MR phlebography was recently proposed as a possible alternative to contrast venography in the detection of deep venous thrombosis. We focused our work on the study of the pelvic veins since it is at this level that contrast venography and the other noninvasive techniques, i.e., phlebography, impedance plethysmography and US, exhibit their major limitations. Thirty patients underwent MR phlebography: 13 of them had a diagnosis of DVT of the pelvic venous district and the other 17 had negative results for this condition. All the patients were also examined with color-Doppler US at the pelvis and legs. In all the patients submitted to MR phlebography, thrombosis site and presence were demonstrated, with diagnostic information also on its extent and adhesion to vein wall. To conclude, MR phlebography can provide contrast venography-like images in a noninvasive way, with high accuracy (100% sensitivity and 90% specificity) especially in the pelvic district where the limitations of other techniques are more apparent. Larger series of patients must be studied to assess the actual role of MR phlebography in the patients with DVT or at high risk for this condition.

Femoral Vein↗

PubMedDate not supplied

[Magnetic resonance in gallbladder carcinoma. Its diagnostic reliability].

The use of magnetic resonance imaging (MRI) to study the liver is currently on the increase. Our study was aimed at evaluating MR diagnostic reliability in the detection and staging of gallbladder carcinomas. Thirty-one patients with gallbladder carcinoma were studied. MRI was performed with a 0.5 T superconductive magnet, using spin-echo (SE) T1- and T2-weighted sequences and gradient-echo (GE) refocusing sequences to evaluate portal system patency. Sixteen patients underwent surgery, while 24 were submitted to angio-CT. MR findings correlated well with angio-CT results. In 4 cases only MRI could not define tumor extent due to the presence of breathing artifacts. In 6 cases the tumor was identified at intracholecystic level, while in 21 cases it involved gallbladder fossa and infiltrated liver parenchyma. In 10 of these patients, the lesion involved also the hepatic hilum, while 7 patients exhibited liver metastases. Twenty patients presented lymphadenopathy at both the hilum and the portocaval space. In 8 patients GE refocusing sequences allowed the evaluation of neoplastic thrombosis of the portal vein. Of 16 patients who underwent surgery, MRI underestimated 2 cases--namely, the presence of micrometastases in one case and tumor spread greater than demonstrated by MRI in the other case. To conclude, in our experience MRI can be considered a valuable diagnostic technique to detect and stage gallbladder carcinomas.

Aged↗

PubMedDate not supplied

[The information management of a radiology department: the development of a new type of software for the archiving of alphanumeric data and images].

The authors report the main characteristics and the goals of the development of the RIS of the II Chair of the Institute of Radiology, La Sapienza University, Rome. The system was developed with a commercial software (4th Dimension), for use with an Ethernet network and Macintosh Apple computers. One of the main problems was to obtain a user-friendly system. The main options of our system are: booking, registration, exam execution, reporting, archives and statistics and system administration. The main characteristics of our RIS is that it allows important images to be archived in limited number and at low resolution. The aim is to use images for consultation and teaching purposes, not for diagnosis which is made on the original images. Low resolution images permit to use limited storage space. Image quality is very similar to that of the original images for the equipment connected on line with the RIS--i.e., US and MR units in our institute. Conventional radiographic and CT images are digitalized by two scanners with maximum resolution of 4k x 4k x 11 bits. To date, good results have been obtained. Our RIS has been used by the medical and non-medical staffs, without any particular instruction and has allowed us to organize and make faster department management and reporting.

Computer Communication Networks↗

PubMedDate not supplied

Non-invasive evaluation of the biliary tree with magnetic resonance cholangiopancreatography: initial clinical experience.

Magnetic resonance cholangiopancreatography is a new, non-invasive imaging technique for visualization of the biliary ducts. Magnetic resonance cholangiopancreatography was performed on 136 patients (20-87 years old) with a superconductive magnet at 0.5T (Philips Gyroscan T5). Volumetric images on coronal planes were acquired; a T2 weighted turbo spin echo sequence (TR = 3000; TE = 700; number of excitations = 8; echo train length = 128; Acquisition time = 5'48") with respiratory compensation was performed. Images were reconstructed on coronal planes rotated at different angles using the MIP algorithm. When neoplastic disease was detected additional images on axial planes (SE Tlw: TR/TE 300/10 and turbo spin echo T2w: TR/TE 3000/120) were acquired. Magnetic resonance cholangiopancreatography allowed images of diagnostic value to be obtained in all cases. In choledocholithiasis, the technique had a sensitivity of 91.6%, specificity of 100% and overall diagnostic accuracy of 96.8%. Of the 48 patients with stenotic lesions, 16 cases were correctly characterized as benign and 30 as malignant. Two cases of focal chronic pancreatitis were misdiagnosed as pancreatic head carcinoma. In patients submitted to bilioenteric anastomosis, the technique was able to detect dilation of intrahepatic ducts, stenosis and associated stones in the 8 positive cases. In all 11 patients with chronic pancreatitis, dilated Wirsung duct and the stenotic tracts were revealed. In conclusion, magnetic resonance cholangiopancreatography can be considered as a technique able to completely replace diagnostic endoscopic retrograde cholangiopancreatography. However, further studies are necessary for a better evaluation of potential advantage and disadvantages.

