Search

Purpose: To determine whether thromboembolic risk factor assessment could accurately indicate the pretest probability for pulmonary embolism (PE), and if so, computed tomographic (CT) angiography might be targeted more appropriately than in current usage, resulting in decreased costs and radiation exposure., Materials and Methods: Institutional review board approval was obtained. Electronic medical records of 2003 patients who underwent CT angiography for possible PE during 1(1/2) years (July 2004 to February 2006) were reviewed retrospectively for thromboembolic risk factors. Risk factors that were assessed included immobilization, malignancy, hypercoagulable state, excess estrogen state, a history of venous thromboembolism, age, and sex. Logistic regressions were conducted to test the significance of each risk factor., Results: Overall, CT angiograms were negative for PE in 1806 (90.16%) of 2003 patients. CT angiograms were positive for PE in 197 (9.84%) of 2003 patients; 6.36% were Emergency Department patients, and 13.46% were inpatients. Of the 197 patients with CT angiograms positive for PE, 192 (97.46%) had one or more risk factors, of which age of 65 years or older (69.04%) was the most common. Of the 1806 patients with CT angiograms negative for PE, 520 (28.79%) had no risk factors. The sensitivity and negative predictive value of risk factor assessment in all patients were 97.46% and 99.05%, respectively. All risk factors, except sex, were significant in the multivariate logistic regression (P < .031)., Conclusion: In the setting of no risk factors, it is extraordinarily unlikely (0.95% chance) to have a CT angiogram positive for PE. This selectivity and triage step should help reduce current costs and radiation exposure to patients.

Purpose: To determine retrospectively the effectiveness of percutaneous radiofrequency ablation (RFA) alone, alcohol ablation alone, or combined RFA and alcohol ablation (hereafter, combined ablation) to treat pain in patients with visceral and soft-tissue malignancies., Materials and Methods: This HIPAA-compliant study was institutional review board approved; the informed consent requirement was waived. Twenty patients, with 28 tumors, who underwent percutaneous computed tomography (CT) or magnetic resonance (MR)-guided RFA and/or alcohol ablation for pain relief over a 2-year period were retrospectively identified, and their medical and imaging data were studied: Nineteen patients were referred for ablation because of persistent pain despite use of analgesics, and one patient had refused analgesics. The 28 tumors were located in the liver, lung, adrenal gland, retroperitoneum, gluteal muscle, inguinal mass, and subcutaneous tissues on the back. Fifteen tumors were treated with RFA alone, 12 were treated with combined ablation (when lesions were > 4 cm in diameter, except in lung or renal tumors), and one was treated with alcohol ablation alone. Pain was quantified on a 0-10 scale before, 1 day after, and 1-6 weeks after ablation. On the basis of changes in pain score and pain medication use, pain was reported with a composite measure as complete, partial, or no pain response. Quantitative pain scale values were compared by using Friedman and Tukey post hoc tests to assess significant changes., Results: At 1-6-week follow-up, pain relief was complete in nine patients (45%) and partial in six (30%); pain relief did not occur in five patients (25%). There was a significant (P < .05) decrease in pain at 1-day and 1-6-week follow-up compared with pain at baseline. Three adverse events were caused by therapy: Two were major complications (femoral neuropathy in one patient, perinephric hematoma and hemobilia in one patient), and one was a side effect of ablation (right shoulder pain) that resolved spontaneously., Conclusion: Percutaneous RFA alone or in combination with alcohol ablation provided pain relief from visceral tumors in most patients with intractable pain., (RSNA, 2008)

Purpose: To retrospectively determine the frequency and severity of various abnormal laboratory test values following percutaneous cryoablation of liver tumors and to estimate the correlation between laboratory test values and tumor and ablation volumes., Materials and Methods: This HIPAA-compliant study had institutional review board approval. Informed consent was waived. Biochemical and hematologic laboratory values from 48 procedures in 39 patients (18 men and 21 women; age range, 29-86 years) who underwent magnetic resonance (MR) imaging-guided percutaneous cryoablation of 65 liver tumors (62 metastases, three hepatocellular carcinomas) were retrospectively reviewed. Changes in laboratory values at baseline and 0-6 hours and 1-2 weeks after the procedure were analyzed with respect to tumor and ablative margin volumes by using generalized estimating equations. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were correlated with percent maximal decrease in platelet count., Results: Mean ablation zone volume was 67.3 cm(3) +/- 41.2 (standard deviation) (range, 7.3-191.4 cm(3)). AST and ALT values increased after all procedures and peaked at 6 hours (median change in AST value, +835 U/L; median change in ALT value, +614.5 U/L). Platelet count decreased after 47 procedures (mean maximal decrease, 92.3 x 10(9)/L [38%]), reaching a nadir at 12-24 hours after 24 procedures (50%) and returning to normal in 31 (84%) of 37 procedures at 1-2 weeks. One procedure was complicated by disseminated intravascular coagulation that necessitated transfusion and arterial embolization. Myoglobin values increased after 21 (44%) of 48 procedures and peaked at 6 hours (trimmed-mean value, 183.4 mug/L). Ablative margin volumes were predictive of changes at 0-6 hours in AST (P = .02), ALT (P = .003), and myoglobin (P < .001) values. Percent maximal decrease in platelet count correlated with peak change in AST (r = 0.72) (P < .001)., Conclusion: Following percutaneous cryoablation of liver tumors, alterations in liver enzymes, myoglobin, and platelet count are common, are usually self-limited, and correlate with ablative margin volume--except for changes in platelet count, which correlate with changes in AST and ALT., ((c) RSNA, 2008.)

