US of the ankle: technique, anatomy, and diagnosis of pathologic conditions.

For specific indications, ultrasound (US) is an efficient and inexpensive alternative to magnetic resonance (MR) imaging for evaluation of the ankle. In addition to the tendons and tendon sheaths, other ankle structures demonstrated with US include the anterior joint space, retrocalcaneal bursa, ligaments, and plantar fascia. Ankle US allows detection of tenosynovitis and tendinitis, as well as partial and complete tendon tears. Joint effusions, intraarticular bodies, ganglion cysts, ligamentous tears, and plantar fasciitis can also be diagnosed. As pressure for cost containment continues, demand for US of the ankle may increase given its lower cost compared with that of MR imaging. In most cases, a focused ankle US examination can be performed more rapidly and efficiently than MR imaging. Familiarity with the technique of ankle US, normal US anatomy, and the US appearances of pathologic conditions will establish the role of US as an effective method of imaging the ankle.

Synovial joints: evaluation of intraarticular bodies with US.

PURPOSE: To determine the efficacy of ultrasonography (US) for the detection of intraarticular bodies. MATERIALS AND METHODS: US was performed in 280 patients with symptoms in various appendicular joints by using 5.0-, 7.5-, or 10.0-MHz transducers. Three patients also underwent US with intraarticular saline infusion. US findings were confirmed at surgery in 61 patients. RESULTS: In the 61 patients with surgical correlation, sonograms were positive in 39 and did not show intraarticular bodies in 22. Surgical results confirmed 37 of the positive and all of the negative sonograms. Sensitivity and specificity of US were 100% and 95%, respectively. CONCLUSION: US is an accurate method for identification of intraarticular bodies.

US depiction of partial-thickness tear of the rotator cuff.

PURPOSE: To test previously defined ultrasound (US) criteria for identification of partial-thickness tears of the rotator cuff. MATERIALS AND METHODS: Before shoulder arthroscopy, 52 patients with shoulder pain for more than 3 months were examined with a 7.5-MHz commercially available linear-array transducer and a standardized study protocol. The criteria used to detect partial-thickness tears were (a) a mixed hyper- and hypoechoic focus in the crucial zone of the supraspinatus tendon and (b) a hypoechoic lesion visualized in two orthogonal imaging planes with either articular or bursal extension. RESULTS: The US findings were reported as partial-thickness tears in 17 shoulders, of which three were false-positive findings. There was one false-negative finding. The sensitivity of US in depiction of partial-thickness tears was 93%, and specificity was 94%. The positive predictive value was 82%, and the negative predictive value was 98%. CONCLUSION: US can depict most partial-thickness tears with use of the criteria described.

Estimation of patient age based on plain chest radiographs.

Patient age is an essential part of a clinical history, but it is not always provided by referring physicians. We assessed the ability of four radiologists with different levels of expertise (first-year resident to professor emeritus) to predict patient age based on postero-anterior and lateral chest radiographs from 171 patients. All four were able to predict age with a mean error of less than 15 years, but there were statistically significant differences among them. Surprisingly, observer experience did not correlate with accuracy of patient age estimation. While many factors probably operate, the estimation of patient age relies heavily on "gestalt."

Carpal ligamentous laxity with bilateral perilunate dislocation in Marfan syndrome.

A case of persistent bilateral perilunate dislocation unrelated to trauma in a patient with Marfan syndrome is discussed. This finding is believed to be a manifestation of the generalized ligamentous laxity occurring in this disorder. Radiographs of eight additional Marfan syndrome patients failed to demonstrate similar carpal instability. Because some carpal derangements are dynamic events, stress views or wrist fluoroscopy may be necessary to demonstrate unsuspected carpal instability in Marfan patients.

Non-obstructive colonic dilation: radiologic findings in 50 patients following colonoscopic treatment.

