Hamid Chalian

Accuracy of MR Elastography and Anatomic MR Imaging Features in the Diagnosis of Severe Hepatic Fibrosis and Cirrhosis

To compare the diagnostic accuracy of magnetic resonance imaging elastography (MRE) and anatomic MRI features in the diagnosis of severe hepatic fibrosis and cirrhosis.

Radiologic Assessment of Response to Therapy: Comparison of RECIST Versions 1.1 and 1.0

Improvements in radiologic imaging technology and therapeutic options available for management of tumors have necessitated the revision of guidelines for the imaging-based assessment of tumor response to therapy. The purpose of this article is to familiarize radiologists with the modifications to the Response Evaluation Criteria in Solid Tumors (RECIST) that have been incorporated in the latest version of the guidelines, RECIST 1.1. The most important differences between this version and the previous one, RECIST 1.0, include reductions in the maximum number of lesions per patient and per organ that may be targeted for measurement, augmentation of the criteria defining progressive disease, additional guidelines for reporting findings of lesions that are too small to measure and for measuring lesions that appear to have fragmented or coalesced at follow-up imaging, new criteria for characterizing lymphadenopathy, new criteria for selecting bone lesions and cystic lesions as targets for measurement, and the inclusion of findings at positron emission tomography among the indicators of disease response.

Hepatic Tumors: Region-of-Interest versus Volumetric Analysis for Quantification of Attenuation at CT

PURPOSE To evaluate the reproducibility of liver tumor attenuation measurement performed by using the routinely used manual region-of-interest (ROI) method and that of measurement performed by using a semiautomated volumetric approach at computed tomography (CT). MATERIALS AND METHODS This HIPAA-compliant retrospective study had institutional review board approval. The requirement for patient informed consent was waived. Attenuation of colon cancer liver metastases in 208 patients was measured on portal venous phase multidetector CT images by using a single ROI, the average measurement in three ROIs on a single section, and with semiautomated segmentation of the entire tumor volume (volumetric attenuation) to evaluate intermethod agreement. Intraobserver and interobserver reproducibility were evaluated in the first 70 patients. Measurements were repeated after 30 days to assess intraobserver reproducibility. Differences between methods were tested by using repeated-measures analysis of variance. Intermethod, intraobserver, and interobserver agreements were tested by using Bland-Altman analysis and the Lin concordance correlation coefficient (ρc). P < .05 was considered to indicate a significant difference. RESULTS A total of 208 pathologically proven colon cancer hepatic metastases larger than 20 mm in diameter in 100 women and 108 men (mean age, 61.6 years ± 11.6 [standard deviation]; range, 28-87 years) were evaluated. Attenuation was significantly different between the three methods of measurement (P < .001 for all). Volumetric measurements had better intraobserver agreement (precision = 3.3%, ρc = 0.996, P < .001) than single-ROI measurements (precision = 12.0%, ρc = 0.947, P < .001) and measurements averaged over three ROIs (precision = 9.3%, ρc = 0.965, P < .001). Volumetric measurements also had better interobserver agreement (precision = 3.6%, ρc = 0.993, P < .001) than single-ROI measurements (precision = 11.3%, ρc = 0.957, P < .001) and the average measurement in three ROIs (precision = 8.5%, ρc = 0.976, P < .001). CONCLUSION Measurements of hepatic tumor attenuation at multidetector CT are reproducible. An approach based on the evaluation of whole-lesion attenuation demonstrated better reproducibility than ROI measurements.

MDCT Necrosis Quantification in the Assessment of Hepatocellular Carcinoma Response to Yttrium 90 Radioembolization Therapy: Comparison of Two-dimensional and Volumetric Techniques

RATIONALE AND OBJECTIVES The purpose of this study is to evaluate the reproducibility and agreement of tumor necrosis quantification performed by two-dimensional and volumetric methods in a cohort of patients with hepatocellular carcinoma (HCC) treated with yttrium-90 ((90)Y) radioembolization. MATERIALS AND METHODS Twenty-nine consecutive patients (21 men, 8 women; mean age 66.6 years; age range, 44-90 years) with HCC treated with (90)Y radioembolization that underwent liver multidetector computed tomography (MDCT) were included. Two independent radiologists evaluated the necrosis proportion of the lesions with two-dimensional (2D) measurements according to the European Association for the Study of the Liver guidelines, and with a volumetric method using a voxel-by-voxel analysis. Interobserver reproducibility for each method was assessed by using within-subject coefficients of variation (WSCV), intraclass correlation coefficients (ICC), and Lins concordance correlation coefficients (LCC). Agreement between both methods was assessed by using the Bland-Altman plot and the paired t-test. RESULTS The volumetric method was more reproducible (WSCV = 27.8%; ICC = 0.914; LCC = 0.909) than the 2D (WSCV = 43.8%; ICC = 0.723; LCC = 0.841). There was a significant difference in the mean calculated necrosis proportions based on 2D and volumetric methods (P = .0129). CONCLUSION Voxel-by-voxel quantification of HCC necrosis is a more reproducible method than 2D analysis.

