Search

Background Angiotensin-converting enzyme 2, a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demonstrates its highest surface expression in the lung, small bowel, and vasculature, suggesting abdominal viscera may be susceptible to injury. Purpose To report abdominal imaging findings in patients with coronavirus disease 2019. Materials and Methods In this retrospective cross-sectional study, patients consecutively admitted to a single quaternary care center from March 27 to April 10, 2020, who tested positive for SARS-CoV-2 were included. Abdominal imaging studies performed in these patients were reviewed, and salient findings were recorded. Medical records were reviewed for clinical data. Univariable analysis and logistic regression were performed. Results A total of 412 patients (average age, 57 years; range, 18 to >90 years; 241 men, 171 women) were evaluated. A total of 224 abdominal imaging studies were performed (radiography, n = 137; US, n = 44; CT, n = 42; MRI, n = 1) in 134 patients (33%). Abdominal imaging was associated with age (odds ratio [OR], 1.03 per year of increase; P = .001) and intensive care unit (ICU) admission (OR, 17.3; P < .001). Bowel-wall abnormalities were seen on 31% of CT images (13 of 42) and were associated with ICU admission (OR, 15.5; P = .01). Bowel findings included pneumatosis or portal venous gas, seen on 20% of CT images obtained in patients in the ICU (four of 20). Surgical correlation (n = 4) revealed unusual yellow discoloration of the bowel (n = 3) and bowel infarction (n = 2). Pathologic findings revealed ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Right upper quadrant US examinations were mostly performed because of liver laboratory findings (87%, 32 of 37), and 54% (20 of 37) revealed a dilated sludge-filled gallbladder, suggestive of bile stasis. Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures. Conclusion Bowel abnormalities and gallbladder bile stasis were common findings on abdominal images of patients with coronavirus disease 2019. Patients who underwent laparotomy often had ischemia, possibly due to small-vessel thrombosis. © RSNA, 2020.

To retrospectively determine imaging findings in patients with autoimmune pancreatitis.Twenty-nine patients (25 male and four female; mean age, 56 years; range, 15-82 years) with histopathologic diagnosis of autoimmune pancreatitis were examined. Data were reviewed by two radiologists in consensus. Imaging findings for review included those from helical computed tomography (CT), 25 patients; magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP), four patients; endoscopic ultrasonography (US), 21 patients; endoscopic retrograde cholangiopancreatography (ERCP), 19 patients; and percutaneous transhepatic cholangiography, one patient. Images were analyzed for appearances of pancreas, biliary and pancreatic ducts, and other findings, such as peripancreatic inflammation, encasement of vessels, mass effect, pancreatic calcification, peripancreatic nodes, and peripancreatic fluid collection. Follow-up images were available in nine patients. Serologic markers such as serum immunoglobulin G (IgG) and antinuclear antibody levels were available in 12 patients.CT showed diffuse (n = 14) and focal (n = 7) enlargement of pancreas. Seven patients had minimal peripancreatic stranding, with lack of vascular encasement, calcification, or peripancreatic fluid collection. Nine patients had enlarged peripancreatic lymph nodes. MR imaging showed focal (n = 2) and diffuse (n = 2) enlargement with rimlike enhancement in one. MRCP revealed pancreatic duct strictures in two and sclerosing cholangitis-like appearance in one. Endoscopic US showed diffuse enlargement of pancreas with altered echotexture in 13 patients and focal mass in the head in six. ERCP showed stricture of distal common bile duct in 12 patients, irregular narrowing of intrahepatic ducts in six, diffuse irregular narrowing of pancreatic duct in nine, and focal stricture of proximal pancreatic duct in six. Serologic markers showed increased IgG and antinuclear antibody levels in seven of 12 patients. At follow-up, CT abnormalities and common bile duct strictures resolved after steroid therapy in three patients.Features that suggest autoimmune pancreatitis include focal or diffuse pancreatic enlargement, with minimal peripancreatic inflammation and absence of vascular encasement or calcification at CT and endoscopic US, and diffuse irregular narrowing of main pancreatic duct, with associated multiple biliary strictures at ERCP.

The purposes of this study were to investigate the imaging findings in patients with primary fallopian tube neoplasms and to determine whether specific imaging features favor the preoperative diagnosis of fallopian tube tumors (FTT).Computerized search of medical records from 1984 to 1994 identified 20 patients with a discharge diagnosis of primary fallopian tube carcinoma. Medical records, imaging studies, and pathology findings were reviewed. Eleven patients had available preoperative imaging.Seventeen of 20 patients with primary FTT had unilateral disease. Of these 17, preoperative imaging was available in nine, showing four solid adnexal masses, four complex cystic adnexal masses, and one normal adnexa. The preoperative imaging of these nine patients included six sonographic and five CT studies. Three patients with primary FTT had bilateral tumors, and preoperative imaging was available for two patients: Two sonographic studies and one CT study showed one complex cystic adnexal mass and three normal adnexa.Primary FTT commonly presents as an adnexal mass on preoperative imaging and mimics other pelvic malignancies, especially ovarian carcinoma. Making a specific preoperative diagnosis is difficult; however, because primary FTT is unlikely to be confused with a benign process, delay in diagnosis is rare.

