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Aims: To compare the efficacy of positron emission tomography (PET) computed tomography (CT), multi-detector helical computed tomography (MDCT) and bone scintigraphy for the detection of extrahepatic metastases in patients with hepatocellular carcinoma (HCC). Methods: Thirty-four patients diagnosed with metastatic HCC were enrolled in this study. The lesions included lung ( n = 18), bone ( n = 12) and lymph node ( n = 16) metastases. For receiver operating characteristic (ROC) analysis, lesions were diagnosed as metastatic HCC by two experienced abdominal radiologists. Another three physicians independently reviewed both positive and negative images. Each physician read three sets of images of MDCT, PET–CT and bone scintigraphy for bone metastasis. Results: The mean sensitivity and specificity for diagnosis of lung metastasis were 85.2 and 88.9% for MDCT, and 59.2 and 92.6% for PET–CT, respectively. For lymph node metastasis, these values were 62.5 and 79.2% for MDCT, and 66.7 and 91.7% for PET–CT, respectively; and for bone metastasis 41.6 and 94.5% for MDCT, 83.3 and 86.1% for PET–CT, and 52.7 and 83.3% for bone scintigraphy, respectively. The mean Az values were 0.95 and 0.77 for MDCT and PET–CT in lung metastasis, respectively, 0.75 and 0.80 for MDCT and PET–CT for lymph node metastasis, respectively, and 0.59, 0.88 and 0.62 for MDCT, PET–CT and bone scintigraphy for bone metastasis, respectively. Conclusion: PET–CT has high sensitivity and is more suitable for the detection of bone metastases from primary HCC, relative to MDCT and bone scintigraphy. [ABSTRACT FROM AUTHOR]

Liver transplantation (LT) is known to improve bleeding esophageal varices (EVs) and portal hypertension. However, many issues related to EVs after LT remain unresolved, such as whether LT reduces blood supply to EVs, improves the diameter of unruptured EVs, or improves or worsens EVs. The aim of this retrospective study was to determine the effects of living-donor liver transplantation (LDLT) in patients with hepatic failure on EVs and inflow vessels to EVs and the factors associated with deterioration of EVs after LDLT. The study subjects were 35 patients with cirrhosis who underwent LDLT. Endoscopy and multidetector helical computed tomography (MDCT) were performed before and after LDLT. The diameter of the inflow vessel of EVs was measured by MDCT before and after LDLT, together with the LDLT-related reduction rate of the diameter of the gastric vein (RRGV). Endoscopic examination showed improvement of EVs in 30 of 35 (86%) patients. RRGV improved in 17/35 (49%) patients, did not change in 13/35 (37%), and deteriorated in 5/35 (14%). The cause of RRGV deterioration seemed to be either the complication of portal vein or graft failure. In patients examined endoscopically at >1 year after LDLT, improvement of EVs was associated with significant changes in the rate of reduction of the major inflow vessel diameter and Child-Pugh score, compared with those who showed no improvement. LDLT results in improvement of EVs. EVs improved in 86% of the patients. Measurement of RRGV with MDCT is a good tool for prediction of EV improvement after LDLT. [ABSTRACT FROM AUTHOR]

High reproducibility on coronary artery calcium scoring is a key requirement in monitoring the progression of coronary atherosclerosis. The purpose of this prospective study is to assess the reproducibility of 1.25-mm- and 2.5-mm-thickness images on prospective electrocardiograph-triggered 64-slice CT with respect to 2.5-mm-thickness images on spiral overlapping reconstruction. One hundred patients suspected of coronary artery disease were scanned twice repeatedly, both on prospective electrocardiograph-triggered step-and-shoot and retrospective electrocardiograph-gated spiral scans. Using 1.25-mm-thickness collimation, 1.25-mm- and 2.5-mm-thickness image sets on prospective scans and 2.5-mm-thickness image sets with 1.25-mm increment (overlapping) on retrospective scans were obtained. Coronary artery calcium scores, interscan variability and interobserver variability were evaluated. The mean interscan variability in coronary artery calcium measurement on 1.25-mm prospective/2.5-mm prospective/2.5-mm overlapping retrospective scans were Agatston: 10%/18%/12%, volume: 10%/12%/10% and mass: 8%/13%/11% for observer 1 and Agatston: 8%/14%/10%, volume: 7%/9%/10% and mass: 7%/10%/9% for observer 2, respectively. The mean interobserver variability was 5% to 14%. In conclusion, prospective electrocardiograph-triggered 64-slice CT using the 1.25-mm prospective scan shows the lowest variability. The 2.5-mm prospective scan on volume or mass scoring shows variability of around 10%, comparable to 2.5-mm-thickness spiral overlapping reconstruction images. [ABSTRACT FROM AUTHOR]

