| The Magnetic Resonance Cholangiopancreatogrphty ( MRCP) is quickly developing and extensive imaging technique in clinical appli-cation in the last few years, and can depict the biliary tree and the pancreatic duct noninvasively and without the injection of contrast ma-terial , the value in diagnosis of malignant bile duct obstruction has been affirmed. Percutaneous transhepatic cholangiography(PTC) dis-play entire biliary tree distinctly,correspond to provide a analyse ima-ging and depict dilated or obstructive degree of intrahepatic and extra-hepatic directly, reliable information of position ang cause of obstruc-tion.Objective; To study the diagnostic value of MRCP in malignant bile duct obstruction.Materials and methods24 cases confirmed to be malignant bile duct obstruction with MRCP and PTC examination were reviewed and analysised between 1999 and June 2002. Among them male 15, female 9, age 39 - 84 years old, the average age is 65.7 years old.Technique considerations of MRCP: 2.0 -Tesla superconductive Magnetic Resonance Imager ( Elscint Company, ISRAEL ). Patients were limosis 6 hours before examination, and drank 250 ~ 300ml 50% Barium sulfate suspension half an hour before procedures to decreasethe influence of high signals from water in the gastrointestinal tract and improve the image quality of MRCP. The patients adopt to lie on the back, A quadrature body coil and breath - hold tecnique were used in all patients. Routine T1 T2 transect scaning were performed firstly, MRCP were performed by using a breath - hold and non - breath -hold single - shot turbo spin - echo 12 weighted sequence with an echo train length of 256 echoes ,an effective echo time of 1,200 msec , TR = 7510 ~ 12800ms,TE = 90 ~ 196ms, section thickness 3mm, ETL=10 ~16;FOV:40.0cm x45. Ocm;MIX:250 x320;NEX:2; The primitive imaging proceed with maximum intensity projection algo-rithum(MIP) to creat 3D images of thd biliary duct and pancreatic -tract.PTC:Adoption 19-21 G PTC paracentic needl ,6 - 12F drain-age - tube, according to category of the obsruction of the bile duct punture the left or right hepatic duct with the guide of ultrasound. In-dwelling drainage - tubeduring in the fluoroscopy. After the clinical symptom remitting, all patiences were proceed therapy with metal -stent ( diameter 8 - 10mm,length3 -8mm).ResultMRCP and PTC images of diagnostic quality were obtained in 24 cases successfully. Among the total, 18 patiences had choiangiocarci-noma;l patient had gallbladder carcinoma;2 patiences had carcinoma of head of pancreas; 2 patiences had heapatocarcinoma ; 1 patiences had ampulla carcinoma. The diagnostic accuracies and the diagnostic rate for obstructive level of MRCP in the malignant bile duct obstruc-tion were 91. 7%. (22/24) and 100% (24/24) , PTC were 79. 2%(19/24) and 100% (24/24).DiscussionThe magnetic resonance cholangiopancreatogrphty reported by German scholar Walker et firstly at 1990s has caused the extensive at-tention. Besides non ?invasiosn and without contast material, MRCP can provide transect scanning , effect of contrast examination , informa-tion that computer tomography and ultrasound can give, and analyse imaging that PTC can give. To malignant bile duct obstruction, MRCP can exactly display the structure of bile duct and the shape of seg-ment. It can truly show the size, shape, invasive range of the tumor combined with axial MR sections. Hence, it can be used to guide pa-tient interventional therapeusis.Tlie MRCP technique is based on heavily T2 - weighted pulse se-quences. As a result, stationary fluids have a high signal intensity while solid organs have a low signal intensity . This combination of im-aging characteristics means that MRCP provides optimal contrast be-tween the hyperintense signal of the bile and the hypointense signal of the background. MRCP techniques can be obtained using variety of pulse sequences. The largest experience with MRCP to date has in-volved using both heavily T2 - weighted gradient - echo and fast spin - echo sequ... |
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