Idiopathic Synovial Osteochondromatosis of the Hip: Radiographic and MR Appearances in 15 Patients

OBJECTIVE: To evaluate the radiographic and MR appearance of idiopathic synovial osteochondromatosis of the hip. MATERIALS AND METHODS: Radiographs and MR images of 15 patients with idiopathic synovial osteochondromatosis of the hip were assessed. The former were analysed in terms of the presence of 1) juxta-articular calcified and/ or ossified bodies, 2) osteophytes, 3) bone erosion, 4) juxta-articular osteopenia, and 5) joint space narrowing, while for the latter, analysis focused on 1) the configuration of intra-articular bodies, 2) bone erosion, 3) synovial thickening, 4) conglomeration of intra-articular bodies, and 5) extra-articular extension. RESULTS: At hip radiography, juxta-articular calcified and/ or ossified bodies were seen in 12 of the 15 patients (80%), bone erosion in eight (53%), osteophytes in seven (47%), juxta-articular osteopenia in five (33%) and joint space narrowing in five (33%). In eight patients (53%), MR imaging depicted intra-articular bodies of focal low signal intensity at all pulse sequences, and areas of isointensity at T1WI and hyperintensity at T2WI. In three (20%), intra-articular bodies of focal low signal intensity and areas of hyperintensity at all pulse sequences were observed, with areas of iso-intensity at T1WI and hyperintensity at T2WI, while in four (27%), intra-articular bodies of only focal low signal intensity at all pulse sequences were apparent. Synovial thickening was present in 13 patients (87%), bone erosion in 11 (73%), conglomeration of the intra-articular bodies in 11 (73%), and an extra-articular herniation sac in six (40%). CONCLUSION: The most common radiographic finding of synovial osteochondromatosis of the hip was the presence of juxta-articular calcified and/ or ossified bodies. MR imaging depicted intra-articular bodies of focal low signal intensity at all pulse sequences, with areas of iso-intensity at T1WI and hyperintensity at T2WI. In addition, the presence of an extra-articular herniation sac was not uncommon.

The Usefulness of Test Bolus Examination in Three-Dimensional Contrast-Enhanced MR Angiography of the Carotid Artery

PURPOSE: To compare the usefulness of test bolus examination in three-dimensional contrast enhanced MR angiography of the carotid artery with that of the fixed delay time method. MATERIALS AND METHODS: Sixty consecutive patients (mean age, 60.1 years) in whom carotid arterial disease was suspected and who were examined during a 17-month period were divided into two equal groups. For group A, a fixed delay time of 5 secs was used, while for group B, the delay time of the test bolus examination was calculated from the signal intensity versus time curve of the carotid artery, obtained after the test injection of 1 ml contrast material into the right brachal vein. Overall image quality, discrimination between the arterial and the venous phase, and the contrast-to-noise ratio(CNR) of the carotid artery were compared between the two groups. Overall image quality was classified as excellent, good, moderate or poor, and discrimination between the two phases was graded IV-I according to the degree of jugular venous enhancement. RESULTS: In group A, overall image quality of the carotid artery was classified as excellent or good in 13 (43.3%)and 9 (30.0%) cases, respectively, while in group B the corresponding figures were 23 (76.7%) and 5 (16.7%). The differences between the two groups were statistically significant (p<0.05). In terms of discrimination between the arterial and venous phase, 20 (66.7%) of the 30 cases in group A were assigned grade IV or III, while 28 (93.3%) of the 30 in group B were assigned these same grades (p<0.05). The CNR of the carotid artery was higher in group B(67.1 +/-16.1) than in group A(27.3 +/-17.8), with statistical significance(p<0.05). CONCLUSION: For examination of the carotid artery, contrast enhanced MR angiography using a test bolus is su-perior to the fixed delay time method.