Background: Multislice computed tomography has recently been shown to have the potential to characterize noncalcified coronary atherosclerotic lesions (NCALs). We evaluated the relationship among computed tomography (CT) density, arterial remodeling, and the adherent calcium morphology of NCALs detected using 64-slice CT. Methods: We studied 138 patients with proven or suspected coronary artery disease who underwent contrast-enhanced 64-slice CT examination. For each NCAL detected within the vessel wall, we determined the minimum CT density, remodeling index (RI = lesion/reference vessel area), and the presence or absence of coronary calcium in or adjacent to each NCAL and its morphology. Intravascular ultrasound (IVUS) was additionally performed in a subset of 21 patients. Results: A total of 202 NCALs were detected in 97 patients. The mean CT density of 98 lesions with positive remodeling (PR) (RI >1.05) was significantly lower than that of 104 lesions without PR (25 +/- 23 vs 56 +/- 28 Hounsfield units, P < .001); and spotty calcium was more frequently observed with the PR lesions than non-PR lesions (59% vs 22%, P < .001). The mean CT density of the PR lesions with spotty calcium (n = 58) was substantially lower than that of the non-PR lesions without adherent calcium (n = 45) (20 +/- 20 vs 67 +/- 24 Hounsfield units, P < .001). Evaluation of the components, RI, and adherent calcium morphology of 38 NCALs by 64-slice CT was in close agreement with the IVUS findings. Conclusions: Lower CT density, PR, and adherent spotty calcium, which may indicate plaque vulnerability, are intimately co-related in NCALs detected using 64-slice CT; these findings are consistent with those of IVUS. [ABSTRACT FROM AUTHOR]

The purpose of our study was to evaluate the long-term outcome and complications of balloon-occluded retrograde transvenous obliteration (B-RTO) in patients with hemorrhage from gastric fundal varices. Thirty-four consecutive patients with bleeding from gastric varices who were treated with B-RTO were enrolled in this study between December 1994 and September 2005 (urgent cases, n = 12; elective cases, n = 22). The long-term outcome, complications, and various liver functions were evaluated. Complete obliteration was achieved in 31 of 34 (91%) patients with an acute bleeding episode. In one of the remaining patients, there was a technical failure, and the other two had only partial obliteration. The two patients with partial obliteration did not obtain hemostasis. Thus, the rate of hemostasis was 94% (31/33). Gastric varices disappeared in all patients with complete obliteration during the treatment. The rate of gastric variceal eradication was 91%. Variceal rebleeding from esophageal varices occurred in three patients. The rate of rebleeding was 10% (3/31). Rebleeding from gastric varices was not observed after complete obliteration. None of the patients showed worsening of their Child-Pugh score. Although the 5-year cumulative worsening rate of esophageal varices was 52%, neither portal hypertensive gastropathy nor ectopic varices were observed. The patients with worsening esophageal varices were successfully treated with an endoscopic procedure. The 5-year survival rate was 68%. B-RTO is useful for treatment of bleeding gastric varices, achieving high eradication of gastric varices, a low rebleeding rate, and a fairly good prognosis with improved hepatic function. [ABSTRACT FROM AUTHOR]

