Skeletal muscle density: effects of obesity and non-insulin-dependent diabetes mellitus.

Obesity is associated with increased lean mass but its effects on lean-tissue density are less clear. To examine the effects of obesity and non-insulin-dependent diabetes mellitus (NIDDM) on lean-tissue composition and density, cross-sectional computed tomography (CT) scans of the midthigh were obtained in 20 men of various weights. Obesity was associated with increases in thigh-adipose (r = 0.75) and lean-tissue volumes (r = 0.52) and with reduced density of lean tissue (r = -0.73). The increased lean tissue in obesity was due to a nonadipose tissue component with a density below the normal range of muscle, an effect compounded by NIDDM, whereas normal-density muscle volume was unchanged.

Long-term prognosis of survivors of Pneumocystis carinii pneumonia. Structural and functional correlates.

Limited data exist detailing the long-term sequelae of Pneumocystis pneumonia. Open lung biopsies were obtained in seven renal transplant recipients within 48 hours of the onset of respiratory failure. Biopsy specimens and simultaneous chest roentgenograms were graded without clinical information according to the severity of alveolar damage and pulmonary infiltrates, respectively. Evaluation of pulmonary function and exercise physiology were performed 15 to 21 months after their illness. Pulmonary function indices were normal except FRC (2.65 +/- 0.56 L or 77 +/- 16 percent of predicted) and Dsb (20.0 +/- 7.2 ml/min/mm Hg or 79 +/- 19 percent of predicted). Two patients developed arterial desaturation with exercise. Alveolar damage scores correlated with later exercise arterial desaturation (r = 0.88, p less than 0.05). Simultaneous roentgenographic scores correlated with later abnormalities of Dsb (r = 0.81, p less than 0.05). Mild residual abnormalities of pulmonary function were found in five of seven adult survivors of Pneumocystis pneumonia. These abnormalities correlated with pathologic and radiographic features of the acute illness.

Effect of observer instruction on ROC study of chest images.

Receiver-operating characteristic (ROC) analysis has been used in many medical imaging applications during the past decade. In order to ensure that reader-confidence ratings are analyzable (well distributed to meet convergence requirements of curve-fitting algorithms) and meaningful (limit extrapolation of the data), many investigators train readers specifically for this purpose. No experimental data are available concerning the possible effects of such training on the results of ROC studies. We performed a multi-observer, multi-disease study in which 300 chest images were rated by four radiologists before and after they were trained to provide well-distributed confidence ratings. The results indicate that for our data set, reader and disease-specific accuracy was not significantly affected by the training process for interstitial disease and pneumothoraces. However, the accuracy of two readers was significantly affected for the detection of nodules (P less than 0.05), and the overall accuracy of one reader was significantly affected for the classification of normal versus abnormal images (P less than 0.01). Thus, in spite of the difficulties associated with the performance of ROC studies in a free-reading environment, one should carefully consider the possible effects of any intervention on the results prior to conducting ROC studies.

Germ cell tumors complicated by pneumothorax.

Spontaneous pneumothorax is an unusual consequence of pulmonary metastases. This complication occurs mainly in children and adolescents with primary osseous sarcomas and is extremely rare in patients with pulmonary metastases secondary to carcinomas. Germ cell tumors have a proclivity to metastasize to the lung, but few instances of pneumothorax have been recorded. The authors present 3 cases of pneumothorax secondary to pulmonary metastases from germ cell tumors, both gonadal and extragonadal in type.

Aneurysms in renal oncocytoma.

Renal oncocytoma is a nonaggressive lesion of the kidney that only recently has been defined as a separate entity pathologically. Clinically they are usually silent and are incidental findings on excretory urography. Sonography and computerized tomography demonstrate that it is a solid lesion, but it is only with angiography that a preoperative diagnosis can be suggested. The angiographic signs are summarized, and it is proposed that aneurysms in or associated with a mass now be included in the angiographic spectrum of oncocytoma.

Acute renal failure, contrast media, and computer tomography.

Acute renal failure (ARF) is recognized as a potential hazard of intravenous administration of radiologic contrast media (RCM). We present a case of contrast-induced ARF which was first detected on an unenhanced computed tomographic examination of the abdomen. A number of postulated mechanisms in the pathogenesis of ARF are discussed. Multiple factors are associated with an increased probability of ARF when contrast material is given intravenously. The significance of advanced age as a risk factor is discussed. Certain predisposing circumstances are amenable to correction by the radiologist, thereby diminishing the chance of causing contrast-induced ARF.

Cystic mesoblastic nephroma.

Mesoblastic nephroma is the most common solid renal neoplasm in the first few months of life. It has been recognized only recently as a distinct entity, having been classified previously as Wilms tumor. There are relatively few ultrasonic descriptions of this entity in the literature. We present an additional case featuring a large peripheral cystic component with a solid central core demonstrated on ultrasonograhy. This feature is not specific for mesoblastic nephroma and occurs in cystic Wilms tumor.

Sonographic characteristics of epidermoid cyst of testicle.

The ultrasonographic characteristics of an epidermoid cyst of the testicle are presented. Since these findings are similar to other published case reports, preoperative sonographic diagnosis of this lesion may be possible.

Reduced dose and improved image quality with a computerized line-scan radiography system.