To characterize endometrial polyps, hyperplasia, and carcinoma with endovaginal ultrasound in postmenopausal women.Seventy-three postmenopausal women with abnormally thick endometria on endovaginal sonograms were retrospectively identified. The endometrial appearance was characterized as hyperechoic, containing cystic spaces, or heterogeneous. The final study group consisted of 68 women, in whom the pathologic and sonographic findings were correlated.Thirty sonograms showed hyperechoic endometria in women with hyperplasia (n = 8), polyps (n = 4), polyps and hyperplasia (n = 2), or atrophy, proliferative change, mild atypia, or normal endometria (n = 16); 27 sonograms showed cystic spaces in women with polyps (n = 21), carcinoma (n = 1), polyps and hyperplasia (n = 2), or atrophy (n = 3); and 11 sonograms showed heterogeneous endometria in women with endometrial carcinoma (n = 7), atrophy (n = 2), proliferative endometrium (n = 1), or secretory endometrium (n = 1). Cystic spaces were predictive of polyps (P = 1.19 x 10(-10)).Endovaginal sonography may be useful for differentiation of endometrial polyps, hyperplasia, and carcinoma.

I i1p I This paper is the result of a panel of experts convened. at . As the right and left hepatic ducts join to form the common the annual meeting of the Society of Gastrointestinal RadiolJ hepatic duct, they arch anteriorly over the portal vein. The o ists in Hawaii, January 14-19, 1990, to discuss the current . common hepatic duct, portal vein, and hepatic artery all lie status of diagnostic radiology of the biliary tract and biliary within the hepatoduodenal ligament (Fig. 1). Although the intervention. The focus of discussion was to update and touch normal intrahepatic bile ducts are not seen on CT, the cornon the highlights of each area rather than to provide a corn-f , mon hepatic duct can readily be distinguished from the adjaprehensive review. . J #{149} cent contrast-enhanced blood vessels. An oblique sonograrn

Because of the difficulty in diagnosing acute cholecystitis in critically ill patients with severe intercurrent illness by clinical and imaging methods or percutaneous aspiration of the gallbladder, a trial of percutaneous cholecystostomy was performed in 24 patients in the intensive-care unit with persistent, unexplained sepsis after a complete clinical, laboratory, and radiologic search showed no alternative source of infection. Persistent high fevers, despite antibiotic therapy, were present in all patients, with elevated WBC count in 18 patients, vague abdominal tenderness in 11, and septic shock requiring vasopressors in 15. Sonographically, all patients had distended, spherical gallbladders, six had gallstones, eight had wall thickening, three had pericholecystic fluid, and four had Murphy's sign. All patients were seen by a senior abdominal surgeon, who agreed to a trial of percutaneous cholecystostomy. Fourteen patients (58%) responded to percutaneous cholecystostomy, as evidenced by a decrease in WBC count, defervescence, and the ability to be weaned off vasopressors. Bile cultures were positive in four patients. Ten patients (42%) did not respond to percutaneous cholecystostomy; five eventually died of unrelated causes. A respiratory source of infection was eventually found in three of these 10 patients, with no proved source of infection in the remainder. No complications related to catheter insertion occurred in this group of patients. Bile leaks occurred in two patients when the percutaneous cholecystostomy catheter was removed, but without serious consequence. Our experience suggests that a lower threshold for performing percutaneous cholecystostomy in this difficult clinical subset of patients is worthwhile.

In a retrospective study of adrenal masses evaluated with computed tomography (CT), lesion x-ray attenuation was compared with size and radiologists' interpretations in discriminating benign lesions from malignant ones. Unenhanced CT attenuation coefficient and size were analyzed electronically in 55 patients with 66 adrenal masses. There were 38 nonhyperfunctioning adenomas in 33 patients and 28 malignant masses in 22 patients. Primary extraadrenal malignancies were present in 45 of the 55 patients. Three blinded readers characterized the adrenal masses using a seven-point scale of certainty. Results were subjected to receiver operating characteristic (ROC) analysis. The mean CT attenuation coefficient for benign adrenal masses was -2.2 HU +/- 16.0 and was significantly different from the mean for malignant lesions (28.9 HU +/- 10.6). The area under the ROC curve for CT attenuation coefficients (0.91 +/- 0.04) was significantly larger than that for lesion size (0.84 +/- 0.05) or best observer interpretation (0.84 +/- 0.05). A threshold CT attenuation value of 0 HU had a sensitivity-to-specificity ratio of 47%:100% for characterizing benign adrenal masses, whereas a threshold attenuation of 10 HU had a ratio of 79%:96%.

