a fulminant fatal course. The magnetic resonance imaging appearance is quite suggestive of Marchiafava-Bignami disease and plays an important role in the premortem diagnosis.

Evaluation of contrast dose reduction for excretory urography using computed radiography.

We prospectively investigated whether performing excretory urography by computed radiography (CR) - with CR's broader dynamic range and potential for post-processing - would permit lower contrast dose while maintaining usual image quality. The rationale for this experiment was to evaluate whether CR had potential in reducing the risks and costs associated with urography. Sixty sequential patients were randomly assigned to undergo computed urography with either our full (282 mg I/kg body weight) or half our usual dose (141 mg I/kg body weight) of intravenous 60% diatrizoate meglumine. Three blinded observers judged automatically post-processed full dose tomograms and KUBs as qualitatively superior to both automatically post-processed and individually, interactively post-processed half dose images. Thus, post-acquisition image manipulation could not fully compensate for diminished image quality due to contrast dose reduction.

Atherosclerotic aneurysms of the axillary artery. A report of two cases and a review of the literature.

Atherosclerotic axillary artery aneurysms are rare. We report two cases of this entity and review the literature with respect to clinical presentation, diagnosis, operative management, and long-term outcome of these lesions.

Selective use of low osmolality contrast agents: cost and benefits.

Recently introduced low osmolality contrasts produce less pain on injection and decrease other adverse side effects of angiography; however, converting completely to these agents is prohibitively expensive. Reserving low osmolality contrasts for high risk patients can provide a marked reduction in the increased cost associated with low osmolality contrasts, while at the same time reducing overall adverse side effects.

Duodenal hematoma: CT demonstration of the ring sign.

This case illustrates the computed tomographic (CT) and sonographic features of duodenal hematoma. In addition, the CT scans demonstrate the ring sign, a characteristic feature noted previously only by magnetic resonance imaging.

Computed tomography findings in squamous cell carcinoma of the pancreas.

This case illustrates previously unreported computed tomography findings in a primary pancreatic squamous cell carcinoma, an unusual pancreatic malignancy. With bolus injection of intravenous contrast, attenuation of this tumor increased from 35 to 61 Hounsfield units, a finding not typical for pancreatic adenocarcinoma.

Coccidioidomycosis in renal dialysis and transplant patients: radiologic findings in 30 patients.

Asymptomatic primary coccidioidal infection is common. After the initial infection is contained, the organism can remain dormant in the body for years. Immunosuppression related to renal transplantation or dialysis may reactivate dormant disease. Thus, symptomatic disease may be seen in those with no known history of previous coccidioidomycosis who have visited endemic areas only briefly. To determine if coccidioidomycosis produces characteristic radiographic findings in renal transplant and dialysis patients, we reviewed the records and radiographs of all patients in either of these two categories who are known to have developed active coccidioidal infection in southern Arizona since 1965. Thirty patients (12 undergoing dialysis and 18 transplant recipients) were identified. We conclude that the radiographic manifestations of pulmonary coccidioidomycosis in renal transplant and dialysis patients are highly variable. Interstitial and alveolar patterns of disease are equally likely to occur. Extrathoracic infection without evidence of pulmonary disease occurred in 11 patients (37%), but was radiographically demonstrable only as septic arthritis or perinephric abscess.

MRI diagnosis of thoracic ossification of posterior longitudinal ligament with concomitant disc herniation.

Ossification of the posterior longitudinal ligament is a potentially curable cause of thoracic myelopathy. As this case illustrates, MRI can confirm the diagnosis, demonstrate other concomitant pathology such as disc herniation, and help assess the clinical significance of OPLL by showing spinal word compression.

Intraoperative arteriography: comparison of conventional screen-film with photostimulable imaging plate radiographs.

This prospective study compared images obtained with a photostimulable imaging plate with matched images obtained with a conventional screen-film combination in 26 patients undergoing intraoperative arteriography. Diagnostic accuracy of the two techniques was assessed objectively, and image quality was assessed subjectively. In 16 patients (62%), the radiation exposure was reduced by 50% for the imaging plate technique by decreasing the mAs level generally used for the screen-film combination. Because of the dynamic range of the imaging plate system, no repeat examinations were necessary, while 12% of the screen-film studies had to be repeated because of over- or under-penetration. Imaging plate studies required 6% more time for processing than screen-film studies. Receiver-operating-characteristic analysis indicated no difference in diagnostic accuracy between the two imaging techniques. Subjective evaluation also revealed no difference in observer preference for imaging plate or screen-film studies. The imaging plate technique is an excellent alternative to screen-film studies in the operating room.

MR angiography of the foot and ankle.

To better understand the use of magnetic resonance angiography (MRA) in evaluating peripheral vascular disease, the authors studied arteries in the foot and ankle. Twenty patients with arterial occlusive disease of the lower extremity were studied with two-dimensional time-of-flight MRA, and the results were compared with those of 10 conventional x-ray arteriograms, four digital subtraction arteriograms, and three intraoperative arteriograms. The studies were reviewed and rated by three radiologists blinded to the patients' clinical history. Also, the first 16 patients were examined with MRA before and after intravenous injection of gadopentetate dimeglumine. The mean confidence levels for the reviewers' interpretations of the MRA studies were significantly higher than those for the conventional arteriograms for the medial plantar, lateral plantar, and plantar arch arteries of the feet (P < or = .005). Postcontrast MRA images were inferior to precontrast images because of overlapping of veins and arteries. Time-of-flight MRA without gadolinium can serve as a useful complementary study for evaluating patients with peripheral vascular disease in the foot and ankle.