Carcinogenicity of 1-(2-hydroxyethyl)-1-nitrosourea and 3-nitroso-2-oxazolidinone administered in drinking water to male MRC-Wistar rats: induction of bone, hematopoietic, intestinal, and liver tumors.

A previous report was made on the carcinogenicity of 1-(2-hydroxyethyl)-1-nitrosourea [(HENU) CAS: 13743-07-2] in rats. Because the cyclic nitrosocarbamate 3-nitroso-2-oxazolidinone (NOZ) is readily produced during the synthesis of HENU and can be confused with HENU, HENU was retested and NOZ was tested for carcinogenicity. Improved syntheses of both compounds are described. They were administered in drinking water to male MRC-Wistar rats for 1 year, starting at 3 or 9 weeks of age. The HENU-treated rats showed incidences of 48% for bone tumors, 32% for intestinal tumors (mostly duodenal adenocarcinomas), and 53% for lymphoma-leukemia. Of the bone tumors, which were evaluated microscopically and radiologically, 68% were osteosarcomas and 32% were osteoblastomas. The skeletal distribution of these tumors was similar to that of human osteosarcoma, with the tumors occurring most frequently in the lower limbs near the knees. Of the hematopoietic tumors, the majority were lymphoblastic lymphoma-leukemia, which showed a diffuse organ distribution resembling human B-cell (Burkitt's-like) lymphoblastic lymphoma-leukemia, and differed from the usual type of convoluted T-cell lymphoma-leukemia induced by other nitrosoureas in rats and mice. NOZ induced intestinal tumors (mostly duodenal adenocarcinomas) in 80% and liver tumors (mostly hepatocellular adenomas) in 53% of the rats.

Pregnancy in a woman with the Brachmann-de Lange syndrome.

We present the first reported pregnancy in a woman with the Brachmann-de Lange syndrome. This 24-year-old primagravid woman was originally seen at 13 weeks of pregnancy with manifestations consistent with this diagnosis. High-resolution chromosome studies, performed on lymphocytes, showed a normal 46,XX chromosome constitution. Because of the stage of pregnancy at which she presented, a genetic amniocentesis was simultaneously performed for chromosome analysis on the fetal cells, which were also normal (46,XX). The uncomplicated pregnancy was monitored carefully and at 37 1/2 weeks of gestation she delivered a clinically normal-appearing female infant.

Aneurysms of the posterior cerebral artery in children.

Intracranial aneurysms in children are very rare and differ from those in adults in several ways. Posterior cerebral artery (PCA) aneurysms are among the least common of intracranial aneurysms and little is known of their presentation and prognosis. Two cases of PCA aneurysms in children are reported, and 21 other cases of PCA aneurysms in patients 20 years of age or younger are reviewed. PCA aneurysms in children have a marked male predominance and are usually large, symptomatic, and tend to occur proximal or distal to the circle of Willis. Diagnostic computed tomography may be warranted earlier in children than in adults with similar symptoms referable to intracranial abnormalities because children are more likely to have an organic cause for such symptoms.

Ultrasonography of post-traumatic soft-tissue lesions.

This article highlights the varied uses of ultrasound for detection of trauma to soft tissues. The emphasis is on the diagnosis of tendon and muscle disruptions. Detection of soft-tissue foreign bodies by ultrasound, an important recent innovation, is also reviewed. Miscellaneous potential applications of ultrasound for diagnosing meniscal injuries, cartilage integrity, epidermoid cysts, and traumatic vascular malformations are discussed briefly. Ultrasound is efficacious because of its low cost, noninvasiveness, wide availability, and accuracy.

Ultrasonography of the musculoskeletal system.

This article reviews the numerous applications of ultrasound in the musculoskeletal system. Emphasis is made on the important and often under-utilized role of ultrasound in infections, vascular lesions, arthritis, and trauma.

Magnetic resonance imaging of the knee: menisci, ligaments, tendons.

Magnetic resonance imaging (MRI) is the technique of choice to depict normal anatomy and to image internal derangements of the knee. The overall accuracy of this method can reach approximately 94%. MRI can effectively replace diagnostic arthroscopy for evaluation of meniscal and ligamentous tears.

The impact of ankle radiographs on the diagnosis and management of acute ankle injuries.