This HIPAA-compliant pilot study had internal review board approval; informed consent was waived. The purpose was to determine retrospectively the diagnostic performance of a computer-aided three-dimensional (3D) analytic tool for assessing local recurrences of liver metastases by quantifying shape changes in ablated tumors on computed tomographic (CT) scans for follow-up of radiofrequency (RF) ablation. Positron emission tomographic and long-term CT follow-up images were reference standards. Fifty-six follow-up CT scans of 12 liver metastases (mean size, 4.0 cm) in nine patients treated with RF ablation were retrospectively analyzed. After the 1st month following RF ablation, the 3D analytic tool helped quantify ablated tumor shape variations and revealed recurrences even in the absence of abnormal enhancement (sensitivity, seven of seven; specificity, three of five). The 3D tool would have revealed a recurrence before it was reported clinically in two patients. Although results are preliminary, a 3D analytic tool based on shape may be useful in assessing RF ablation results., ((c) RSNA, 2006.)

Unlabelled: The purpose of this study was to evaluate the feasibility and performance of an augmented reality (AR) visualization prototype for virtual computed tomography (CT)-guided interventional procedures in a multimodality abdominal phantom. With the aid of AR guidance, three radiologists performed 30 attempts at targeting simulated liver lesions of different sizes (range, 5-15 mm) with a biopsy needle. The position of the needle tip relative to the lesion was verified by using ultrasonography and CT. With AR guidance, lesions were successfully targeted with the first needle pass in all cases. On the basis of these results, AR visualization for CT-guided intervention appears feasible and allows intuitive and accurate lesion targeting in a phantom., Supplemental Material: radiology.rsnajnls.org/cgi/content/full/2401040018/DC1, (RSNA, 2006)

Purpose: To retrospectively describe and categorize the presence of portal venous gas (PVG) from radiofrequency (RF) ablation of hepatic tumors., Materials and Methods: The study was HIPAA compliant, and informed consent was waived. Thirty-four consecutive computed tomography (CT)-guided percutaneous RF ablations of liver tumors in 26 patients (13 men, 13 women; mean age, 69 years) with five hepatocellular carcinomas and 21 metastatic liver tumors (13 colon, five other, and three unknown primary tumors) were performed with an institutional review board-approved protocol. Two treatment modalities were used: RF ablation alone (13 procedures) and combined RF ablation and ethanol injection (21 procedures). Presence of PVG was quantified with three parameters: maximum length of a portal venous branch with gas, number of Couinaud segments in which PVG was seen, and total number of portal venous branch points with gas. Then an overall PVG score from 0 to 5 was determined. Also, when tumoral gas was seen on CT scans, the largest cross-sectional area of gas was measured. The two ablation methods were compared for quantities of PVG and tumoral gas. The role of N(2)O anesthetic in PVG and tumoral gas formation during ablation also was studied. Statistical analyses were performed with Wilcoxon rank sum and Student t tests., Results: In 25 procedures (74%), gas was found in portal vein branches; in 30 procedures (88%), gas was also found in tumoral and peritumoral tissues. There was no significant difference in frequency of PVG between the ablation methods. Combined therapy yielded significantly greater lengths of PVG (P < .002) and more portal venous branch points (P < .001) than did RF ablation alone. Mean PVG score was 2.4 +/- 0.4 (standard error of the mean) for combined therapy and 0.9 +/- 0.2 for RF ablation alone (P < .004). N(2)O anesthetic was associated with greater amounts of tumoral gas (P < .008) and PVG (P < .03). Tumoral gas, peritumoral gas, and PVG dissipated within 20 minutes after ablation in all patients. No morbidity or mortality was associated with PVG., Conclusion: RF ablation is a common yet benign cause of transient PVG, tumoral gas, and peritumoral gas. Combined RF and ethanol ablation was associated with more PVG than was RF ablation alone.

