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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

Fewer than 5% of pancreatic tumors are cystic [1 , 2]; microcystic cystadenoma and macrocystic cystadenocarcinoma are the most common. The rarest cystic neoplasm is the primary pancreatic sarcoma, with approximately 25 cases having been documented [3-8]. We encountered a case of a pancreatic sarcoma that mimicked a pancreatic pseudocyst. Multiple operations and percutaneous drainage were undertaken mistakenly, because of the misimpression that the lesion was a pancreatic pseudocyst. Retrospective evaluation of the CT scans suggests features of pancreatic sarcoma rather than pseudocyst. The markedly shaggy and thickened wall without definable cysts on CT should exclude pancreatic pseudocyst and other cystic pancreatic tumors. The tumor in this patient may be unique; no similar report of pleomorphic pancreatic sarcoma could be found.

In this prospective study, computed tomography (CT) was used to examine the resolution of pleural abnormalities following radiologic catheter drainage of empyemas. Ten patients with empyemas surrounded by pleural peels underwent thoracic CT scanning at 4, 8, and 12 weeks after removal of their catheter(s). The scans demonstrated extensive pleural thickening 4 weeks after catheter removal in all 10 patients. The pleural thickening had decreased 8 weeks after catheter removal. At 12 weeks, the pleura was essentially normal in four patients, demonstrated only a small area of plaque-like thickening in four patients, and was mildly thickened in two patients. This study demonstrates that the pleural surfaces have a remarkable capacity for healing after empyema drainage. The pleural peel resolves in most cases. These results suggest that decortication need not be performed routinely when such empyemas are encountered; rather, patients should be treated on an individualized basis and studied with serial CT to determine the necessity of decortication.

We describe the diagnostic workup and therapeutic management of patients with hepatolithiasis from the viewpoint of the interventional radiologist. The diagnosis is best established by direct cholangiography such as percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography. We consider percutaneous transhepatic stone removal a highly successful, minimally invasive, and safe procedure. Access can be gained to the biliary system in almost 100% of patients and complete stone clearance through percutaneous techniques, including stone fragmentation, removal of stones and fragments by baskets, and dilatation of underlying strictures in more than 90%. The role of these radiologic techniques is discussed vis-à-vis endoscopic and surgical alternatives.

Topical dissolution of cholesterol gallbladder stones using methyl tert-butyl ether (MTBE) is useful in symptomatic patients judged too ill for surgery. Previous studies showed that ethyl propionate (EP), a C5 ester, dissolves cholesterol gallstones rapidly in vitro, but differs from MTBE in being eliminated so rapidly by the liver that blood levels remain undetectable. Our aim was to test EP as a topical dissolution agent for cholesterol gallbladder stones. Five high-risk patients underwent topical dissolution of gallbladder stones by EP. In three patients, the solvent was instilled via a cholecystostomy tube placed previously to treat acute cholecystitis; in two patients, a percutaneous transhepatic catheter was placed in the gallbladder electively. Gallstone dissolution was assessed by chromatography, by gravimetry, and by catheter cholecystography. Total dissolution of gallstones was obtained in four patients after 6-10 hr of lavage; in the fifth patient, partial gallstone dissolution facilitated basketing of the stones. In two patients, cholesterol dissolution was measured and averaged 30 mg/min. Side effects were limited to one episode of transient hypotension and pain at the infusion site; no patient developed somnolence or nausea. Gallstone elimination was associated with relief of symptoms. EP is an acceptable alternative to MTBE for topical dissolution of cholesterol gallbladder stones in high-risk patients. The lower volatility and rapid hepatic extraction of EP suggest that it may be preferable to MTBE in this investigational procedure.

