MR Cholangiopancreatography Of The Cystic Duct

Objective To study the best method which showed the cystic duct by MR cholangiopancreatography。To study the display of the cystic duct compared by oral administration of ferric ammonium citrate(FAC). To observe the normal anatomy and various variants of the cystic duct. To study the relationship between the anatomic variations and related diseases of the cystic duct. To analyze the clinical application of the anatomic variations of the cystic duct.Materials and Methods During an 5-month period from September 2006 to January 2007, 378 consecutive patients in North Sichuan Medical College Hospital performed MR cholangiopancreatography were included in this study. There are 149 cases which met the inclusion and exclusion criteria, there were 86 men and 63 women with aged ranging from 5 to 78 years of age, with an average age of 50 years of age. 53 cases of conventional MRCP were as control group, 69 cases of oral examination with FAC as the trial group. In Another 27 cases, the first acquisitions was conventional MRCP, MRCP was repeated after oral FAC solution. The first acquisitions were conventional cross-sectional respiratory gating fast spin-echo T2-weighted fat-suppression sequence. Then axial T2-weighted images showed the cystic duct and the common bile duct was selected to localization. A series of different angles MRCP images were obtained by running along the cystic duct and the common bile duct using a series of multi-angle oblique thick samples.In 27 patients performed MRCP before and after oral FAC solution, the first acquisitions were cross-sectional respiratory gating fast spin-echo T2-weighted fat-suppression sequence and conventional MRCP. Then the body position of patients were maintained, patients administrated oral FAC solution with long disposable bending pipette were performed other conventional scanning sequence. In 5-20 minutes after taking the drug, MRCP performed with the same scanning parameters were repeated.On MRCP images, the display of the cystic duct was acquired by multi-angle, multi-faceted observation. As for the unsharpness cystic duct, MRCP images were combined with SSFSE sequence cross-sectional T2-weighted images. The length and diameter of the cystic duct was observed and measured. The courser, the confluence and the anatomic variants of the cystic duct were investigated. The display of the cystic duct was compared between normal group and the control group, between before and after oral FAC solution. The relationship between the anatomic variations and related diseases of the cystic duct were studied.Results In the control group of 53 patients, the frequencies of visualization of the cystic duct was 72% (38/53) on conventional MRCP examination , 85%(45/53)combined with SSFSE sequence cross-sectional T2-weighted images, respectively. In the trial group of 69 patients, the frequencies of visualization of the cystic duct was 87%(60/69)after oral FAC solution., 96 % ( 66/69 ) combined with SSFSE sequence cross-sectional T2-weighted images, respectively. In the 27 patients who take orally FAC solution by self-control study, the frequencies of the visualization of the cystic duct were, respectively, 72%(19/27), 89%(24/27) and 96%(26/27)before oral FAC, after oral FAC and combined with SSFSE sequence cross-sectional T2-weighted images.The display of the cystic duct taked orally FAC was increased obviously compared between the control group and trial group, between before and after oral FAC solution, increased obviously combined with SSFSE sequence cross-sectional T2-weighted images. There were significant statistically.Cases of the cystic duct depicted well on MRCP images were add up to 122, The average length and diameter of the cystic duct was (20.83±8.92) mm and (2.82±1.04)mm, 70% (85/122) course was tubular, 30% (37/122) course was tortuous. In the 122 patients, the cystic duct inserted into the middle one-third of the extrahepatic bile duct in 66%(80/122)of cases, into the upper one-third in 31%(38/122), and into the distal one-third in 3%(4/122). The cystic duct entered the extrahepatic bile duct from the right aspect in 74%(90/122)of cases, from the medial aspect in 3%(4/122), and from an anterior and posterior position in 23%(28/122). The cystic duct joined the common hepatic duct at an oblique angle in about 73%(89/122)of cases. In about 15%(18/122)of cases, the cystic duct spiraled around the common hepatic duct . In another 12%(15/122), it runned parallel to it before the two ducts unite.In the 122 patients, congenital anatomic variants of the cystic duct were common, occurring in 20%(24/122)of cases. In the 24 patients, the cystic duct runned parallel to extrahepatic bile duct in 54%(13/24), inserted into the distal one-third in 17%(4/24), entered from the medial aspect in 17%(4/24). Long cystic duct was in 4% (1 /24), cyst of cystic duct was in 4%(1/24), anomalous right hepatic duct was in 4%(1/24).In the 378 patients, anatomic variants of the cystic duct were majority accompanied with stones of the cystic duct, the gallbladder and / or the common bile duct.Conclusion MRCP was the best non-invasive imaging method demonstrating the cystic duct, The display of the cystic duct was increased obviously after oral FAC solution, also increased obviously combined with SSFSE sequence cross-sectional T2-weighted images. The courser, the confluence and the anatomic variants of the cystic duct can be depicted well by MRCP. MRCP can also facilitate precise visualization of the disease of the cystic duct. Anatomic variants of the cystic duct were majority accompanied with stones of the cystic duct, the gallbladder and / or the common bile duct. This technique is very important to assess preoperatively the anatomic variants of the cystic duct to avoid unnecessary operative exploration and postoperative complications.