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Biomedical subjects

D I McCauley

Publications and source records attributed to D I McCauley.

At least 19 recordsLinked to original sources
PubMed1997

Volumetric (helical/spiral) CT (VCT) of the airways.

Volumetric computed tomography (VCT) represents an important improvement over conventional CT for assessing most airway abnormalities. Elimination of misregistration due to variations in respiration coupled with decreased motion artifact and the ability to obtain routine overlapping sections allow a more confident estimation of the presence and extent of disease. Recently, attention has focused on newer reconstruction techniques including: multiplanar reconstructions (MPRs), including curved multiplanar reformations; multiplanar volume reconstructions (MPVRs) using ray projection techniques, such as maximum and minimum projection imaging; external rendering, or 3D-shaded surface displays; and, most recently, internal rendering or so-called "virtual bronchoscopy". Given the often redundant nature of many of these methodologies determining indications for their use remains to be established, especially by comparison to axial imaging. The purpose of this article is to review these various reconstruction techniques and, based on current knowledge, place them in an appropriate clinical context.

Humans↗
PubMed1996

Diffuse lung disease: assessment with helical CT--preliminary observations of the role of maximum and minimum intensity projection images.

PURPOSE: To evaluate assessment of diffuse lung disease with helical computed tomography (CT) and maximum intensity projection (MIP) and minimum intensity projection images. MATERIALS AND METHODS: Six patients with suspected lung disease (the control group) and 20 patients with documented disease underwent axial helical CT through the upper and lower lung fields. Findings on the MIP and minimum intensity projection images of each helical data set were compared with findings on the thin-section scan obtained at the midplane of the series. RESULTS: Owing to markedly improved visualization of peripheral pulmonary vessels (n = 26) and improved spatial orientation, MIP images were superior to helical scans to help identify pulmonary nodules and characterize them as peribronchovascular (n = 2) or centrilobular (n = 7). Minimum intensity projection images were more accurate than thin-section scans to help identify lumina of central airways (n = 23) and define abnormal low (n = 15) and high (ground-glass) (n = 8) lung attenuation. Conventional thin-section scans depicted fine linear structures more clearly than either MIP or minimum intensity projection images, including the walls of peripheral, dilated airways (n = 3) and interlobular septa (n = 3). MIP and minimum intensity projection images added additional diagnostic findings to those on thin-section scans in 13 (65%) of 20 cases. CONCLUSION: MIP and minimum intensity projection images of helical data sets may help diagnosis of a wide spectrum of diffuse lung diseases.

Adult↗
PubMed1995

Unusual lymphoproliferative disorders in nine adults with HIV or AIDS: CT and pathologic findings.

PURPOSE: To identify characteristic computed tomographic (CT) findings in unusual pulmonary lymphoproliferative disorders seen in adults with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). MATERIALS AND METHODS: The authors retrospectively reviewed the CT scans and pathologic specimens from nine patients with pulmonary lymphoproliferative disorders. CT scans were evaluated for nodules, reticulation, areas of ground-glass attenuation, consolidation, and bronchial disease. Changes seen in pathologic specimens were classified as consistent with classic lymphocytic interstitial pneumonitis (LIP), mucosa-associated lymphoid tissue lymphoma (MALTOMA), or atypical lymphoproliferative disorder (ALD). Immunopathologic results were reviewed when available. RESULTS: Eight patients had AIDS. Five patients had classic LIP. One patient had MALTOMA, and three patients had ALD. Altogether, 2-4-mm-diameter nodules were the predominant CT finding in eight patients; these were peribronchovascular in four patients. The presence of interstitial nodules correlated with the pathologic finding of nodular disease in seven patients. CONCLUSION: Familiarity with these AIDS-related disorders and their CT appearance should assist in the differential diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Cytomegalovirus pneumonitis: spectrum of parenchymal CT findings with pathologic correlation in 21 AIDS patients.