During extracorporeal shock wave lithotripsy of gallstones, sonography often shows a swirling pattern of echogenic foci shortly after the application of shock waves. This effect has been thought to represent gallstone fragments in suspension. However, evidence suggests that this finding is in part due to cavitation, a physical phenomenon associated with the formation or movement of gas bubbles in the fluid-filled gallbladder. Condoms filled with degassed water and five human bile specimens were positioned in the focus of an MPL 9000 lithotriptor (Dornier Medical Systems, Munich). A solitary nonradiopaque gallstone was then added to a bile-filled condom, and the sonographic pattern was observed before and after fragmentation. The mean clearance time of the cavitation bubbles was 4 seconds for degassed water and 22 seconds for human bile. Gallstone fragments were distinguished from cavitation bubbles by their prolonged settling time (up to 30 minutes) along the dependent gallbladder wall.

To compare fusion, positron emission tomography–computed tomography (PET–CT) with CT alone in detecting ovarian carcinoma recurrence. Fifty-one consecutive patients underwent 53 restaging PET–CT scans with a concurrent diagnostic quality CT scan. Two body imaging radiologists independently assessed the CT’s; each then teamed with a nuclear medicine specialist to review the PET–CT’s. Two teams conferred for consensus on the presence of disease in the chest, abdomen, and body overall with CT alone and with PET–CT, using a six-point reader confidence metric to determine accuracy and receiver operating characteristic (ROC) curves. Reader agreement was compared using kappa. Recurrence was determined by two gynecologic oncologists reviewing clinical records from time of presentation to at least 13 months (mean 22.7) after imaging. Recurrence was based on histopathology in 17% (9/53). Seventy-two percent (38/53) cases had recurrence, with two cases showing isolated chest recurrence. PET–CT accuracy exceeded CT for body 92% (49/53) vs. 83% (44/53), chest 96% (51/53) vs. 89% (47/53), and abdomen 91% (48/53) vs. 79% (42/53). ROC curves for PET–CT dominated that for CT alone; this difference was statistically significant for abdomen and for body overall (P

We assessed whether specific sonographic characteristics are indicative of the extent of adenomyosis and whether fibroids alter this assessment.Patients' records were evaluated for the diagnosis of adenomyosis determined by hysterectomy and for sonography performed within 2 months of surgery. Seventy-three sonograms were evaluated by sonologists without knowledge of the extent of adenomyosis. Sonographic categories included visualization of the endometrium, presence of a diffuse uterine process, presence of fibroids, and normal findings. Pathologic results included mild, focal, and severe adenomyosis. Histologic and sonographic categories were correlated using the chi-square and Fisher's exact tests.Forty-six specimens contained mild adenomyosis, 18 contained severe disease, and nine contained focal disease. Forty-one specimens contained fibroids. The endometrium was visualized in 10 cases of severe adenomyosis, seven cases of adenomyoma, and 35 cases of mild disease. Visualization of the endometrium did not relate to the severity of disease (p = 0.6). Of 18 cases of severe disease, 13 sonograms showed a diffuse process. Of nine cases of adenomyomas, no sonograms showed a diffuse process; and of 46 cases of mild disease, nine sonograms showed a diffuse process. A diffuse process was related to the severity of adenomyosis (p0.001). When fibroids were present, a diffuse process did not relate to the extent of adenomyosis (p = 0.01).In the absence of focal fibroids, a diffuse uterine process seen on sonography relates to the severity of adenomyosis. Fibroids limit the ability to diagnose the severity of adenomyosis. The visualization of the endometrium does not relate to the severity of adenomyosis.

The aim of this study was to illustrate and discuss the sonographic spectrum of surgically proven cystic nodal metastases from papillary thyroid carcinoma. By correlative evaluation of the sonographic imaging findings to gross pathology and histology, our purpose was to provide useful hints to differentiate cystic lymph node metastases from other benign cystic neck lesions such as branchial cysts.Sonographic examinations of 74 patients (47 women, 27 men; mean age, 49 years) with 97 histologically confirmed cystic lymph nodes metastases from papillary thyroid carcinoma were included in the study. The anatomic relationship of the nodes relative to the primary tumor was recorded, and all cystic nodes were qualitatively categorized as either simple (purely cystic) or complex (thickened outer wall, internal nodules, internal septations, and calcifications). All imaging findings were compared with gross pathologic specimens.Most of the cystic metastases were ipsilateral to the primary tumor (87.8%) and located in the mid or lower jugular chain (73.2%). In 14.9% of all patients, cystic lymph node metastases were the initial manifestation of disease. Only 6.2% of all lymph node metastases were purely cystic (all of these occurred in patients less than 35 years old). Of the 91 complex metastases, a thickened outer wall was present in 35.2% of patients, internal nodules in 42.9%, and internal septations in 57.1%. No calcifications were seen in the 91 complex metastases, and two or more findings were seen in 23.1%. All sonographic findings were verified by surgery.In most of the patients, cystic lymph node metastases are characterized sonographically by the presence of a thickened outer wall, internal echoes, internal nodularity, and septations. However, in younger patients, the lymph nodes might appear purely cystic, thereby mimicking branchial cysts and thus requiring biopsy for final diagnosis and therapy planning.