Purpose: To evaluate the initial clinical experience of magnetic resonance (MR) imaging-guided percutaneous cryotherapy of renal tumors., Materials and Methods: Twenty-six renal tumors (diameter range, 1.0-4.6 cm; mean, 2.6 cm) in 23 patients were treated with 27 cryoablation procedures by using a protocol approved by the human subjects committee at the authors' institution. The study complied with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from each patient. There were 17 men and six women with an average age of 66 years (range, 43-86 years). Of 26 masses, 24 were renal cell carcinoma, one was a transitional cell carcinoma, and one was an angiomyolipoma. By using a 0.5-T open MR imaging system and general anesthesia in patients, one to five (mean, 2.4) needlelike cryoprobes were placed and lesions were ablated by using real-time MR imaging for intraprocedural monitoring of ice balls. Tumors were considered successfully ablated if they demonstrated no contrast enhancement at follow-up computed tomography or MR imaging (mean, 14 months; range, 4-30 months)., Results: Twenty-four of 26 tumors were successfully ablated, 23 of which required only one treatment session. Two complications occurred in a total of 27 cryoablations: one hemorrhage, which required a blood transfusion, and one abscess, which was treated successfully with percutaneous catheter drainage., Conclusion: MR imaging-guided percutaneous cryotherapy of renal tumors shows promise for the treatment of selected small renal tumors, and MR imaging can be used to monitor the treatment intraprocedurally. This technique may prove useful for ablation of renal tumors completely in one session, but long-term follow-up is needed.

Purpose: To investigate a new pattern of tumor recurrence observed at imaging in patients with metastatic gastrointestinal stromal tumor (GIST) after initial partial response to imatinib mesylate., Materials and Methods: Ninety-two patients with metastatic GIST who underwent treatment in a clinical trial with oral imatinib mesylate were followed up for 29 months. An institutional review board-approved protocol was used. The study complied with the Health Insurance Portability and Accountability Act, and written informed consent was obtained from all patients. Images of the chest, abdomen, and pelvis, acquired with computed tomography (CT), positron emission tomography (PET), and, in some cases, magnetic resonance imaging, were evaluated for treatment response and disease recurrence. Thirty-nine patients (29 men, 10 women; age range, 18-84 years; mean, 49.2 years) had recurrent disease after an initial variable period of response (range, 2-24 months; median, 14.4 months). Initial response was determined with findings of decreased uptake of fluorine 18 fluorodeoxyglucose at PET, shrinkage of tumor, and decreased attenuation at CT. Images were evaluated for disease recurrence by two experienced radiologists who were blinded to each other's interpretation but not to clinical details. Final reading was performed by consensus., Results: A nodule within a mass was seen in 21 of 39 patients (in intrahepatic tumor [n = 8], extrahepatic tumor [n = 10], or both intra- and extrahepatic tumors [n = 3]) and was the first sign of disease progression in 17 of 21 patients. Other patterns of recurrence included new site of disease (n = 7), regrowth of preexistent lesion (n = 20), and mixed (more than one) pattern (n = 9). Disease progression was verified at needle biopsy (n = 16), follow-up imaging (n = 14), and/or surgical resection (n = 9)., Conclusion: A nodule within a mass is an important sign of recurrent GIST, but measurements of overall tumor size may not enable detection of such nodules., (Copyright RSNA, 2005.)

Purpose: To determine prospectively if assessment of telomerase activity in percutaneous needle biopsy specimens improves sensitivity and specificity in the diagnosis of abdominal and pelvic malignancy., Materials and Methods: The study was approved by the institutional review board, and written informed consent was obtained from all patients. A prospective double-blinded design was used to assess telomerase activity in abdominal and pelvic biopsy specimens from 99 patients (64 men, 35 women; age range, 22-87 years). After the clinical sample was retrieved, a study specimen from an extra needle pass was divided and independently analyzed for cytologic characteristics and telomerase activity. The final diagnosis was based on chart review at a minimum 1-year follow-up. Statistical analyses included sensitivity, specificity, and accuracy of cytologic examination and/or telomerase activity in predicting malignancy., Results: Data from study specimens indicated that the sensitivity, specificity, and accuracy of telomerase activity (n=99) in predicting malignancy were 55%, 79%, and 60%, respectively. For cytologic examination (n=86), the sensitivity, specificity, and accuracy in predicting malignancy were 74%, 94%, and 78%, respectively. Combining the two tests (n=86) and classifying a positive reading with either test as malignant improved sensitivity (83%) (P <.05) without altering specificity (76%). In 20 patients who had clinical sample reports that were classified as indeterminate, telomerase activity (n=20) yielded a higher sensitivity (62%) (P <.05) and similar specificity (86%) compared with cytologic examination (n=15), which yielded a sensitivity of 11% and a specificity of 83%., Conclusion: In percutaneous biopsy specimens of the abdomen and pelvis, the combination of cytologic examination and telomerase activity yielded an increased sensitivity in predicting malignancy. In addition, assessing telomerase activity can help identify cancer even when cytologic results are indeterminate.