Anesthetic agents inhibit the respiratory activity of upper airway muscles more than the diaphragm, creating a potential for narrowing or complete closure of the pharyngeal airway during anesthesia. Because the underlying mechanisms leading to airway obstruction in sleep apnea and during anesthesia are similar, it was hypothesized that anesthesia-induced pharyngeal narrowing could be counteracted by applying nasal continuous positive airway pressure (CPAP).Anesthesia was induced in ten healthy volunteers (aged 25-34 yr) by intravenous administration of propofol in 50-mg increments every 30-s to a maximum of 300 mg. Magnetic resonance images of the upper airway (slice thickness of 5 mm or less) were obtained in the awake state, during propofol anesthesia, and during administration of propofol plus 10 cm nasal CPAP.Minimum anteroposterior diameter of the pharynx at the level of the soft palate decreased from 6.6 +/- 2.2 mm (SD) in the awake state to 2.7 +/- 1.5 mm (P0.05) during propofol anesthesia and increased to 8.43 +/- 2.5 mm (P0.05) after nasal CPAP application. Anteroposterior diameter of the pharynx at the level of the dorsum of the tongue increased from 7.9 +/- 3.5 mm during propofol anesthesia to 12.9 +/- 3.6 mm (P0.05) after nasal CPAP. Pharyngeal volume (from the tip of the epiglottis to the tip of the soft palate, assuming this space to be a truncated cone) significantly increased from 2,437 +/- 1,008 mm3 during propofol anesthesia to 5,847 +/- 2,827 mm3 (P0.05) after nasal CPAP application.In contrast to the traditional view that relaxation of the tongue causes airway obstruction, this study suggests that airway closure occurs at the level of the soft palate. Application of nasal CPAP can counteract an anesthesia-induced pharyngeal narrowing by functioning as a pneumatic splint. This is supported by the observed reduction in anteroposterior diameter at the level of the soft palate during propofol anesthesia and the subsequent increase in this measurement during nasal CPAP application.

An International Symposium was held in Atlanta in 1992 to present the state of the art of diagnostic evaluation and management of acute pancreatitis and to agree on an acceptable series of clinical definitions for classifying the disease and its complications. The symposium was composed of 40 internationally recognized experts in pancreatic disease from 15 countries representing six disciplines (anatomy, gastroenterology, internal medicine, pathology, radiology, and surgery). The purpose of this article is to present the radiologically relevant aspects of the symposium; to define the state of the art of imaging and intervention in acute pancreatitis, particularly how and when to use computed tomography and how and when to perform percutaneous therapy versus surgery; and to encourage radiologists to use precise and proper nomenclature when describing the morphologic manifestations of acute pancreatitis as depicted by various imaging modalities.

We reviewed our experience with ultrasound-guided biopsies of masses of the thyroid gland that were either nonpalpable or difficult to localize by palpation to evaluate the technique and correlate the results. Thirty-two biopsies were performed upon 25 patients whose clinical presentations were palpable nodule (six patients), throat discomfort (two patients), postpartial thyroidectomy follow-up evaluation (two patients), incidental discovery of a mass--by ultrasound of the neck (two patients), roentgenogram of the chest (two patients), computed tomography of the chest (one patient) and during tracheostomy placement (one patient). Other presentations were eliminate infection (one patient), odynophagia (one patient), hoarseness (one patient), cold nodule on a nuclear medicine study (one patient), hyperparathyroidism (one patient), rule out metastasis from carcinoma of the colon (one patient), persistent cough (one patient), enlarged thyroid gland (one patient) or family history of carcinoma of the thyroid gland (one patient). Fifteen patients had nuclear medicine studies showing either a cold nodule (ten patients), multinodular goiter (one patient), normal examination (two patients), hot nodule (one patient) or no thyroid gland activity (one patient). The ultrasound examinations showed either a hypoechoic nodule (25 patients), inhomogeneous or mixed echogenic nodule (six patients) or a hyperechoic nodule with hypoechoic rim (one patient). The nodules ranged in size from 3 milliliters to 7 centimeters. Twenty-six lesions were less than 3 centimeters in diameter; of the other six, four were substernal goiters. Six patients had a previous nondiagnostic biopsy directed by palpation only. Biopsy was performed using real-time ultrasound guidance with various needles. One patient had a small hematoma, which was the only complication in the study. The results of the biopsies were diagnostic in 26 of 32 patients. The final diagnosis was benign follicular cells (ten patients), adenomatous nodule (seven patients), follicular neoplasm (three patients), colloid cyst (two patients), aspergillus (two patients), fibrosis (one patient) and papillary carcinoma (one patient). Six of the biopsies yielded unsatisfactory specimens. One of the patients with a diagnosis of benign follicular cells on biopsy had a follicular carcinoma after surgical pathologic factors were obtained; that was the only false-negative result. We conclude that ultrasound-guided biopsy of the thyroid is a safe and useful method of evaluating nonpalpable and difficult to palpate thyroid masses.