Injection cholecystography is often employed during invasive gallbladder procedures to determine the number of gallstones that are present. The authors undertook this study to define the optimal radiographic technique for performance of injection cholecystography. Condoms filled with 100 mL of contrast medium at four different iodine concentrations (30%, 15%, 7.5%, and 3.8% [wt/vol]) and containing up to five 4-mm-thick gallstones or a single 10-mm-thick gallstone were radiographed in a 20-cm-deep water bath by using four kilovolt peak settings (70, 80, 90, and 100 kVp). Images were read by three radiologists who were blinded to the radiographic technique. significantly (P less than .05) improved Decreasing iodine concentration significantly (P less than .05) improved detection of 4-mm-thick gallstones at a constant kilovolt peak setting. However, increasing the kilovolt peak setting while using the same concentration of contrast medium had no statistically significant influence on gallstone detectability, although radiologists did indicate a preference for the high-kilovolt peak technique. Results of the authors' experiments showed that for detection of small gallstones at injection cholecystography, use of a low-concentration contrast medium and a high kilovolt peak setting is the recommended radiographic technique.

We performed a prospective study in 96 patients to determine accuracy of sonographically guided fine-needle aspiration biopsy of thyroid masses and cervical lymph nodes.Real-time sonography was used to guide biopsy of 112 cervical masses in 96 patients (71 patients with impalpable masses, 16 with failed unguided attempts, patient's or physician's preference in nine). The diameters of all masses were less than 3 cm, with a mean of 1.5 cm and a median of 1.5 cm. Twenty-nine masses measured 1 cm or less in diameter, 60 masses between 1.1 and 2.0 cm, and 23 masses between 2.1 and 3.0 cm. Cervical masses that were sampled by biopsy included 75 thyroid masses and 37 lymph nodes.Diagnostic specimens were obtained in 102 (91%) of 112 masses sampled. Sixty-eight (91%) of 75 biopsies of thyroid tissue and 34 (92%) of 37 biopsies of lymph nodes were diagnostic. Nondiagnostic thyroid biopsies included four of complex cysts and three of solid nodules. Sonographic follow-up (1 year) revealed no change or decrease in size of those seven lesions. Sixty of 68 diagnostic thyroid biopsies showed benign processes: 42 macrofollicular adenomas, six colloid adenomas, five microfollicular adenomas, four probable cases of thyroiditis, and three hemorrhagic cysts. The remaining eight diagnostic thyroid biopsies showed malignant processes: seven papillary carcinomas and one metastatic small-cell carcinoma. Of 34 diagnostic biopsies of lymph nodes, 26 showed malignant processes and eight showed benign processes. Surgery in the three patients with nondiagnostic biopsies of lymph nodes revealed two recurrent medullary cancers and one benign node.Sonographically guided fine-needle aspiration biopsy of neck masses has a high sensitivity (91%) and should be routinely used to evaluate indeterminate masses in the neck.

Tissue levels of thyroglobulin (Tg) or calcitonin were compared with specimens from neck lymph node biopsy in patients with suspected recurrent differentiated (papillary or follicular) or medullary thyroid cancer. Thirty-six neck lymph node biopsies were performed in 29 patients. Tissue Tg levels were obtained from 31 specimens from patients with differentiated thyroid cancers, and tissue calcitonin levels were obtained from five specimens from patients with medullary cancer. Thirteen nodes were diagnosed as negative for cancer at surgery (n = 3) or follow-up sonography (n = 10). Malignant disease was confirmed at surgery in 23 of the 36 lymph nodes. Cytopathologic examination had a sensitivity of 91% and a specificity of 100%. Tissue Tg levels ranged from 0 to 3.5 ng/mL (mean, 1.5 ng/mL; median, 1.2 ng/mL) in 12 of the 13 benign lymph nodes and from 21 to 247,500 ng/mL (mean, 30,600 ng/mL; median, 2,330 ng/mL) in the 23 malignant nodes. Tissue calcitonin levels were elevated (range, 850-703,125 pg/mL; mean, 184,762 pg/mL; median, 17,538 pg/mL) in four malignant nodes and were normal (3.0 pg/mL) in one benign node. Diagnostic sensitivity of tissue markers was 91%. Specificity was 91%. The combined diagnostic sensitivity and specificity of tissue marker analysis and cytopathologic examination was 100%.

