SPECT showed progress ion o f local tumor in three patients after treatment while MRI showed interval change in one patient. Three patients had no change at brain SPECT or MRI.

Conclusion: Funct ional eva lua t ion o f somatos ta t in receptor up- take in patients with skull base m e n i n g i o m a is a sensi t ive and useful me thod in moni to r ing t rea tment response fo l lowing stereo- tactic radiosurgery.

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Creation of a Vascular Model for Resident Training Paul V. Connaugh ton , MD, Johns Hopkins Hospital, Baltimore, MD, Kieran J. Murphy , MD, John M. Mathis , MD, MSc

P u r p o s e : The n u m b e r o f angiographic t ra ining cases per res ident has decreased due to improved imag ing techniques such as M R A and CTA, and to increased compet i t ion f rom fel lows. A vascular mode l was developed to train beg inn ing res idents in anglo- graphic procedures .

Method a n d Mate r ia l s : A glass-blown model of the aorta was de- signed to replicate h u m a n anatomy. Aortic arch configuration was based on a cadaveric wax-casted arch (D. Rufenacht, Geneva). Ab- dominal branches were determined from a C T provided by the im- aging section. A piston pump circulated b lood-mimicking fluid. The model was immersed in fluid consist ing o f water and glycerin that approached the optical refractive index of glass. Silicone models of the carotid bifurcations and vertebral-basilar sys tem were attached.

Resu l t s : The m o d e l ' s glass sect ion compr i s ing the aorta, arch, and major abdomina l vesse ls provided good t ra ining opportuni- t ies for beg inn ing residents . The p u m p created pulsat i le ante- grade f low suitable for contrast angiography. F luoroscopy for optical ly opaque vascular les ions provided pract ice in interven- t ional procedures inc lud ing angioplas ty .

Conclusion: With the decrease in resident-performed angiograms, alternative training methods for clinical practice are necessary. This mode l provides a safe realistic sett ing for residents to practice basic catheter technique and fel lows to per form more advanced endovascular procedures.

0 9 - 7 0 Radiology Research Participation Survey Sohail Contractor, MD, UMDNJ-New Jersey Medical School, New- ark, NJ, Stephen R. Baker, MD, Kenne th R. Tomkovich , MD, Piotr S. Kisza, M D

Purpose: To determine participation by radiology residents in re- search and factors promot ing such participation

M a t e r i a l s and Methods: A quest ionnaire was mai led to cha i rmen and p rogram directors o f radiology res idency programs, 193 re- sponses were received and analyzed.

Resul t s : 58 progrmaas listed research as a requirement for residency completion, while 83 felt research participation should be encour- aged but not mandatory for residents. The three mos t important rea- sons for resident participation, in order, include (1) personal desire of resident: 84 respondents; (2) perceived help in obtaining a fel- lowship: 65 respondents; (3) obtaining a paid trip to a national meeting: 51 respondents. 154 respondents encouraged/strongly en- couraged resident research participation, o f these, 30 provided spe- cific mentors, 64 had research elective time, 101 had awards for re- search and 148 provided expenses for national meetings. Compar- ing faculty versus resident participation:

Participation Faculty Residents

Inact ive 6 3

Somewha t active 87 70

Act ive 69 52

Very active 39 32

Conclusions: Self motivat ion best predicts resident research par- ticipation. An active faculty also appears highly conducive to re- search involvement.

09-71 Desmoplastic Small Round Cell Tumor of the Abdo- men: Radiologic-Pathologic Correlation Perry J. Pickhardt, MD, Mallinckrodt Institute o f Radiology, Saint Louis, MO, Andrew J. Fisher, MD, Dennis M. Balfe, MD, Louis P. Dehner, MD, Phyllis C. Huettner, M D

Purpose: To describe the imaging features o f desmoplas t ic small round cell tumor (DSRCT) of the abdomen and correlate with the pathologic findings.

Methods: 11 o f 14 cases o f D S R C T identif ied at our inst i tut ion be tween 1991 and 1997 had pr imary abdomina l involvement . Im- ag ing studies (9 CT scans, 3 sonograms) and pathologic speci- m e n s f rom 9 o f these pat ients (mean age, 20 years) were retro- spect ively analyzed.

Resu l t s : The presence o f lobulated per i toneal-based masses , rang ing f rom 2 to 12 c m in size (mean, 5.0 cm) and 1 to 17 in n u m b e r (mean, 4.4), was the ha l lmark imag ing feature. Omenta l and paravesical tumors were each present in 6 o f 9 patients. Ret- roperi toneal m a s s e s were present in 3 patients. T u m o r ma sse s were well def ined and hypoecho ic on sonography . Heterogenei ty f rom tumor hemor rhage or necros is was seen in 7 patients. As - cites was present in 5 patients . Pa renchymal and/or serosal l iver metas tases , puncta te calcif icat ions, d i f fuse peri toneal th ickening, l ymphadenopa thy , hydronephros is , and bowel obst ruct ion were less c o m m o n associa ted f indings .

Conclusion: Bulky peritoneal soft t issue masses without an appar- ent organ-based pr imary site are characteristic o f intra-abdominal DSRCT. Al though the f indings are nonspecif ic , this diagnosis can be considered in adolescents and young adults based on cross-sec- tional imaging.

0 9 - 7 2 Posttransplantation Lymphoproliferative Disorder of the Abdomen: CT Evaluation in 51 Patients Perry J. Pickhardt , MD, Mallinckrodt Institute o f Radiology, Saint Louis, MO, Mari lyn J. Siegel, M D

P u r p o s e : To s tudy the role of CT in evaluat ing the abdomen for post t ransplantat ion lymphoprol i ferat ive disorder (PTLD) involve- ment .

Methods: Pretreatment abdominal CT scans in 51 solid organ transplant patients with pathological ly proven PTLD were retro- spectively analyzed (mean age, 36 years).

Resu l t s : CT demons t ra ted abdomina l i nvo lvemen t by P T L D in 36 o f 51 pat ients (71%). None of the 15-patients with negat ive CT scans had clinical or pathologic evidence of abdominal PTLD. In the 36 pat ients with positive CT findings, 22% had lymph node enlargement, 28% demons t ra ted splenic involvement , and 81% showed extranodal , extrasplenic involvement . Extra- nodal abdomina l sites on CT inc luded liver (53%), small bowel (28%), k idney (17%), mesen te ry (11%), adrenal (8%), abdomina l wall (8%), colon (6%), and s tomach (3%). F requency of abdomi- nal i nvo lvemen t was greater for heart and liver t ransplants (94%) compared with lung and k idney t ransplants (58%). 17 o f 36 pa- tients (47%) with abdominal f indings had no evidence of extra- abdominal PTLD.

Conc lu s ion : CT is a reliable me thod for both detect ing and ex- c luding abdominal PTLD. Extranodal involvement is more com- mon than splenic or nodal disease. Presence o f such findings in a transplant patient should s t rongly sugges t the d iagnos is o f P T L D and warrants aggress ive evaluat ion.

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A Low-Cost Approach to Generate Digital Teaching Files Using Commercially Available Software on a Personal Computer Gary J. Wendt , MD, University o f Wisconsin Hospital & Clinics, Madison, WI

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