Subscapularis tendon tear: primary and associated signs on MRI.

PURPOSE: The purpose of this work was to investigate signs of subscapularis tendon tear on MRI. METHOD: Preoperative written interpretations of high field (n = 9) and low field (n = 7) MRI of 16 patients with tears confirmed at surgery or arthroscopy were reviewed, followed by retrospective review of these studies. RESULTS: A preoperative diagnosis of subscapularis tear was made in five (31%) cases. On retrospective review, primary signs of tear were present in 15 (94%) cases and in two-thirds were limited to the cranial third of the tendon. Supraspinatus tears were present in 69% of cases. Associated findings included medial dislocation (n = 4) or subluxation (n = 3) of biceps tendon, biceps tendinopathy (n = 2), superior labral tear (n = 5), and effusions of superior subscapularis recess (n = 6), subcoracoid bursa (n = 2), or both (n = 5). One or more associated signs were present in 94% of cases. CONCLUSION: Subscapularis tear is frequently missed on MRI. Recognizing that primary signs of tear may be limited to the cranial third of the subscapularis tendon and identifying associated signs should facilitate diagnosis.

CT of blunt trauma bowel and mesenteric injury: typical findings and pitfalls in diagnosis.

Detection of bowel and mesenteric injury can be challenging in patients after blunt abdominal trauma. Early diagnosis and treatment are critical to decrease patient morbidity and mortality. Computed tomography (CT) has become the primary modality for the imaging of these patients. Signs of bowel perforation such as free air and contrast material are virtually pathognomonic. Bowel-wall thickening, free fluid, and mesenteric infiltration may be seen with this type of injury and partial thickness injuries. The authors present and discuss the range of CT findings seen with bowel and mesenteric injuries. Examples of observation and interpretation errors are also provided to highlight pitfalls encountered in the evaluation of abdominopelvic CT scans in patients after blunt trauma.

CT cystography in the evaluation of major bladder trauma.

Computed tomographic (CT) cystography has been advocated in lieu of conventional cystography in the initial work-up of patients with suspected urinary bladder trauma. CT cystography was applied to a classification scheme for bladder injury based on the degree of wall injury and anatomic location and demonstrated characteristic imaging features for each type of injury. In bladder contusion (type 1), findings are normal. In intraperitoneal rupture (type 2), CT cystography demonstrates intraperitoneal contrast material around bowel loops, between mesenteric folds, and in the paracolic gutters. Manifestations of interstitial injury (type 3) include intramural hemorrhage and submucosal extravasation of contrast material without transmural extension. In extraperitoneal rupture (type 4), the path of extravasated contrast material is variable: Extravasation is confined to the perivesical space in simple extraperitoneal ruptures, whereas in complex extraperitoneal ruptures, contrast material extends beyond the perivesical space and may dissect into a variety of fascial planes and spaces. Combined intra- and extraperitoneal rupture (type 5) usually demonstrates extravasation patterns that are typical for both types of injury. Familiarity with these CT cystographic features allows accurate classification of bladder injury and allows prompt, effective treatment with less radiation exposure than and without the added cost of conventional cystography.

High-field and low-field MR imaging of superior glenoid labral tears and associated tendon injuries.

OBJECTIVE: The purpose of this study was to determine the performance characteristics of high-field and low-field MR imaging for the diagnosis of a glenoid superior labral anteroposterior (SLAP) tear. MATERIALS AND METHODS: High-field (n = 46) or low-field (n = 21) MR imaging was performed on 41 patients with SLAP tears and 26 patients with normal superior labra. The superior labrum was classified into one of four types on the basis of patterns of intralabral signal intensity. The relative frequency of rotator cuff tears and long head of the biceps tendinopathy was also assessed. RESULTS: For the diagnosis of SLAP tear, the sensitivity of high-field MR imaging was 90% (95% confidence interval = 74%, 98%), specificity was 63% (35%, 85%), and accuracy was 80% (66%, 91%). The sensitivity of low-field MR imaging was 64% (31%, 89%), specificity was 70% (35%, 93%), and accuracy was 67% (43%, 85%). A branched linear or stellate focus of abnormal intralabral signal intensity was associated with a SLAP tear in 86% of patients. Conversely, two other labral patterns correlated with a normal superior labrum in 71% of patients. Abnormal signal intensity in the biceps tendon was seen in 15% of patients with a SLAP tear. Full-thickness (37%) and partial-thickness (31%) rotator cuff tears were often seen. CONCLUSION: The performance characteristics of high-field MR imaging are superior to those of low-field MR imaging for the diagnosis of a superior labral tear. Rotator cuff tears can be seen in many patients with superior labral tears, but abnormal signal intensity in the biceps tendon is uncommon.

Detecting hepatic lesions: the added utility of CT liver window settings.

