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J F Simeone

Publications and source records attributed to J F Simeone.

At least 19 recordsLinked to original sources
PubMed1991

Benign and malignant adrenal masses: CT distinction with attenuation coefficients, size, and observer analysis.

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%.

Adrenal Gland Neoplasms↗
PubMed1991

Optimal technique for detection of gallstones at injection cholecystography: in vitro analysis.

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.

Cholecystography↗
PubMed1991

Treatment of critically ill patients with sepsis of unknown cause: value of percutaneous cholecystostomy.

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.

Acute Disease↗
PubMed1990

Evaluation and treatment of the dominant dorsal duct syndrome (pancreas divisum redefined).

The controversial association of pancreatitis and pancreas divisum was studied in 100 patients (77 women, 23 men, median age 35) with episodic acute pancreatitis (49%) or "pancreatic pain" (51%). Seventy-one had classic pancreas divisum (type 1); 23 had only a dorsal duct with an absent Wirsung's duct (type 2); and 6 had a filamentous connection between the two duct systems (type 3). Accessory papilla sphincteroplasty was performed in 88 patients, with a mean follow-up of 53 months. The orifice was stenotic at the mucosal level in 66 patients. Seventy percent of patients have shown improvement: 85% if the accessory papilla was stenotic, compared with 27% if it was not (p less than 0.0001); and 82% with discrete attacks, compared with 56% with chronic pain (p = 0.002). Judged against intraoperative calibration of accessory papilla orifice diameter, ultrasonography with secretin stimulation was 78% sensitive for accessory papilla stenosis, with 3% false-positive results. Ultrasonography with secretin stimulation was the best predictor of surgical success: positive = 92% success (attacks or pain) versus negative = 40% success (64% with attacks; 21% with pain). There have been seven restenoses with six reoperations. We conclude that (1) pancreas divisum is but one variety of pancreatic anatomy characterized by a dominant dorsal duct and dependence on secretion through the accessory papilla; (2) accessory papilla stenosis appears to be a necessary cofactor to produce a morbid state, whether episodic pancreatitis or pancreatic pain; (3) presentation with pancreatitis and a positive result on the ultrasound-secretin test are the best predictors of successful accessory papilla sphincteroplasty.

Adolescent↗
PubMed1990

Simulation of gallstone fragments by cavitation bubbles during extracorporeal shock wave lithotripsy: physical basis and in vitro demonstration.

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.

Bile↗
PubMed1989

Clinical use of a nonferromagnetic needle for magnetic resonance-guided biopsy.

Five patients who had liver lesions detected by magnetic resonance (MR) and/or computed tomography (CT) were biopsied using MR guidance with a specially designed nonferromagnetic needle. The 20-gauge needle was constructed from Type 316 stainless steel in order to maximize needle visibility and minimize needle-tip artifact. In all cases adequate tissue was obtained for diagnosis and no side effects were observed during the biopsy or on clinical follow-up despite the fact that the needle was within the patient in MR for an average of 30 min.

Biopsy, Needle↗
PubMed1989

Extracorporeal shock-wave lithotripsy of gallstones: Boston experience with the Dornier MPL 9000 lithotripter.

After the success of shock-wave therapy for fragmentation of renal stones, machines for shock-wave therapy of gallbladder stones were quick to follow. In Munich, gallstones were successfully treated in 174 of 175 patients who were also taking ursodiol to help solubilize the calculous rubble left after treatment. In Boston, of the initial 87 patients accepted, 58 were treated for a single stone (mean diameter 15.7 mm), 16 were treated for 2 stones, and 13 for 3 stones. Although reporting of exact results is not possible before the Food and Drug Administration issues a clearance, it is fair to say that both patients and physicians are generally pleased with the results.

Boston↗
PubMed1989

Infected abdominal tumors: percutaneous catheter drainage.

Sixteen patients underwent percutaneous catheter drainage of infected primary (n = 9) or metastatic (n = 7) abdominal tumors. Twelve of the patients improved clinically, as evidenced by defervescence and decrease or normalization of leukocytosis. Four patients did not respond to catheter drainage and required surgery. Three of the twelve who improved underwent operations for attempts at surgical cure or debulking of tumor volume despite an initial "good" response to percutaneous drainage. Of the nine patients who did not undergo surgery after percutaneous drainage, four underwent catheter removal after 5 weeks of drainage and had no recurrence of infection, two remained alive with the catheter in place up to 8 months and 1 year after drainage, and two died with the catheter in place. One patient had the catheter removed inadvertently after 3 weeks of drainage and had recurrences that required replacement of the catheter until his death. The major differences between drainage of necrotic tumors and drainage of standard abscesses were the need for surgery in the majority of the cases and the fact that patients needed the catheters for continued palliation until their death.

Abdominal Neoplasms↗
PubMed1989

The sonographic diagnosis of acute gangrenous cholecystitis: importance of the Murphy sign.

