Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure.

PURPOSE: To identify post-liver transplant CT findings which predict graft failure within 1 year. MATERIALS AND METHODS: We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed. RESULTS: Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n = 18/25, or 67%, versus 15/98, or 15%, p < 0.001), parenchymal hypoattenuation (n = 20/41, or 48.8% versus 17/161, or 10.6%, p < 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 ± 2.7 mm versus 14.7 ± 2.2 mm, and left portal vein [LPV], 9.8 ± 3.0 mm versus 12.4 ± 2.2 mm, p < 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43, p < 0.001) and small portal vein diameters (HR, RPV, 3.33, p < 0.001, and LPV, 3.13, p < 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233~0.597). CONCLUSION: For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure. KEY POINTS: •Failed grafts are highly associated with liver perfusion defect, hypoattenuation, and small portal vein. •Right portal vein < 11.5 mm and left portal vein < 10.0 mm were associated with poor graft outcome. •Liver perfusion defect and small portal vein diameter independently predicted graft failure.

The increase in total knee replacement surgery in Taiwan: A 15-year retrospective study.

Total knee replacement (TKR) is considered as one of the most success among clinical interventions for patients with who suffering from knee osteoarthritis (OA). We sought to estimate the incidence of TKR using demographics, incidence rates, lengths of hospital stay, and costs from 1996 to 2010 by analyzing Taiwan's National Health Insurance Research Database. A total of 154,553 patients obtained primary TKR surgery between 1996 and 2010. The diagnosis code for knee OA and the procedure code for TKR were selected from the records. To compare the rate of TKR between covariables, we calculated the TKR risk ratios and 95% confidence interval (CI) of these variables (gender, age, age group, and primary diagnoses). A 2-tailed P-value of .05 was considered statistically significant. The statistical package SPSS version 20.0 (SPSS, Chicago, IL) was used to conduct all the statistical analyzes. We analyzed 154,553 TKRs performed by surgeons in Taiwan from 1996 to 2010. The overall crude incidence increased from 26.4 to 74.55 TKR per 100,000 inhabitants from 1996 to 2010. TKR incidence for the 70 to 79 years age group increased from 227 to 505 per 100,000 people from 1996 to 2010. The age-standardized rate ratios for TKR of women to men ranged from 2.5 to 3.0. The mean average length of stay in hospital was 15 days in 1996 and decreased to 8 days in 2010. During the study period, the adjusted mean cost per patient decreased from US$7485 to US$4827. Health expenditures for TKR were 5% of total National Health Insurance expenditure every year. Over the 15-year period, Taiwan's TKR incidence tripled, which is consistent with population ageing. Arthritis will be a major public health issue in the ageing population in the future.

Assessment of factors that could affect the success of US-guided contrast injection for hip MR arthrography.

BACKGROUND: To retrospectively evaluate the association between possible influencing factors and failed first attempts to inject a contrast agent intra-articularly under ultrasound (US)-guidance for direct magnetic resonance (MR) arthrography of the hip joint. METHODS: Ninety consecutive patients (38 women and 52 men; mean age, 42 years) undergoing US-guided hip MR arthrography (3 bilaterally) were retrospectively included in this study. The potential influencing factors were sex, age, body mass index (BMI), side of injection, target site, trajectory of the needle, additional use of needle tip rotation, failed first-attempt, and capsule elongation at the site of needle insertion. RESULTS: First-attempt failure was significantly associated with reduced capsule elongation at the target site and no additional use of needle tip rotation (OR 10.708; 95% CI 1.847-62.059; OR 3.518; 95% CI 1.120-11.047). Capsule elongation (sufficient for needle bevel insertion) was significantly larger at the femoral head-neck junction (5.2 ± 1.5 mm) than at the femoral head (2.9 ± 1.3 mm) (p < 0.001). CONCLUSION: Less capsular elongation of the femoral head and no additional use of needle tip rotation to reduce the difficulty in contrast material delivery can increase the first-attempt failure rate in patients undergoing US-guided hip arthrography.

Idiopathic growth hormone deficiency in the morphologically normal pituitary gland is associated with perfusion delay.

PURPOSE: To investigate quantitatively the topographic perfusion characteristics of the adenohypophysis by using dynamic contrast material-enhanced magnetic resonance (MR) imaging in a subgroup of patients with idiopathic growth hormone deficiency (IGHD) and with normal-appearing pituitary morphology on MR images. MATERIALS AND METHODS: This HIPAA-compliant, prospective study was approved by an institutional review board, and informed consent was obtained for all patients. Twenty-five patients (mean age, 10.6 years ± 3.3 [standard deviation]) with clinical growth retardation, proved IGHD, and normal pituitary morphology on MR images were included for analysis. Sixteen children (mean age, 10.8 years ± 5.5) were included as control subjects. Time to peak (TTP) perfusion properties of the adenohypophysis in 10 regions of interest from multisection coronal dynamic contrast-enhanced T1-weighted MR images were quantitatively derived by using the Brix pharmacokinetic model. Significant difference was determined with a two-tailed Student t test. The Pearson correlation coefficient was used to correlate the perfusion parameters, including maximal enhancement peak and slope, with serum growth hormone levels in the IGHD group. RESULTS: TTP for the IGHD group was significantly prolonged compared with that for the control group (P < .005). The prolonged TTP in the IGHD group was found to be diffuse. The levels of growth hormone deficiency were negatively correlated with the peak enhancement and the slope of the wash-in phase, which suggests increased blood volume in IGHD within the pituitary gland. CONCLUSION: IGHD and the degree of growth hormone deficiency are associated with nonregional perfusion delay in morphologically normal adenohypophyses. The lack of lateralization of perfusion delay may suggest that microvascular structural abnormalities play a role in IGHD.