PURPOSE: To prospectively evaluate the utility of adding computed tomographic (CT) liver windows to conventional soft-tissue windows for the detection of hepatic disease. MATERIALS AND METHODS: One of four radiologists experienced in abdominal imaging interpreted 1,175 consecutive abdominal CT scans from one institution. Hepatic images were first interpreted by using standard soft-tissue windows. The number of lesions and confidence in lesion detection were recorded. The liver-window images were then interpreted in conjunction with the soft-tissue-window images, and the number of lesions and confidence in detection were recorded again. The proportion of patients in whom additional lesions were found by using liver windows was determined. RESULTS: On soft-tissue-window and liver-window scans interpreted together, 869 (74%) patients had no hepatic lesions. Thirty-six (3.1%) patients had new lesions seen with the addition of liver windows. Twelve of these 36 patients had no lesions seen on soft-tissue-window scans. Twenty-six of the 36 patients with additional lesions seen had a history of neoplasm. There was a change in diagnosis in 1.7% of the patients with the addition of liver windows and a change in recommendation for follow-up in 0.85%. CONCLUSION: Routine interpretation of liver-window scans for all abdominal CT scans has limited added utility in detecting hepatic disease.

Endovaginal sonography for the diagnosis of upper genital tract infection.

OBJECTIVE: To determine the clinical utility of transvaginal sonography for the diagnosis of upper genital tract infection. METHODS: Fifty-five women who either met the Centers for Disease Control and Prevention's minimal criteria for acute pelvic inflammatory disease or were being seen for non-classic signs of upper genital tract infection were evaluated. During abdominal and endovaginal ultrasound testing, fluid in the cul-de-sac, discrete tubes with or without tubal fluid, multicystic ovaries, and adnexal masses were noted. Upper genital tract infection was confirmed by laparoscopic visualization or histologic or microbiologic evidence of salpingitis of endometritis. RESULTS: The specificity of identifying fallopian tubes with or without intraluminal fluid on ultrasound was 97% (35 of 36); the sensitivity, however, was only 32% (six of 19). Calculated using Bayes theorem and based on a prevalence rate of 50%, the positive predictive value of visualizing fallopian tubes was 91%. The sensitivities associated with the visualization of a multicystic ovary or tubo-ovarian abscess were 42% (eight of 19) and 32% (six of 19), with specificities of 86% (31 of 36) and 97%, (35 of 36), and positive predictive values of 75% and 91%, respectively. Cul-de-sac fluid was associated with low sensitivity (37%; seven of 19), low specificity (58%; 21 of 36), and the lowest positive predictive value (47%). CONCLUSION: Endovaginal sonography has limited clinical utility in the diagnosis of upper genital tract infection due to its low sensitivity.

Contemporary imaging of athletic injuries.

The team physician is faced with an array of imaging studies to evaluate the injured athlete, including CT scans, conventional and cross-sectional arthrography, bone scanning, sonography, and MR imaging. An understanding of the clinical usefulness of these examinations requires some knowledge of the physical principles on which they are based. This article presents the fundamental physical principles and summarizes the indications for these tests to the evaluation of common athletic injuries.

Vaginal leiomyoma. A case report with imaging findings.

BACKGROUND: Vaginal leiomyoma is a rare tumor with a variable clinical presentation. The imaging features have not been described previously. CASE: A 42-year-old nulligravida presented with a vaginal mass. Ultrasound demonstrated a solid, rather than cystic, mass. Magnetic resonance imaging (MRI) showed a homogeneous lesion with a signal similar to that of the myometrium. Excision of a benign vaginal leiomyoma was performed without difficulty. CONCLUSION: Vaginal leiomyoma presenting as a mass is most often diagnosed clinically and readily treated at surgery. An uncommon presentation may necessitate imaging studies. The lesion described had MRI and ultrasound features similar to its uterine counterpart.

Tubal torsion appearing as acute pelvic inflammatory disease.

Torsion of the fallopian tube is an uncommon event with variable features, and may occur in the absence of adnexal disease. A woman had signs, symptoms, and ultrasound findings consistent with acute pelvic inflammatory disease. Laparoscopy established the definitive diagnosis of tubal torsion.

Computed tomography in blunt hepatic trauma.

BACKGROUND: Nonoperative management of blunt hepatic injury in hemodynamically stable trauma patients is now common. Recently, it has been proposed that the finding of hepatic periportal tracking (PPT) of blood on the initial computed tomographic (CT) scan is a sensitive marker of significant hepatic and subhepatic injury that might militate against nonoperative management. While CT scan is useful in diagnosing the injury, the utility of follow-up CT scans has not been elucidated. DESIGN: Retrospective chart review. SETTING: Regional trauma center. PATIENTS: The records of 58 hemodynamically stable patients with blunt hepatic trauma were reviewed and the following data recorded: age, outcome, Injury Severity Score (ISS), operative intervention, and complications. Computed tomographic scans were taken on admission and reviewed for the presence of PPT. The timing and radiographic appearance of follow-up CT scans was also recorded. RESULTS: Seventeen patients (29%) had radiographic evidence of PPT while 41 patients (71%) did not. Age, ISS, injury grade, overall success rate of nonoperative management, and incidence of complications were not statistically significant between the two groups. In no instance did a routine follow-up CT scan affect subsequent management of the patient. CONCLUSIONS: The finding of PPT on the admission CT scan is not clinically significant and does not preclude nonoperative management of patients with blunt hepatic injury. Furthermore, routine follow-up CT scans are not indicated, as treatment is not influenced by their results. Rather, follow-up CT scans should be obtained as dictated by the patient's clinical course. Extrapolation of these findings to all patients with blunt hepatic trauma in the United States would result in considerable savings of health care dollars, without negatively affecting patient care.