Purpose: To report our experience regarding the feasibility and safety of 25-gauge needles for biopsy of thoracic lesions., Materials and Methods: Twenty-six patients with thoracic lesions, predominately pulmonary nodules, measuring 0.7-5.2 cm (mean, 1.6 cm) underwent biopsy with computed tomographic (n = 24), ultrasonographic (n = 1), or fluoroscopic (n = 1) guidance. Nineteen patients had severe chronic obstructive pulmonary disease (COPD), one had severe restrictive lung disease, and one had a coagulopathy; the other five patients had nonpulmonary primary tumors. Biopsy with an inner 25-gauge needle traversing an outer extrapleural coaxial cannula was performed in all patients. Cytologic quick staining was performed routinely to determine specimen adequacy and to establish a preliminary diagnosis. Complications, specimen adequacy, and need for larger specimens were evaluated., Results: Adequate specimens (as determined by cytopathologists) were obtained in 24 (92%) of 26 patients, with a definitive diagnosis achieved in 23 (88%) patients during initial quick staining (17 malignant and six benign diagnoses). Two cases initially considered suspicious for malignancy were reclassified as benign (thymoma and histoplasmosis). At the request of cytopathologists, a larger needle was used to supplement the 25-gauge needle in six patients: In one patient, it provided further diagnostic information; in four, it did not; and in one, it confirmed non-Hodgkin lymphoma. Five patients developed a small pneumothorax (<10%) with use of the 25-gauge needle alone; one other patient, in whom larger needles were placed, received a radiologic chest catheter to evacuate the pneumothorax, thereby allowing the biopsy to continue., Conclusion: Image-guided 25-gauge needle biopsy is both feasible and safe., (Copyright RSNA, 2003)

Purpose: To describe the cryoablation of liver tumors by using a percutaneous approach and intraprocedural magnetic resonance (MR) imaging monitoring and to assess the feasibility and safety of the procedure., Materials and Methods: Fifteen hepatic tumors (mean diameter, 2.9 cm) in 12 patients were treated (18 total cryoablations). Fourteen were metastases and one was a hemangioma; all were proved at biopsy. By using a 0.5-T open MR imaging system, cryoneedles were placed and lesions ablated by using real-time monitoring. Clinical signs and symptoms were assessed and laboratory tests performed. Intraprocedural depictions of iceballs were compared with contrast material-enhanced MR imaging-based estimates of cryonecrosis that were obtained 24 hours after cryoablation., Results: MR imaging-guided percutaneous cryotherapy resulted in no serious complications and no clinically important changes in serum liver enzymes or creatinine or myoglobin levels. Intraprocedural MR imaging demonstrated iceballs as sharply marginated regions of signal loss that expanded and engulfed tumors. The maximal iceball size was 4.9 x 2.2 x 2.2 cm with the use of one cryoneedle and 6.0 x 5.6 x 4.9 cm with three cryoneedles. Intraprocedural iceball depictions correlated well with postprocedural cryonecrosis estimates., Conclusion: MR imaging-guided percutaneous cryotherapy of liver tumors is feasible and safe. MR imaging can be used to estimate cryotherapy effects and guide therapy intraprocedurally.

Purpose: To assess the relationship between the cause and severity of pancreatitis and the development of persistent pancreatocutaneous fistula (PPCF) after percutaneous drainage of pancreatic fluid collections., Materials and Methods: Sixty patients (44 male, 16 female; age range, 10-74 years) were included in the study. The cause of pancreatitis was postoperative in 29 patients, alcoholism in 20 patients, biliary in six patients, hyperlipidemia in two patients, unknown in two patients, and trauma in one patient. Patients requiring intensive care unit treatment for their condition at the time of drainage were considered to have severe pancreatitis. Thirty-seven patients had mild pancreatitis, and 23 had severe pancreatitis. PPCF was defined as catheter drainage of pancreatic fluid of more than 10 mL/d for more than 4 weeks after catheter placement., Results: PPCF developed in 27 of the 60 patients. It occurred in five of the six patients with biliary pancreatitis, 10 of the 20 with alcohol-related pancreatitis, and 10 of the 29 with postoperative pancreatitis (P > .2). The prevalence of PPCF was higher in patients with severe pancreatitis (n = 16 [70%]) than in those with mild pancreatitis (n = 11 [30%]). This difference was statistically significant (P < .002)., Conclusion: Development of PPCF correlated with severity of pancreatitis, regardless of the cause of pancreatitis.

Purpose: The authors report their experience with percutaneous image-guided sclerotherapy for treatment of unresectable lymphangiomas., Materials and Methods: Five patients with unresectable lymphangiomas of the pelvis (n = 2), neck (n = 1), abdomen (n = 1), or leg (n = 1) were treated at two medical centers with sclerotherapy, with use of doxycycline as the sclerosant. Computed tomography was used to guide the procedures, with supplemental lymphoscintigraphy, ultrasound, and magnetic resonance imaging used as needed., Results: Symptomatic relief of lymphedema, lymphorrhea, or a decrease in size of lymphatic pools was achieved, to varying degrees, in the five patients. Follow-up is ongoing, and further sclerotherapy may be indicated as the clinical course dictates., Conclusion: Percutaneous sclerotherapy with doxycycline is safe and appears effective for palliative treatment of unresectable lymphangiomas on the basis of our initial clinical experience.

