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R M Steiner

Publications and source records attributed to R M Steiner.

At least 37 records · Page 2Linked to original sources
PubMed1994

The practice of chest radiology in departments with residency programs.

OBJECTIVES: The authors assessed to what extent radiology teaching programs employed dedicated chest radiologists and their functions. METHODS: Information regarding the clinical, teaching, and research role of the chest radiologist was available from responses to a survey of radiology departments with residency training programs in the United States and Canada. Emphasis was placed on the role of chest subspecialists, "dedicated chest radiologists" (DCRs), who spent at least two thirds of their clinical time interpreting and directing chest-related imaging studies and procedures. RESULTS: Among the 171 residency programs that responded, 118 had DCRs. There were 262 full-time and 233 part-time DCR positions, of which 43 were not filled. Among departments with DCRs, 66% were medical school programs while the remaining 34% were independent or medical-school-affiliated programs; 30% were organized by organ system, 5% by technology, and 65% had a combination of both; and 78% had more than 12 residents. DCRs interpreted routine chest radiographs in 96%, critical care radiographs in 94%, chest computed tomography (CT) studies in 72%, and chest magnetic resonance imaging (MRI) studies in 44% of their departments. Departments without DCRs were usually smaller, 70% having 12 or fewer residents. Their designated chest radiologists interpreted all chest radiographs in 21%, all critical care radiographs in 19%, all chest CT studies in 13% and all chest MRI studies in 8% of these departments. CONCLUSIONS: Dedicated chest radiologists were more involved than non-DCRs in all aspects of chest imaging, teaching, and research including analysis of image quality and acquisition of new technology. The highest quality of chest radiology training, defined as programs in which the chest fellowship positions were filled in 1991, was found in departments in which DCRs interpreted all chest radiographs, all chest CT studies, and most MRI studies.

Canada↗
PubMed1994

Single breath-hold pulmonary magnetic resonance angiography. Optimization and comparison of three imaging strategies.

RATIONALE AND OBJECTIVES: Ultrafast gradient-recalled-echo techniques for obtaining high-quality pulmonary magnetic resonance angiograms within a single breath-hold were optimized. METHODS: Fourteen subjects were imaged with both the body coil and a phased-array surface coil, using three gradient-recalled-echo pulse sequences: 1) two-dimensional sequential; 2) two-dimensional interleaved; and 3) volumetric acquisitions. Image quality was assessed with varied flip angle, receiver bandwidth, slice thickness/number, and matrix size. Cardiac compensation diminished ghost artifacts in the interleaved sequence. Individual sagittal sections and maximum intensity projections were reviewed. RESULTS: Pulmonary magnetic resonance angiograms acquired with volumetric and two-dimensional interleaved gradient-recalled-echo pulse sequences benefit greatest from intravenous gadolinium and result in greater pulmonary arterial visualization than traditional time-of-flight techniques. Phased-array coils result in improved vessel detection. CONCLUSIONS: High-quality breath-held pulmonary magnetic resonance angiography can be obtained with an intravenous contrast-enhanced gradient-recalled-echo acquisition; however, image quality is dependent on the pulse sequence.

Adult↗
PubMed1994

US-assisted bronchoscopy with use of miniature transducer-containing catheters.

PURPOSE: To demonstrate the value of ultrasound (US) guidance during flexible bronchoscopic procedures in a series of patients with known or suspected pulmonary neoplasms. MATERIALS AND METHODS: US-guided bronchoscopy was carried out as an adjunct to conventional bronchoscopy for the diagnosis of mediastinal, hilar, or parenchymal neoplasms in 25 patients with masses previously detected with chest radiography or computed tomography. Miniature transducer-containing catheters were inserted through the biopsy port of the flexible bronchoscope, and cross-sectional real-time US scans of tumors, lymph nodes, and blood vessels were obtained. RESULTS: Among six cases of peripheral masses and 19 cases of central masses, additional information was provided in 18 cases (72%). This information was used to choose the optimal site for transmural biopsy. CONCLUSION: These preliminary results suggest that this US procedure may become an important diagnostic tool during bronchoscopy, due to the ability to identify structures beyond the lumen of the tracheobronchial tree.

Adult↗
PubMed1993

Pulmonary calcinosis following orthotopic liver transplantation.