Diode-array digital radiography (DADR) is a patented technology which shows promise for producing improved radiographic image quality while reducing the X-ray dose to the patient. DADR combines geometric scatter rejection with a scintillator and solid-state photodiode array detector of large dynamic range to create diagnostic X-ray images which makes efficient use of the patient dose. Engineering measurements were made to determine the basic characteristics of the system. Engineering measurements were made to determine the basic characteristics of the system. A number of image postprocessing techniques were examined for further improving the image quality of the DADR system. Unsharp masking, local contrast stretching, and modified local contrast stretching were used. The modified local contrast stretching has produced the best results to date, with image quality exceeding that of standard film/screen chest images. Images have been postprocessed using facilities of the Pittsburgh Supercomputer Center.

Lingual mandibular bony defects: CT in the buccolingual plane.

OBJECTIVE: Our goal was to record the appearance of lingular mandibular bony defects (LMBD) on CT imaging of the mandible in the buccolingual plane. MATERIALS AND METHODS: During the CT evaluation of patients planning to undergo dental implant surgery, five cases of LMBD were found. Axial 1.2 x 1.00 mm overlapping CT sections of the mandible and the maxilla were obtained. Then with use of specific software (DentaCT; Elscint), panoramic and cross-sectional (buccolingual) images of the mandible and maxilla were reformatted. RESULTS: Five cases of posterior LMBD were identified; one patient had both a posterior as well as the much rarer anterior LMBD. All cases were incidental findings and all were asymptomatic. CT features of LMBD were displayed in axial, panoramic, and buccolingual planes. The characteristic opening of the bony defect in the lingual aspect of the mandible was clearly displayed on the axial as well as the buccolingual images; however, this key feature was not manifest on the panoramic images of the mandible. CONCLUSION: CT features of LMBD in the buccolingual plane are added to the known radiologic description of this entity.

Therapeutic implications of an intraoral malignancy complicated by Darier-White's disease.

A 69-year-old white male with a long history of severe Darier-White's disease presented with an extensive intraoral malignancy. High dose external supervoltage radiotherapy (Cobalt-60) to the tumour caused remarkable clearing of the hyperkeratotic lesions involving the overlying skin. Subsequently, surgical resection of the tumour with staged reconstruction of the jaw was carried out. The presence of the skin disorder did not adversely affect the surgical procedure nor the subsequent wound healing. Darier-White's disease, therefore, should not be a deterrent to radical radiotherapy and/or surgery for concomitant malignancy.

Midline pericardial cyst in the posterior mediastinum: sonographic and computed tomographic correlation.

A chest radiograph revealed an incidental finding of a large mediastinal mass located in the midline posterior to the lower aspect of the heart. The computed tomogram and sonographic examinations of the chest showed the mass to be cystic in nature, contiguous with the heart, and anterior to the displaced distal esophagus. At surgery this proved to be a pericardial cyst. The unusual location of this entity, which has never before been documented, now behooves us to include pericardial cyst and diverticulum in the differential diagnosis of mediastinal masses, posterior to the heart.

Sonography of Nabothian cysts.

Retention cysts of the cervix (nabothian cysts) are common gynecologic findings that have not been previously reported in the sonographic literature. Experience with 25 cases is presented. Cyst size varied from 6 to 20 mm. Most cysts (14/25) were multiple and most (17/25) were eccentric in relation to the cervical canal. Cysts within 1 cm of the external os were classified as "low" (10/25); those cranial to this level were "high" (15/25). Six patients had both high and low cysts. Many of the cysts (9/25) caused enlargement of the cervix. Representative cases are presented with a discussion of the pathogenesis of nabothian cysts and their clinical significance.

Ascending colon compression by psoas muscle hypertrophy.

Extrinsic compression of the ascending colon was observed on the barium enema of a professional athlete. Ultrasound examination demonstrated psoas muscle enlargement as the cause of this abnormal radiographic finding. The effect of psoas muscle hypertrophy should be considered when extrinsic compression of the colon is observed on the barium enema of muscular individuals. Ultrasound is useful to differentiate anatomic variant from pathological conditions which may deviate the ureters and/or the ascending colon.

Value of portable real-time ultrasound in the ICU.

A 2-yr retrospective analysis was undertaken of the value of portable real-time sonography on 107 patients in the ICU. A total of 88 abnormal findings were detected in 69 of 107 patients. Of these, 36 were clinically significant as the patients' therapy and clinical courses were modified by the ultrasound findings. In many instances, where the ultrasound findings were negative, this information had, nevertheless, important ramifications to the clinician and was frequently as helpful to him as a positive finding. A 20% yield of unsuspected abnormalities was also found, some of which were clinically significant and warranted specific action. We believe that the portable real-time ultrasound examination is, indeed, a valuable diagnostic tool to the ICU clinician and is most likely underutilized.

Spiculation of antral margin in erosive gastritis.

Because of the low yield, conventional barium studies had been considered an unreliable methods of detecting erosions of the stomach. With the advent of the double contrast examination, the literature is now replete with examples of erosive demonstrated by this technique. As in endoscopy, the erosions are visualized "en face" only. No case, however, has been recorded in which the diagnosis was made on a profile view of the erosions. We present such a case of erosive gastritis with two unusual features in which 1) the diagnosis was made on a conventional single contrast study and 2) the lesions were identified in profile.

Diabetes mellitus: the predominant cause of bilateral renal enlargement.

The authors reviewed 102 cases of bilateral renal enlargement seen on excretory urography (excluding hydronephrosis and duplex kidneys) to determine the clinical significance of this finding. Associated abnormalities were found in 48 patients, including diabetes mellitus in 29; nondiabetic obesity, large body structures, or chronic steroid use in 16; acromegaly in 1; and unknown etiology in 37, 2 of whom were found to have diabetes five years later. Because of the striking preponderance of diabetes in this study, a fasting blood glucose analysis is recommended for patients with unexplained bilateral renal enlargement on excretory urography.