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.

Purpose: To evaluate the usefulness of a self-contained pneumothorax treatment device, in which a catheter and a one-way valve compose a single unit, in cases of postbiopsy pneumothorax., Materials and Methods: Twenty-one patients underwent placement of the device to drain a postbiopsy pneumothorax. Treatment was considered successful when no therapy other than the device was needed., Results: Treatment was successful in 16 (76%) of the 21 patients. Causes of treatment failure were dislodgment of the device (n = 3), malfunction of the device (n = 1), and a persistent air leak that led to pneumothorax recurrence after removal of the device (n = 1). Eight patients (38%) experienced problems after insertion of the device: The device dislodged in seven patients and malfunctioned in one patient. These problems led to treatment failure in four patients (see above). In the remaining four, further treatment after device dislodgment was not required., Conclusion: Treatment with the self-contained pneumothorax treatment device shows promise. Modifications to the device may alleviate technical problems and insertion difficulties.

Purpose: To test the technical feasibility and results of placement of metal stents into ureters obstructed by extensive tumor., Materials and Methods: Six consecutive patients (two men and four women, aged 35-66 years and with incurable malignancies) underwent insertion of metallic endoprostheses in nine obstructed ureters through percutaneous tracts., Results: Metal stents were inserted without technical difficulty in all obstructed ureters. The stents functioned well in four patients. In two patients, the metal were not tolerated and plastic double-J stents were placed through the metal stents; this permitted effective functioning and withdrawal of the protective external catheter. Intraluminal ultrasonography depicted stent clogging and debris, dimensions of stent opening, and tumor level., Conclusion: Insertion of metal stents in the ureter is technically straightforward and was well tolerated by patients. However, the efficacy is variable, and a greater beneficial effect than is achieved with plastic stents is not established.

Purpose: To evaluate the authors' experience with treatment of symptomatic hepatic cysts by means of percutaneous catheterization and sclerosis., Materials and Methods: Twenty patients with 24 symptomatic hepatic cysts underwent percutaneous drainage and sclerosis. Ten patients had polycystic disease, and 10 had solitary cysts. Sclerosants used were alcohol, tetracycline, doxycycline, or a combination., Results: Twenty-one of 24 cysts in 17 of 20 patients were treated successfully. Treatment was unsuccessful in three patients: one patient with innumerable medium-size and small cysts, one patient in whom only a needle was inserted (no catheter), and one patient with a cystic metastasis (rather than a simple cyst) that recurred. Complications included pleural effusion in two patients and secondary infection in one patient. The range of blood alcohol levels was 0-0.8 mg%., Conclusion: Percutaneous catheter drainage with sclerosis is an effective method of therapy for symptomatic hepatic cysts; careful patient selection is essential for proper therapy.

Purpose: To assess the technique, results, and patient tolerance of transsternal biopsy of anterior mediastinal lesions under computed tomographic (CT) guidance., Materials and Methods: Seven patients (four women and three men) with anterior mediastinal lesions underwent eight transsternal biopsies. Patients were included in the study if there was a risk of injury to internal mammary vessels or a danger of tranversing the lung by the biopsy needle. Patients were specifically questioned about the pain caused by the transsternal needle. A pain scale was not used. Conscious sedation and local anesthesia requirements provided gross evaluation of the patients' tolerance to the procedure. CT scans were used to guide and confirm optimal alignment of the transsternal needle with the lesion., Results: Patients experienced minimal discomfort when the sternum was traversed. No instances of pneumothorax, postprocedural pain, or infection were encountered. In six of the seven patients, biopsy specimens were diagnostic., Conclusion: The transsternal approach for biopsy of anterior mediastinal lesions appears safe and is well tolerated.

The authors describe their experience in management of bile duct injuries (n = 11), bile leaks or abscesses (n = 11), and bleeding (n = 1) as complications of laparoscopic cholecystectomy in 21 patients. Clinical presentations included jaundice, sepsis, pain, abdominal distention, and persistent gallstones. Twelve patients underwent operative cholangiography, three underwent conversion to open cholecystectomy, and 12 reoperations were performed in nine patients before interventional radiologic procedures, which included diagnostic percutaneous transhepatic cholangiography (n = 13), percutaneous biliary drainage (PBD) (n = 13), percutaneous stricture dilation (n = 3), stent insertion (n = 1), percutaneous abscess or biloma drainage (n = 19), and gallstone removal (n = 1). Each procedure was technically successful. Clinical improvement occurred in 18 of 19 patients. PBD was used as an operative guide before reconstructive surgery in two patients. Reoperation was unnecessary in 10 of 21 patients (48%). One patient died of fungal sepsis and pulmonary complications. This radiologic-surgical approach provided rapid and safe management of these complications.

