0 7 - 4 7 Percutaneous Abdominal Abscess Drainage: Effective Use of Small-Bore Catheters in Selected Patients Frank J. Brennan, MD, Gregory L. Denison, MD, M B A, Naval Medical Center, San Diego, CA, Lee D. Hall, M D

Purpose : To investigate the effectiveness of small-bore catheters in the percutaneous drainage of suspected intra-abdominal abscesses.

M e t h o d s : Data f rom a two-year period (July 1996 to July 1998) were collected retrospectively f rom interventional radiology de- par tment logs and the hospi ta l ' s informat ion system. The majority of catheters were placed under CT guidance, with a smaller number placed under f luoroscopic or u l t rasound guidance. Catheter place- ment / funct ion were evaluated frequent ly post-procedure via con- trast s inography.

Resu l t s : Catheters were successful ly placed in 72 of 73 at tempts in 60 patients, a technical success rate of 98%. Preprocednre goals were either abscess resolut ion without surgery or temporizat ion until de- finitive surgical intervention. These goals were met in 59 of 60 pa- tients, a success rate of 98%. 52 patients had abscesses without fis- tulas at non-pancreat ic sites. 61 o f the 62 catheters (98%) placed in this subgroup were either 6Fr (72%) or 8Fr (26%). No major compli- cat ions were reported.

Conc lus ion: Al though prev ious series have r e c o m m e n d e d large- bore catheters for abdomina l abscess drainage, comparab le resul ts in selected patients can be achieved us ing smaller catheters. Fre- quent catheter checks and advances in catheter manufac tur ing are felt to be important in mainta in ing h igh success rates with smal ler catheters.

0 7 - 4 8 Unenhanced Helical CT with Enteric Contrast for the Evaluation of Appendicitis in Adults Brian S. Funaki, MD, University of Chicago, Chicago, IL, Alexandra N. Funaki, DO, Clarence N. Funaki, MD, Scott R. Grosskreutz, M D

Purpose : The accuracy of unenhanced helical CT with enteric con- trast material was evaluated in the diagnosis of appendicitis in adults

M a t e r i a l s a n d M e t h o d s : Over a 10-month period, 127 consecu- tive patients (ages 18-91 years, mean 39 years) with right lower quadrant pain and suspected appendicit is were prospect ively evalu- ated. Thin-col l imat ion helical scanning was performed after ad- minis trat ion o f enteric contrast material. C T interpretations were correlated with surgical pathology (49 patients) and clinical fol- low-up (78 patients).

Resu l t s : Forty-one CT scans were interpreted as posit ive for ap- pendicit is (35 true posit ives and 5 false positives), and 86 CT scans were interpreted as negative for appendicitis (84 true negatives and 2 false negatives) . Sensit ivity was 95%, specificity was 94%, posi- tive predictive value was 88%, and negat ive predictive value was 98%. In 86 scans interpreted as negat ive for appendicitis, an alter- native diagnosis was made in 36 patients (42%).

Conc lus ion: U n e n h a n c e d helical C T with enteric contrast mate- rial for the evalua t ion o f appendici t is in adults has excel lent sen- sit ivity and specifici ty.

0 7 - 4 9 MR Cholangiopancreatography: Evaluation of a New Sequence True FISP Compared with Conventional Thin-Slice HASTE and Thick-Slice HASTE and Thick-Slab RARE Techniques Declan G. Sheppard, MD, Northwestern University, Chicago, IL, Frank H. Miller, MD, John P. Finn, MD, Frederick L. Hoff, MD, F. Scott Pereles, MD, Helena Gabriel, M D

P u r p o s e : To compare the ability of three different M R cholangio- pancreatography (MRCP) sequences to evaluate the pancreatico- biliary tree.

Ma te r i a l s a n d Me thods : 15 patients referred for M R C P were pro- spectively examined us ing all three sequences. The demonstrat ion of the pancreaticobiliary tree and overall image quality were scored on a five-point scale by two reviewers. Specific advantages and limitations were recorded.

Resul t s : The intra-hepatic ducts were best visualized us ing H A S T E (score 4.2), and least well demonstrated, t l ~ i ~ e fast- imaging steady-state precession (FISP.~.~cl[~2~fl~, '~g~t'~eessels being dif- ficult to d i f f e r e n ~ l k e f ~ ] ~ ] [ l ~ I ~ { s ~ v i t h True-FISP. Tile com- m o n hepatic and ~i1~ dludbs "~ere equally well-delineated by all se- quences, a l though H A S T E was marginal ly superior (score 4.0). H A S T E and rapid acquisition with relaxation enhancement (RARE) were marginal ly better for demonstrat ing the proximal, mid-and distal pancreatic duct (score 2.8-3.8), al though true FISP also per- formed satisfactorily (score 2.6-3.4). The ampulla and duodenum were best demonstra ted us ing HASTE, and least with RARE.

Conclusions: H A S T E is the best sequence overall for demonstrat- ing the pancreaticobiliary tree. However, there were multiple inci- dences where R A R E and True-FISP performed as well. Whi le R A R E is acquired as a breath-hold, and image quality is generally better i f H A S T E is acquired as a breath-hold, True-FISP has the ad- vantage o f being a non-breath-hold technique. In summary , reliance on a single sequence is likely to be unreliable and, given the short scan t imes involved, additional sequences would seem appropriate.

0 7 - 5 0 Complications of Percutaneous Nephrostomy and Nephroureterostomy Catheter Placement Jonathan M. Lorenz, MD, University of Chicago, Chicago, IL, George X. Zaleski, MD, Bruce H. Lin, MD, Jordan D. Rosenblum, MD, Jeffrey A. Leef, M D

P u r p o s e : To evaluate the safety of u l t rasound-guided percutane- ous nephros tomy and nephroure teros tomy catheter placement.

Ma te r i a l s a n d M e t h o d s : Over a 3-year period, 227 catheters were placed in 180 patients. Access to the collecting system was achieved with a 21G Accus t ick TM sys tem or an 18G Tef lon-coated needle under u l t rasound guidance. Signif icant hemor rhage was def ined as hematnr ia last ing greater than three days or requiring interven- t ion in the first three days such as catheter change/ removal or em- bolization. Signs o f obstruct ion included fever, decreased drain- age, and urine leakage. Migration was defined as withdrawl o f the catheter f rom the renal pelvis into pf i renchyma or calyx with asso- ciated occlusion.

Resu l t s : Technical success was 99%. Compl ica t ions included ac- cidental removal in 6% (after a mean of 33 days), s ignif icant hem- orrhage in 5% (requiring embolization in one patient), catheter ob- struction in 2%, catheter migrat ion in 6%, urinary tract perforation in 1%, pain requii 'ing tube change in less than 1% and oxygen desaturat ion related to sedation in one patient. 17 catheters were placed in renal transplant grafts without associated complicat ions.

Conclusion: Percutaneous nephrostomy and nephroureterostomy catheter placement is associated with a low complication rate, the vast majority of complications being minor.

07-51 Detection of Bleeding Sites Using Helical CT Examination Frank H. Miller, MD, Northwestern University, Chicago, IL, Arvydas Vanagunas , MD, Frederick L. Hoff, MD, F. Scott Pereles, MD, Helena Gabriel, MD, et al

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