RATIONALE AND OBJECTIVES: We assessed the impact of ankle radiographs on referring physicians' diagnoses and treatment of acute ankle injuries. METHODS: Twenty emergency department physicians prospectively completed questionnaires before and after radiography on 101 patients with acute trauma receiving ankle radiographs. The questionnaires asked physicians to estimate the probability (0-100%) of their most likely diagnosis before and after receiving the radiographic information. We also asked their anticipated and final treatment plans. We calculated the mean gain in diagnostic confidence percentage and the proportion of patients with changed initial diagnoses or anticipated management. RESULTS: The mean gain in diagnostic certainty from ankle radiographs was 34% (95% confidence interval [CI] = 28-40%). Ankle radiographs changed physicians' initial diagnoses in 37% (95% CI = 28-47%) of the patients. Immediate clinical management changed in 30% (95% CI = 22-40%) of the patients. CONCLUSION: Plain ankle radiographs have considerable impact on referring physicians' diagnoses and treatment of acute ankle trauma.

Water on the knee: cysts, bursae, and recesses.

Many synovial-lined cavities occur around the knee, and MR imaging is capable of demonstrating the precise anatomic relationships of these spaces. Knowledge of normal anatomy, however, is necessary to accurately assess abnormal, fluid-filled structures. This article reviews the MR imaging appearance of normal and pathologic bursae and joint recesses, and the appearance of common cystic masses. Distinguishing features of several noncystic lesions occurring around the knee also are discussed because these can mimic bursae, recesses, and cysts.

MR imaging of ligamentous abnormalities of the elbow.

With high-resolution MR imaging, the collateral ligament of the elbow can be directly evaluated; thus ligamentous injuries can be detected, localized, and graded. The functional anatomy of the ligaments of the elbow is reviewed. The normal appearance of the ligaments on MR images as well as the clinical and MR imaging findings of medial and lateral collateral ligament injury are presented.

Imaging of the knee. Current status.

This article reviews the variety of imaging modalities that are currently being used to evaluate the knee. Nuclear scintigraphy is discussed with emphasis on prosthesis abnormalities. Sonography is discussed with regard to the evaluation of popliteal masses. The uses of computed tomography, especially in the evaluation of the tibial plateau fracture, are discussed, and the role of fluoroscopy, computed tomography, and sonography in image-guided needle procedures are reviewed. Emphasis is placed on the role of MR imaging in knee imaging, with attention to internal derangements, bursal and capsular pathology, and other assorted intra- and extra-articular disorders. The focus of this article is to review the wealth of information that may be obtained by using these imaging modalities.

Normal and abnormal temporomandibular joints: quantitative evaluation of inferior joint space arthrography.

Arthrography has been shown to provide important diagnostic information in patients with temporomandibular joint (TMJ) dysfunction. In this study, 60 arthrograms on totally asymptomatic patients and 64 arthrograms on symptomatic patients were evaluated. Quantitative evaluation of inferior joint space arthrography was performed with the help of a computer digitizing morphometry program. Results indicate a significant difference in the areas of the anterior and posterior recesses between normal and abnormal joints in the closed-mouth position. Differences between the 2 groups also exist in linear measurements of the anterior recess. This data further defines important diagnostic criteria in the arthrographic evaluation of both the normal and abnormal TMJ.

Fibrous dysplasia: magnetic resonance imaging appearance at 1.5 tesla.

Fibrous dysplasia has been described in a small number of cases in the literature as showing low signal intensity on T1- and T2-weighted magnetic resonance images. We reviewed magnetic resonance scans of 13 patients with fibrous dysplasia to determine if there might be a characteristic appearance. All lesions had sharply defined borders and were of intermediate signal intensity on T1-weighted images. With T2 weighting, six lesions (46%) showed high signal intensity, four (31%) showed persistent intermediate signal intensity, and three (23%) showed mixed intermediate and high signal intensity. Ten lesions (77%) had inhomogeneous signal intensity and three (23%) had homogeneous signal intensity. We concluded that fibrous dysplasia does not have a characteristic appearance on magnetic resonance imaging. However, magnetic resonance may be helpful in establishing the diagnosis of fibrous dysplasia if low to intermediate signal intensity is seen on both T1- and T2-weighted images. This situation occurred in 54% of our cases, whereas the other 46% had nonspecific signal characteristics indistinguishable from many other bone lesions.

MRI of the knee: a simplified approach.

Magnetic resonance imaging (MRI) of the knee is the most frequently performed musculoskeletal MRI examination and, after initial study with plain radiographs, has supplanted arthrography and arthroscopy as the imaging procedure of choice in the investigation of internal derangement and arthritic disorders of the knee. Knee MRI is a highly accurate, noninvasive procedure that provides exquisite depiction of the soft tissues and bone marrow. In this article a simplified approach to knee MRI is presented, including a practical discussion on the basics of MRI physics, review of the normal anatomy, and illustration of the most commonly encountered pathologic conditions.

Magnetic resonance imaging of the wrist.