Pulmonary opacities following orthotopic liver transplantation (OLT) are frequent due to pneumonia, infarction, or pulmonary edema. Metastatic pulmonary calcifications are present as persistent opacities that may mimic these conditions. In a series of 91 patients who underwent OLT, chest radiographs of 77 were reviewed and pulmonary calcinosis was seen in 4 (5.2%). Pulmonary calcinosis may be due to a variety of conditions, including dystrophic calcification in damaged lung and primary or secondary hyperparathyroidism. In this series, patients with pulmonary calcinosis had significantly higher levels of serum phosphate and calcium postoperatively and had received more intraoperative platelets and other blood products containing exogenous calcium than other patients. Pulmonary calcinosis should be considered in patients following OLT when stable, nonspecific pulmonary opacities are present. CT or radionuclide studies will aid in confirming this diagnosis.

Adolescent↗
PubMed1993

Localization of peripheral pulmonary nodules for thoracoscopic excision: value of CT-guided wire placement.

OBJECTIVE: One of the indications for the rapidly expanding use of thoracoscopic surgery as an alternative to thoracotomy is the excision of peripheral lung nodules. Nodules judged too small or too far from the pleural surface to be seen or palpated during thoracoscopy must be localized beforehand. The purpose of this study was to evaluate the feasibility and effectiveness of percutaneous placement of spring hookwires to localize such nodules before video-assisted thoracoscopy. SUBJECTS AND METHODS: Under CT guidance, 17 nodules in 14 patients were preoperatively localized with the Kopans breast lesion localization system. Three patients who had solitary nodules had thoracoscopic resections for diagnosis because a previous transthoracic needle or transbronchial biopsy had been unsuccessful. Four patients who had lesions less than 8 mm in diameter had thoracoscopic biopsies because transthoracic fine-needle aspiration biopsy was not likely to be diagnostic. Seven patients, who had a total of 10 nodules, had therapeutic wedge resections of either limited metastases or a second bronchogenic carcinoma. Mean nodule diameter was 10 mm (range, 3-20 mm). The mean distance from nodule to costal pleura was 9 mm (range, 0-25 mm). At the end of the procedure, wire placement was confirmed by CT scanning. After thoracoscopy, the surgeons were questioned about the stability and utility of each hookwire localization. RESULTS: In all 17 procedures, a hookwire was placed successfully. In one case, the wire dislodged before thoracoscopy (after a 6-hr preoperative delay and severe bending of the wire during induction of anesthesia). In 16 of the 17 resections, the surgeon thought that thoracoscopic identification of the lesion would not have been possible without hookwire localization. Only one localization, across a major fissure, required placement of a second wire to localize a nodule. Wire-related complications included two instances of serious pain, five cases of clinically insignificant pneumothorax, and one large pneumothorax requiring drainage before a second nodule in the same lung was localized. CT scanning showed presumed local pulmonary hemorrhage in six cases without hemoptysis or hemothorax. CONCLUSION: CT-guided hookwire localization is easily and safely performed and permits thoracoscopic resection of lung nodules, which might otherwise be impossible.

Adult↗
PubMed1993

Magnetic resonance imaging of diffuse bone marrow disease.

MR is a highly sensitive alternative to plain films, CT, and radionuclide studies for the imaging of normal and abnormal marrow and can characterize differences between fatty, fibrotic, cellular, hypercellular, and hemosiderotic marrow. MR is helpful in depicting the extent of disease and has been a useful method to follow the clinical course of many disorders. It has been found to be particularly useful in explaining the unrepresentative biopsy, as the distribution of many diseases is frequently heterogeneous as exemplified by the mixed fatty and cellular patterns of aplastic anemia, myeloma, lymphoma, and skeletal metastases. Patterns of cellular and fatty marrow in the epiphysis and apophysis after marrow reconversion were not completely understood prior to the introduction of MR scanning. Because it has the advantage of imaging the entire bone marrow compartment (unlike the situation with biopsy on aspiration), MR allows a better understanding of the distribution of skeletal disease.

Bone Marrow↗
PubMed1992

Recognition of chest radiograph orientation for picture archiving and communications systems display using neural networks.