The purpose of this study is, using a 16-section multidetector-row helical computed tomography (MDCT) scanner with retrospective reconstruction, to compare variability in repeated coronary calcium scoring and qualitative scores of the motion artifacts. One hundred forty-four patients underwent two subsequent scans using MDCT. According to Agatston and volume algorithms, the coronary calcium scores during mid-diastole (the center corresponding to 70% of the R-R cycle) were calculated and the inter-scan variability was obtained. Motion artifacts from coronary artery calcium were subjectively evaluated and classified using a 5-point scale: 1, excellent; no motion artifacts; 2, fine, minor motion artifacts; 3, moderate, mild motion artifacts; 4, bad, severe motion artifacts; 5, poor, doubling or discontinuity. Each reading was done by vessels (left main, left descending, left circumflex and right coronary arteries) and the motion artifact score (mean of the scales) was determined per patient. The variability in the low (1.2+/-0.2) and high (2.4+/-0.6) motion artifact score groups was 7+/-6 (median, 6)% and 19+/-15 (16)% on the Agatston score (P<0.01) and 7+/-7 (6)% and 16+/-13 (14)% on the volume score (P<0.01), respectively. In conclusion, motion has a significant impact on the reproducibility of coronary calcium scoring. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: The therapeutic response to radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) often is evaluated by comparing pre- and post-RFA computed tomography (CT). However, judgment about whether an ablative margin, ie, 5-10 mm of normal hepatic tissue, is ensured sometimes is difficult. The aim of this study is to assess the feasibility of fusion images of pre- and post-RFA CT. Materials and Methods: HCCs (n = 20) sized 13 +/- 5 mm (range, 4-23 mm) were included. For pre-RFA CT, the arterial phase of intravenous dynamic CT (n = 17), CT arterioportography (n = 2), and CT hepatic arteriography (n = 1) was used. Using automatic image registration software (n = 20) and a manual segmentation technique (n = 4), fusion images were created in combination with post-RFA CT (equilibrium phase of intravenous CT). Results: Automatic image registration and manual segmentation technique took approximately 2-3 and 5 minutes, respectively. Total time required for the creation of fusion images was less than 10 minutes in all cases. Fusion images enabled easier understanding of the relationship between the tumor and ablation zone, helping judge whether an ablative margin was ensured. Conclusion: Fusion of pre- and post-RFA CT images is considered a feasible tool in the evaluation of RFA therapy for HCC. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Slow heart rate and small changes in heart rate are factors for improving image quality on spiral cardiac computed tomography (CT). The purpose of this study is to investigate whether it is possible to improve nonenhanced cardiac CT quality by delaying the data-acquisition window after breath hold. Materials and Methods: Electrocardiograph files (n = 240) for 16-slice nonenhanced cardiac CT scans were analyzed. Mean heart rates and maximal changes in heart rates between adjacent cardiac cycles were compared between phase 1 (defined as cardiac cycles 1–5), phase 2 (cardiac cycles 2–6), … , and phase 6 (cardiac cycles 6–10). Results: Heart rates gradually increased by phases, but were limited to a range of 66.8–68.0 beats/min. Maximal changes in heart rates were 2.5 beats/min (phase 1) at the highest and 1.3 beats/min (phases 5 and 6) at the lowest (t-test; P < .01). Maximal changes in heart rates for more than five beats/min occurred in 24, eight, and eight patients on phases 1, 5, and 6, respectively (chi-square test; P < .01). Conclusion: The delayed scan (four or five cardiac cycles after breath hold) has the potential to improve the quality of nonenhanced cardiac CT. [Copyright &y& Elsevier]

Multidetector row CT is a feasible diagnostic tool in pre- and postoperative liver partial transplantation. We can assess vascular anatomy and liver parenchyma as well as volumetry, which provide useful information for both donor selection and surgical planning. Disorders of the vascular and biliary systems are carefully observed in recipients. In addition, we evaluate liver regeneration of both the donor and the recipient by serial volumetry. We present how multidetector row CT with state-of-the-art three-dimensional volume renderings may be used in right lobe liver transplantation. [ABSTRACT FROM AUTHOR]