Evaluation of Hepatocellular Carcinoma Size Using Two-dimensional and Volumetric Analysis : Effect on Liver Transplantation Eligibility

RATIONALE AND OBJECTIVES Milan criteria recommends selection of candidates with hepatocellular carcinoma (HCC) for liver transplantation based on strict tumor size thresholds. The purpose of this study is to compare the effect of two-dimensional and three-dimensional tumor measurements on the selection of candidates for liver transplantation using Milan criteria. MATERIALS AND METHODS This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by our institutional review board. Patient-informed consent was waived. Forty-five HCCs in 19 patients, evaluated with triphasic multidetector row computed tomography scans, were included in the analysis. The largest diameters in each two-dimensional orthogonal plane (Max2D) and within three-dimensional tumor boundaries (Max3D) were calculated for each lesion. Diameters were compared and the eligibility based on lesion size for liver transplantation was assessed. RESULTS The mean Max2D diameter of HCC was 3.2 ± 0.9 cm and the mean Max3D diameter was 3.5 ± 1.2 cm. There was a significant difference between the mean Max2D and Max3D diameters (P < .001). Among the 45 lesions, 22 of them (48.9%) were ineligible for transplantation according to Max2D diameter, whereas 29 of them (64.44%) were ineligible when Max3D diameter was applied (P < .001). CONCLUSION HCC diameter based on 3D measurements is significantly different than the conventional 2D measurements and may affect eligibility for liver transplantation.

CT Attenuation of Unilocular Pancreatic Cystic Lesions to Differentiate Pseudocysts from Mucin-Containing Cysts

CONTEXT There is extensive overlap among the imaging characteristics of pseudocyst, mucinous cystic neoplasm (MCN) and side branch intraductal papillary mucinous neoplasm (IPMN) on CT images. OBJECTIVE The purpose of this study was to evaluate the usefulness of attenuation measurement in differentiating pseudocysts from MCN and IPMN of pancreas on CT images. PATIENTS Seventy-five pathologically proven unilocular pancreatic cysts including 31 pseudocysts, 29 MCN and 15 IPMN imaged with multidetector computed tomography (MDCT) before resection were evaluated. MAIN OUTCOME MEASURES Attenuation values were measured by conventional region of interest (ROI) method. DESIGN Attenuation values (in Hounsfield unit, HU) were compared between the cyst pathologies. Receiver operating characteristic (ROC) curve analysis was performed to obtain the best attenuation threshold between mucin-containing cysts and pseudocysts. Correlation between attenuation values and cyst size was assessed. RESULTS Maximum transaxial diameters of pseudocysts (4.5 cm), MCNs (3.7 cm) and IPMNs (4.0 cm) were comparable (P=0.919). Mean attenuation was 18.9 HU, 13.0 HU and 11.4 HU for pseudocyst, MCNs and IPMNs, respectively. Attenuations were significantly higher in pseudocysts versus mucin-containing (MCN+IPMN) cysts (P=0.001) and comparable between MCNs and IPMNs (P=0.390). ROC curve showed 14.5 HU the best cut-off (accuracy: 73.5%) for differentiating pseudocysts from mucin-containing cysts (P<0.001). Pancreatic cyst attenuation measurement did not significantly correlate with cyst size (r=-0.03, P=0.772). CONCLUSION Attenuation measurement may help in differentiating pseudocysts from unilocular mucin-containing simple cysts of the pancreas on CT images.

