B. Simon Slasky

Sonographic characteristics of epidermoidcyst of testicle

Abstract 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 lagon may be possible.

Subjective and objective assessment of image quality—A comparison

Forced-choice just noticeable difference (JND) studies are extremely sensitive to image quality variations that are below the threshold at which the differences are apparent to or definable by the observer. Paired comparisons of 4K and 2K laser-printed posteroanterior chest images consistently demonstrated that although images are viewed as comparable by radiologists, when forced to choose the better (“sharper”) image, they actually select the higher-resolution images in 83% of the paired observations. We conclude that small differences in image quality may be detectable even in image sets which are considered to be comparable by subjective assessments.

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.

Acute lymphocytic leukemia of the ovary the value of sonography

Leukemic involvement of ovary has been found in up to 30% of patients with acute lymphocytic leukemia (ALL) at autopsy, but is rarely found clinically. Since the ovary may be a sanctuary for ALL to reseed the marrow, early clinical detection of ovarian involvement is important. The use of sonography in evaluating the ovary is suggested as part of the management routine in ALL. It can be used prior to cessation of chemotherapy and on subsequent follow-up to assess the state of the ovary. A case is presented in which a young woman with ALL in remission developed a pelvic mass, documented by ultrasound, subsequently shown to represent leukemic infiltration of the ovary.

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.

Right-sided splenorenal fusion with arteriographic, ultrasonic, and computerized tomographic correlation

The first known case of right-sided splenorenal fusion imaged with intravenous urography, sonography, computerized tomography, and arteriography is reported. The embryologic origin and radiologic differential diagnosis are discussed.

Bone-forming gastric metastases in muscle—Computed tomographic demonstration

Bone-forming metastases to soft tissues and muscle are a rare entity. An unusual case of heterotopic ossification occurring within metastases to muscle arising from a primary gastric adenocarcinoma is reported. No bone was found in the primary gastric malignancy. There is one prior report of ossification in muscle occurring in metastases from gastric malignancy, but no previous computed tomographic demonstration of this. The mechanism of osseous metaplasia is discussed, but its precise morphogenesis remains obscure.

Tracheal chondrosarcoma with an overview of other tumors of the trachea

Chondrosarcomas of the trachea are extraordinarily rare tumors, with only four cases documented in the English literature. An additional case is reported with conventional and computed tomography correlation. Because primary tumors of the trachea are such rare neoplasms, a review of the subject is presented to put chondrosarcomas of the trachea into perspective. Malignant tumors are slightly more common than benign tumors of the trachea and occur more frequently in adults. The most common tumor involving the trachea is carcinoma, accounting for 80 to 90% of all cases. This, however, represents only 0.2% of all malignancies of the respiratory tract.

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.

Cross-Sectional Imaging of Multilocular Cystic Nephroma

AbstractMultilocular cystic nephroma is an unusual renal mass lesion of uncertain taxonomy. Until the advent of cross-sectional imaging correct preoperative differentiation from a malignant tumor was not made with any degree of confidence. We report a case in which complementary imaging with ultrasound and computerized tomography revealed distinctive morphologic characteristics of multilocular cystic nephroma and allowed preoperative diagnosis. Specific diagnosis of multilocular cystic nephroma preoperatively obviates the need for extensive staging or radical surgery.