Complex cystic lesions of the breast on ultrasonography: feature analysis and BI-RADS assessment.

PURPOSE: To analyze the features of breast complex cystic lesions at ultrasonography (US) and to determine appropriate Breast Imaging Reporting and Data System (BI-RADS) categories and management recommendations for these lesions based on US findings with pathologic correlation. MATERIALS AND METHODS: From July 2001 to June 2007, 152 consecutive pathologically proven complex cystic lesions on US were retrospectively reviewed. All lesions at US were evaluated for size, lesion characteristics, margins, and presence of abnormal axillary nodes. US features of lesions were classified into four types, and positive predictive values (PPVs) were calculated for each type. Clinical, imaging, and histopathological findings were reviewed. RESULTS: Of the 152 lesions based on US appearance, 36 (24%) were classified as type I, 49 (32%) as type II, 28 (18%) as type III, and 39 (26%) as type IV. The PPVs for malignancy in each type were 14% for type I, 16% for type II, 14% for type III, and 41% for type IV. There was a significantly higher frequency of malignancy among lesions of type IV compared with the other three types (16/39=41% vs 5/36=14%, p=0.0089; 16/39=41% vs 8/49=16%, p=0.0098; and 16/39=41% vs 4/28=14%, p=0.018 [Chi-squared test]). Lesions with maximum diameter equal to or larger than 20mm, not circumscribed margins, or a mammographic finding of suspected malignancy had a high probability of malignancy (p<0.05 for each). CONCLUSION: US is useful in evaluating the complex cystic lesions and in clarifying the indication for biopsy of these lesions. The four types of US classifications used in our study establish accepted benchmarks for these breast abnormalities when stratified according to BI-RADS categories.

Ultrasonographic alterations associated with the dilatation of mammary ducts: feature analysis and BI-RADS assessment.

OBJECTIVE: The purpose of this study was to analyse the lesion characteristics and the patterns of dilated ducts on ultrasonography (US) to determine the appropriateness of the Breast Imaging Reporting and Data System (BI-RADS) categories. MATERIALS AND METHODS: From July 2001 to June 2006, 172 consecutive pathologically proved lesions with dilated ducts on US were reviewed retrospectively. All the lesions were classified into four types according to their US features, and in combination with the size, location, margins and number of lesions, the corresponding positive predictive values (PPVs) were obtained. RESULTS: Of the 172 lesions, 55 (32%) were classified as type I, 68 (40%) as type II, 14 (8%) as type III and 35 (20%) as type IV. The PPVs for malignancy were 9% for type I, 13% for type II, 43% for type III and 17% for type IV. There was a significantly higher frequency of malignancy among type III lesions than among type I (43% vs 9%, respectively, P = 0.002; chi (2) test) or type II lesions (43% vs 13%, respectively, P = 0.009; chi (2) test). Lesions with a nonsubareolar location and noncircumscribed margins had a high probability of malignancy (P < 0.001 and P = 0.03, respectively). CONCLUSION: The four types of US classifications used in our study establish reliable references for the dilated duct patterns when stratified according to BI-RADS categories, and they clarify the indications for biopsy of these lesions.

Salivary glands: echo-planar versus PROPELLER Diffusion-weighted MR imaging for assessment of ADCs.

PURPOSE: To compare the image distortion and the quantification variation in parotid gland apparent diffusion coefficients (ADCs) on periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) versus echo-planar diffusion-weighted (DW) magnetic resonance (MR) images and to investigate the relationship between parotid gland ADC and parotid gland fat content. MATERIALS AND METHODS: This prospective study was approved by a local institutional review board. Written informed consent was obtained from all 33 enrolled healthy volunteers (15 men, 18 women; mean age, 36.4 years +/- 11.8 [standard deviation]). All participants underwent 1.5-T non-fat-saturated and fat-saturated PROPELLER DW MR imaging as well as 1.5-T nonaccelerated and twofold-accelerated echo-planar DW MR imaging. Image distortion on the DW images was qualitatively scored, and parotid ADC was quantitatively analyzed. The correlation between parotid ADC and parotid fat content was evaluated by using linear regression analysis. Wilcoxon signed rank and t tests were used for statistical analysis, with Bonferroni correction applied for multiple comparisons. RESULTS: Echo-planar DW images showed distortion, which was completely eliminated on the PROPELLER DW images. The mean parotid ADCs measured with non-fat-saturated PROPELLER (0.670 x 10(-3) mm(2) +/- 0.149), nonaccelerated echo-planar (0.892 x 10(-3) mm(2) +/- 0.128), twofold-accelerated echo-planar (1.088 x 10(-3) mm(2) +/- 0.124), and fat-saturated PROPELLER (1.307 x 10(-3) mm(2) +/- 0.217) DW imaging differed significantly from one another (P < .001 for all comparisons). Parotid ADC had a significant negative correlation with parotid fat content (x) measured at non-fat-saturated PROPELLER DW imaging: ADC = -0.0087x + 1.1173 (r = 0.80, P < .001). CONCLUSION: PROPELLER DW imaging pulse sequences can yield distortion-free images for parotid ADC measurements and enable quantitative evaluation of the relationship between parotid ADC and parotid fat content. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531082228/-/DC1.