Anterior segment findings in AIDS patients with cytomegalovirus retinitis.

BACKGROUND: Anterior segment findings in AIDS patients presenting with cytomegalovirus (CMV) retinitis have not been specifically addressed in the American literature. METHODS: Our study evaluated 21 AIDS patients with CMV retinitis. RESULTS: Nineteen (90%) of these patients exhibited corneal endothelial deposits concurrent with CMV retinitis. The endothelial deposits were microscopic, opaque, linear flecks arranged in a reticular-like fashion. Of 42 eyes evaluated, 32 (76%) demonstrated active CMV retinitis. Corneal endothelial deposits were noted in 26 (81%) of the 32 eyes with retinitis. These corneal endothelial deposits were absent in the eyes which did not have CMV retinitis. CONCLUSION: Meticulous examination of the retina of an HIV-positive or AIDS patient who presents with reticularly arranged, linear, flecked corneal endothelial deposits should be performed to ensure that the diagnosis of CMV retinitis can be ruled out.

Multiple myeloma presenting with bilateral exudative macular detachments.

Bilateral exudative macular detachments were present on a 64-year-old diabetic Caucasian male who presented with bilateral blurring of vision. Besides the exudative macular detachments there was no diabetic retinopathy or congestive retinopathy, and a previous fluorescein angiogram revealed no focal leakage. Laboratory investigation, bone marrow biopsy, and a bone survey revealed the diagnosis of multiple myeloma.

Determination of an RNA structure involved in splicing inhibition of a muscle-specific exon.

We have investigated the RNA structure of the region surrounding the muscle-specific exon 6B of the chicken beta-tropomyosin gene. We have used a variety of chemical and enzymatic probes: dimethylsulfate, N-cyclohexyl-N'-(2-(N-methylmorpholino)-ethyl)-carbodiimide-p-tolu enesulfonate) , RNase T1 and RNase V1. Lead acetate was also used to obtain some information on the tertiary structure of this region. Probing the wild-type sequence suggests a model involving one-stem and three-stem-loop structures in and around this exon. Two of these, hairpin I and stem III, have previously been implicated in repression of splicing of the intron following exon 6B in a HeLa nuclear extract. Stem I includes sequences at the beginning of exon 6B and stem III results from interaction of the intron upstream from exon 6B with sequences in the middle of the intron downstream from this exon (the intron whose splicing is repressed). Neither stem I nor stem III directly involves the consensus sequences (5' splice site, branch-point, 3' splice site) of the repressed intron. Probing RNAs that are derepressed for splicing of this intron show that there are structural changes around the 5' splice site and branch-point sequence that correlate with the derepression. This is true, despite the fact that the derepressed RNAs are altered in a region far from these consensus sequences. The most striking structural correlation with splicing capacity of the intron downstream from exon 6B is seen by probing with lead acetate. Lead ions cut RNA at specific residues; these sites are very sensitive to RNA tertiary structure. Repressed and derepressed RNAs show entirely different cleavage patterns after incubation with lead acetate. Remarkably, hybridizing a derepressed RNA with an RNA comprising the ascending arm of stem III not only re-establishes repression, but also converts the pattern of susceptibility to attack by lead ions over the whole molecule. We suggest that RNA conformation plays a role in keeping exon 6B from being spliced into non-muscle cell mRNA.

Detection of tissue injury after extracorporeal shockwave lithotripsy of gallstones.

We evaluated seven patients undergoing gallstone lithotripsy for evidence of hepatic or renal trauma after each of 10 lithotripsy treatments. Postlithotripsy magnetic resonance imaging (MRI) and sonography showed no evidence of hepatic or renal injury as compared with baseline studies. Four treatments resulted in sonographic evidence of gaseous hepatic microbubbles (analogous to "the bends") due to cavitation effects of the shockwaves. Three of these four treatments produced serum glutamicoxaloacetic transaminase and -pyruvic transaminase elevation. One patient had microscopic hematuria. Minimal tissue damage results from gallstone lithotripsy. MRI and ultrasound, performed after lithotripsy, appear to be less sensitive than transaminasemia in detecting this low-grade injury.

Gastric tuberculosis: a manifestation of acquired immunodeficiency syndrome.

A Haitian man with acquired immunodeficiency syndrome (AIDS), fever, malaise, and diarrhea is described. A computed tomographic (CT) scan showed a retrogastric mass with an associated ulcer. An upper gastrointestinal tract study showed an ulcer with both benign and malignant features. Endoscopy revealed a malignant-appearing ulcer, but cultures and histologic examinations of surgical biopsy specimens indicated gastric tuberculosis. The relationship between tuberculosis and AIDS is discussed.