Bile Duct Neoplasms↗

PubMedDate not supplied

Endorectal magnetic resonance imaging in the preoperative staging of rectal tumors.

A proper preoperative staging of rectal tumors is important for correct treatment planning. We included in our study 23 patients with rectal carcinoma in order to evaluate the diagnostic accuracy of endorectal MRI. This technique enabled us to show neoplasms as a hyperintense lesion as compared to the muscolaris. To better delineate the renal dimensions of the neoplasms and reduce chemical shift artifact we performed T2 weighted TSE sequences with and without fat suppression. The diagnostic accuracy in the evaluation of T and N factors as compared to surgery was respectively 78.2% and 78.9%. The major problem has been a slight tendency to overstage parietal infiltration and lymphnodal involvement. Endorectal MRI allows us to obtain an excellent anatomic detail of the three rectal wall layers and a very high spatial resolution which might make this technique the examination of choice in the evaluation of rectal carcinoma.

Humans↗

PubMedDate not supplied

[Cholangiopancreatography with magnetic resonance in the assessment of pancreatic ducts].

We investigated MR cholangiopancreatography (MRCP) findings in patients with pancreatic conditions, which are mainly diagnosed based on US and CT morphologic findings. Sixty-three patients were submitted to MRCP using a .5T magnet. MRCP was performed with non-breath-hold fat-suppressed 3D turbo spin echo sequences (TR = 3000 ms, TE = 700 ms, ETL = 128, NEX = 6) with 3 min acquisition time. For better depiction of Wirsung duct and secondary ducts in the last 11 patients, a high resolution technique with a 128 x 256 matrix, 8 NEX and 8 min 36 s acquisition time was developed. MRCP images were studied both on MIP reconstructions and on single slices as well as T1- and T2-weighted TSE axial images. The diagnosis was compared with endoscopy, percutaneous procedure or CT findings in all cases. A hypointense focal mass was observed on T1-weighted TSE images in 39 pancreatic carcinoma patients (100%) and parenchymal atrophy was shown in 13 patients (33%); a sudden obstruction of the Wirsung duct was observed in 16 cases (41%) with homogeneous dilatation in 11 cases (28%). A tapered appearance of the distal Wirsung duct was demonstrated in 19 chronic pancreatitis patients, with diffuse patchy signal changes in 12 patients (63%); bead-like appearance of the Wirsung duct was shown in 6 cases (32%) and pseudocysts in 7 cases (37.3%). MRCP is the only imaging method demonstrating pancreatic conditions between carcinoma and pancreatitis, similarly to ERCP.

Adult↗

PubMedDate not supplied

[Biliary complications of liver transplant. Role of cholangiography with magnetic resonance].

INTRODUCTION: Orthotopic liver transplantation is considered the treatment of choice in several hepatic conditions. The five-year patient survival rate is approximately 75%, thanks to progress in both surgical techniques and postoperative medical treatment. Biliary complications are one of the commonest causes of failure and their prompt identification is difficult due to their insidious clinical pattern and to the poor predictive value of a negative US examination. To date, invasive contrast cholangiography (endoscopic retrograde cholangiography and percutaneous transhepatic cholangiography) may be the only way to identify anatomic abnormalities and it is therefore a necessary examination when biliary obstruction is suspected. The aim of our work was to assess the possible role of MR cholangiography in late biliary complications of liver transplanted patients. MATERIAL AND METHODS: Twenty-three liver transplant recipients (11 men and 12 women, mean age: 51.1 years) were submitted to MR cholanglography using non-breath-hold, fat-suppressed three-dimensional turbo spin echo sequences, (TR = 3000 ms, TE = 700 ms, ETL = 128). Our patients presented with clinical, laboratory and US patterns doubtful for biliary obstruction. The diagnostic confirmation was obtained at percutaneous transhepatic cholangiography (four cases), endoscopic retrograde cholangiography (eight cases), T-tube cholangiography (one case) or clinical follow-up (ten cases). RESULTS: No biliary tract abnormalities were detected at MR cholangiography in 11 cases. Twelve strictures were diagnosed in eleven patients (9 anastomotic, two nonanastomotic/intrahepatic and one nonanastomotic/extrahepatic, with associated anastomotic and nonanastomotic strictures in two cases). MR cholangiography correctly defined the stricture site and the dilation of the bile ducts above in all cases, with optimal correlation with contrast cholangiographic findings. The common bile duct below the stricture was visible in 9 of 10 patients with extrahepatic strictures on MR cholangiography and in 8 of 10 patients on contrast cholangiograms. The distal common bile duct was missed on both MR cholangiography and diagnostic percutaneous transhepatic cholangiography in a patient only. The strictures were correctly graded in 8 of 10 patients, with two cases of overestimation. Other findings were a 1-cm stone proximal to the obstructed common bile duct, multiple intrahepatic stones in another case and common bile duct kinking at the anastomosis. CONCLUSIONS: MR cholangiography is a useful imaging method in the follow-up of liver transplant recipients which can assess the biliary obstruction and therefore permit to limit the use of invasive procedure only for interventional purposes.

Biliary Tract Diseases↗