Precocious puberty in young girls is defined as the development of secondary sexual characteristics and gonadal growth before 8 years of age. Approximately 60% of isosexual precocious development in girls has no organic cause and is termed idiopathic precocious puberty. Thirteen young girls with idiopathic precocious puberty were treated with LHRH analogue under a well-established protocol. Pelvic ultrasound was added to the protocol to examine ultrasound's role in supplying a morphologic parameter of suppression of the pubertal process. Initially, 11 patients had ovarian volumes greater than normal, and ovarian cysts measuring 0.5 cm to 4 cm in diameter were identified in seven patients. All 13 patients had enlarged pretreatment uteri greater than 3 cm in length. Eleven of these patients had a pubertal or adult uterine configuration. After 1 year of therapy, 11 patients had normal prepubertal ovarian volumes, and 12 of 13 patients had a decrease in ovarian volume. No demonstrable cysts were present at 1 year. Eleven had a reduction in uterine length. Nine of the 11 patients with a pubertal uterine configuration reverted to a more prepubertal-like morphology. The sonographic morphologic changes correlated well with laboratory and clinical data indicating suppression of the hypothalamic-pituitary-gonadal axis.

Computed tomographic(CT)-guided biopsy of presacral masses after abdominoperineal resection for colorectal carcinoma was performed in 28 patients, using a transgluteal approach. The masses were divided into three groups according to their morphologic appearance: solid mass, mass with central low-density area, and gas-containing mass. Of 19 patients with a homogeneous solid mass, 15 had biopsy-proven recurrent adenocarcinoma. In the other nine patients, who had low-density masses with or without gas, it was not possible to offer a diagnosis on the basis of the CT appearance alone. In these cases, needle biopsy disclosed various entities, including recurrent tumor, abscess, and posttreatment necrosis. There was only one complication, transient hematuria. CT-guided needle biopsy of presacral masses after abdominoperineal resection is a simple, relatively safe, and valuable diagnostic technique.

A method for percutaneous biopsy and aspiration of posteriorly located retroperitoneal, adrenal, renal, and hepatic masses using computed tomographic or sonographic guidance of an angled needle was used on 17 occasions in 16 patients. The technique uses the Pythagorean theorem for right triangles, and tangent ratios to provide an extrapleural, extraperitoneal route in the prone position for otherwise inaccessible lesions. The more precise geometric planning reduced time to complete the procedure and avoided the complication of pneumothorax which had been previously encountered. Needles were accurately positioned in all patients, and a positive diagnosis was achieved in 13 (three patients had intrahepatic hemangiomas and there was one false-negative necrotic carcinoma).

The criteria by which patients are selected for new, nonsurgical forms of gallstone therapy will influence the use of these techniques. We estimated the number of patients with gallbladder stones who are potentially suitable for extracorporeal shock-wave lithotripsy according to the current Food and Drug Administration protocol for the United States trials of the Dornier gallbladder lithotriptor. Exclusion criteria include patients with (1) more than three stones, (2) stones less than 0.5 cm or more than 3.0 cm in diameter, (3) radiopaque stones, and (4) a nonfunctioning gallbladder. The gallbladder contents in 100 consecutive patients undergoing cholecystectomy were analyzed according to the number, size, and calcium content of the stones as determined by specimen radiographs. Because none of these patients underwent preoperative oral cholecystography, an estimated percentage of functioning gallbladders was taken from the literature. Preoperative symptoms were not considered in determining a patient's eligibility for gallbladder lithotripsy. On the basis of these criteria, we estimated that 85% of our surgical patients would have been excluded from extracorporeal shock-wave lithotripsy according to the current Food and Drug Administration protocol for the Dornier gallbladder lithotriptor.

The sonographic response of the biliary tree to a fatty meal was assessed in 78 individuals by measuring common hepatic duct caliber before and after fat ingestion. In the normal cases, the common hepatic duct remained the same or decreased in caliber. Abnormal responses consisted of a normal-caliber duct that increased in size or a slightly dilated duct that remained the same or increased in size. By employing these criteria, we discovered patients with ampullary stenosis, common duct stones, cholangiocarcinoma, and chronic pancreatitis. It is concluded that biliary sonography after ingestion of a fatty meal can aid in the evaluation of a common hepatic duct that is equivocally or mildly dilated and can indicate the need for further invasive studies.

The clinical and radiographic features of 2 patients with dissecting pancreatitis-associated fluid collections involving the spleen are described. A typical appearance of left upper quadrant fluid collection lateral to the splenic pulp was observed by ultrasonography (US) or computed body tomography (CBT). Although these findings are nonspecific, a left upper quadrant fluid collection may be characterized definitively by US/CBT-guided needle aspiration.