When polymorphonucleocytes are incubated in proteinaceous fluid, they cause extensive protein degradation, which leads to accumulation of free amino acids. The authors tested whether these free amino acids, particularly valine and leucine, also accumulate in human abscess fluids, but not in other body fluids, and thus could be a specific and distinguishing marker for the presence of an abscess.Thirty fluids, obtained by percutaneous drainage from 28 patients, were lyophilized and reconstituted in 2H2O before in vitro 1H magnetic resonance (MR) spectroscopy. Concentrations of valine and leucine were determined by comparison of spectra before and after addition of known amounts of valine and leucine. Two chart reviewers, blinded to the spectroscopic results, categorized cases as abscess (n = 14), non-abscess (n = 15), or infection but not abscess (n = 1).The concentration of valine and leucine was significantly higher in the abscess fluids, 2.57 +/- 1.90 mM than in the non-abscess fluids, 0.25 +/- 0.33 mM (P.001). The one infected fluid which was not an abscess had no amino acids. Using 0.8 mM as the threshold concentration of valine and leucine necessary for the diagnosis of abscess resulted in a sensitivity rate of 86% and a specificity rate of 94%.The authors conclude that identification of high concentrations of valine and leucine by 1H MR spectroscopy may be a specific test for the diagnosis of abscess. This technique merits further investigation in vivo.

Therapeutic gallbladder procedures offer new options for treatment of gallbladder disease. These procedures may be life-saving, may be easier than other available techniques, or may merely provide an alternative form of therapy. Further use of these techniques will likely result in improvements in PC, as well as providing an ongoing definition of the role of these percutaneous procedures.

Interventional radiologic techniques for the treatment of gallstone disease are becoming more widely available. Percutaneous cholecystostomy [corrected] can be lifesaving in critically ill elderly patients who have acute cholecystitis. Contact dissolution of stones with methyl tert-butyl ether and percutaneous extraction (with or without fragmentation) of calculi are treatment options in patients who are at high risk for surgery or who do not desire an operation. With increasing use of intracorporeal gallstone lithotripsy techniques in the gallbladder and bile ducts, combined fluoroscopic and direct visualization during percutaneous procedures is becoming more important. Percutaneous chemical ablation of the gallbladder offers a potential solution to the problem of gallstone recurrence.

Contact dissolution of cholesterol gallstones with organic solvents is emerging as a rapid, safe, alternative treatment for symptomatic cholesterol gallbladder stones. Placement of a percutaneous transhepatic catheter into the gallbladder is a rapid and safe technique. The availability of safe, effective cholesterol solvents and solvent transfer devices means that cholesterol gallbladder stones can be eliminated rapidly and safely by CDOS, without the risk of general anesthesia or surgical dissection of the gallbladder bed. Patients with single gallstones are better candidates for CDOS than are patients with multiple gallstones because recurrence after dissolution is less common. Contact dissolution may well be judged the treatment of choice by the medical-surgical gallstone management team in some patients.

This report summarizes diagnostic and therapeutic radiologic procedures in 45 patients who suffered major complications from cholecystectomy. Complications were divided into (1) bile duct injury or ligation and (2) a variety of pathologic fluid collections. Specific lesions were bile duct injury (n = 6), accidental bile duct ligation (n = 12), ductal stricture (n = 12), abscess (n = 11), biloma (n = 7), hematoma (n = 5), infected pancreatic pseudocyst (n = 3), and stones (n = 2). Presenting problems were sepsis, jaundice, and intermittent cholangitis. The patients underwent 104 interventional radiologic procedures including 29 percutaneous transhepatic cholangiograms, 21 percutaneous biliary drainages, 12 balloon dilatations of strictures, drainage of 11 abscesses, 8 bilomas, 5 hematomas, and 3 pancreatic pseudocysts. Stones were removed by baskets in 2 patients; 12 pressure and perfusion studies were performed. One hundred of 104 procedures were successful; there was one failed biliary drainage, one unsuccessful stricture dilatation, one unsuccessful hematoma drainage, and one recurrent biloma. Thirty patients were spared another operation. The percutaneous procedures were beneficial although not curative in 14 of 15 patients who underwent reoperation; in those patients the procedures helped to establish a diagnosis, improve the patient's preoperative status, or serve as a landmark for the surgeon to locate and repair the ligated or injured duct. One patient died after reoperation, a 2.2% mortality rate. Sectional imaging studies combined with interventional radiologic procedures help to diagnose promptly and effectively treat major complications of cholecystectomy. These interventional procedures either cure the complication and obviate reoperation or aid the surgeon by relieving sepsis and jaundice before reoperation and providing an intraoperative guide for bile duct reconstruction.

