(P-41) Spiral CT Scanning or HASTE MRU in Acute Calculus Ureter ic Obstruction: Pretenders to the Throne! Fintan Regan, M D Johns Hopkins Bayview Medical Center, Balti- more, MD, Brian S. Kuszyk, MD, Mark E. Bohlman, MD, John D. Petronis, M D

Purpose : Al though IV urography (IVU) has been traditionally used to image the acutely obstructed ureter, other modalit ies have re- cently been used. The aim of this study is to compare spiral CT to the combinat ion of H A S T E M R urography (MRU) with plain ab- dominal radiography (KUB).

M a t e r i a l s a n d M e t h o d s : 65 pat ients with suspec ted acute calcu- lus ureteric obst ruct ion were evaluated. Perirenal fluid, p resence and level o f ureteric obst ruct ion and s tones were a s sessed on both techniques .

Resul t s : 43/65 patients had proven acute calculus ureteric obstruc- tion. M R U showed perirenal fluid with a sensitivity of 85% (CT- 73%), specificity of 96% (CT-88%), and accuracy of 89% (CT- 78%). A dilated ureter was demonstra ted by M R U with a sensitivity of 87% (CT-73%), specificity of 100% (CT-95%), and accuracy o f 72% (CT-83%). The combinat ion of fluid and ureteric dilation on M R U showed a sensitivity of 89% (CT-77%), specificity o f 94% (CT-85%), and accuracy of 89% (CT-78%). M R U / K U B missed stones (<5ram diameter) in 11 patients with stones shown by CT. Overall, M R U / K U B revealed 3.2 abnormalit ies per acutely ob- structed ureter compared to 2.2 abnormalit ies detected by CT in the same patients (P <.005).

Conclus ion : M R U / K U B can diagnose the presence and level o f acute calculus ureteric obstruction with greater accuracy than CT.

(P-42) Appearances of Benign Calci f icat ions on Mammogra- phy Alexandra Osorio, M D Temple University Hospital, Philadelphia, PA, Beth A. Scott, DO

Purpose : To demonstrate the various appearances o f benign calcifi- cations seen on mammography .

M a t e r i a l s a n d M e t h o d : Ret rospect ive review of ben ign calcifi- cat ions seen on m a m m o g r a p h y at our insti tution.

R e s u l t s / C o n c l u s i o n s : Identif icat ion of calcif icat ions in m a m m o - g rams is impor tan t in the detect ion of pathology. It is impor tant to recognize them and character ize them, s ince calcif icat ions m a y some t imes be the only m a m m o g r a p h i c s ign of cancer. There are several calcif icat ions seen on m a m m o g r a p h y that are associa ted with ben ign disease. Dermal ca lc ium, calcif ied lipid cysts , secre- tory calcif icat ions, mi lk o f ca lc ium and disappear ing calcifica- t ions are only some of these f indings. The radiologis t should be able to recognize these pat terns and make m a n a g e m e n t r ecom- menda t ions to referr ing doctors.

(P-43) Scint igraphic Determinant for Tc .99m.MIBI Parathy- roid Imaging Sung M. Kim, M D Thomas Jefferson University Hospital, Phila- delphia, PA, Char les M. Intenzo, MD, David Capuzzi , MD, Jef- frey M. Miller, M D

P u r p o s e : To de te rmine wh ich scint igraphic, cellular and chemi- cal parameter is the mos t respons ib le de te rminant for detect ion of parathyroid lesion(s) in T c - 9 9 m methoxyisobuty l - i soni t r i l e (MIBI) parathyroid imaging .

M e t h o d s a n d M a t e r i a l s : Dua l -phase para thyroid scan was per- fo rmed in 22 patients with hyperpara thyro id i sm. This analys is in- cludes 17 adenomas , 8 hyperplas t ic leasions and 65 no rma l par- athyroid glands. T c - 9 9 m - M I B I tracer uptake in initial (IT) and delayed phase (DT) was semiquant i ta t ive ly calculated. Les ion detectabil i ty was correlated with several parameters respons ib le

for hyperpara thyro id i sm; IT, DT, total n u m b e r o f parathyroid cells, each % compos i t ion o f parathyroid cell types, size o f le- sion, s e rum ca lc ium and para thyroid ho rmone (PTH) levels.

