Gadobenate Dimeglumine as an Intrabiliary Contrast Agent: Comparison with Mangafodipir Trisodium with Respect to Non-dilated Biliary Tree Depiction

OBJECTIVE: To compare the efficacy of Mangafodipir trisodium (Mn-DPDP) -enhanced MR cholangiogrphy (MRC) and Gadobenate dimeglumine (Gd-BOPTA) -enhanced MRC in visualizing a non-dilated biliary system. MATERIALS AND METHODS: Eighty-eight healthy liver donor candidates underwent contrast-enhanced T1-weighted MRC. Mn-DPDP and Gd-BOPTA was used in 36 and 52 patients, respectively. Two radiologists reviewed the MR images and rated the visualization of the common duct, the right and left hepatic ducts, and the second-order branches using a 4-point scale. The contrast-to-noise ratio (CNR) of the common duct to the liver in the two groups was also compared. RESULTS: Mn-DPDP MRC and Gd-BOPTA MRC both showed similar visualization grades in the common duct (p = .380, Mann-Whitney U test). In the case of the proximal bile ducts, the median visualization grade was significantly higher with Gd-BOPTA MRC than with Mn-DPDP MRC (right hepatic duct: p = 0.016, left hepatic duct: p = 0.014, right secondary order branches: p = 0.006, left secondary order branches, p = 0.003). The common duct-to-liver CNR of the Gd-BOPTA MRC group was significantly higher (38.90+/-24.50) than that of the Mn-DPDP MRC group (24.14+/-17.98) (p = .003, Student's t test). CONCLUSION: Gd-BOPTA, as a biliary contrast agent, is a potential substitute for Mn-DPDP.

Hilar Branching Anatomy of Living Adult Liver Donors: Comparison of T2-MR Cholangiography and Contrast Enhanced T1-MR Cholangiography in Terms of Diagnostic Utility

PURPOSE: To compare T2-weighted MR cholangiography (T2-MRC) and contrast-enhanced T1-weighted MRC (enhanced T1-MRC) in the assessment of biliary anatomy in donor candidates for living related liver transplantation (LRLT). MATERIALS AND METHODS: Thirty-three potential donors underwent MR examination for preoperative evaluation. Using the single-shot half-Fourier RARE sequence, T2-weighted single-section and coronal images were obtained, and enhanced T1-MRC was performed, using 3D GRE sequences after the administration of mangafodifir trisodium. To assess the hilar ductal branching pattern and determine diagnostic confidence, two reviewers first evaluated the unpaired T2-MRC and enhanced T1-MRC images, and then paired T2-MRC and enhanced T1-MRC images together. In particular, in 12 cases in which direct cholangiographys were performed, the feasibility of single duct-to-duct anastomosis was assessed using the unpaired and the paired sets sequentially. RESULTS: The reviewers' confidence tended to be higher for enhanced T1-MRC than T2-MRC, but the difference was not statistically significant. For both reviewers, confidence was significantly higher for the paired set than for T2- or enhanced T1-MRC alone (p < .001). The types of biliary anatomy determined in the paired set matched the consensus reading in 33 (100%) and 30 cases(91%) assessed by reviewer 1 and 2, respectively. The separate interpretation of T2- and enhanced T1-MRC findings matched the consensus interpretation in 30 (91%) and 28 cases (85%), respectively, assessed by reviewer 1, and 26 (79%) and 28 cases (85%), respectively, assessed by reviewer 2. The possibility of single anastomosis was accurately predicted in 91.6% of cases in T2-MRC, and 100% at enhanced T1-MRC and the combined set. CONCLUSION: In the evaluation of the biliary anatomy of potential donors for LRLT, the combined use of T2-MRC and enhanced T1-MRC may improve diagnostic confidence and decrease the occurrence of a non diagnostic or equivocal interpretation at T2-MRC alone.

Hip and Pelvis Diseases on Lumbar AP Radiographs Including Both Hip Joints

PURPOSE: To determine the frequency of diseases of the hip and pelvis, as seen of plain radiography of the lumbar spine in patients with suspicious lumbar disease, and to evaluate the methods used for lumbar spine radiography in Korea. MATERIALS AND METHDOS: Sixty university and training hospitals were randomly selected and asked to describe the projections, film size and radiographic techniques employed for routine radiography in patients with suspected disease of the lumbar spine. Plain radiographs of 1252 patients, taken using 14"x17"film and depicting both hip joints and the lumbar region, were analysed between March 1999 and February 2000. RESULTS: In 15 patients (1.2%), the radiographs revealed hip or pelvic lesions, confirmed as follows: avascular necrosis of the femoral head (n=11, with bilateral lesions in four cases); sustained ankylosing spondylitis (n=2); acetabular dysplasia (n=1); and insufficiency fracture of the pubic rami secondary to osteoporosis (n=1). In 11 of the 20 hospitals which responded, 14"x17"film was being used for lumbar radiography, while in the other nine, film size was smaller. CONCLUSION: Plain radiography of the lumbar spine including both hip joints, may be a useful way to simultaneously evaluate lesions not only of the lumbar spine but also of the hip and/or pelvis.

New Film-Cassette System to Obtain Wider Field of Craniocaudal View Compared with Conventional Technique in Screening Mammography

PURPOSE: To evaluate the efficacy of a newly designed cassette and film system used to obtain a craniocaudal(CC) image during mammographic examination. MATERIALS AND METHODS: We designed a film-cassette system for use inobtaining a CC image. The merit of this system is that the contact plane between the film and film cassette andthe thoracic wall of the examinee changed from linear to concave, thus including more tissue on the image. Twentywomen examined by screening mammography underwent conventional and new CC plane examinations. The distance fromthe nipple to the posterior margin of the included breast tissue, as seen on CC mammograms, was measured using thetwo techniques, and the difference between the respective results was analyzed by paired t-test. RESULTS: Thedistance from the nipple to the posterior margin was 12.9 +/-1.7cm and 14.5 +/-1.4cm at the lateral portion of theconventional and new CC image, respectively. This distance was thus significantly greater on the new than on theconventional image (p<0.001), but there was no significant difference between their me-dial portions. CONCLUSION:The newly designed cassette and film system used to obtain a craniocaudal image during mam-mography includes morebreast tissue than the conventional system and may be helpful for the mammograph-ic screening and diagnosis ofperipheral breast lesions.

Impact of Image Post-Processing on PACS Workstation: Dynamic Range Suppression(DRS) of Chest Radiographs

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.

Impact of Image Post-Processing on PACS Workstation: Dynamic Range Suppression(DRS) of Chest Radiographs

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.

Percutaneous Transhepatic Cholangiography and Biliary Drainage by Antegrade Puncture Technique: Technical Note

The antegrade puncture technique represents a new approach to percutaneous transhepatic cholangiography andbiliary drainage. With this technique, ductal puncture begins with the liver capsule toward the hepaticparenchyma. This report briefly describes this new technique, and its safety and feasibility.