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Biomedical subjects

D Fleischmann

Publications and source records attributed to D Fleischmann.

At least 55 records · Page 3Linked to original sources
PubMed1997

Radiographically occult scaphoid fractures: value of MR imaging in detection.

PURPOSE: To evaluate the diagnostic value of magnetic resonance (MR) imaging in patients with clinical suspicion of scaphoid fractures and normal initial plain radiographs. MATERIALS AND METHODS: MR imaging was performed within 7 days after trauma in 42 patients with clinical suspicion of scaphoid fractures and normal plain radiographs. T1-weighted spin-echo, T2*-weighted gradient-echo, and short inversion time inversion-recovery (STIR) sequences were performed. MR images were evaluated independently by two radiologists. Six-week follow-up radiographs were used as a standard to diagnose fractures. RESULTS: MR imaging depicted occult fractures of the scaphoid bone in 14 patients (33%), the capitate bone in four (10%), the trapezium in one (2%), and the distal radius in two (5%). All wrist fractures were detected with a combination of STIR and T1-weighted spin-echo sequences. The sensitivity and specificity for detection of radiographically occult fractures of the wrist were 100% each for the first and 95% and 100%, respectively, for the second radiologist with an almost perfect interobserver agreement (K = 0.953). CONCLUSION: MR imaging has a high sensitivity for detection of fractures of the scaphoid bone and wrist not evident on plain radiographs and may enable early diagnosis and treatment.

Adolescent↗
PubMed1997

Comparison of T2-weighted and fluid-attenuated inversion-recovery fast spin-echo MR sequences in intracerebral AIDS-associated disease.

PURPOSE: To compare the value of fast fluid-attenuated inversion-recovery (FLAIR) with T2-weighted fast spin-echo MR imaging in the detection of acquired immunodeficiency virus (AIDS)-related lesions of the brain. METHODS: Forty-four human immunodeficiency virus (HIV)-positive patients were examined with both sequences on either a 1.0-T or a 1.5-T MR system. The number, size, location, and conspicuity of the lesions were evaluated by two independent observers. Contrast ratios between lesions and normal brain/cerebrospinal fluid were determined, and contrast-to-noise ratios were calculated. RESULTS: FLAIR was found to be superior to T2-weighted fast spin-echo in detection of small lesions and of lesions located in cortical/subcortical regions and deep white matter. The two techniques were equal in delineation of lesions larger than 2 cm and for lesions located in the basal ganglia and posterior fossa. In 24 patients, more lesions were detected with the FLAIR fast spin-echo technique. Lesion/cerebrospinal fluid contrast ratios and contrast-to-noise ratios were significantly higher for the FLAIR fast spin-echo sequences than for the T2-weighted fast spin-echo sequences. CONCLUSION: FLAIR allows early detection of small lesions in subcortical and cortical locations, especially in HIV encephalitis. Because of its improved lesion detection rate and greater overall lesion conspicuity, we believe FLAIR is useful in the evaluation of subtle changes in the brains of AIDS patients with central nervous system disease, and could even replace the T2-weighted fast spin-echo technique.

AIDS Dementia Complex↗
PubMed1996

Lung metastases.

The lungs are among the most prominent target organs for metastatic disease. Most frequently, lung metastases originate from cancers of the head and neck, breast, stomach, pancreas, kidney, bladder, the male and female genitourinary tract, and sarcomas. Plain chest radiography is typically the modality used for detection and therapeutic monitoring; however, the use of CT for these purposes is becoming more frequent. Currently, spiral CT appears to be the most sensitive imaging technique in the identification of metastases, because it detects a higher number of pulmonary nodules compared to other techniques. Pulmonary metastatic disease manifests itself by the presence of pulmonary nodules, lymphangitic carcinomatosis, endobronchial tumors, and pleural involvement. Nevertheless, the differential diagnosis is an important consideration, particularly in patients with solitary pulmonary nodules, systemic disorders, and signs or symptoms indicative of infection. The role of the radiologist involves the identification of metastatic disease, monitoring of response to therapy, and the use of invasive procedures when the differential diagnosis indicates the need for biopsy and histopathologic proof. The radiologist must be aware of the impact of his diagnosis on patient management and should be familiar with oncologic strategies as well as the terminology used to characterize tumor response. In future, the role of imaging may further expand due to the increased sensitivity in lesion detection, increased specificity in lesion (tissue) characterization using MR imaging imaging, and reduced radiation exposure.