MR imaging of the wrist has the unique capability of simultaneously demonstrating bone and soft tissue structures. Its exquisite sensitivity for detecting bone marrow edema makes it and ideal screening tool for diagnosing radiographically occult osseous injuries and areas of AVN. This, together with its ability to provide a comprehensive, non-invasive assessment of the ligaments, tendons, nerves, and components of the TFC make MRI a very powerful tool for evaluating patients with wrist pain of uncertain etiology. Its exact role in the work-up of these patients has not been entirely established, but with further advances in technology and the radiologist's understanding of wrist anatomy and pathology, MRI is assuming a more central role in this clinical setting.

Magnetic resonance imaging of the elbow.

Technical improvements in MR imaging have resulted in the ability to detect soft tissue and bone pathology, with great facility in the elbow joint. This allows application of MRI to the elbow in the same valuable ways it has been used in other joints for a much longer period.

Mucocutaneous and peripheral soft-tissue hemangiomas: MR imaging.

Hemangiomas are common congenital lesions that may have devastating sequelae. The extent and location of a lesion determines the therapeutic approach. We describe 11 patients with mucocutaneous or peripheral soft-tissue hemangiomas to illustrate the ability of magnetic resonance (MR) imaging to define clearly and noninvasively the extent and anatomic relationships of hemangiomas. The major advantage of MR imaging over computed tomography or angiography is the exquisite difference in contrast between hemangiomas and the surrounding structures on T2-weighted MR images, in which hemangiomas have a relatively intense signal. Hemangiomas demonstrated relatively low signal intensity (similar to muscle) on T1-weighted images, which were markedly inferior to T2-weighted images in defining the extent of the lesions. Phleboliths and feeding or draining vessels were rarely visible. The information obtained with MR imaging may be valuable clinically in planning surgical resection or laser therapy of aggressive lesions, in evaluating effectiveness of medical or embolic therapy, and in defining recurrence.

Stress-induced osteolysis of the clavicle.

Osteolysis in the distal clavicle--manifested radiographically by erosions, resorption of the subchondral cortical bone, and an increased space between the acromion and clavicle--may occur in patients who experience repeated stress or microtrauma to the shoulder. This entity has a radiographic appearance similar to posttraumatic osteolysis of the clavicle. One patient with painful shoulders and typical osteolytic changes of the clavicles on radiographs is described, with three other cases reported.

Superficial peroneal nerve block for leg venography.

Insertion of a needle into the dorsum of the foot for lower-extremity venography is painful for many patients, and several attempts at puncture may be necessary. A regional anesthetic technique, superficial peroneal nerve block, has been devised to alleviate this pain. The nerve block is simple to perform, consisting of infiltration of lidocaine just above the ankle. Discomfort from performance of the block was minimal in all 20 cases in which it was performed. The block was effective in eliminating or significantly reducing pain in 17 of the 20.

Temporomandibular joint arthrography following surgical treatment of internal derangements.

Arthrograms of the temporomandibular joint were obtained in 20 symptomatic joints that had previous reconstructive arthroplasty with disk repositioning because of internal derangements. Preoperative arthrograms were available for comparison in 18 joints. Symptoms resulting in a postoperative arthrogram included pain, limited ability to open the mouth, and clicking of the joints. Postoperative arthrographic findings included limited anterior translation of the condyle (90%), irregularity in outline of the intraarticular contrast agent (60%), a conical configuration of the posterior recess (25%), decreased size of the joint (28%), anterior displacement of the meniscus (25%), and perforated meniscus (15%). Many of these findings may have resulted from fibrosis and scarring, which may be a response to intraarticular bleeding. The mechanism by which the fibrosis causes the postsurgical arthrographic features is discussed.

Comparison of omnipaque with hypaque in temporomandibular arthrography.

Decreasing or alleviating pain experienced by some patients during or after temporomandibular arthrography would make this relatively inexpensive and highly accurate technique more attractive. This is particularly true for those patients without access to MR or those whose referring physicians prefer arthrography to other techniques for diagnosing internal derangements. Ionic and nonionic contrast agents were compared in a randomized, double-blind trial to determine if pain could be decreased by using a nonionic contrast material. Forty patients received either Omnipaque 300 (nonionic, iohexol) or Hypaque 60 (ionic, diatrizoate meglumine). Radiographs were assessed for diagnostic quality, and patients were asked to note their level of discomfort. No significant differences between the agents were detected. Maximal discomfort was noted at 24 hr. Discomfort was classified as none, mild, or moderate, with no patients describing marked discomfort. This study does not support the use of nonionic contrast agents over the less expensive ionic agents for decreasing pain or improving film quality in temporomandibular joint arthrography.