Abstract: The impact of visceral adiposity on subclinical coronary atherosclerosis is unclear in Japanese patients. We investigated the sex-specific relationship between the amount of visceral fat and coronary artery calcium (CAC) using multislice computed tomography (MSCT). This is a cross-sectional study of 321 consecutive Japanese patients (213 men and 108 women) who underwent MSCT scanning for the examination of coronary heart disease. CAC score, visceral fat area (VFA), subcutaneous fat area (SFA), and waist circumference (WC) were determined by MSCT for all patients. The prevalence of detectable CAC was 73% and 57% in men and women, respectively. Using a multivariable logistic and ordinal regression analyses adjusting for traditional cardiovascular risk factors and adiposity measurements, VFA represented an independent predictor of the presence and extent of CAC (odds ratio (95% confidence interval) per one-unit-standard deviation increase in VFA: 2.48 (1.23–6.05) in logistic regression analysis; 2.05 (1.18–3.98) in ordinal regression analysis). Similar relationships were observed across the gender. We further assessed the sex-specific cut-off levels of VFA and WC to predict the presence of CAC. The results of receiver operator characteristic analysis indicated that the VFA cut-off level in men was 116cm2; and in women, it was 82cm2, corresponding to WC values of 87.7cm in men and 82.6cm in women. In conclusion, we found that visceral adiposity measured by MSCT is significantly associated with the presence and extent of CAC as a marker of subclinical atherosclerosis in Japanese patients. [Copyright &y& Elsevier]

Abstract: Background: A method to objectively detect in-stent restenosis (ISR) with multi-slice computed tomography (MSCT) has not been established yet. We aimed to evaluate the usefulness of measuring coronary lumen density with MSCT to detect ISR. Methods: Forty-seven coronary stented lesions in 38 patients were evaluated with 16-slice CT (collimation thickness, 0.625 mm). In each assessable lesion, the stent lumen was visually evaluated, and reference CT density proximal to the stent (RCTD) and minimum CT density of the in-stent lumen (SCTD) were measured. ISR was defined as >50% diameter stenosis measured by quantitative coronary angiography (QCA). Results: Of 47 stented lesions, 35 (74%) were assessable, and there were 12 ISR (+) and 23 ISR (−) lesions. Mean ΔCTD (RCTD−SCTD) of the ISR (+) group was significantly greater than that of the ISR (−) group (196±101 vs. 7±30 HU, p <0.001). Predictive accuracy of quantitative evaluation of ISR using our best cutoff value of ΔCTD was higher than that of visual evaluation (97% vs. 83%, p <0.05). The ΔCTD showed a higher correlation with percent diameter stenosis (r =0.85, p <0.001) than with SCTD (r =−0.73, p <0.001). Conclusions: Measuring differences of CT densities between reference vessel lumens and in-stent lumens using MSCT is a convenient and useful technique to detect ISR. [Copyright &y& Elsevier]

Purpose: To evaluate in healthy volunteers the reproducibility of organ position using a voluntary breath-hold method with a spirometer and the feasibility of this method for extracranial stereotactic radiotherapy in a clinical setting. Methods and Materials: For this study, 5 healthy volunteers were enrolled. After training sessions, they held their breath at the end-inspiration and the end-expiration phase under spirometer-based monitoring. Computed tomography (CT) scans were performed twice at each respiratory phase, with a 10-min interval, on 2 separate days. The total number of CT scans was four at each respiratory phase. After CT volume data were transferred to a three-dimensional treatment-planning system, digitally reconstructed radiographs (DRRs) were calculated for anterior-posterior and left-right beams. Verification was performed with DRRs relative to the diaphragm position, bony landmarks, and the isocenter in each healthy volunteer at each respiratory phase. To evaluate intrafraction reproducibility, we measured the distance between diaphragm position and bony landmarks. To evaluate interfraction reproducibility, we measured the distance between diaphragm position and the isocenter. Reproducibility and setup error were defined as the average value of the differences between each DRR with regard to the first DRR. Results: Intrafraction reproducibility of the caudal-cranial direction was 4.0 +/- 3.5 mm at the end-inspiration phase and 2.2 +/- 2.0 mm at the end-expiration phase. Interfraction reproducibility of the caudal-cranial direction was 5.1 +/- 4.8 mm at the end-inspiration phase and 2.1 +/- 1.8 mm at the end-expiration phase. The end-expiration phase was more stable than the end-inspiration phase. Conclusions: The voluntary breath-hold method with a spirometer is feasible, with relatively good reproducibility. We are encouraged about the use of this technique clinically for extracranial stereotactic radiotherapy. [ABSTRACT FROM AUTHOR]

Predicts the occurrence of obstructed individual coronary arteries, vessel by vessel, based on the detection of coronary artery calcium by electron beam computed tomography (EBCT). Patients involved in the study; Diagnostic equipment used in the study.