Diagnosis, Differential↗
PubMed1996

[Spiral CT in acute pulmonary embolism].

Pulmonary embolism is a frequent and potentially life-threatening event with uncharacteristic clinical manifestations. Diagnosis is commonly established by ventilation/perfusion scintigraphy and pulmonary angiography. Both methods, however, carry substantial drawbacks. Therefore, clinicians claim that there is a need for an accurate and non-invasive diagnostic modality. Spiral CT of the pulmonary arteries is a recent modality, that allows reliable visualization of emboli in pulmonary arteries up to fourth-order branches. This paper reviews the technical aspects, typical findings and diagnostic pitfalls of this recent technique. The potential role of spiral CT in the screening of patients with suspected pulmonary embolism is discussed and selected cases are presented.

Algorithms↗
PubMed1996

[Spiral-CT [corrected] in chronic lung thromboembolism.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare result of recurrent pulmonary embolism and is treated by pulmonary thromboendarterectomy. Knowledge of the exact location of the thrombi is necessary in planning this operation. To date, pulmonary, angiography is the diagnostic imaging gold standard. Since the introduction of spiral CT excellent vascular opacification of the pulmonary arteries has become feasible, and thrombi in the pulmonary arteries can be visualized directly. Spiral CT is superior to angiography in demonstrating thrombi in the central pulmonary arteries, whereas angiography proves superior to CT in the evaluation of abnormalities within segmental arteries. The sensitivity of spiral CT in confirming the diagnosis of CTEPH is reported to be more than 90%. According to the literature and based on our own results, the decision concerning operability is possible on the basis of spiral CT images in more than 80% of patients with CTEPH. Spiral CT as a non-invasive tool may be used for CTEPH screening, for postoperative follow-up after pulmonary thrombendarterectomy and, combined with pulmonary angiography, to optimize operation planning.

Angiography↗
PubMed1996

[Calcium in the lung or: it might not always be tuberculosis].

Pulmonary calcifications are a frequent finding in CT examinations of the chest. In many cases, characteristic CT morphology and distribution of pulmonary and mediastinal calcifications may lead to a straightforward specific diagnosis of the underlying disease. In that respect, calcifications are often the residual finding of previous infections. Less often, they may be due to neoplasms, metabolic disorders, occupational exposure or previous therapy. This review focuses on the etiology, pathogenesis and morphological CT features of pulmonary calcifications. A knowledge of the technical aspects of CT imaging is required to verify calcifications and avoid pitfalls.

Calcinosis↗
PubMed1996

[Computerized tomography of AIDS associated thoracic diseases].

Pulmonary infections and tumors are a major cause of death in patients with AIDS. The combination of clinical, radiological, laboratory, and pathohistological data helps to narrow the spectrum of differential diagnoses or even allows a specific diagnosis in many patients. Nevertheless, an accurate diagnosis should be obtained as soon as possible during the clinical course of the illness to initiate treatment in time. Computed tomography (CT) has proven to provide promising results in the diagnosis of AIDS-related thoracic diseases. The aim of this paper was to demonstrate the diagnostic capacities of CT in the context of particular AIDS-related thoracic pathologies. Additional information on the spectrum of pathological agents and on differential diagnostic signs is summarized.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Pleural and pulmonary changes within the scope of rheumatoid arthritis].

Pulmonary complications caused by rheumatoid arthritis are a clinically relevant aspect of this chronic arthropathy. Those complications can involve all parts of the thorax, including the lung parenchyma, the pleura, and the thoracic cage. The most common complications are necrobiotic nodules, pleural abnormalities, Caplan's syndrome, parenchymal fibrosis, bronchiolitis obliterans, and iatrogenic damage of lung the parenchyma. This article reviews pulmonary abnormalities induced by rheumatoid arthritis and their clinical and radiological findings. In addition, the role of different imaging modalities in the diagnostic work-up of pulmonary complications caused by rheumatoid arthritis is discussed.

Arthritis, Rheumatoid↗
PubMed1996

Three-dimensional spiral CT cholangiography in patients with suspected obstructive biliary disease: comparison with endoscopic retrograde cholangiography.