Indium-111-labeled white-blood-cell scanning is a useful modality in abscess detection and has replaced gallium scanning in many institutions. Sensitivities of 72% to 90% and specificities of 90% to 100% have been reported. In searching for abscesses seven cases of indium-111-labeled leukocyte uptake were encountered in collections subsequently proved to be noninfected hematomas. Abundant red blood cells with few or no white blood cells, no bacteria, and a benign clinical course identified these noninfected hematomas. Five of the patients were being treated with hemodialysis and three were recent allograft recipients. The results indicate some limitation and nonspecificity in indium-111 scanning, despite its many benefits.

The original concept of percutaneous, radiological abscess drainage was confined to well circumscribed, solitary abscesses, that could be reached by a short access avoiding transgression of uninvolved organs or compartments. With increasing experience criteria for percutaneous abscess drainage have been expanded to radiological treatment of pancreatic, periappendiceal, diverticular, interloop and mediastinal abscesses and fluid collections. The authors present their experience with percutaneous treatment of such "complicated" abscesses in 140 patients.

Complications of pancreatitis are common, protean in their manifestations, and can be catastrophic. When complications occur, the morbidity and mortality are high. Expeditious radiologic detection of the complication, together with the plethora of nonoperative interventional techniques, offers new and improved methods for diagnosis and treatment. This article focuses on the essential role of radiology and the natural integration of imaging and interventional radiology for pancreatitis and its complications.

Percutaneous gastrostomies or gastroenterostomies serve for temporary or permanent enteric feeding in patients with obstruction or functional derangement of the esophagus or hypopharynx. In addition, this radiological procedure may be indicated for small bowel decompression. The authors present their experience in 71 patients. Insufflation of air through a nasogastric tube or catheter is the preferred method for gastric distension. The inferior margin of the left lobe of the liver and the transverse colon are localized sonographically and fluoroscopically prior to puncture. Either Seldinger or Trocar-techniques have proven effective in establishing access to the stomach. The feeding tube is advanced into the proximal jejunum to reduce the likelihood of gastroesophageal reflux and possible aspiration. Complications were encountered in four patients and included catheter dislocation in three and respiratory distress in one patient.

Modern real-time gray scale ultrasonography has contributed new diagnostic and therapeutic information in patients with diseases of the lungs and pleura. This article will discuss the ways in which ultrasound is most clinically useful in patients with thoracic disease.

Seventy-three fluid samples obtained via percutaneous aspiration and drainage were analyzed by proton magnetic resonance spectroscopy. The fluids included abscess contents, bile, ascitic fluid, cyst and pseudocyst fluid, urine, hematomas, pleural fluid, lymphoceles, seromas, cerebrospinal fluid, pancreatic ductal fluid, and necrotic tumor. They were grouped by their clinical etiology and analyzed with respect to their inherent magnetic relaxation properties. In addition, some of the samples were tested for the following chemical parameters which were correlated with T1 and T2 values: total protein content (n = 36), osmolality (n = 24), specific gravity (n = 11), and amylase levels (n = 23). A large overlap was found in the T1 (spin-lattice) and T2 (spin-spin) relaxation times of the fluids; however, the mean T1 values of abscesses and hematomas were significantly lower than those of other fluids. Similar variability was seen in T2 values, though hematomas and abscesses again could be distinguished by shorter relaxation times. The spin-lattice (1/T1) and spin-spin relaxation rates (1/T2) showed a moderate correlation with total protein content, osmolality, and specific gravity. It is concluded that there is some predictability to MR analysis of body fluids, though the overlap in magnetic relaxation times limits specificity.

Diverticulitis can be detected accurately by computed tomography (CT) and staged according to an established system that is meaningful to both radiologists and surgeons. Diverticulitis limited to the wall of the sigmoid colon or small diverticular abscesses contained within the pericolic mesentery generally respond well to antibiotic therapy; larger abscesses must be drained. CT-guided catheter drainage is an effective method to treat these large diverticular abscesses. Overall management is simplified since one-stage sigmoid resection can be performed electively on a nonseptic patient. High-risk patients may be spared surgery entirely in selected cases.