CT- and ultrasound-guided catheters were used to locate and drain empyemas in 17 patients, most of whom had failed to improve with conventional chest-tube drainage due to a poorly positioned tube. Fifteen patients (88.2%) were treated successfully, averting surgery or further drainage, and bacteremia in 1 patient was the only complication. Previously unrecognized communications with the bronchi, esophagus, and subphrenic space were demonstrated, and intracavitary tumor biopsy and instillation of a sclerosing agent were performed in several patients. Compared to the tubes used to drain abdominal abscesses, empyema catheters need less irrigation; dionosil is often the preferred contrast agent, the catheter can be withdrawn in one step, and a residual fibrotic or tumor cavity may persist after pus has been evacuated.

To define the optimal diagnostic approach for suspected chronic cholecystitis comprehensive management strategies were developed. Using a computer model, the frequency of appropriate surgery, inappropriate surgery, complications, death, and medical costs were compared in populations of patients with various disease prevalences. The optimal strategy began with ultrasonography, followed by an oral cholecystogram when the ultrasonogram was inconclusive. Oral cholecystogram also was employed when additional diagnostic studies failed to provide another explanation for the patient's symptoms. Compared with strategies using only ultrasonography or oral cholecystography, the combination strategy lowered the frequency of inappropriate surgery from 7.1 to 4.4% and direct medical costs from $1,877 to $1,766 per patient in a population with a 20% prevalence of chronic cholecystitis. The differences persisted at higher prevalences of cholecystitis and when sensitivities and specificities of the tests were varied over ranges reported in the literature. Diagnostic accuracy and direct medical costs could be improved by a more frequent interpretation of subtle abnormal ultrasonographic findings as inconclusive and by a more liberal use of oral cholecystography. This analysis demonstrates that a strategy combining ultrasonography and oral cholecystography is superior to the use of either test alone and is cost-efficient.

Localized collections of bile within the peritoneal cavity, "biloma," may occur after surgery or trauma and are readily detected by sonography and computed tomography. Eleven cases in which the diagnosis was confirmed by percutaneous needle aspiration and treatment carried out by radiologic catheter drainage are reported. Specific identification of bile was made by visual inspection, initial rapid dip-stick (Multistix) technique, and formal chemical analysis. Evidence of continued free bile leak included a positive technetium HIDA scintigram and copious amounts of bilious catheter drainage over a prolonged period. Unexpected clinical features of biloma included presentation as a pyogenic subhepatic abscess in four (36%) of 11 cases, localization of the biloma collection in the left upper abdomen despite surgery on the right side in four (36%) cases, and the presence of an active bile fistula in five (45%) cases. Percutaneous radiologic catheter drainage provided adequate therapeutic drainage in all but two patients in whom a continuing active bile leak eventually required surgical correction.

A clinical study of body computed tomography (CT) at Massachusetts General Hospital evaluated 2,619 patients who were prospectively assigned to one of 12 examination protocols. Data obtained from referring physicians and patient records just before CT examination and later in the course of care served as a basis for judging the contribution of CT to diagnostic understanding, use of other tests, and choice of therapy. Fifty-three percent of examinations produced a substantial or unique contribution to diagnostic understanding, and 15% contributed to a change in treatment. Performance in different protocols varied greatly: lymphoma, pancreas, retroperitoneum, lung, and liver ranked in the top half for both diagnostic and therapeutic efficacy; pelvis, urology, and colon fell in the bottom third. Overall, CT reduced surgery by an estimated 14% and angiography by an estimated 11% in the study population. Availability of CT was also associated over time with significant declines in the frequency of sonographic examinations and of lymphangiography, though not of endoscopic retrograde cholangiopancreatography. Compared with an 18-sec scanner, examinations on a 3-sec unit more frequently contributed to improved diagnostic understanding (p less than 0.05) and to increased physician confidence in previously chosen treatment (p less than 0.001). Studies of the diagnostic and therapeutic efficacy of devices like CT can guide clinical expectations and provide a basis for evaluating new imaging methods.

In a prospective blind study of liver/spleen trauma, 32 consecutive patients were evaluated by radionuclide imaging (99mTc-sulfur colloid) and gray-scale ultrasound. Six patients (19%) had inadequate sonograms due to injuries and pain. Thirteen (41%) were normal, 13 (41%) were abnormal with one technique or the other, and there was a discrepancy in 2 (6%). Of the 13 abnormal patients, 1 had a lacerated spleen, 2 had angiographic confirmation of a subcapsular hematoma, and 10 showed resolution on follow-up. Two patients with left-sided trauma had abnormal radionuclide scans of the liver; sonograms were initially normal in one of them, but subsequent imaging confirmed the abnormality. The authors feel that imaging with 99mTc-sulfur colloid should be the primary screening examination for liver/spleen trauma.