In an attempt to decrease catheter drainage of pancreatic pseudocysts, a combined regimen of percutaneous drainage and administration of octreotide acetate was used in eight symptomatic patients. Indications for the combined therapy were pseudocyst recurrence (four patients), pancreatic fistula from percutaneous drainage (two patients), or elective treatment to restrict pancreatic drainage. Octreotide acetate was administered subcutaneously in doses of 50-1,000 micrograms three times a day. The drug was well tolerated and produced only limited adverse effects in four patients: pain at the injection site, hypoglycemia, diarrhea, headaches, and lower-extremity edema (more than one adverse effect was experienced by each patient). The combined use of percutaneous drainage and administration of octreotide was effective in seven patients and failed in one patient who had distal pancreatic duct occlusion. In five patients, catheter drainage decreased to no measurable amount by a mean of 13.8 days. These results suggest octreotide is effective in decreasing the output from pancreatic pseudocysts drained percutaneously.

The authors describe the value of computed tomographic (CT) guidance for percutaneous gastrostomy (PG) or gastroenterostomy (PGE) in 22 patients with anatomic or pathologic difficulties precluding fluoroscopic guidance. Indications for PG or PGE were decompression for gastrointestinal obstruction (n = 15) or for feeding (n = 7). Thirteen patients previously underwent an unsuccessful attempt at or had been rejected as unsuitable for percutaneous endoscopic gastrostomy. CT guidance was selected because of inability to pass a nasogastric tube due to esophageal obstruction (n = 4), inability to tolerate gastric distention (n = 1), abnormal morphology in or around the stomach (n = 16), or simultaneous performance of a PG in one patient who was undergoing emergency CT-guided abscess drainage. Catheters were placed successfully in all 22 patients. No major complications occurred. CT is valuable for PG or PGE when anatomic or pathologic problems make fluoroscopic or endoscopic puncture unsafe or impossible.

Aberrant right hepatic ducts are the most common biliary tract anomaly and are particularly susceptible to injury at cholecystectomy because of their critical location. The authors report radiologic diagnosis and therapy in five cases of inadvertent ligation of this duct at cholecystectomy. The diagnosis was unsuspected prior to the radiologic studies in each patient. Four patients experienced recurrent cholangitis; one patient had chronic pain as the only symptom. Prior to diagnosis, the duration of symptoms ranged from 2 weeks to 126 months. Findings at ultrasound, computed tomography, and percutaneous transhepatic cholangiography with differential biliary pressures helped establish the diagnosis in each patient. Findings at endoscopic retrograde cholangiopancreatography were nondiagnostic in four patients. Percutaneous biliary drainage provided palliation of symptoms, improved each patient's condition prior to reconstructive surgery, and provided an intraoperative landmark for the surgeon. Two patients had associated bilomas, one of which was infected and was drained percutaneously. All patients survived and recovered without further complications.

The authors describe the technical results in 127 patients who underwent diagnostic gallbladder puncture and percutaneous cholecystostomy. The procedures were performed for a variety of indications including treatment of acute calculous or acalculous cholecystitis, drainage of obstructive jaundice or gallbladder perforation, percutaneous removal or dissolution of gallstones, diagnostic cholecystocholangiography, and gallbladder biopsy. Successful completion of the intended procedure was achieved in 125 of 127 patients (98.4%). Major complications occurred in 11 patients (8.7%); these included bile peritonitis, bleeding, vagal reactions, hypotension, catheter dislodgement, and acute respiratory distress. Minor complications were noted in five patients (3.9%). The 30-day mortality rate was 3.1% (four patients); the deaths were due to the underlying diseases. The data help support percutaneous cholecystostomy as a primary interventional radiologic procedure that has an extremely high likelihood of technical success. Recommendations to minimize or avoid complications are presented.

The authors describe their initial experience with a dedicated intraluminal ultrasound (US) device that was coupled to a catheter and introduced percutaneously into the gallbladder and/or bile ducts. Access was created with interventional radiologic techniques in 22 patients and at laparoscopy in four patients. Thirty-one examinations in 26 patients revealed information on normal anatomy, pathologic processes, and responses to therapy. The pathologic processes seen included bile duct and gallbladder debris, stones, ductal strictures, and tumors. Additional information provided with this technique over other diagnostic studies included differentiation of intraluminal filling defects, examination of areas inaccessible to conventional imaging, and observations about the walls of the ducts and gallbladder. Percutaneous US examination of metallic stents within the bile ducts and of filling defects in the ducts at laparoscopic cholecystectomy was of particular interest and altered subsequent therapy. The procedure is simple, straightforward, and devoid of complications. While refinements and improvements are needed, this diagnostic technique holds promise.

Dislodgment is a major drawback with large-bore Malecot catheters. A locking mechanism with a suture affixed to the distal portion of the mushroom tip is described. In a 32-month period, 17 Malecot catheters with locking mechanisms were placed in 15 patients. One catheter dislodged as a result of suture failure. A variation in design prevented subsequent failure of sutures. This simple locking mechanism prevents collapse of the catheter wings and thereby maintains catheter placement.

