Synergistic Role of Quantitative Diffusion Magnetic Resonance Imaging and Structural Magnetic Resonance Imaging in Predicting Outcomes After Traumatic Brain Injury.

OBJECTIVE: This study aimed to assess if quantitative diffusion magnetic resonance imaging analysis would improve prognostication of individual patients with severe traumatic brain injury. METHODS: We analyzed images of 30 healthy controls to extract normal fractional anisotropy ranges along 18 white-matter tracts. Then, we analyzed images of 33 patients, compared their fractional anisotropy values with normal ranges extracted from controls, and computed severity of injury to white-matter tracts. We also asked 2 neuroradiologists to rate severity of injury to different brain regions on fluid-attenuated inversion recovery and susceptibility-weighted imaging. Finally, we built 3 models: (1) fed with neuroradiologists' ratings, (2) fed with white-matter injury measures, and (3) fed with both input types. RESULTS: The 3 models respectively predicted survival at 1 year with accuracies of 70%, 73%, and 88%. The accuracy with both input types was significantly better (P < 0.05). CONCLUSIONS: Quantifying severity of injury to white-matter tracts complements qualitative imaging findings and improves outcome prediction in severe traumatic brain injury.

3D MR Neurography.

High-resolution isotropic volumetric three-dimensional (3D) magnetic resonance neurography (MRN) techniques enable multiplanar depiction of peripheral nerves. In addition, 3D MRN provides anatomical and functional tissue characterization of different disease conditions affecting the peripheral nerves. In this review article, we summarize clinically relevant technical considerations of 3D MRN image acquisition and review clinical applications of 3D MRN to assess peripheral nerve diseases, such as entrapments, trauma, inflammatory or infectious neuropathies, and neoplasms.

Imaging Assessment of Thoracic Outlet Syndrome.

Imaging studies play a significant role in assessment of thoracic outlet syndrome. In this article, we discuss the etiology and definition of thoracic outlet syndrome and review the spectrum of imaging findings seen in patients with thoracic outlet syndrome. We then discuss an optimized technique for computed tomography and MRI of patients with thoracic outlet syndrome, based on the experience at our institution and present some representative examples. Based on our experience, a combination of computed tomography angiography and MRI (with postural maneuvers) effectively demonstrate thoracic outlet syndrome abnormalities.

Current Applications and Future Impact of Machine Learning in Radiology.

Recent advances and future perspectives of machine learning techniques offer promising applications in medical imaging. Machine learning has the potential to improve different steps of the radiology workflow including order scheduling and triage, clinical decision support systems, detection and interpretation of findings, postprocessing and dose estimation, examination quality control, and radiology reporting. In this article, the authors review examples of current applications of machine learning and artificial intelligence techniques in diagnostic radiology. In addition, the future impact and natural extension of these techniques in radiology practice are discussed.

Proposal of a New Adverse Event Classification by the Society of Interventional Radiology Standards of Practice Committee.

PURPOSE: To develop a new adverse event (AE) classification for the interventional radiology (IR) procedures and evaluate its clinical, research, and educational value compared with the existing Society of Interventional Radiology (SIR) classification via an SIR member survey. MATERIALS AND METHODS: A new AE classification was developed by members of the Standards of Practice Committee of the SIR. Subsequently, a survey was created by a group of 18 members from the SIR Standards of Practice Committee and Service Lines. Twelve clinical AE case scenarios were generated that encompassed a broad spectrum of IR procedures and potential AEs. Survey questions were designed to evaluate the following domains: educational and research values, accountability for intraprocedural challenges, consistency of AE reporting, unambiguity, and potential for incorporation into existing quality-assurance framework. For each AE scenario, the survey participants were instructed to answer questions about the proposed and existing SIR classifications. SIR members were invited via online survey links, and 68 members participated among 140 surveyed. Answers on new and existing classifications were evaluated and compared statistically. Overall comparison between the two surveys was performed by generalized linear modeling. RESULTS: The proposed AE classification received superior evaluations in terms of consistency of reporting (P < .05) and potential for incorporation into existing quality-assurance framework (P < .05). Respondents gave a higher overall rating to the educational and research value of the new compared with the existing classification (P < .05). CONCLUSIONS: This study proposed an AE classification system that outperformed the existing SIR classification in the studied domains.