PURPOSE: To identify characteristic features of cytomegalovirus (CMV) pneumonitis at computed tomography (CT), particularly markers that may help differentiate CMV from Pneumocystis carinii pneumonia. MATERIALS AND METHODS: Bronchoalveolar lavage (BAL) and biopsy results in 21 patients with acquired immunodeficiency syndrome, cytopathologic evidence of CMV infection without other infections, and available CT scans were retrospectively evaluated. CT findings were correlated with radiographic and pathologic findings when available. RESULTS: BAL findings were positive for CMV in only six cases, 13 patients had extrathoracic CMV infection, and 10 had Kaposi sarcoma. CT findings included ground-glass attenuation, dense consolidation, bronchial wall thickening or bronchiectasis, and interstitial reticulation without air-space disease (12 patients had discrete pulmonary nodules or masses). Biopsy revealed air-space disease as the dominant process in eight cases. Histopathologic findings correlated well with CT appearances. CONCLUSION: CMV pneumonitis should be suspected in patients with either extrathoracic CMV or documented Kaposi sarcoma, especially when radiographic or CT evidence of pulmonary nodules or masses exists.

AIDS-Related Opportunistic Infections↗
PubMed1993

Variables affecting pulmonary nodule detection with computed tomography: evaluation with three-dimensional computer simulation.

To meaningfully evaluate factors determining the overall accuracy of computed tomography (CT) for identifying pulmonary nodules, computer-generated nodules were superimposed on normal CT scans and interpreted independently by three experienced chest radiologists. Variables evaluated included nodule size, shape, number, density, location, edge characteristics, and relationship to adjacent vessels, as well as technical factors, including slice thickness and electronic windowing. The overall sensitivity in identifying nodules was 62% and the specificity was 80%. On average, the observers identified 56, 67, and 63% of nodules on 1.5-, 5-, and 10-mm-thick sections, respectively (p = 0.037). Nodules were more difficult to identify on 1.5-mm-thick sections. On average, observers identified 1, 48, 82, and 91% of nodules < 1.5, < 3, < 4.5, and < 7 mm in diameter, respectively (p < 0.001). Other factors that made a significant contribution (p < 0.01) in identifying nodules, as determined by linear discriminant function analysis, included nodule location, angiocentricity, and density. We concluded that computer-generated nodules can be used to assess a large number of imaging variables. We anticipate that this approach will be of considerable utility in assessing the accuracy of interpretation of a wide range of pathologic entities as well as in optimizing three-dimensional scan protocols within the thorax.

Humans↗
PubMed1993

Bronchiectasis: CT evaluation.

CT is the imaging method of choice after standard chest radiography for examining patients with suspected bronchiectasis. In most institutions throughout the world, CT has largely eliminated the need for bronchography in the diagnosis of bronchiectasis. Nonetheless, controversy persists concerning the overall accuracy of CT. In an effort to improve overall diagnostic accuracy, we review the wide range of CT appearances of this protean disorder, and emphasize potential problems and technical pitfalls that may arise in routine clinical imaging.

Bronchiectasis↗
PubMed1992

The left atrial catheter: its uses and complications.

The authors describe the radiographic appearance of the left atrial catheter, a widely used postsurgical intracardiac device. Recognition of the characteristic appearance of this catheter should be of value in detection of potential complications, including line fracture with resultant retention and/or embolization, infection, prosthetic valve dysfunction, and even cardiac tamponade.

Aged↗
PubMed1991

Cystic fibrosis: scoring system with thin-section CT.

The progression of lung disease in patients with cystic fibrosis (CF) was evaluated with chest radiography. The severity and extent of the various radiographic changes were scored with the Chrispin or the Birmingham method, which involves the use of imprecise and subjective terms, such as line shadows, large pulmonary shadows, and nodular cystic lesions. Although computed tomography (CT) has been shown to be helpful in the evaluation of lung disease in CF, no scoring system or other objective criteria have been developed for the evaluation of the wide range of pulmonary changes in these patients. A CT scoring system was devised that incorporates all of the changes seen in the lungs of patients with CF. Such a scoring system may facilitate objective evaluation of existing and newly developed therapeutic regimens and may be a valuable tool in the preoperative evaluation of patients being considered for lobectomy or bullectomy and in the selection of patients for lung transplantation.

