In a field of contrast-enhanced magnetic resonance imaging of the liver, attention has been focused on evaluation of liver function using gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid(EOB). In this study, we examined the possibility of obtaining liver function in only one hepatobiliary phase 60 minutes after injection. First, in regard to the difference between the signal intensity of two materials, we examined the effects of slice gap, surface coil intensity correction(SCIC), and others. Secondly, we compared the difference between liver and spleen signal intensity with biochemical laboratory tests, Child-Pugh class, liver damage class, and the two indices(HH(15) and LHL(15))calculated by 99mTc-DTPA-galactosyl-human serum albumin hepatic scintigraphy in patients with chronic liver diseases. Finally, we designated the "Liver EOB uptake index(L-EOB(60))" from those results, compared with HH(15) and LHL(15). The results demonstrated that the difference between the signal intensity of two materials increased in the lack of slice gap explained by cross talk, and decreased with SCIC. The difference between liver and spleen signal intensity decreased with worsened liver and kidney function. In the case of slice gap >20% and direct bilirubin <0.5 mg/dL without SCIC, the correlation coefficient between L-EOB(60) and LHL(15) was 0.97. L-EOB(60) was strongly proportional to LHL(15). We conclude that L-EOB(60) meeting the above conditions can be employed as a useful index to determine liver function.
Few practical evaluation studies have been conducted on X-ray protective aprons in workplaces. We examined the effects of exchanging the protective apron type with regard to exposure reduction in experimental and practical fields, and discuss the effectiveness of X-ray protective aprons. Experimental field evaluations were performed by the measurement of the X-ray transmission rates of protective aprons. Practical field evaluations were performed by the estimation of the differences in the transit doses before and after the apron exchange. A 0.50-mm lead-equivalent-thick non-lead apron had the lowest transmission rate among the 7 protective aprons, but weighed 10.9 kg and was too heavy. The 0.25 and 0.35-mm lead-equivalent-thick non-lead aprons differed little in the practical field of interventional radiology. The 0.35-mm lead apron had lower X-ray transmission rates and transit doses than the 0.25-mm lead-equivalent-thick non-lead apron, and each of these differences exceeded 8 % in the experimental field and approximately 0.15 mSv/month in the practical field of computed tomography (p < 0.01). Therefore, we concluded that the 0.25-mm lead-equivalent-thick aprons and 0.35-mm lead apron are effective for interventional radiology operators and computed tomography nurses, respectively.
Gadoxetate Sodium (Gd-EOB-DTPA, EOB) is a new contrast agent for magnetic resonance (MR) imaging that allows both vascular and hepatobiliary imaging in one examination. Often in the arterial phase, however, appropriate scan timing is missed and contrast enhancement is not enough. In addition, to shorten the complete examination, some studies have been conducted to examine scan timing at the hepatobiliary phase earlier than 20 min after injection. We studied the optimal scan timing both at the arterial and the hepatobiliary phase. It was appropriate that multiphase acquisition of MR imaging at the arterial phase should be aimed around 25 sec after injection. Moreover, the liver-spleen contrast ratio (C(L-S)) at the hepatobiliary phase was highest at 60 min after injection, and the acquisition of an image earlier than 20 minutes lowered the C(L-S). In the future, it is desirable to establish how to use Gd-EOB-DTPA (EOB) for hepatic MR imaging after taking the extent of liver damage into consideration.
AbstractWe invented a drape-like shield against scattered X-rays that is safe to come into contact with medical equipment or people during fluoroscopically guided procedures.The shield can be easily removed by one hand from a C-arm unit. We evaluated the use of the novel removable shield under the endoscopic retrograde cholangiopancreatography (ERCP) procedure. We measured the dose rate of scattered X-rays around endoscopists with and without this removable shield, and surveyed the occupational doses to the ERCP staff. We also examined the endurance of the shield.The removable shield reduced the dose rate of scattered X-rays to one-tenth and reduced the monthly dose to an endoscopist by at least two-fifths. For 2.5 years, there was no damage to the shield and no loosening of the seam. We invented a shield removable by 1 hand from C-arm units.The removable shield reduces the dose rate of X-rays to one-tenth.The removable shield reduces the exposure of the operator to two-fifths.The removable shield is endurable for several years.The drape-like removable shield is light, simple, and useful.
The liver-spleen contrast (LSC) using hepatobiliary-phase images could replace the receptor index (LHL15) in liver scintigraphy; however, few comparative studies exist. This study aimed to verify the convertibility from LSC into LHL15. In 136 patients, the LSC, not at 20 min, but at 60 min after injecting gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid was compared with the LHL15, albumin–bilirubin (ALBI) score, and the related laboratory parameters. The LHL15 was also compared with their biochemical tests. The correlation coefficients of LSC with LHL15, ALBI score, total bilirubin, and albumin were 0.740, − 0.624, − 0.606, and 0.523 (P < 0.00001), respectively. The correlation coefficients of LHL15 with ALBI score, total bilirubin, and albumin were − 0.647, − 0.553, and 0.569 (P < 0.00001), respectively. The linear regression equation on the estimated LHL15 (eLHL15) from LSC was eLHL15 = 0.460 • LSC + 0.727 (P < 0.00001) and the coefficient of determination was 0.548. Regarding a contingency table using imaging-based clinical stage classification, the degree of agreement between eLHL15 and LHL15 was 65.4 %, and Cramer's V was 0.568 (P < 0.00001). Therefore, although the LSC may be influenced by high total bilirubin, the eLHL15 can replace the LSC as an index to evaluate liver function.
The liver-spleen contrast (LSC) using hepatobiliary-phase images could replace the receptor index (LHL15) in liver scintigraphy; however, few comparative studies exist. This study aimed to verify the convertibility from LSC into LHL15. In 136 patients, the LSC, not at 20 min, but at 60 min after injecting gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid was compared with the LHL15, albumin–bilirubin (ALBI) score, and the related laboratory parameters. The LHL15 was also compared with their biochemical tests. The correlation coefficients of LSC with LHL15, ALBI score, total bilirubin, and albumin were 0.740, –0.624, –0.606, and 0.523 (P < 0.00001), respectively. The correlation coefficients of LHL15 with ALBI score, total bilirubin, and albumin were –0.647, –0.553, and 0.569 (P < 0.00001), respectively. The linear regression equation on the estimated LHL15 (eLHL15) from LSC was eLHL15 = 0.460 · LSC + 0.727 (P < 0.00001) and the coefficient of determination was 0.548. Regarding a contingency table using imaging-based clinical stage classification, the degree of agreement between eLHL15 and LHL15 was 65.4%, and Cramer's V was 0.568 (P < 0.00001). Therefore, although the LSC may be influenced by high total bilirubin, the eLHL15 can replace the LSC as an index to evaluate liver function.
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