PURPOSE: To evaluate the diagnostic potential of spiral computed tomography (CT) performed after the administration of cholangiographic contrast material (spiral CT cholangiography) in patients with suspected obstructive biliary disease. MATERIALS AND METHODS: After infusion of meglumine iodoxamate, 29 patients underwent upper abdominal spiral CT with subsequent three-dimensional rendering of the biliary tract. In 27 patients, the presence, site, and extent of biliary obstruction were compared with that at endoscopic retrograde cholangiography (ERC). RESULTS: Spiral CT cholangiography correctly depicted biliary obstruction in 14 of 27 patients, with no false-positive or false-negative cases. In one patient, the precise length of a common bile duct stenosis could not be assessed with spiral CT cholangiography. ERC demonstrated intrahepatic ductal stenoses more clearly in two patients. In two patients with hilar cholangiocarcinomas, spiral CT cholangiography depicted undrained areas not seen with ERC. CONCLUSION: Spiral CT cholangiography allows accurate assessment of the biliary system in patients with suspected obstructive biliary disease.

Adult↗
PubMed1996

Bronchial wall thickness: appropriate window settings for thin-section CT and radiologic-anatomic correlation.

PURPOSE: To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation. MATERIALS AND METHODS: Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined. RESULTS: Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001). CONCLUSION: Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.

Adult↗
PubMed1996

Deep venous thrombosis of the lower extremity: efficacy of spiral CT venography compared with conventional venography in diagnosis.

PURPOSE: To compare the efficacy of spiral computed tomographic (CT) venography with conventional venography in the diagnosis of suspected deep venous thrombosis (DVT). MATERIALS AND METHODS: In a prospective study, 52 consecutive patients with clinically suspected unilateral or bilateral DVT were studied with CT venography and conventional venography. In cases in which conventional venographic findings were inconclusive, color-coded duplex sonography and follow-up examinations were performed to make a final diagnosis. CT venography of both extremities covered a 100-cm section from the ankle to the inferior vena cava (IVC). Contrast material diluted with saline was injected in a dorsal vein of each foot. CT and conventional venography (including color-coded duplex sonography and follow-up findings) were correlated for three venous regions for each patient. RESULTS: Correlation was excellent between CT and conventional venographic findings in the detection of DVT. The sensitivity of CT venography was 100% (confidence interval: 0.92, 1.00), specificity was 96% (confidence interval: 0.84, 0.98), positive predictive value was 91%, and negative predictive value was 100%. CT venography more clearly demonstrated thrombus extension of DVT into the pelvic veins and IVC than conventional venography alone. CONCLUSION: CT venography is a valuable tool in the diagnosis of DVT. Compared with conventional venography, CT requires use of 80% less contrast material.

Contrast Media↗
PubMed1996

[Radiological diagnosis of emphysema prior to volume-reduction surgery].

Conventional chest X-ray and computed tomography as the main diagnostic tools are demonstrated with their possibilities in the diagnosis of emphysema. They were correlated with lung function tests and pathology in literature. Volume reduction surgery as a new operation technique for patients with advanced emphysema needs different radiologic evaluation. The radiologic possibilities for evaluation of operability of these patients and for operation planning will be discussed.

Eligibility Determination↗
PubMed1995

Update: abdominal tuberculosis--unusual findings on CT.

To update our knowledge of abdominal tuberculosis as manifested on computed tomography (CT), we reviewed the CT scans of 12 patients with proven abdominal tuberculosis. The nature, range and extent of abdominal involvement was determined. The CT findings were compared to those reported in the literature. The aetiologic agent was Mycobacterium tuberculosis in all patients. One patient had an increased risk because of AIDS. In nine patients, tuberculosis was limited to the abdomen, and three patients had previously unknown thoracic tuberculous disease. Characteristic features in our patients included low density ascites and uncommon patterns of adenopathy. Findings reported to be typical in abdominal tuberculosis were present in only five of our 12 patients. Unusual findings in our patients included solitary and multiple pelvic, adrenal, splenic and hepatic lesions. In six of 12 patients, those findings mimicked malignancy. We conclude that knowledge and early recognition of these unusual manifestations of abdominal tuberculosis should help to optimize clinical management of the disease and avoid misdiagnosis.