Sixty-two patients who presented with subphrenic abscesses had the abscesses drained percutaneously. Diagnosis of a subphrenic collection was usually made with sonography. Initial percutaneous drainage was accomplished with a combination of sonography and fluoroscopic guidance. More recently (in the last 31 cases) most drainages were done with sonographic guidance alone. Successful catheter drainage was achieved in 85% with a complication rate of 4.8%. Failure of catheter drainage (defined as any patient who was not cured by percutaneous drainage alone) occurred in patients with multiple collections or in whom the primary cause of the abscess necessitated surgery, for example, perforated ulcer, acute cholecystitis. Considerations for successful drainage include understanding the anatomy of the subphrenic space, recognizing the importance of a correct access route (avoidance of the pleura and lung), and the long time necessary for adequate drainage (longer than 10 days in 60%). An angled subcostal approach to the subphrenic space was used in 56 (90%) of 62 cases. No complications occurred in this group. The one pneumothorax that occurred in the remaining six cases was a direct result of using an intercostal approach through the parietal pleura into a subphrenic collection. We conclude that percutaneous drainage is a safe and effective method of treatment of subphrenic abscesses.

A case of ganglioneuroblastoma in an adult is presented. The precise localization of the tumor mass with computer assisted tomography aided the planning of radiation therapy. In addition, follow-up scans allowed evaluation of tumor response to both radiation and chemotherapy. The clinical and radiologic characteristics of this unusual tumor are discussed.

Fifteen patients who would not have been candidates for percutaneous abscess drainage previously, and who were exceedingly high-risk for surgery, underwent initial catheter drainage. The patients were critically ill and had complicated abscesses, which were poorly defined, multiloculated, phlegmonous, and had associated fistulas. The percutaneous drainages were not curative. However, the patients dramatically improved and became fit for surgery (13 patients) or another interventional procedure (three patients). Five hypotensive patients were stabilized by the catheter drainage; mean white blood cell count in the 15 patients decreased by 14,000/mm3; mean temperature decreased from 40 degrees C to 38.1 degrees C; and anemia, coagulation factors, and overall condition improved. Eventual surgery was more limited (directed to the cause of the abscess) and less time-consuming. All these high-risk patients survived with this combined radiologic-surgical approach. Temporizing percutaneous abscess drainage in gravely ill patients with complex abscesses offers significant therapeutic benefit, although it may not be curative. With realistic expectations for partial success rather than cure, the scope of candidates for percutaneous drainage has broadened.

Transgression of the parietal pleura may occur during placement of interventional drainage catheters into the liver and upper abdomen, and occasionally results in lethal complications. In a review of nearly 2,000 such procedures, four deaths were found to be related directly to pleural transgression from biliary drainage. Therefore, the anatomy of the pleura pertinent to abdominal needle or catheter insertion was analyzed. In 14 cadavers examined after intercostal needle insertion into the liver, needles inserted through the 9th intercostal space or higher punctured the pleura in all but one cadaver. Radiologic studies of 15 clinical cases revealed that elderly patients rarely depressed the diaphragm below the 9th intercostal space, which increases the risk of unsuspected puncture of the pleura. Review of clinical material revealed that diagnostic needle puncture through the parietal pleura carries far less risk than placement of a long-term drainage catheter. Methods to avoid puncture of the pleura, as well as the technical problems involved in such maneuvers, are given.

Forty-three patients with thoracic empyema were treated by means of image-guided catheter drainage. In 40 patients, image-guided catheter drainage was the primary treatment method; in three it was used after conventional, surgical chest tube placement failed. Drainage was performed with ultrasound guidance in 30 patients (69.8%), computed tomography in eight (18.6%), and fluoroscopy in five (11.6%). A combination of guidance modalities was used in six patients. Image-guided catheter drainage alone was successful in 31 of 43 patients (72.1%). In three patients (7%), empyemas were initially drained, but a thoracotomy was ultimately required because of a persistent pleural peel. In eight patients (18.6%), the procedure failed, predominantly due to tube clogging, persistent pneumothorax, or progressive development of a pleural peel. In one patient, drainage was successful but he died 10 days later of complications of renal failure. No major complications were encountered. Treatment of these patients requires a thorough understanding of the pathogenesis of pleural space infection, principles of empyema drainage, techniques of abscess drainage under image guidance, and the use of a pleural drainage system.