The authors performed percutaneous drainage of 27 tubo-ovarian abscesses (TOAs) in 16 patients in whom medical therapy with triple antibiotics prior to catheter drainage had not been successful. Percutaneous drainage was successful in 15 of 16 patients (94%). One patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy 3 days after catheter placement because of persistent symptoms and lack of drainage from the catheter; at laparotomy, a large infected phlegmon was found. Two patients had recurrent disease at 3 and 4 months after catheter placement. Bilateral salpingectomy was performed in one patient and total abdominal hysterectomy and bilateral salpingo-oophorectomy in the other. One of these patients had cervical carcinoma, and the other had a long history of recurrent pelvic inflammatory disease and TOAs. The long-term avoidance of surgery was 81.2%. Access routes for catheter drainage were through the anterior abdominal wall for 10 abscesses, through the posterior transgluteal route for 11, and through the transvaginal route for six. Duration of drainage was 1-20 days (mean, 6 days). Complications consisted of transient sciatic pain in two patients and mild bacteremia in one. The results indicate that percutaneous drainage of TOAs is effective in patients in whom medical therapy is not successful.

The technique and observations in 28 patients who underwent imaging of the percutaneous cholecystostomy (PC) tract are described. Imaging of the tracts was performed by injecting contrast material through an end-hole dilator during catheter removal (n = 13) or through an end-hole dilator with a side adapter over a thin guide wire (n = 15); the latter method permitted simple catheter reinsertion if the tract was poorly formed. Catheters were removed between 9 and 158 days (mean, 36.6 days; median, 29.5 days) after PC. Twenty-three patients had well-formed tracts and five patients did not. Among the five patients with a poorly formed tract, two experienced no sequela as a result of catheter withdrawal, two underwent immediate catheter reinsertion, and one developed bile peritonitis; this last patient was treated with repeated PC and antibiotics. All patients in whom a catheter was placed for at least 20 days had a well-formed, intact tract. Imaging of the PC tract is helpful to identify patients who have an immature tract. In a patient with a poorly formed tract, catheter reinsertion may be advisable to prevent bile leakage and peritonitis.

Ultrasound (US)-guided transvaginal needle or catheter drainage was performed in 14 women for a variety of pelvic abscesses and fluid collections; tubo-ovarian abscesses and postoperative collections were most common. Diagnosis was achieved in all 14 patients (100%), including one patient with suspected ovarian carcinoma who underwent only diagnostic needle aspiration and no therapeutic drainage. Abscesses or fluid collections were evacuated in 13 of 13 patients (100%) with either needle (n = 7) or catheter (n = 6) drainage (with appropriate antibiotics). Twelve of the 14 patients (86%) were spared an operation; surgery was undertaken in two patients for a persistent tubo-ovarian phlegmon. No major complications were associated with drainage. Catheters were removed an average of 6.7 days after insertion. The success, safety, and advantages of US-guided transvaginal drainage in our early experience suggest its use as an alternative to standard percutaneous catheter procedures to diagnose and drain certain pelvic abscesses and fluid collections.

Three patients with spontaneous gallbladder perforation and one with an iatrogenic bile leak causing bile peritonitis were treated successfully by means of percutaneous catheter drainage. Three patients had cholelithiasis as the cause of perforation; the fourth patient had previously undergone gallstone dissolution with methyl tert-butyl ether lavage and developed bile peritonitis a few hours after removal of the catheter. In three patients, a percutaneous cholecystostomy catheter provided successful decompression; in the fourth patient, drainage was performed with a percutaneous sump catheter in the subhepatic space adjacent to the gallbladder. No specific complications occurred. Follow-up was performed at 1, 12, 22, and 59 months, respectively. To date, one of the four patients has undergone elective cholecystectomy (1 month after drainage). The remainder of the patients are asymptomatic. This preliminary experience suggests that the severe complication of gallbladder perforation and bile leakage may be treated, at least temporarily, by means of percutaneous drainage.

Lung abscesses were drained by means of catheters guided by computed tomography (CT) in 19 patients who still had sepsis despite standard medical therapy; all patients had received antibiotics for at least 5 days, and 11 of the 19 patients had undergone bronchoscopy. The abscess was cured (by clinical and radiographic criteria) in all 19 patients (100%), and surgery was avoided in 16 of the 19 patients (84%). Three patients underwent surgery for removal of organized tissue or decortication after the lung abscess was evacuated. Complications included a hemothorax that required a chest tube in one patient and three minor complications (a clogged catheter in two patients and transient elevation of intracerebral pressure in one patient). The hemothorax occurred in one of two patients in whom the catheter traversed normal lung. The percutaneous drainage catheters traversed juxtaposed abnormal pleura on route to the abscess in 17 of the patients. CT-guided drainage of lung abscess is an effective method to treat lung abscesses that are refractory to conventional therapy; the procedure should obviate major operation in most patients. A catheter route through abscess-pleural syndesis is preferable, and CT is useful for planning this route.