A neural network classification scheme was developed that enables a picture archiving and communications system workstation to determine the correct orientation of posteroanterior or anteroposterior chest images. This technique permits thoracic images to be displayed conventionally when called up on the workstation, and therefore reduces the need for reorientation of the image by the observer. Feature data were extracted from 1,000 digitized chest radiographs and used to train a two-layer neural network designed to classify the image into one of the eight possible orientations for a posteroanterior chest image. Once trained, the neural network identified the correct image orientation in 888 of 1,000 images that had not previously been seen by the neural network. Of the 112 images that were incorrectly classified, 106 were mirror images of the correct orientation, whereas only 6 actually had the caudal-cranial axis aligned incorrectly. The causes for misalignment are discussed.

Humans↗
PubMed1992

Rounded atelectasis: a pulmonary pseudotumor.

Rounded atelectasis is a benign entity that is often misinterpreted as a pulmonary neoplasm. The roentgenologic appearance of a mass is due to an infolding of atelectatic tissue intermingled with pleura, blood vessels, and bronchi. Rounded atelectasis is usually asymptomatic and is commonly associated with chronic pleural disease or pleural effusions. The distinctive radiologic features include a rounded, pleural-based opacity associated with adjacent pleural thickening and volume loss of the affected lobe. The pathognomonic sign is the "comet tail" that results from the crowding of vessels and bronchi as they enter the atelectatic region. Many authors consider this constellation of findings diagnostic. Rounded atelectasis usually remains stable over time; however, slow growth, as well as diminution in size, has been described. A retrospective analysis revealed 7 cases of rounded atelectasis at our institution over a 9-year period. Three were operated on to exclude malignancy, one was confirmed at operation performed for other reasons, and 3 were followed up expectantly. We conclude that recognition of this entity and its radiologic features can be diagnostic and render further workup, including thoracotomy, unnecessary.

Aged↗
PubMed1992

Polycythemia vera and myelofibrosis: correlation of MR imaging, clinical, and laboratory findings.

Magnetic resonance (MR) imaging was performed in 14 patients with biopsy-proved polycythemia vera (n = 4) or myelofibrosis (n = 10) to determine whether MR imaging findings can be correlated with the clinicopathologic diagnosis and established clinical parameters of severity (serum lactate dehydrogenase [LDH] and cholesterol levels) and chronicity (spleen size). Evaluation of marrow in the proximal femurs showed that patients could be categorized into three distinct groups based on anatomic patterns of normal fatty and abnormal low-signal-intensity (non-fatty) marrow in the femoral capital epiphysis (FCE) and greater trochanter (GT). Patients with nonfatty marrow in both the FCE and GT (n = 8) had significantly higher serum LDH (P less than .02) and lower serum cholesterol (P less than .02) levels than patients with fatty marrow in at least the GT (n = 6). Splenic volume, as measured from MR images, was significantly greater in the myelofibrosis group than in the polycythemia vera group (P less than .001). MR imaging provided a better understanding of these hematologic disorders and novel parameters for classification that are different from conventional histologic and laboratory data.

Adult↗
PubMed1992

The pelvis: T2-weighted fast spin-echo MR imaging.

Fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging provides images with highly T2-weighted contrast in substantially reduced imaging times. In a prospective evaluation, fast SE T2-weighted imaging of the pelvis was compared with conventional SE T2-weighted imaging in 30 consecutive patients in whom pelvic pathologic conditions were suspected. Three reviewers independently analyzed the images for (a) overall image quality, (b) pelvic organ definition, (c) conspicuity of pelvic fluid, and (d) conspicuity of pelvic pathologic conditions. Fast SE images were rated superior to conventional SE T2-weighted images in 60% (54 of 90) of the case reviews for overall image quality, in 69% (62 of 90) for pelvic organ definition, in 63% (57 of 90) for conspicuity of pelvic fluid, and in 68% (43 of 63) for conspicuity of pelvic pathologic conditions. The fast SE examinations were typically three to four times faster than conventional SE T2-weighted examinations. No pathologic findings seen on conventional SE T2-weighted images were undetected on fast SE images. Fast SE images may replace conventional SE T2-weighted images in MR imaging of the pelvis.

Abdomen↗
PubMed1992

Occupationally induced neoplasms of the lung and pleura.