Fifty patients with acute onset of colonic dilatation without mechanical obstruction were evaluated before and after colonoscopic decompression. Colonic dilatation, as demonstrated radiographically, was segmental or consistent with mechanical obstruction in 33 (66%). Signs of impending cecal perforation were seen in five (10%) and these patients had colonoscopic decompression, tube cecostomy, or both. Following colonic decompression, cecal diameter may remain unchanged for two to four days, despite decreased abdominal girth and even shortening of the colon radiographically. Improvement in pain, distention, tenderness, fever and leukocytosis may precede radiographic improvement. The radiologist must recognize this entity, look for signs of impending perforation and signs of bowel shortening, with or without decompression after treatment. Barium studies of the colon should be avoided since they can hamper the endoscopic diagnosis and treatment of colonic dilatation.

Detection of occult colovesical fistula by the Bourne test.

The value of different diagnostic tests in the detection of colovesical fistulas was studied in 28 surgically proven cases seen during the last 10 years at the University of Michigan, Ann Arbor. Etiologies were diverticulitis (19), Crohn disease (three), postradiation therapy (four), previous trauma (one), and bladder carcinoma (one). The fistulas were demonstrated by barium enema in 10 of 20 patients and by cystography in eight of 26. Cystoscopy was diagnostic in 11 of 25 patients and sigmoidoscopy in four of 24. Methylene blue test was positive in five of six patients, and in one patient given a charcoal enema the material appeared in the urine. The Bourne test, consisting of radiography of the centrifuged urine samples obtained immediately after a nondiagnostic barium enema, was positive in nine of 10 patients. In seven of these 10 patients, the Bourne test was the only positive evidence of an otherwise occult colovesical fistula later proven at surgery.

Evaluation of the pulmonary hilum: comparison of conventional radiography, 55 degrees posterior oblique tomography, and dynamic computed tomography.

In 84 patients with suspected intrathoracic neoplasms we compared the accuracy of conventional radiography, 55 degrees posterior oblique tomography, and contrast-enhanced dynamic incremental computed tomography (CT) in evaluation of the pulmonary hilum. We found dynamic incremental CT to be better than either conventional radiography or oblique tomography in hilar evaluation. In addition, significant information was detected in extrahilar and extramediastinal locations by CT in 21% of patients. This study, unlike earlier reports, indicates a role for CT in hilar evaluation.

Differentiation of aortic and mitral valve prostheses based on postoperative frontal chest radiographs.

The authors reviewed the postoperative frontal chest radiographs of 77 patients given aortic or mitral prostheses in one year and evaluated the criteria for distinguishing between the two: position (cephalocaudal or transverse), orientation (vertical or horizontal), orifice (en face or in profile), direction of flow through the valve (toward the cardiac apex or ascending aorta), and information given on the consultation form. 91% of patients had at least one form containing incomplete or incorrect information. Direction of flow appears to be the best criterion, being discernible in all Starr-Edwards and most Björk-Shiley prostheses; orifice and orientation are considerably less reliable, while position is totally unreliable.

Abdominal complications of ventriculoperitoneal shunts with emphasis on the role of imaging methods.

Four hundred ventriculoperitoneal shunt procedures in 280 patients were retrospectively evaluated regarding complications relating to the peritoneal end of the catheter. There were 100 complications requiring 120 surgical revisions. Common complications consisted of mechanical shunt malfunction in 28, catheter tip occlusion in 40 and shunt infection in 25. In addition, there were abdominal cerebrospinal fluid loculations and pseudocysts formation in seven patients, intestinal perforation, migration of shunt tip in the right pleural cavity and intractable ascites in one patient each. The currently available diagnostic imaging modalities by which the peritoneal end of a malfunctioning ventriculoperitoneal shunt can be evaluated are reviewed.

Unusual abdominal complications of ventriculo-peritoneal shunts.