Eleven selected patients with obstructive jaundice underwent percutaneous cholecystostomy (PC) for decompression. Ten of these patients had the constellation of distal common duct obstruction, nondilated or minimally dilated intrahepatic ducts, and a distended gallbladder; one patient with a bleeding dyscrasia had moderately dilated intrahepatic bile ducts. All procedures were successful and effective, and 10 of 11 cholecystostomies were performed within 5-15 minutes. No specific complications occurred. The success, ease, and safety of the procedure indicate primary use of PC for biliary decompression when the intrahepatic bile ducts are minimally dilated or nondilated, because standard transhepatic biliary drainage may be difficult in these cases. Because cannulation of the cystic duct and hence internalization through the tumor may be difficult, PC may be most valuable preoperatively, or before standard percutaneous biliary drainage, or as an alternative to endoscopic drainage. This is a rapid and safe method with which to achieve biliary decompression, especially with minimally dilated or nondilated intrahepatic bile ducts.

Percutaneous cecostomy (PCC) was evaluated in dogs and cadavers and by means of review of intraperitoneal contrast material-enhanced computed tomographic (CT) scans and clinical experience in five patients with Ogilvie syndrome. It was shown that PCC can be accomplished with a variety of techniques (e.g. Seldinger or trocar puncture, tacking) and instruments (various types and sizes of retention and nonretention catheters). Anatomic studies revealed that the cecum is surrounded by the peritoneum for as much as 270 degrees of its circumference, so that a retroperitoneal approach to PCC would probably be unfeasible in most patients. PCC was effective in treating all five patients in this study, despite their advanced age and complicated medical conditions. Decompression of colonic gas was achieved with 8-12-F catheters, and no major complications occurred. Endoscopic decompression had been unsuccessfully attempted in four of the patients previously. It is concluded that PCC may be an important option in the treatment of Ogilvie syndrome and that the procedure may obviate surgery and be lifesaving in certain high-risk patients.

Despite the widespread use of interventional radiologic techniques, there has been reluctance to apply these to the spleen. Concern for bleeding and difficulty in negotiating around the colon and pleura have limited its use. The authors report their experience with interventional radiology of the spleen in 35 cases, including percutaneous biopsy (n = 5), diagnostic and therapeutic fluid aspiration (n = 14), and catheter drainage of abscesses (n = 9), hematomas (n = 2), intrasplenic pancreatic pseudocysts (n = 2), and necrotic tumor (n = 1). Transsplenic fluid aspiration and biopsy of the pancreas and adrenal gland were performed as well (n = 2). All procedures were performed under computed tomographic or ultrasound guidance. Biopsies were performed with 22- or 20-gauge needles only; no complications were encountered. Diagnoses included primary and secondary malignancies and an infectious process. Drainages were successful in 11 of 14 patients; pleural effusions occurred in two cases, but neither required specific therapy. Interventional radiologic procedures in the spleen are feasible, and the authors discuss methods to promote their safe application.

In four of our initial five cases of percutaneous cholecystostomy, performed under ultrasound guidance for septicemia due to suspected cystic duct obstruction and hydrops of the gallbladder, patients suffered profound vagal reactions with severe hypotension and bradycardia. One patient had cardiac arrest. The patients had experienced recent myocardial infarction, ventricular ectopy, or septicemia, and each had a greatly distended gallbladder. The reactions occurred immediately, though in the first patient recognition was delayed. One patient had infected bile, three had obstructing cystic duct stones with inflammatory response, and one had a sterile and nonobstructed gallbladder. All patients survived the acute insult. Treatment consisted of minimizing intravisceral manipulations, administration of intravenous atropine, fluids, antibiotics, and dopamine. Atropine administered prior to the procedure appeared to blunt the reaction in one patient. Two patients died within a week of other causes. At autopsy neither peritoneal cavity had bile staining. The other patients had follow-up ultrasound examinations; no intraperitoneal fluid collections were seen.

A technique for biopsy of small or inaccessible mediastinal, hilar, or pulmonary lesions with computed-tomographic (CT) guidance is described. A modified coaxial system was used in order to make multiple passes possible without multiple punctures. The size of the original puncture needle (23 gauge) provided the inherent safety associated with a fine needle. All repositioning was done using this needle and CT until the lesion was engaged. The hub of the needle was then cut, and a 19-gauge needle was inserted coaxially over the larger needle. After removal of the 23-gauge needle, multiple biopsy specimens were then obtained coaxially with a 22-gauge needle through the 19-gauge needle. One small pneumothorax and no bleeding occurred in 10 instances. Results suggest that the combined use of CT guidance and this modified coaxial system may offer an extra margin of safety for difficult cases.