Adolescent↗
PubMed1990

Low-dose CT of the lungs: preliminary observations.

The potential of low-dose computed tomography (CT) of the lungs was critically evaluated in two patients with normal-appearing lungs and 10 patients with a wide diversity of underlying parenchymal abnormalities. At each of five levels, in addition to routine scans obtained at 120 kVp and 140 mA, a scan at 10 mA and a half scan at 10 mA were obtained, with all other parameters held constant. Each scan was evaluated visually to assess anatomic clarity as well as the presence of artifacts and the extent of graininess. At all levels of the thorax, visualization of parenchymal structures was not affected by decreasing the milliamperage. It appears that high-quality, diagnostic images of the lung can be obtained with a very low radiation dose. Although further evaluation is necessary, the potential of low-dose CT for use in the pediatric population in particular, as well as for screening in patients at high risk for developing lung cancer, is apparent.

Humans↗
PubMed1990

Lung hernia: radiographic features.

Lung hernia is an abnormal protrusion of the lung beyond the confines of the thoracic cage. Hernias are classified as cervical, intercostal, or diaphragmatic. Each of these types can be either congenital or acquired. Acquired hernias can be spontaneous, posttraumatic, or pathologic as a result of a neoplastic or inflammatory process. This report describes five cases of lung hernias. Two were congenital cervical hernias, detected as incidental findings on chest radiographs of infants. One was a posttraumatic intercostal hernia detected on a chest radiograph and confirmed with CT. The remaining two were acquired intercostal hernias at the site of prior chest-tube drainage of tuberculous empyemas. Although both of these were clearly shown on CT scans, only one was visible on chest radiographs.

Aged↗
PubMed1989

Septic pulmonary emboli: CT-radiographic correlation.

Radiographic and CT findings in 15 patients with clinically documented septic pulmonary emboli were compared retrospectively. In most cases, radiographic changes were nonspecific. In comparison, on CT a combination of specific signs could be identified in all patients. These included peripheral nodules with clearly identifiable feeding vessels associated with metastatic lung abscesses (10 [67%] of 15 cases), and subpleural, wedge-shaped densities with and without necrosis caused by septic infarcts (11 [73%] of 15 cases). Ancillary pleural, mediastinal, axillary, and pericardial abnormalities also were more easily identified with CT. We conclude that CT is complementary to other imaging techniques in the recognition of septic pulmonary emboli.

Adult↗
PubMed1989

Spontaneous intramural hematoma of the esophagus.

Spontaneous intramural hematoma of the esophagus (SIHE) is a rare condition usually affecting middle-aged or elderly women. It presents as acute substernal or epigastric pain, typically accompanied by dysphagia or hematemesis. SIHE is not usually associated with vomiting, and is therefore clearly distinguished from emetogenic esophageal disorders, such as the Mallory-Weiss lesion and the Boerhaave syndrome. The diagnosis has traditionally been made by barium esophagram. Therapy is conservative; a favorable prognosis is the rule. The pathogenesis is in dispute. We present a case of SIHE without a discernible mucosal breach, suggesting a primary intramural bleed as the initiating event. We document the utility of computed tomographic scan and magnetic resonance imaging in the diagnosis of SIHE.

Aged↗
PubMed1988

Cardiovascular disease: evaluation with MR phase imaging.

Magnetic resonance phase images are derived from conventional spin-echo (SE) pulse sequences and display properties of proton movement that occurs with blood flow. SE magnitude and phase images were obtained and retrospectively evaluated in 21 patients referred for potential cardiovascular abnormalities in which intracardiac or intravascular signal was detected. Abnormalities included intravascular and intracardiac thrombus, aneurysm, aortic dissection, flow alteration, atherosclerotic disease, and congenital cardiac anomaly. Thrombosis (six cases) was successfully differentiated from flow-related signal (15 cases) by comparing phase images with SE magnitude images; in cases of thrombosis, there was no phase shift in corresponding areas of increased signal intensity. In comparison, SE magnitude signal intensities alone were not an accurate indicator in differentiating thrombus from flow-related enhancement. Because phase images are sensitive for identifying flow, the SE magnitude signal of intravascular tumor or thrombus can be differentiated from that of flow effects with more clinical confidence.