Socioeconomic and Demographic Predictors of Missed Opportunities to Provide Advanced Imaging Services.

PURPOSE: The extent to which racial and socioeconomic disparities exist in accessing clinically appropriate, advanced diagnostic imaging has not been well studied. This study assesses the relationship between demographic and socioeconomic factors and the incidence of imaging missed care opportunities (IMCOs). METHODS: We performed a retrospective review of outpatient CT and MRI appointments at a quaternary academic medical center and affiliated outpatient facilities during a 12-month period. Missed appointments not rescheduled in advance were classified as IMCOs. Appropriateness criteria scores and demographics were also obtained. Univariate and multivariate analyses were performed to determine if demographic and socioeconomic factors were predictive of IMCOs. RESULTS: Overall, 57,847 patients met inclusion criteria, representing 89,943 scheduled unique imaging appointments of which 5,840 (6.1%) were IMCOs; 0.8% of IMCO appointments had low appropriateness scores compared with 1.2% of completed appointments (P < .01). Appointments covered by commercial insurance (5.2%) had a significantly lower rate of IMCOs than other payers: Medicare = 6.3%, Medicaid = 14.5%, self-pay = 12.0% (P < .05). The following factors were independent predictors of a patient having ≥ 1 IMCO: noncommercial insurance [odds ratio (OR) = 1.7-2.6], African American (OR = 1.8), Hispanic (OR = 1.2), other race (OR = 1.1), language other than English or Spanish (OR = 1.2), male gender (OR = 1.2), age ≥ 65 (OR = 0.71), and median household income of patient home zip code <$50,000 (OR = 1.4). CONCLUSIONS: Race and socioeconomic status are independent predictors of IMCOs. In efforts to enhance patient engagement, radiologists should be aware of the impact of race and socioeconomic status on access to clinically appropriate advanced diagnostic imaging.

Effectiveness of second-opinion radiology consultations to reassess the cervical spine CT scans: a study on trauma patients referred to a tertiary-care hospital.

PURPOSE: A second opinion is a valuable resource in confirming proper medical diagnosis and treatment. This study evaluates the effectiveness of second-opinion radiology consultations to reassess the cervical spine computed tomography (CT) scans of the trauma patients referred to our hospital. METHODS: Cervical spine CT scans of 301 consecutive adult trauma patients, who were referred to our hospital from outside institutions, were analyzed. The emergency radiologists at our institution completed the over-read reports on the CT images obtained at the outside facilities. A single radiologist compared the outside- and over-read reports and determined the discrepancy of the radiologic reports. RESULTS: Based on the outside reports, 31% of the CT scans had cervical traumatic injury. In 92% of patients, the first-read and the over-read reports had consistent radiologic findings. About 90% of the positive, and 93% of the negative radiologic findings, were reported consistently in the over-read reports. Our analysis showed that the over-read reporting resulted in reassurance of negative findings in 63%; confirmation of positive findings in 29%; clearing a false diagnosis in 3%; and detection of a missed diagnosis in 5%. A rescan was done in 80% of patients with inconsistent and 20% of patients with consistent findings (P < 0.05). The most common missed radiologic findings in the first-reports were transverse and spinous process fractures and the most common misdiagnoses were dens fractures. CONCLUSION: For a service offering second-opinion consultations on cervical spine trauma, review of outside CT studies improves diagnosis and benefits patient care.

Hospital Evaluations by Social Media: A Comparative Analysis of Facebook Ratings among Performance Outliers.