Usefulness of Fat-Suppressed Turbo SE MR Imaging for the Evaluation of Meniscal Tears

PURPOSE: Suppression of the relatively high signal intensity of fat leads to more efficient use of thedynamic range for display of tissue contrast. In order to evaluate meniscal tears, we compared a fat-suppressedturbo spin-echo(FSTSE) sequence with turbo SE(TSE). MATERIALS AND METHODS: One hundred and seven knees in 103consecutive patients referred for MR study of the knee were imaged using both FSTSE and TSE sequence. The turbo SEsequence provided proton density-weighted and T2-weighted images (dual echo technique) with an effectiveecho-train length of five. For fat-suppression, a frequency-selective chemical presaturation pulse was applied.Forty-two knees (84 menisci) were studied arthroscopically and the findings were taken as the reference standard.FSTSE and TSE images were reviewed retrospectively by two radiologists. Next, for each patient, the quality ofFSTSE and TSE images was compared;the former were scored by each reviewer as either superior to, equal to, orinferior to TSE images. RESULTS: Among the 214 menisci evaluated, the results of FSTSE and TSE imaging were verysimilar (kappa index 0.87). Twenty four tears were found during arthroscopy in 84 menisci. FSTSE imaging was moresensitive than TSE (96% versus 83%), though specificity was equal(98%). Among the 107 cases, FSTSE images wererated by both observers as superior to TSE images for overall quality and visualization of the meniscus itself.CONCLUSION: For the evaluation of meniscal tears, FSTSE sequences were more sensitive than those obtained withTSE, and their image quality was superior. For the study of meniscus tears among a large population, FSTSE istherefore more useful than TSE.

Opacification of Portal Vein on CT during Hepatic Arteriography Via Normal Vascular Flow

PURPOSE: To evaluate the frequency, distribution, and associated factors of the opacified normal portal veinas seen on CT, during hepatic arteriography(CTHA). MATERIALS AND METHODS: One hundred and eighty-nine patientswho underwent both CTHA and CT during arterioportography (CTAP) during a three-year period were reviewed. Ofthese, 66 patients without anomalous hepatic arterial supply and arterioportal (AP) shunt on celiac angiographywere analyzed. Comparing CTHA with CTAP, we determined whether or not the portal vein(PV) is opacified within thesecond-order branch. The degree of contrast enhancement in the stomach, duodenum, and pancreas was graded asfollows : grade I, all three organs were hypodensely enhanced; grade II, some organ were isodensely enhanced, butothers hypodensely ; grade III, all three organs were isodensely enhanced relative to the CHA. The relationshipbetween opacified portal vein (OPV) and the degree of enhancement of the three organs, amount of contrast media,and Child classification was statistically examined. RESULTS: The PV was opacified in 18 of the 66 patients (27%); This was the main PV in 16, right PV in 13, and left PV in two. Of the single branches, the right post posteriorbranch was most commonly opacified. Among 18 patients with OPV, the degree of three organs (stomach, duodenum, andpancreas) was grade I in two, grade II in two, and grade III in 14 while among 48 patients with nonopacified PV, thefindings were grade I in 27, grade II in seven, and grade III in 14. The relationship between OPV and degree ofenhancement of the three organs was statistically significant (p=0.001). There was however, no statisticallysignificant difference between OPV and Child classification and the amount of contrast media. CONCLUSION: PVopacification during CTHA is not rare and this finding should not therfore be regarded as indicator of apathologic conditions such as AP shunt.

Zebra Pattern in CT during Arterial Portography: Analysis of Associated Factors

PURPOSE: To analyze the factors associated with the zebra pattern in CT during arterial portography(CTAP). MATERIALS AND METHODS: In 275 CTAP procedures, the factors associated with the zebra pattern, such as laminar flow in the portal vein, the presence of liver cirrhosis, the artery selected for CTAP, location of the catheter tip in the superior mesenteric artery(SMA), splenic volume, and the existence of an aberrant right hepatic artery(RHA) emerging from the SMA were analyzed. RESULTS: In 106 of 275 procedures (38.5%), a zebra pattern was apparent. Portal venous laminal flow was seen in 92 % of procedures in the group with this pattern and in 63 % in the group without it. Eighty-three of 235 procedures (35.3 %) in which the SMA was injected and 23 of 40(57.5 %) involving splenic artery injection showed the zebra pattern. In 22 of 35(62.8 %) in which the catheter tip was located in the distal SMA and 61 of 200 ( 30.5 %) in which this was at a proximal site, the zebra pattern was evident. Mean splenic volume was less in the group with the zebra pattern. The effect on the zebra pattern of liver cirrhosis and an aberrant RHA emerging from the SMA was not statistically significant. CONCLUSION: In CTAP, the incidence of the zebra pattern was 38.6%, and was related to laminal flow in the portal vein. The pattern is frequently seen in CTAP involving contrast injection via the splenic artery, distal location of a catheter tip in the SMA, and small splenic volume.