The relationship between asbestos and mesothelioma has been well delineated in the past. The epidemiologic, clinical, radiologic, and pathologic features of mesothelioma are discussed with reference to the diagnostic evaluation of asbestos-exposed patients. The extensive epidemiologic data correlating asbestos, tobacco smoke, and induction of lung carcinoma are also reviewed. These data provide a model for evaluation of other occupationally induced lung carcinogens such as organic and metallic industrial inhalants.

Humans↗
PubMed1991

Parenchymal versus reticuloendothelial iron overload in the liver: distinction with MR imaging.

Parenchymal iron deposition occurs in hemochromatosis, while iron is deposited in reticuloendothelial (RE) cells after blood transfusions or rhabdomyolysis. Magnetic resonance images of patients with decreased liver signal intensity on T2-weighted images at 1.5 T were blindly compared in an effort to distinguish these conditions. In each of five patients with hemochromatosis, the pancreas had low signal intensity, but splenic signal intensity was decreased in only one. In contrast, only three of the 16 patients with RE iron overload had low pancreatic signal intensity, while all of these patients either had low splenic signal intensity (n = 14) or previously underwent splenectomy (n = 2). Distinction among these causes of iron deposition is clinically important because parenchymal iron overload from hemochromatosis may produce significant tissue damage, while the RE iron of transfusions and rhabdomyolysis is of little clinical consequence.

Adolescent↗
PubMed1991

Noninvasive diagnostic imaging in hemoglobinopathies.

We have provided a global review of the current applications of newer modalities, particularly MR imaging, as applicable to the major manifestations of sickle cell disease, the most common hemoglobinopathy. There is a need for well-designed prospective longitudinal studies utilizing MR imaging to gain further insight into the pathophysiology of this intriguing disease. Additionally, MR imaging, because of lack of ionizing radiation, is ideally suited for long-term sequential studies and may thus provide an objective means for monitoring response to therapy.

Adolescent↗
PubMed1991

Radiographic manifestations of congenital heart disease in the adult patient.

Improvements in the preoperative evaluation, surgical treatment, and postoperative care of patients with congenital cardiac disease have allowed a large patient population with congenital cardiac abnormalities to reach adolescence and adulthood. Noninvasive diagnostic imaging procedures (e.g., plain film radiography, echocardiography, computed tomography, and magnetic resonance imaging) are playing an increasingly important role in the evaluation and management of adults with both treated and untreated congenital cardiac disease. The role of plain film radiology is emphasized.

Adult↗
PubMed1990

Magnetic resonance imaging of bone marrow: diagnostic value in diffuse hematologic disorders.

Magnetic resonance imaging (MRI) has value in characterizing normal and abnormal bone marrow because of its ability to distinguish fat from other tissues. Due to this advantage, hematologic disorders resulting in alterations of the normal cellular and fatty marrow distribution can be appreciated. In this article, the role of MRI in diffuse hematologic disorders is emphasized. At birth, almost all marrow is cellular, but by age 25, cellular marrow is restricted to the axial skeleton and proximal femoral and humeral metaphysis. The remainder is fatty, consisting of 80% fat, 15% water, and 5% protein. With increased need for hematopoiesis, reconversion from fatty to cellular marrow occurs in many diffuse disease states. Diffuse diseases that affect bone marrow production are divided into four categories representing conditions that affect the pluripotent hematopoietic stem cell. These include stem cell failure resulting in aplastic anemia, uncontrolled stem cell proliferation as exemplified by polycythemia vera, stem cell dysplasia such as sickle cell anemia, and malignant transformations or replacement. The MRI appearance of these disorders is discussed in this article. The use of spin-echo (SE) sequences is the most common approach to bone marrow imaging. With T1-weighted SE images, fatty marrow will appear bright and cellular marrow, with lower fat content, will exhibit a lower density signal. With T2-weighted SE pulse sequences, contrast between fatty marrow and cellular marrow decreases. Contrast between fatty and cellular marrow is enhanced with chemical shift imaging, including Dixon out-of-phase imaging, as emphasized in this article. MRI presents a more global view of the bone marrow than biopsy material and should provide a better understanding of diffuse hematologic disease progression and resolution.

Bone Marrow↗