Gadomer-17 in Contrast Enhanced MR Imaging of Reperfused Myocardial Infarction in a Cat Model

PURPOSE: To evaluate in reperfused myocardial infarction in a cat model, the time-course of signal enhancement as seen on Gadomer-17 enhanced MRI, and to correlate the size of the enhanced area with that of the infarct area as revealed by on histochemical examination. MATERIALS AND METHODS: Five cats which had undergone occlusion of the LAD followed by reperfusion underwent MR imaging. After T2-weighted imaging, Gadomer-17 enhanced T1-weighted images were obtained in four cats during a six-hour period, and in one during a three-hour period. Signal intensities were measured in the enhanced and non-enhanced areas of enhanced T1-weighted images. and using 2,3,5-triphenyl tetrazolium chloride (TTC) histochemical staining, the size of the abnormal signal area on each image was compared with that of the infarct area. RESULT: The enhanced area seen on enhanced T1-weighted images showed rapidly increased signal intensity following the administration of Gadomer-17. Maximum enhancement was detected during a 40 -60 minutes period, with an average enhancement of 168 +/-9.9% of normal myocardium. TTC staining revealed that the size of the high signal area on T2-weighted images and of the enhanced area on enhanced T1-weighted images was greater than that of the infarct area (p<0.05). CONCLUSION: In reperfused myocardial infarction in a cat model, Gadomer-17 enhanced MR imaging delineates both reversibly and irreversibly damaged myocardium, with strong enhancement and a broad temporal window. We may therefore expect that Gadomer-17 is useful for demonstrating myocardial injury.

Prostate Volume Measurement by TRUS Using Heights Obtained by Transaxial and Midsagittal Scanning : Comparison with Specimen Volume Following Radical Prostatectomy

OBJECTIVE: The purpose of this study was to determine, when measuring prostate volume by TRUS, whether height is more accurately determined by transaxial or midsagittal scanning. MATERIALS AND METHODS: Sixteen patients who between March 1995 and March 1998 underwent both preoperative TRUS and radical prostatectomy for prostate cancer were included in this study. Using prolate ellipse volume calculation (height x length x width x pi/6), TRUS prostate volume was determined, and was compared with the measured volume of the specimen. RESULTS: Prostate volume measured by TRUS, regardless of whether height was determined transaxially or midsagittally, correlated closely with real specimen volume. When height was measured in one of these planes, a paired t test revealed no significant difference between TRUS prostate volume and real specimen volume (p = .411 and p = .740, respectively), nor were there significant differences between the findings of transaxial and midsagittal scanning (p = .570). A paired sample test, however, indicated that TRUS prostate volumes determined transaxially showed a higher correlation coefficient (0.833) and a lower standard deviation (9.04) than those determined midsagittally (0.714 and 11.48, respectively). CONCLUSION: Prostate volume measured by TRUS closely correlates with real prostate volume. Furthermore, we suggest that when measuring prostate volume in this way, height is more accurately determined by transaxial than by midsagittal scanning.

Prostate Volume Measurement by TRUS Using Heights Obtained by Transaxial and Midsagittal Scanning : Comparison with Specimen Volume Following Radical Prostatectomy

OBJECTIVE: The purpose of this study was to determine, when measuring prostate volume by TRUS, whether height is more accurately determined by transaxial or midsagittal scanning. MATERIALS AND METHODS: Sixteen patients who between March 1995 and March 1998 underwent both preoperative TRUS and radical prostatectomy for prostate cancer were included in this study. Using prolate ellipse volume calculation (height x length x width x pi/6), TRUS prostate volume was determined, and was compared with the measured volume of the specimen. RESULTS: Prostate volume measured by TRUS, regardless of whether height was determined transaxially or midsagittally, correlated closely with real specimen volume. When height was measured in one of these planes, a paired t test revealed no significant difference between TRUS prostate volume and real specimen volume (p = .411 and p = .740, respectively), nor were there significant differences between the findings of transaxial and midsagittal scanning (p = .570). A paired sample test, however, indicated that TRUS prostate volumes determined transaxially showed a higher correlation coefficient (0.833) and a lower standard deviation (9.04) than those determined midsagittally (0.714 and 11.48, respectively). CONCLUSION: Prostate volume measured by TRUS closely correlates with real prostate volume. Furthermore, we suggest that when measuring prostate volume in this way, height is more accurately determined by transaxial than by midsagittal scanning.

