Richard J. Wechsler

Computed tomography diagnosis of distal radioulnar subluxation

Eight patients with suspected diagnosis of distal radioulnar joint (DRUJ) subluxation underwent computed tomographic (CT) scans of the wrist. Five underwent surgery and had DRUJ subluxation or dislocation; CT scans revealed subluxation in four. Three CT criteria for the evaluation of DRUJ subluxation are discussed and compared in this manuscript.

CT-pathologic correlation of axillary lymph nodes in breast carcinoma

A prospective study was performed to determine whether thoracic CT yielded useful information regarding the status of axillary lymph nodes (LNs) in patients with breast cancer. Thirty-five consecutive patients with clinically suspected stage II or III breast carcinomas were scanned preoperatively from the supraclavicular regions to the lung bases. Axillary LNs measuring greater than or equal to 1 cm were considered abnormal. The lymph nodes were classified according to their relationship to the pectoralis muscle. Extracapsular lymph node extension was diagnosed when there was irregularity and spiculation of the lymph node margin with surrounding fatty infiltration. Correlation with axillary dissection was obtained in 20 patients, giving a positive predictive value for axillary metastases of 89% with 50% sensitivity, 75% specificity, and 20% negative predictive value. CT was also able to detect the level of axillary involvement accurately when the lymph nodes were enlarged and to evaluate extracapsular LN extension. Although superior to physical examination, CT was not an accurate predictor of axillary LN involvement, primarily because of its low negative predictive value.

Significance of ground-glass opacity on HRCT in long-term follow-up of patients with systemic sclerosis.

Despite little supportive evidence, ground-glass opacity at high-resolution computed tomography, without other signs of fibrosis, has been equated with potentially reversible disease, and in systemic sclerosis, frequently prompts aggressive anti-inflammatory treatment to prevent pulmonary fibrosis. Our study evaluates ground-glass opacity on sequential high-resolution computed tomography in 41 patients with systemic sclerosis over a mean follow-up period of 27 months (r6 to 60 mo). Ground-glass opacity was the most common imaging finding, present in 66%, and usually associated with other signs of interstitial disease, including nonfibrotic interstitial opacities in 27% and fibrotic interstitial opacities in 32%. Improvement was only documented in 2(5%) patients with ground glass and nonfibrotic interstitial opacities. In systemic sclerosis, ground-glass opacity is most commonly associated with irreversible disease. Disease progression or improvement could not be predicted by the presence of ground-glass opacity.

Posterior arch defects of the cervical spine

Spondylolysis and absence of the pedicle are congenital anomalies of the posterior cervical spine. Their roentgenographic changes may be confused with other more serious entities which may necessitate either emergent therapy or require extensive diagnostic testing and treatment. Four cases are present and the literature is reviewed. A hypothesis for the embryologic etiology of these entities is proposed.

Actinomycosis and nocardiosis of the lung

Actinomyces and Nocardia species are frequently overlooked pulmonary pathogens until their presence is histologically proved. These infections often are not considered in the differential diagnosis of lung disease because of the spectrum of their presentation, the similarity of their appearance to other granulomatous or neoplastic diseases, and coexistence of these infections with other pulmonary conditions. Pulmonary actinomycosis is characterized by pulmonary consolidation, frequently with cavitation and spread to contiguous tissues without regard for normal anatomic barriers. The appearance often is confused with that of bronchogenic carcinoma or other granulomatous infections, especially tuberculosis. Pulmonary nocardiosis most frequently develops in immunocompromised patients, and the incidence of this infection is increasing. The radiographic manifestations of nocardiosis are pleomorphic, but early recognition is essential to initiate appropriate therapy.

Mediastinal Lipomatosis: CT Confirmation of a Normal Variant

Mediastinal lipomatosis is a common benign cause of mediastinal widening. While it may be associated with exogenous obesity, steroid ingestion, or Cushings syndrome, these factors often are not present. Evaluation of the mediastinum by CT should be the initial diagnostic study in the work-up of patients with abnormalities of the mediastinal contour; indeed, in many cases it can eliminate the need for other procedures.

Spiral CT of acute pulmonary thromboembolism: evaluation of pleuroparenchymal abnormalities.