BACKGROUND: An increasing number of hospitals and health systems utilize social media to allow users to provide feedback and ratings. The correlation between ratings on social media and more conventional hospital quality metrics remains largely unclear, raising concern that healthcare consumers may make decisions on inaccurate or inappropriate information regarding quality. OBJECTIVES: The purpose of this study was to examine the extent to which hospitals utilize social media and whether user-generated metrics on Facebook(®) correlate with a Hospital Compare(®) metric, specifically 30-day all cause unplanned hospital readmission rates. DESIGN AND PARTICIPANTS: This was a retrospective cross-sectional study conducted among all U.S. hospitals performing outside the confidence interval for the national average on 30-day hospital readmission rates as reported on Hospital Compare. Participants were 315 hospitals performing better than U.S. national rate on 30-day readmissions and 364 hospitals performing worse than the U.S. national rate. MAIN MEASURES: The study analyzed ratings of hospitals on Facebook's five-star rating scale, 30-day readmission rates, and hospital characteristics including beds, teaching status, urban vs. rural location, and ownership type. KEY RESULTS: Hospitals performing better than the national average on 30-day readmissions were more likely to use Facebook than lower-performing hospitals (93.3 % vs. 83.5 %; p < 0.01). The average rating for hospitals with low readmission rates (4.15 ± 0.31) was higher than that for hospitals with higher readmission rates (4.05 ± 0.41, p < 0.01). Major teaching hospitals were 14.3 times more likely to be in the high readmission rate group. A one-star increase in Facebook rating was associated with increased odds of the hospital belonging to the low readmission rate group by a factor of 5.0 (CI: 2.6-10.3, p < 0.01), when controlling for hospital characteristics and Facebook-related variables. CONCLUSIONS: Hospitals with lower rates of 30-day hospital-wide unplanned readmissions have higher ratings on Facebook than hospitals with higher readmission rates. These findings add strength to the concept that aggregate measures of patient satisfaction on social media correlate with more traditionally accepted measures of hospital quality.

Technical limitations of dual-energy CT in neuroradiology: 30-month institutional experience and review of literature.

BACKGROUND: Dual-energy CT (DECT) has been shown to be a useful modality in neuroradiology. OBJECTIVE: To assess failure modes and limitations of DECT in different neuroimaging applications. PATIENTS AND METHODS: Dual-source DECT scans were performed in 72 patients over 30 months to differentiate contrast agent staining or extravasation from intracranial hemorrhage (ICH) (n=40); to differentiate calcium from ICH (n=2); for metal-artifact reduction (n=5); and for angiographic assessment (n=25). A three-material decomposition algorithm was used to obtain virtual non-contrast (VNC) and iodine (or calcium) overlay images. Images were analyzed in consensus by two board-certified radiologists to determine the success of the algorithm and to assess confounding factors. Furthermore, a dilution experiment using cylinders containing defined heparinized swine blood, normal saline, and selected iodine concentrations was conducted to assess other possible confounding factors. RESULTS: Dual-energy analysis was successful in 65 (90.2%) patients. However, the algorithm failed when images were affected by beam hardening (n=3, 4.2%), the presence of a fourth material (parenchymal calcification) (n=3, 4.2%), or motion (n=1, 1.4%). In the dilution experiment, a saturation effect was seen at high iodine concentrations (≥37 mg/ml). VNC and iodine overlay images were not reliable above this concentration, and beam-hardening artifacts were noted. CONCLUSIONS: DECT material decomposition is usually successful in neuroradiology. However, it can only distinguish up to three preselected materials. A fourth material such as parenchymal calcium may confound the analysis. Artifacts such as beam hardening, metallic streak, or saturation effect can also impair material decomposition.

Coronary artery calcification is often not reported in pulmonary CT angiography in patients with suspected pulmonary embolism: an opportunity to improve diagnosis of acute coronary syndrome.

OBJECTIVE: In patients with suspected pulmonary thromboembolism (PTE), coronary artery calcification (CAC) can be an incidental finding on pulmonary CT angiography. We evaluated the frequency of CAC not being reported and its association with a diagnosis of acute coronary syndrome (ACS). MATERIALS AND METHODS: Data of 469 consecutive patients who were referred to the emergency radiology department for pulmonary CT angiography of suspected PTE were reviewed. Radiology reports were rechecked and positive CAC findings were recorded. All pulmonary CT angiograms were reevaluated by one radiologist and CAC findings were recorded. The rates of ACS and PTE as final diagnoses for that hospital admission were calculated. The association between CAC and ACS diagnosis was assessed in different subgroups of patients. RESULTS: Approximately 11.1% of patients had PTE and 43.8% had CAC. The incidence of CAC was significantly higher in patients with an ACS diagnosis than in those without ACS (56.2% vs 40.4%, respectively; odds ratio [OR] = 1.9). There was a strong positive association (OR = 3.5) between CAC and ACS in younger patients (men ≤ 45 years and women ≤ 55 years), patients without PTE (OR = 2.2), and those without cardiometabolic risk factors (OR = 3.8). CAC was not reported in 45% of patients (n = 98) with positive CAC findings on imaging. ACS was the final diagnosis in 31.6% of patients with unreported CAC. There was a significant association between CAC and ACS in patients with unreported CAC (OR = 2.2). This association was more prominent in the subgroups described. CONCLUSION: CAC is often not reported in pulmonary CT angiography studies. CAC is a significant predictor of ACS particularly in younger patients, patients without PTE, and those without cardiometabolic risk factors. Especially in these subgroups, radiologists should assess CAC findings.