Value of Cardiac MR Imaging for the Diagnosis of Arrhythmogenic Right Ventricular Dysplasia:Comparison of Clinical and MR Imaging Diagnostic Grades

PURPOSE: To evaluate the usefulness of cardiac MRI in the diagnosis of clinically suspected arrhythmogenic right ventricular dysplasia (ARVD). MATERIALS AND METHODS: Between February 1991 and January 1999, 15 patients [M:F=13:2, aged 2 -60 (mean, 37 -7) years] with clinically suspected ventricular arrhythmia due to unknown causes underwent MR imaging. Using a CP body array coil and the single slice breath hold technique, ECG-gated T1-weighted images were obtained. In all patients, these were acquired transaxially from the diaphragm to the aortic arch and along the true short and long axis, and in two, coronal images were obtained. On the basis of clinical and MRI diagnostic criteria, ARVD was classified as one of four types. The significance of differences in diagnostic grades between clinical and MRI criteria was determined using Wilcoxon's signed rank test. RESULTS: According to both clinical and MRI criteria, it was highly probable that three of the 15 patients had ARVD. In eleven, both sets of criteria indicated the same diagnostic grade. Wilcoxon's signed rank test indicated no significant differences in diagnostic grades between clinical and MRI criteria (p > 0.05). CONCLUSION: For the diagnosis or exclusion of ARVD, MR imaging is a useful modality.

Value of Cardiac MR Imaging for the Diagnosis of Arrhythmogenic Right Ventricular Dysplasia:Comparison of Clinical and MR Imaging Diagnostic Grades

PURPOSE: To evaluate the usefulness of cardiac MRI in the diagnosis of clinically suspected arrhythmogenic right ventricular dysplasia (ARVD). MATERIALS AND METHODS: Between February 1991 and January 1999, 15 patients [M:F=13:2, aged 2 -60 (mean, 37 -7) years] with clinically suspected ventricular arrhythmia due to unknown causes underwent MR imaging. Using a CP body array coil and the single slice breath hold technique, ECG-gated T1-weighted images were obtained. In all patients, these were acquired transaxially from the diaphragm to the aortic arch and along the true short and long axis, and in two, coronal images were obtained. On the basis of clinical and MRI diagnostic criteria, ARVD was classified as one of four types. The significance of differences in diagnostic grades between clinical and MRI criteria was determined using Wilcoxon's signed rank test. RESULTS: According to both clinical and MRI criteria, it was highly probable that three of the 15 patients had ARVD. In eleven, both sets of criteria indicated the same diagnostic grade. Wilcoxon's signed rank test indicated no significant differences in diagnostic grades between clinical and MRI criteria (p > 0.05). CONCLUSION: For the diagnosis or exclusion of ARVD, MR imaging is a useful modality.

Usefulness of Additional Prone pad compression Study in Upper Gastrointestinal Series for Detecting EarlyGastric Cancer

PURPOSE: To evaluate the usefulness of prone pad study in upper gastrointestinal series(UGIS) for thedetection of early gastric cancer(EGC). MATERIALS AND METHODS: During an eight-month period, 88 of 170 patientswho underwent gastrectomy due to EGC were also the subjects of prone pad study as well as double contrast(n=92),mucosal relief(n=76), or compression(n=91) studies. The EGCs were single in 84 patients and double in four. Wecompared prone pad study with the three other techniques for detecting a tumor and depicting the surroundingmucosal changes. Lesional conspicuity was rated 'complete', 'incomplete','suspicious'. or 'undetected'. Thedepiction of surrounding mucosal change was rated 'excellent', 'good', 'fair', or 'poor'. RESULTS: Mean tumorsize was 3.2cm, with a range of 0.3-9cm. Tumors were located in the antrum(n=55), angle(n=13), lower or midbody(n=16), or the sign body and cardia(n=5). Among the 92 EGCs evaluated, UGIS missed the lesion in threecases(sensitivity, 97%). The rates of 'complete' lesional conspicuity were 49% inn prone pad, 29% in compression,20% in double contrast, and 9% in mucosal relief. The rates of excellent' in depicting surrounding mucosal changewere 45% in prone pad, 11% in double contrast, 9% in mucosal relief, and 9% in compression. The tumor wasdemonstrated only in prone pad study in five(5%) of the 92 EGCs. CONCLUSION: prone pad study during UGIS improvesboth the detection rate of EGC and the depiction of mucosal change around the tumor.