Placement of ventriculo-peritoneal (VP) shunts is an established procedure for treatment of hydrocephalus. With increasing longevity following successful treatment, complications are becoming more common. The authors reviewed 350 VP shunts in 242 patients and found five uncommon complications relating to the peritoneal end of the catheter: (a) cerebrospinal fluid (CSF) pseudocyst of the lesser sac, (b) subphrenic CSF loculation, (c) bowel perforation and formation of a CSF-enteric fistula, (d) intrathoracic migration of the tip of the shunt, and (e) intractable CSF ascites.

Radiographic findings in the chest of patients following cardiac transplantation.

The postoperative chest radiographic findings in 38 patients undergoing orthotopic (37 patients) and heterotopic (1 patient) cardiac transplantation were evaluated. Findings were correlated with those of echocardiograms, sputum and blood cultures, and lung and heart biopsies. The radiographic manifestations in the chest of these patients are classified in the following three main categories: (1) Newly formed cardiac silhouette findings due to the transplanted heart itself, i.e., changes in size and shape of the new heart and pericardial effusion resulting from the placement of a smaller heart in a larger pericardial sac. (2) Infectious complications due to bacteria, fungal, and other opportunistic agents secondary to immunosuppressive therapy, and (3) Usual postoperative complications following thoracotomy and open-heart surgery.

Carcinoma of the esophagus: assessment of submucosal extent.

Submucosal extension of carcinoma of the esophagus is common, often presenting as a varicoid pattern on the esophagogram. Forty-two per cent of our 153 patients with carcinoma of the esophagus showed area(s) of a varicoid pattern in association with the other usual pattern(s) (fungating, ulcerating or infiltrating). A few of the patients have findings similar to those associated with esophageal varices on the esophagogram. Such patients are identical to those with "varicoid carcinoma" reported in the literature. The differentiation between varicoid carcinoma dn esophageal varices may be made on fluoroscopy, where the former is characterized by rigidity and the latter by flexibility.

Subhepatic sonography following cholecystectomy.

The subhepatic placement of prophylactic drains following cholecystectomy remains a common practice despite studies demonstrating the safety of omitting such drains. The accumulation and fate of subhepatic fluid constitute the chief concern. In a prospective comparative study, 76 patients were randomized into drained and non-drained groups. Postoperative ultrasonographic studies showed no localized fluid accumulations in the majority of instances. Small accumulations of fluid in the gallbladder bed were demonstrated on the initial postoperative sonograms in nine patients in the two groups. Long-term patient follow-up confirmed such fluid, which remained stable or decreased in size, to be clinically insignificant.

Sensitivity of scintigraphy for detection of pulmonary capillary albumin leak in canine oleic acid ARDS.

Computerized gamma scintigraphy was shown in this study to be a sensitive technique for the detection and kinetic analysis of a pulmonary capillary protein leak. A rising lung:heart radioactivity of 'slope of injury' was found at each dose of intravenous oleic acid in dogs from 0.01 to 0.20 ml/kg (p less than 0.01). This 'slope of injury' was proportional to the dose of oleic acid (r = +0.97; p less than 0.004) and was more sensitive than changes in arterial oxygen tension, standard chest radiography, bloodless wet:dry lung weight, or alveolar epithelial membrane permeability. Only standard light microscopy and right lymphatic duct flow were able to document the leakage of protein detected by gamma scintigraphy at 0.01 ml/kg oleic acid.

The effect of prophylactic drainage on subhepatic fluid collections after elective cholecystectomy: a prospective randomized ultrasonographic study.

Seventy-six patients undergoing elective cholecystectomy were randomly divided into drained and nondrained subjects and studied with sonography preoperatively and postoperatively to determine the incidence and fate of subhepatic fluid collections. In the drained group, detectable subhepatic fluid was seen in 5 per cent of patients, whereas it occurred in 20 per cent of nondrained patients. Although this difference achieved statistical significance (P less than 0.05), there were no complications directly attributable to the retained subhepatic fluid. On the contrary, this study supports previous observations that patients undergoing cholecystectomy without drainage have less postoperative fever. Subhepatic fluid collections occurred in a small number of patients so managed but were of no clinical significance in this study.