Adolescent↗
PubMed1988

Basilar segmental bronchi: thin-section CT evaluation.

Thin (1.5- and 5.0-mm) section contiguous computed tomographic (CT) scans obtained through the basilar segmental bronchi in 31 patients were reviewed in order to delineate normal anatomy and common variations of lower lobe airways. In each case, the frequency with which individual segmental and subsegmental bronchi were seen was established, as were variations in branching patterns. All basilar segmental bronchi were identified except in one case in which images of the left lung were obscured due to respiratory and cardiac motion. In the right lung, a division into subsegmental bronchi was identified in 84 of 150 (56%) visualized segmental bronchi. Six separate patterns of basilar segmental subdivision were found. In the left lung, subsegmental bronchi were identified arising from 51 of 145 (35%) visualized segmental bronchi. Five separate patterns of bronchial subdivision were found in the left lung. It is concluded that thin-section CT allows precise identification of all basilar segmental bronchi and, consequently, can play a significant role in the cross-sectional evaluation of lower lobe bronchial and parenchymal abnormalities.

Bronchi↗
PubMed1987

Comparison of CT and fiberoptic bronchoscopy in the evaluation of bronchial disease.

CT was compared to fiberoptic bronchoscopy in a large series of patients to study the value of CT for visualizing bronchial disease. CT scans were available for review in 64 cases in which focal airway disease was identified with fiberoptic bronchoscopy and in 38 patients in whom the airways appeared normal at bronchoscopy. CT was positive in 59 of 64 cases in which lesions were detected endoscopically. If the results are analyzed according to the extent of involvement of individual bronchi, CT successfully identified 88 (90%) of 98 lesions. CT correctly excluded disease in 35 (92%) of 38 cases that were subsequently verified to be normal by fiberoptic bronchoscopy. In no case was the diagnosis of malignancy missed by CT. While extremely accurate in detecting focal lesions, CT was inaccurate in predicting whether a given abnormality was endobronchial, submucosal, or extrinsic (peribronchial). In three cases CT failed to detect submucosal extension into the left mainstream bronchus, which has important implications concerning the value of CT in staging bronchial malignancy. It is concluded that CT is helpful when bronchoscopy is contraindicated or refused. CT may also be used in selected cases when there is low clinical suspicion of endobronchial disease and as a complementary procedure to fiberoptic bronchoscopy for outlining the exact location of major mediastinal and hilar vessels, lymph nodes, and tumor in relation to adjacent airways.

Bronchial Diseases↗
PubMed1987

Gallium-67 scans of the chest in patients with acquired immunodeficiency syndrome.

Eighty-six [67Ga]citrate chest scans were performed in 71 adult patients with the acquired immunodeficiency syndrome. Forty-five of these patients also had Kaposi's sarcoma. Only 29 of 57 abnormal scans were correlated with abnormal chest radiographs. Chest radiographs were negative for 27 scans and unavailable for one. Several scan patterns were seen. Diffusely increased lung uptake was seen most commonly with Pneumocystis carinii pneumonia, but also other infections and noninfectious inflammatory conditions. Focal uptake corresponding to regional lymph node groups occurred most often with Mycobacterium avium-intracellulare but aslo with lymphoma. Localized intrapulmonary uptake was seen in bacterial pneumonias. Perihilar activity occurred in two cases. When chest radiographs were abnormal and 67Ga scans negative, the most common diagnosis was pulmonary Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The Hermansky-Pudlak syndrome: radiographic features.

We present the radiologic features of four patients proven to have Hermansky-Pudlak syndrome. All four patients had evidence of pulmonary involvement characterized by a progressive, diffuse, bilateral interstitial fibrosis. Extensive bullous changes were seen in one patient. Two patients with evidence of diffuse colitis exhibited an asymmetrical pattern of focal, superficial, and deep ulcerations similar to that of Crohn's disease. The association of these radiographic abnormalities with albinism, ocular abnormalities, bleeding diathesis, and Puerto Rican ancestry establishes the diagnosis.

Adult↗