Abdominal Pain↗
PubMed1995

Discrete lung involvement in systemic lupus erythematosus: CT assessment.

PURPOSE: To study the computed tomographic (CT) appearance of early lung involvement in systemic lupus erythematosus (SLE). MATERIALS AND METHODS: In a prospective study, 48 patients with serologically confirmed SLE but no prior clinical evidence of lung involvement underwent chest radiography, CT, and lung function tests. Radiographs and CT scans were compared, and CT scans were evaluated for signs suggestive of parenchymal and pleural disease. Extent and distribution of disease were determined. CT findings were correlated with clinical and functional data. RESULTS: Of 45 patients with normal chest radiographs, 17 (38%) had abnormal CT findings. Extent of disease was statistically significantly correlated with duration of clinical history (r = .93) and decreased single-breath diffusing capacity for carbon monoxide (r = .8) and ratio of forced expiratory volume in 1 second to forced vital capacity (r = .77). CONCLUSION: CT is superior to chest radiography for detection of functionally relevant pulmonary disease and is an important adjunct in early assessment of SLE.

Adult↗
PubMed1995

Automatic patient-instruction devices in thin-section CT of the thorax: impact on image quality.

PURPOSE: To determine what influence automatic patient-instruction (API) devices have on image quality of chest computed tomographic (CT) scans and whether the qualitative outcome justifies their routine use. MATERIALS AND METHODS: Thin-collimation CT scans of two age- and sex-matched groups of 64 patients each were evaluated prospectively for the presence of breathing artifacts and for concomitant deterioration of image quality. Breathing commands in group 1 were given with the API device and in group 2 with technologist-performed patient instruction. Cardiac motion artifacts were not evaluated. The frequency of scans repeated owing to breathing artifact was determined. RESULTS: Image quality was worse in group 1 compared with that of group 2. The percentage of scans repeated was higher with API (38%) than without API (16%). CONCLUSION: API devices cannot be recommended for thin-section CT of the thorax. The large number of scans that must be repeated leads to a considerable increase in patient irradiation, scanning time, and cost.

Adult↗
PubMed1995

Position of jugular oxygen saturation catheter in patients with head trauma: assessment by use of plain films.

OBJECTIVE: The purpose of this study was to establish a plain radiographic technique for the assessment of the position of a jugular oxygen saturation catheter in patients with head trauma. MATERIALS AND METHODS: In the experimental study, jugular oxygen saturation catheters were introduced into the internal jugular veins of four cadavers. Correct positioning of the catheter tips was monitored by CT. Concurrent anteroposterior radiographs of the skulls were obtained with the tubes angled in a transverse plane and in a sagittal plane at intervals of 5 degrees and within a total range of 70 degrees for each plane. Three radiologists judged the visibility of the catheter tips and measured the distance of the catheter tips to previously determined bony landmarks of the skull. Then, preliminary radiologic criteria for correct positioning of the catheters were defined. In the clinical study, we prospectively evaluated radiographs for 32 patients who received jugular oxygen saturation catheters. Eleven patients had digital radiographs done, and 21 patients had radiographs with a conventional screen film system done. Radiographs were analyzed for consistency of findings with the experimental results and for consistency of the suspected catheter position with laboratory data. RESULTS: Results of the cadaveric study showed that catheter position is best assessed on strict anteroposterior radiographs with the orbitomeatal-basal line perpendicular to the plane of the film. A correctly positioned catheter tip should lie cranial to a line extending from the atlantooccipital joint space and caudal to the lower margin of the orbit. The catheter tip also should lie cranial to a line connecting the tips of the mastoid processes, with a catheter tip-to-line distance averaging 20% of the overall distance between the tips of the mastoid processes. According to these criteria, the catheter was properly positioned in 26 of 32 patients. In three patients, the catheter obviously was improperly positioned. Catheter position was equivocal in three other patients; in two of these patients, the catheter was looped within the internal jugular vein. Whereas for all 26 patients with properly positioned catheters values for jugular venous oxygen saturation were congruent with other laboratory data, incongruent saturation values were recorded for five of the six patients with equivocally or obviously improperly positioned catheters. CONCLUSION: Accurate assessment of the position of a jugular oxygen saturation catheter can be made by use of specific bony landmarks seen on anteroposterior radiographs of the skull.

Brain Edema↗