PURPOSE The goal of this work was to identify and categorize the spectrum of pulmonary parenchymal and pleural abnormalities identified by CT in patients with acute pulmonary thromboembolism (PE). METHOD A review of interpretations from 4,715 consecutive contrast-enhanced thoracic CT studies identified 41 examinations in which the diagnosis of PE was reported. Thirty-four studies were available for review, and two radiologists confirmed intraluminal defects in 31 patients. The number of emboli were counted and localized using bronchopulmonary nomenclature. Associated parenchymal and pleural abnormalities were tabulated. RESULTS Of the 31 patients, 13 underwent confirmatory or correlative studies including angiography, radionuclide study, or autopsy. In addition, deep venous thrombosis was confirmed by ultrasound or MRI in 13 patients. An average of 7.5 emboli per patient was detected. Pleuroparenchymal findings were as follows: Nine patients (29%) had no acute pulmonary parenchymal or pleural abnormality. In the remaining 22 patients, pleural effusion was the most common abnormality, found in 14 of 31 (45%). Ten patients (32%) had peripheral wedge-shaped parenchymal opacities suggestive of pulmonary infarction. Normally enhancing lobar atelectasis was seen in nine patients (29%). Six patients (19%) demonstrated heterogeneous parenchymal enhancement within nonaerated lung, two of whom had pathologically proven pulmonary infarct. Thirteen of 31 patients underwent high resolution CT; a typical mosaic perfusion pattern was seen in only 1 patient. CONCLUSION Twenty-nine percent of patients with acute PE had no acute lung parenchymal abnormality on CT; thus, the absence of parenchymal abnormality on CT does not exclude PE. High resolution CT mosaic perfusion was not a common feature of acute pulmonary embolism. Regions of decreased enhancement within nonaerated lung, seen in 19%, may prove to be an indicator of pulmonary infarction; however, this is a nonspecific finding.

Helical CT of talar fractures

Since the degree of comminution, fracture alignment, and articular congruity of talar fractures are important determinants of treatment, we review the helical CT technique for detecting and assessing the extent of acute talar fractures. Helical CT can be used to classify talar neck fractures which often cannot be determined by radiography. It is also useful in detecting posterior process, lateral process, and avulsion fractures, as well as acute osteochondral fractures. Multiplanar CT using 1-mm acquisitions allows optimal evaluation, detects fractures initially missed on radiographs, and determines further extent of fractures.

US, CT, and MR evaluation of accessory renal arteries and proximal renal arterial branches*

RATIONALE AND OBJECTIVES The purpose of this study was to compare color Doppler ultrasound (US), computed tomographic (CT) angiography, and magnetic resonance (MR) angiography for the evaluation of accessory renal arteries and proximal branches of the main renal artery. MATERIALS AND METHODS Fifty-six subjects who had undergone conventional arteriography of the renal arteries participated in a prospective comparison of Doppler US (45 patients), CT angiography (52 patients), and nonenhanced MR angiography (28 patients). Conventional arteriography depicted 28 accessory renal arteries and 21 proximal branches of the main renal artery within 2 cm of the aorta. RESULTS US depicted five of 24 accessory renal arteries seen at arteriography but no proximal arterial branches. CT angiography depicted 24 of 26 accessory renal arteries and 13 of 17 proximal arterial branches, as well as 15 additional accessory renal arteries not seen at conventional arteriography. MR demonstrated 11 of 15 accessory arteries, as well as four additional accessory arteries not seen at conventional arteriography. MR did not depict any of nine proximal arterial branches seen at conventional arteriography. CONCLUSION When compared with US or nonenhanced MR angiography, CT is the preferred method for evaluation of accessory renal arteries and proximal branches of the renal artery.

Comparison of Doppler US and CT angiography for evaluation of renal artery stenosis

Rationale and Objectives. The authors compared Doppler ultrasound (US) with computed tomographic (CT) angiography in the evaluation of stenosis of the main renal artery. Materials and Methods. Fifty-six patients who had undergone conventional angiography of the renal arteries participated in a prospective comparison of Doppler US (45 patients) and CT angiography (52 patients). US evaluation included both the main renal artery and segmental renal arteries. Results. There were 27 main renal arteries with at least 50% stenosis in 20 patients. In 36 patients, there was no significant stenosis. All cases of main renal artery stenosis detected with Doppler US of the segmental arteries were also identified with Doppler US of the main renal artery. The by-artery sensitivity (63%) of US of the main renal artery was greater than that (33%) of US of the segmental arteries. CT angiography was more sensitive (96%) than Doppler US (63%) in the detection of stenosis, but the specificity of CT (88%) was similar to that of US (89%). The difference in the area under the receiver operating characteristic curve (AUC) between CT (AUC = 0.94) and US (AUC = 0.82) was statistically significant (P = .038). Conclusion. Doppler US of the main renal artery is more sensitive than Doppler US of segmental arteries in the detection of stenosis. CT angiography is more accurate than Doppler US in the evaluation of renal artery stenosis.