Evaluation of Characteristics of Cyanoacrylate-Lipiodol Mixtures Injected in the Different Flow Layers

PURPOSE: To observe the pattern of glue cast formation when glue was injected into the different fow layersof a flow phantom, and to demonstrate the effect in an animal experiment. MATERIALS AND METHODS: A flow phantom model consisted of a circulating pump (Simon varistaltic pump, Manostat Corporation, U.S.A.) connected via a tygon tube with a specially designed glass tube. Flow of about 4ml/sec was maintained by saline. The glass tube consisted of (1) a small-caliber (2.4-3.2mm inner diameter) straight inflow portion (feeder), (2) a round, larg-caliber portion (nidus), and (3) a medium-caliber (6.7mm inner diameter) straight outflow portion (vein). Glue mixed with Lipiodol (glue: Lipiodol=1:1-3:1) was loaded into a 1cc syringe and slowly injected through a microcatheter ; cast formation along the glass tube was observed. The feeder and nidus portions were injected twelve times and the shape of the cast was compared. In an animal experiment, glue at various concentrations was used to stop rapid flow through a surgically-constructed arteriovenous fistula in porcine carotid artery. RESULTS: When mixture was injected into the straight inflow portion (1), it formed a cast along the wall of the glass tube, with a large cast in the nidus portion. Further injection caused enlargement of the cast in the nidus, but no change in the wall of the inflow portion. When mixture was injected into the nidus portion (2) of the glass tube, a cast formed continuously within the nidus. In the animal experiment, rapid injection of glue at a high conentration staunched flow through the arteriovenous fistula. CONCLUSION: Glue-Lipiodol mixture can be injected slowly and continuously under the surface of the polymerized glue cast which forms along the wall or slow flow portion (nidus) of the glass tube in an experimental flow phantom. However, the effect did not appear during rapid flow in the animal arteriovenous fistular model in which only rapid injection of glue which was either pure or at a glue concentration of more than 75% was effective.

Idiopathic Hypereosinophilic Syndrome Involving the Liver: CT Features vs. Peripheral Eosinophilia

PURPOSE: To correlate CT features with peripheral eosinophilia in patients with idiopathic hypereosinophilic syndrome involving the liver. MATERIALS AND METHODS: During the last three years, features of liver involvement in nine of 20 patients with idiopathic hypereosinophilic syndrome were evaluated on CT. The shape and distribution of intrahepatic low densities and the presence of hepatomegaly and/or splenomegaly were reviewed on CT, and the percentage of eosinophils in peripheral blood was also determined. In seven cases, interval change in hepatic lesion and the percentage of eosinophils were reviewed on follow-up examination. RESULTS: On initial CT, varying low-density patterns were seen in the liver in all cases ; hepatomegaly was seen in four cases, and hepatosplenomegaly in two. The percentage of eosinophils was 89% in a case with diffuse patch low densities in the liver, 65-85% in three cases with numerous nodular low density lesions, 12-29% in four cases with multiple (below ten) nodular or small geographic hypodense lesions, and 24% in a case with a single nodular hypodense lesion. On follow-up CT, seven patients showed a decrease in the percentage of eosinophils, and in six, improved intrahepatic low densities were seen. CONCLUSION: On CT, intrahepatic low densities were seen in patients with idiopathic hypereosinophilic syndrome, and these were distributed more extensively when peripheral eosinophilia was more severe. With improvement in peripheral eosinophilia, the low densities also improved.