Location specific sleep spindle activity in the early visual areas and perceptual learning.

Visual perceptual learning (VPL) is consolidated during sleep. However, the underlying neuronal mechanisms of consolidation are not yet fully understood. It has been suggested that the spontaneous brain oscillations that characterize sleep stages are indicative of the consolidation of learning and memory. We investigated whether sleep spindles and/or slow-waves are associated with consolidation of VPL during non-rapid eye movement (NREM) sleep during the first sleep cycle, using magnetoencephalography (MEG), magnetic resonance imaging (MRI), and polysomnography (PSG). We hypothesized that after training, early visual areas will show an increase in slow sigma, fast sigma and/or delta activity, corresponding to slow/fast sleep spindles and slow-waves, respectively. We found that during sleep stage 2, but not during slow-wave sleep, the slow sigma power within the trained region of early visual areas was larger after training compared to baseline, and that the increase was larger in the trained region than in the untrained region. However, neither fast sigma nor delta band power increased significantly after training in either sleep stage. Importantly, performance gains for the trained task were correlated with the difference of power increases in slow sigma activity between the trained and untrained regions. This finding suggests that slow sigma activity plays a critical role in the consolidation of VPL, at least in sleep stage 2 during the first sleep cycle.

White matter changes in comatose survivors of anoxic ischemic encephalopathy and traumatic brain injury: comparative diffusion-tensor imaging study.

PURPOSE: To analyze white matter pathologic abnormalities by using diffusion-tensor (DT) imaging in a multicenter prospective cohort of comatose patients following cardiac arrest or traumatic brain injury (TBI). MATERIALS AND METHODS: Institutional review board approval and informed consent from proxies and control subjects were obtained. DT imaging was performed 5-57 days after insult in 49 cardiac arrest and 40 TBI patients. To control for DT imaging-processing variability, patients' values were normalized to those of 111 control subjects. Automated segmentation software calculated normalized axial diffusivity (λ1) and radial diffusivity (λ⊥) in 19 predefined white matter regions of interest (ROIs). DT imaging variables were compared by using general linear modeling, and side-to-side Pearson correlation coefficients were calculated. P values were corrected for multiple testing (Bonferroni). RESULTS: In central white matter, λ1 differed from that in control subjects in six of seven TBI ROIs and five of seven cardiac arrest ROIs (all P < .01). The λ⊥ differed from that in control subjects in all ROIs in both patient groups (P < .01). In hemispheres, λ1 was decreased compared with that in control subjects in three of 12 TBI ROIs (P < .05) and nine of 12 cardiac arrest ROIs (P < .01). The λ⊥ was increased in all TBI ROIs (P < .01) and in seven of 12 cardiac arrest ROIs (P < .05). Cerebral hemisphere λ1 was lower in cardiac arrest than in TBI in six of 12 ROIs (P < .01), while λ⊥ was higher in TBI than in cardiac arrest in eight of 12 ROIs (P < .01). Diffusivity values were symmetrically distributed in cardiac arrest (P < .001 for side-to-side correlation) but not in TBI patients. CONCLUSION: DT imaging findings are consistent with the known predominance of cerebral hemisphere axonal injury in cardiac arrest and chiefly central myelin injury in TBI. This consistency supports the validity of DT imaging for differentiating axon and myelin damage in vivo in humans.

Accuracy of anthropometric parameters in identification of high-risk patients predicted with cardiovascular risk models.