The sonographic Murphy sign is defined as the presence of maximal tenderness elicited by direct pressure of the transducer over a sonographically localized gallbladder. The reported prevalence of this sign is more than 95% in patients with acute cholecystitis. In this series of 18 patients with pathologically proved gangrenous cholecystitis, the sonographic Murphy sign was positive in only six (33%). Clinical examination showed a positive Murphy sign in eight patients (44%), diffuse abdominal pain in nine patients (50%), and no pain in one patient (6%). Other sonographic findings included pericholecystic fluid (10), thickening of the gallbladder wall (10), and a dilated gallbladder (five). Our experience suggests that the absence of the Murphy sign increases the possibility of gangrenous cholecystitis in patients with abdominal pain and sonographic findings of cholecystitis.

Abdomen↗
PubMed1989

Imaging of pancreatic neoplasms: comparison of MR and CT.

Thirty-two patients with pathologically proved pancreatic carcinomas or cystadenomas were evaluated with MR images obtained with T1-weighted spin echo (short TR/short TE), inversion recovery, and T2-weighted spin-echo (long TR/long TE) pulse sequences. CT was used as the reference standard to determine the ability of MR to delineate normal and abnormal pancreatic anatomy and thereby to exclude or detect pancreatic malignancy. Short TR/short TE spin-echo sequences were significantly better (p less than .05) than inversion recovery or T2-weighted spin-echo sequences in resolution of both normal and abnormal anatomy. Resolution of pancreatic anatomy correlated (r = .9) with the image signal-to-noise ratio. In seven (22%) of 32 cases, MR visualized pancreatic tumors better than CT did because it showed a signal intensity difference between the tumor and normal pancreatic tissue. Overall, the slight superiority of MR over CT for tumor visualization tended to occur in larger tumors and was not statistically significant. On T1-weighted images, 63% (20 of 32) of pancreatic tumors studied had lower signal intensities than normal pancreatic tissue, whereas on T2-weighted sequences (TE = 60, 120, and 180 msec) only 41% (13 of 32) of tumors had increased signal intensities. Currently available MR imaging techniques offer no significant advantages over CT for evaluating the pancreas for neoplasia.

Adult↗
PubMed1989

Routine sonographic techniques fail to quantify gallstone size and number: a retrospective study of 111 surgically proved cases.

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.

Cholelithiasis↗
PubMed1988

Image-guided pleural biopsies: indications, technique, and results in 23 patients.

Twenty-six pleural biopsies were performed on 23 patients over a 3-year period. Twenty-three biopsies were performed guided with ultrasound; one, with computed tomography; and two, with fluoroscopy. Indications for an image-guided pleural biopsy were (a) pleural masses or thickening that were either not seen on chest radiographs or seen only on one view and (b) small or loculated pleural effusions of unknown cause with no mass seen. If only pleural fluid was present, reverse bevel needles were used for biopsy (n = 15). If a discrete pleural mass or thickening was seen with cross-sectional imaging, standard (16-20 gauge) biopsy needles were used (n = 11). In the 23 patients, biopsy results were true positive in ten (nine with malignancy, one with tuberculous pleurisy), true negative in ten (confirmed either at subsequent thoracotomy or clinical follow-up), and false negative in three. Complications were few, with a significant pneumothorax occurring in two patients (8.7%). Image-guided biopsy of small pleural lesions and small pleural effusions can be performed by the radiologist who understands the special needles and techniques involved.

Biopsy, Needle↗
PubMed1988

Thoracic empyema: management with image-guided catheter drainage.

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.

Adult↗
PubMed1988

Severe acute pancreatitis after percutaneous biopsy of the pancreas.

A retrospective review of 184 pancreatic biopsies in 178 patients was performed to assess the prevalence of severe postbiopsy pancreatitis. The size, contour, and pathology of the lesions biopsied; the course of the needle (i.e., through bowel or other viscera); the size of the needle; the number of needle passes made; and the guidance technique used were analyzed. Severe pancreatitis developed in five cases (five patients) 5/184 or 3% of the biopsies), usually within 24-48 hr. Three of the five patients who developed pancreatitis had true-negative biopsies (normal pancreas) proved either at surgery (two) or at clinical follow-up (one). The diagnoses for the two remaining patients were adenocarcinomas. In four of the five patients, the diagnosis of severe pancreatitis was made by inspection at surgery. The fifth case was diagnosed by CT. Three patients who underwent surgery and one patient who had percutaneous drainage recovered from the pancreatitis. The fifth patient died despite surgical intervention. All five patients with pancreatitis had masses 3 cm or smaller as compared with the overall group, in which 71 (39%) of the 184 biopsies performed had masses smaller than 3 cm. Overall, 18% of the biopsies were true negative, compared with the 60% true-negative rate in the pancreatitis group. The bowel was transgressed in 21% of all 178 patients, including three of the five pancreatitis patients. We conclude that although the risk of pancreatitis is exceedingly small in percutaneous needle biopsies, it may occur, and at a higher rate than previously reported.

Acute Disease↗
PubMed1988

Physical characteristics of gallstones removed at cholecystectomy: implications for extracorporeal shock-wave lithotripsy.

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.

Calcium↗