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.
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.
...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.
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.
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.
To evaluate the initial clinical experience of magnetic resonance (MR) imaging-guided percutaneous cryotherapy of renal tumors.
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).
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.
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.
The authors report their experience with percutaneous image-guided sclerotherapy for treatment of unresectable lymphangiomas.
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.
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.
Percutaneous sclerotherapy with doxycycline is safe and appears effective for palliative treatment of unresectable lymphangiomas on the basis of our initial clinical experience.
This study was conducted to assess the correlation with patient outcome and interobserver variability of a modified CT severity index in the evaluation of patients with acute pancreatitis compared ...with the currently accepted CT severity index.
Of 266 consecutive patients diagnosed with acute pancreatitis during a 1-year period, 66 underwent contrast-enhanced MDCT within 1 week of the onset of symptoms. Three radiologists who were blinded to patient outcome independently scored the severity of the pancreatitis using both the currently accepted and modified CT severity indexes. The modified index included a simplified assessment of pancreatic inflammation and necrosis as well as an assessment of extrapancreatic complications. Outcome parameters included the length of hospital stay; the need for surgery or percutaneous intervention; and the occurrences of infection, organ failure, and death. For both the current and modified indexes, correlation between the severity of the pancreatitis and patient outcome was estimated using the Wilcoxon's rank sum test and Fisher's exact test. Interobserver agreement for both indexes was calculated using the kappa statistic.
When applying the modified index, the severity of pancreatitis and the following parameters correlated more closely than when the currently accepted index was applied: the length of the hospital stay (0-34 days) (modified index p = 0.0054-0.0714 vs current index p = 0.0052-0.3008); the need for surgical or percutaneous procedures (10/66 patients) (modified index p = 0.0112 vs current index p = 0.0324); and the occurrence of infection (21/66 patients) (modified index p < 1e(-10) vs current index p < 1e(-04)). Significant correlation between the severity of pancreatitis and the development of organ failure (9/66 patients) was seen only using the modified index (p = 0.0024), not the current index (p = 0.0513). The interobserver agreement was similar with the modified (kappa range, 0.71-0.85) and the current (kappa range, 0.63-0.86) indexes.
The modified CT severity index correlates more closely with patient outcome measures than the currently accepted CT severity index, with similar interobserver variability.
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.
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.
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).
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.
To evaluate the authors' experience with treatment of symptomatic hepatic cysts by means of percutaneous catheterization and sclerosis.
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.
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%.
Percutaneous catheter drainage with sclerosis is an effective method of therapy for symptomatic hepatic cysts; careful patient selection is essential for proper therapy.
The purpose of our retrospective study was to evaluate the sensitivity and negative predictive value of percutaneous biopsy of renal masses stratified by clinical setting and the size of the mass.
We ...categorized 115 consecutive percutaneous biopsies of renal masses in 113 patients into four clinical settings and three groups of mass sizes. The sensitivity and negative predictive value were computed (with 95% confidence intervals CI) for each clinical setting and for each size group.
For all procedures (n = 115), the sensitivity and negative predictive value were 90% (95% CI, 81-95%) and 64% (95% CI, 44-81%), respectively. For patients with a known malignancy who presented with a renal mass (n = 55), the sensitivity and negative predictive value were 90% (95% CI, 78-96%) and 38% (95% CI, 10-74%), respectively. For patients with no known malignancy and suspected unresectable tumor (n = 36), the sensitivity and negative predictive value were 92% (95% CI, 76-98%) and 0%, respectively. For patients with no known malignancy who presented with a cystic mass (n = 16), the sensitivity and negative predictive value were 33% (95% CI, 2-87%) and 87% (95% CI, 58-98%), respectively. For patients who were not surgical candidates with a renal cell carcinoma (n = 8) that was thought to be resectable, both the sensitivity and negative predictive value were 100%. For masses 3 cm and less (n = 31), the sensitivity and negative predictive value were 84% (95% CI, 63-95%) and 60% (95% CI, 27-86%), respectively. For masses between 4 and 6 cm (n = 42), the sensitivity and negative predictive value were 97% (95% CI, 83-100%) and 89% (95% CI, 51-99%), respectively. For masses greater than 6 cm (n = 42), the sensitivity and negative predictive value were 87% (95% CI, 71-95%) and 44% (95% CI, 15-77%), respectively.
Percutaneous renal mass biopsy has a high sensitivity in three clinical settings: patients with a known malignancy, patients with no known malignancy and suspected unresectable tumor, and nonsurgical patients with a mass suspected to be a resectable renal cell carcinoma. Negative results in small (< or = 3 cm) and large (> 6 cm) masses should be viewed with caution.
Percutaneous drainage of 101 pancreatic pseudocysts (51 infected, 50 noninfected) in 77 patients is described. In this group of patients, 91 of 101 pseudocysts were cured by means of catheter ...drainage (90.1%) (noninfected, 43 of 50 86%; infected, 48 of 51 94.1%). Six patients underwent operation after percutaneous treatment due to persistent drainage. In patients with infected pseudocysts, the infection was eradicated by percutaneous drainage before operation. Four pseudocysts recurred and were redrained percutaneously. The mean duration of drainage was 19.6 days (infected pseudocysts, 16.7 days; noninfected, 21.2 days). Various access routes were used for catheter drainage: transperitoneal, retroperitoneal, transhepatic, transgastric, transduodenal, and transsplenic (inadvertent). Four major (superinfections) and six minor complications occurred. An unexpected finding in seven patients was spontaneous fistulization of the pseudocyst into the gastrointestinal tract. Percutaneous drainage is an effective front-line treatment for most pancreatic pseudocysts; cure is likely if fluid collections are drained adequately and if sufficient time is allowed for closure of fistulas from the pancreatic duct.
Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, we sent questionnaires to 688 radiologists in ...various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. We received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain.
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