Twenty-five patients with grade D or E pancreatitis underwent percutaneous drainage. These patients required multiple computed tomography (CT) examinations, multiple catheter insertions, multiple catheter manipulations, and long-term catheter drainage. Eight of the 25 patients were successfully treated with catheter drainage alone. Sixteen underwent surgical drainage, ten after attempts at percutaneous drainage and six prior to radiologic drainage. Of the ten patients who had initial percutaneous drainage, only four were clinically improved from the drainage procedure alone. Although the fluid component of the abscess was often adequately drained in all ten patients, surgery was required to remove pieces of necrotic debris. Six patients who underwent surgical debridement had residual abscesses in the post-operative period and were all successfully treated with percutaneous drainage. One patient died from unrelated causes. Successful interventional management of patients with pancreatic abscesses requires intensive radiologic intervention and monitoring and may be better served by a combination of radiologic and surgical means.

Percutaneous needle sampling of suspected malignant tumors was carried out in 150 patients using a technique providing specimens for both cytologic and histologic analyses. Adequate samples for pathologic analysis were obtained in 97% and 89%, respectively. An overall accuracy rate of 85% was achieved with histologic results providing a positive diagnosis in 7% of patients in whom corresponding cytologic information was falsely negative. Both in vivo and in vitro experiments suggest no superiority in the tissue retrieval rate of the different 22 gauge needles used for biopsy. Since the core biopsy technique adds no increase in complication rate and provides a small but definite incremental gain in accuracy, its routine use is suggested.

A prospective, preoperative study was conducted of 50 electively repaired abdominal aortic aneurysms comparing the CT and angiographic findings with those described at surgery. CT demonstrated all 50 aneurysms and correctly identified their proximal extent in relation to the takeoff of the renal arteries in 47 patients (94%), while angiography detected 48 aneurysms (96%) and their correct relation to the renal arteries in all (100%). CT correctly identified 40 (98%) of 41 patients with two renal arteries, but only two (29%) of seven with three and none of two patients with four arteries. Common iliac artery involvement or lack thereof was accurately predicted in 42 (84%) of the 50 patients and internal iliac artery aneurysms found in one (33%) of three patients. It was concluded that CT is not sufficiently accurate for documenting location and patency of the renal arteries to allow its routine substitution for angiography in patients undergoing preoperative assessment of abdominal aortic aneurysms.

We analyzed sonographic images retrospectively to determine their value in quantifying gallstone size and number in 111 surgically proved stone-containing gallbladders for which routine preoperative sonograms were available. The number and size of of stones found on pathologic examination were correlated with the results of image analysis. In patients with more than one stone, observable size differences were recorded if the smallest stone diameter was less than 50% of the largest stone diameter. Estimates of gallstone size and number from preoperative sonograms were correct in only 23 (21%) of 111 cases. Stone size and number were overestimated as often as they were underestimated. Stones of a uniform size were recognized correctly in 59 (92%) of 64 cases. Stones of two different sizes were correctly identified in only 14 (30%) of 47 cases; the second, smaller stones were missed in 26 (79%) of 33 cases. These findings indicate poor sonographic characterization of gallbladder contents when imaging studies are performed solely to determine the presence or absence of gallstones.

The sonographic appearance of the response of the common hepatic duct to physiologic stimulation by a fatty meal was assessed in 131 patients referred because of right upper quadrant symptoms or abnormal liver chemical studies. In the determination of the presence or absence of biliary obstruction, the sensitivity of the examination was 84%, the accuracy of a positive test was 84%, and the accuracy of a negative test was 93%. This test proved helpful in several circumstances: equivocal duct caliber (6-10 mm); abnormal caliber (6-14 mm) with normal laboratory values; normal caliber duct with abnormal laboratory values; persistent question of cholelithiasis or asymptomatic pancreatic duct dilatation. Measurements of bile duct caliber alone may be insufficient to ascertain the presence of bile duct obstruction and fatty meal stimulation significantly improves diagnostic accuracy.

Thirty-five patients with postoperative enteric and/or biliary fistulae were diagnosed and treated by percutaneous catheter drainage. All were initially considered to have postoperative abdominal abscesses, and the enteric or biliary communications were unrecognized before radiologic intervention. In addition, at the time of initial catheter insertion, only six of the 35 abscesses were recognized as being associated with an underlying fistula. In the other 29 patients the fistulae were found either by clinical follow-up or contrast sinogram after 24-72 hr of catheter drainage. Percutaneous catheter drainage was the definitive treatment in 28 (80%) of the 35 patients. The seven failures were either from inadequate catheter positioning or inability to treat the primary cause of the fistula (e.g., radiation enteritis, perforated cancer). These data suggest that even abscesses with underlying fistulae, traditionally an indication for surgical intervention, may be successfully managed by percutaneous methods.

The plain chest film may be critical in deciding whether a seriously injured patient should undergo aortography in order to exclude traumatic aortic rupture. The roentgen findings suggestive of aortic transection reflect the presence of mediastinal bleeding. A left apical extrapleural cap is frequently seen in these patients but heretofore has not been emphasized in the literature.