Resu l t s : Correlat ion coeff ic iencies be tween tracer uptake and other parameters were as fol lows: IT (+0.67), D T (+0.55), total n u m b e r o f cell (+0.51), % oxyphi l ic cell (+0.32), % chief cell (+0.26), size o f lesion (+0.22), s e rum ca lc ium and PTH (0), and % clear cell ( -0 .21) .

C o n c l u s i o n : Initial Tc -MIBI uptake is the mos t responsib le de- t e rminant for detect ion o f parathyroid adenoma and hyperplas ia , whereas % clear cell content in parathyroid lesion showed nega- five correlation.

(P -44) Thrombolyt ic Therapy in the Treatment of Radial Ar- tery Thrombosis due to Indwel l ing Radial Artery Lines Drew L. Lamber t , BS Johns Hopkins Hospital, Baltimore, MD, Jean-Francois Geschwind , MD, Dav id G. Omdal , MD, Scott J. Savader, MD, Sally E. Mitchel l , M D

P u r p o s e : The purpose of this s tudy was to evaluate the role o f urokinase in the t rea tment o f radial artery th rombos is due to arte- rial l ines placed in the radial artery.

M a t e r i a l s & M e t h o d s : The records o f five pat ients who under- went pe rcu taneous catheter-directed th rombolys i s ~of th rombosed radial arteries at our inst i tut ion be tween 1995-98 were reviewed. The ou tcome of six h igh-dose urokinase infus ions in these pa- t ients was examined . A success fu l ou tcome was def ined as an- g iographic restorat ion o f f low with min ima l or no residual t h rombus within the radial artery. An antegrade approach was used in four o f six cases, with access ach ieved through the low branchial or radial artery.

Resu l t s : An angiographica l ly success fu l ou tcome was achieved in four o f six h igh-dose urokinase infus ions . Signif icant clinical i m p r o v e m e n t in ischemic signs and symptoms was noted in all suc- cessful cases. Two infusions yielded no significant change, likely due to advanced disease (late discovery o f the ischemic hand) or un- derlying factors such as sepsis.

C o n c l u s i o n : Radial artery th rombos is is a rare and serious co m - pl icat ion o f radial arterial l ine p lacement . This s tudy demon- strates the eff icacy o f h igh-dose urokinase infusion, with near comple te restorat ion o f f low in four o f six infusions . It is essen- tial to recognize the presence of hand i schemia as quickly as pos- sible when the patient has an arterial l ine in place s ince these pa- t ients can improve angiographica l ly and clinically with p rompt thrombolyt ic therapy.

(P .45 ) Comparat ive Imaging Modal i t ies for CT Cystography L. Kirldand Coilrad, M D University of Chicago, Chicago, IL, Abraham Dachman, MD, Edward J. Kirsh, MD, Glenn Gerber, M D

Purpose : To compare the speed and ease of use of CT cystography using various reconstructive techniques for the detection, localiza- tion, measurement , and characterization of urinary bladder masses .

M a t e r i a l s a n d M e t h o d s : Four techniques were employed to in- terpret data f rom 10 patients: convent iona l two-d imens iona l (2D) data with 3D prob lem solving, s tandardized vo lume- rende red (VR) and sur face-shaded display (SSD) 3D images , and an inter- active 3D stereoscopic sys tem. The images were compared to convent iona l cys toscopy by a radiologis t and a urologist .

Resu l t s : 22 (100%) of 22 m a s s e s detected on convent iona l cys- toscopy were v isua l ized us ing the var ious reconst ruc t ive tech- niques. By convent iona l cys toscopy 5 patients were no rma l and 5 were abnormal , with 1 to 10 polyps each.

C o n c l u s i o n : The s tandard 2D data d isplay with 3D prob lem solv ing and the interact ive 3 D s tereoscopic modal i ty as used by the radiologis t had a sensi t iv i ty and specif ici ty o f 100%. The in- teractive 3D stereoscopic modal i ty as used by the urologis t and

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