Colorectal Liver Metastasis After 90Y Radioembolization Therapy: Pilot Study of Change in MDCT Attenuation as a Surrogate Marker for Future FDG PET Response

OBJECTIVE The purpose of this study was to investigate whether changes in attenuation and size of liver metastatic lesions of colorectal cancer at MDCT 1 month after (90)Y radioembolization treatment are predictive of response at FDG PET 3 months after treatment. MATERIALS AND METHODS Twenty patients with colorectal liver metastasis consecutively treated with (90)Y radioembolization underwent triphasic MDCT of the liver at baseline and 1 and 3 months after treatment and FDG PET at baseline and 3 months after treatment. Percentage change in tumor attenuation at MDCT (volumetric attenuation), tumor size at MDCT (according to Response Evaluation Criteria in Solid Tumors [RECIST] and World health Organization [WHO] criteria), and volume-weighted maximum standardized uptake value at FDG PET were evaluated. The correlation between FDG PET response 3 months after treatment and response according to RECIST, WHO criteria, and attenuation 1 month after treatment was evaluated. RESULTS Only 13.3% of patients with FDG PET findings of response 3 months after treatment were identified according to RECIST and WHO criteria 1 month after treatment. According to attenuation criteria at 1 month, however, 53.3% of patients with an FDG PET response at 3 months were identified. A strong association was found between FDG PET response at 3 months and response based on attenuation criteria (odds ratio, 12.4; 95% CI, 0.58-265.3; p = 0.05). CONCLUSION Early changes in the attenuation of liver metastatic lesions of colon cancer after (90)Y radioembolization treatment may be predictive of future response at FDG PET.

Urine macrophage migration inhibitory factor in pediatric systemic lupus erythematosus

We reported a series of ten patients with lupus nephritis (five patients in the relapse phase and five in the remission phase) and measured the macrophage migration inhibitory factor (MIF), an important pro-inflammatory cytokine with probable role in the pathogenesis of many inflammatory diseases, in their urine samples. MIF/creatinine (Cr) ratio directly correlated with disease activity and it does not have any significant difference between inactive disease and normal ones. We found that the urine MIF/Cr ratio not only differentiates active disease from inactive disease and normal ones but also correlates with the activity indices of renal pathology.

Pancreatic Mucinous Cystic Neoplasm Size Using CT Volumetry, Spherical and Ellipsoid Formulas: Validation Study

CONTEXT The accuracy for determining pancreatic cyst volume with commonly used spherical and ellipsoid methods is unknown. The role of CT volumetry in volumetric assessment of pancreatic cysts needs to be explored. OBJECTIVES To compare volumes of the pancreatic cysts by CT volumetry, spherical and ellipsoid methods and determine their accuracy by correlating with actual volume as determined by EUS-guided aspiration. Setting This is a retrospective analysis performed at a tertiary care center. Patients Seventy-eight pathologically proven pancreatic cysts evaluated with CT and endoscopic ultrasound (EUS) were included. Design The volume of fourteen cysts that had been fully aspirated by EUS was compared to CT volumetry and the routinely used methods (ellipsoid and spherical volume). Two independent observers measured all cysts using commercially available software to evaluate inter-observer reproducibility for CT volumetry. MAIN OUTCOME MEASURES The volume of pancreatic cysts as determined by various methods was compared using repeated measures analysis of variance. Bland-Altman plot and intraclass correlation coefficient were used to determine mean difference and correlation between observers and methods. The error was calculated as the percentage of the difference between the CT estimated volumes and the aspirated volume divided by the aspirated one. RESULTS CT volumetry was comparable to aspirated volume (P=0.396) with very high intraclass correlation (r=0.891, P<0.001) and small mean difference (0.22 mL) and error (8.1%). Mean difference with aspirated volume and error were larger for ellipsoid (0.89 mL, 30.4%; P=0.024) and spherical (1.73 mL, 55.5%; P=0.004) volumes than CT volumetry. There was excellent inter-observer correlation in volumetry of the entire cohort (r=0.997, P<0.001). CONCLUSIONS CT volumetry is accurate and reproducible. Ellipsoid and spherical volume overestimate the true volume of pancreatic cysts.

Short-term and long-term effects of slow graft function on graft survival in pediatric live donor renal transplantation

Otukesh H, Hosein R, Fereshtehnejad S‐M, Riahifard A, Basiri A, Simforoosh N, Chalian M, Jazayeri S, Chalian H, Safarzadeh AE, Sharifian M, Hoseini S. Short‐term and long‐term effects of slow graft function on graft survival in pediatric live donor renal transplantation. Pediatr Transplantation 2010:14:196–202.