BACKGROUND: Overweight and obesity are associated with unfavorable outcomes on the cardiovascular system. Early detection of the patients' high risk for developing cardiovascular disease (CVD) is a primary care priority. Simple-to-use screening tools derived from anthropometric parameters and obesity-related indices could serve this purpose. METHODS: A total of 2,716 women and 1,132 men aged 18 years and older, free of known CVD at baseline were enrolled in this study. Ten-year risk of incident CVD based on 3 computational models, namely Systematic COronary Risk Evaluation (SCORE), United Kingdom Prospective Diabetes Study and Framingham was calculated and served as the main outcome event. Weight, height, body mass index, waist circumference, hip circumference, blood pressure, high-density lipoprotein cholesterol, total cholesterol, serum triglyceride, glycated hemoglobin A1c and fasting plasma glucose concentrations were also determined. RESULTS: Waist-to-hip ratio (WHR) had the largest area under the curve (AUC) in identification of all outcome variables (high-risk United Kingdom Prospective Diabetes Study, SCORE, Framingham; AUC: 0.64-0.69) in women and in 2 of 3 (SCORE, Framingham; AUC: 0.62-0.64) in men; making it the best parameter followed by waist-to-height ratio and waist circumference. Body mass index and hip circumference consistently produced smaller AUC. WHR optimal cutoff points in prediction of outcome variables were in the range of 0.87 to 0.90 in women and 0.90 to 0.94 in men. CONCLUSIONS: WHR is superior to other anthropometric parameters in identification of high-risk patients based on different CVD risk prediction models and can be used for screening purposes.

Appropriate BMI cut-off values for identification of metabolic risk factors: third national surveillance of risk factors of non-communicable diseases in Iran (SuRFNCD-2007).

AIM: To determine the appropriate threshold of body mass index (BMI) associated with increased risk of cardiovascular diseases in a large representative sample of an Iranian population. SUBJECTS AND METHODS: Data of third national surveillance of risk factors of non-communicable diseases (SuRFNCD-2007) were used in this study. Sensitivity, specificity, and shortest distance on the receiver-operating characteristic (ROC) curves were used to determine gender-specific optimal cut-offs of BMI for cardiometabolic risk factors including elevated blood pressure, low high-density lipoprotein cholesterol, high triglycerides, high fasting plasma glucose and for ≥ 2 of the aforementioned risk factors. RESULTS: There was a continuous increase in the prevalence of cardiometabolic risk factors with increasing BMI (p < 0.001). At the BMI of 25-29 kg/m(2) men were at higher risk of cardiovascular diseases compared to women (p < 0.001). The appropriate BMI cut-offs ranged from 24.6-26.1 kg/m(2) for men and from 26.9-28.8 kg/m(2) for women. The optimal BMI cut-offs for identifying any two or more of those risk factors were 25.2 and 27.3 kg/m(2) in men and women, respectively. CONCLUSION: In men the appropriate BMI cut-offs are ~25 kg/m(2), while in women higher BMI values are associated with risk of cardiovascular diseases.

The value of visfatin in the prediction of metabolic syndrome: a multi-factorial analysis.

We describe the adipokine concentration in patients with metabolic syndrome, stressing the role of visfatin. A cross-sectional single center study on 70 patients with metabolic syndrome plus 76 controls was performed. Patients with metabolic syndrome had higher visfatin levels compared to controls, following adjustments for age, sex, waist/hip circumference, systolic, and diastolic blood pressure, fasting plasma glucose (FPG), HbA1c, body mass index, and homeostasis model assessment of insulin resistance (HOMA-IR) [(5.39 ± 0.29 vs. 3.88 ± 0.32); F(1, 129) = 10.8, P < 0.01]. A logistic regression analysis revealed that circulating visfatin levels and HbA1c were the top variables for predicating metabolic syndrome. In patients with metabolic syndrome, visfatin did not correlate with any of the measured variables, with the single exception of adiponectin; in patients without metabolic syndrome, circulating visfatin levels were significantly associated with FPG, HbA1c, insulin, HOMA-IR, HDL, and triglyceride. These findings may contribute to our current knowledge about visfatin in metabolic syndrome.

Physical inactivity is correlated with levels of quantitative C-reactive protein in serum, independent of obesity: results of the national surveillance of risk factors of non-communicable diseases in Iran.

Increased C-reactive protein (CRP) levels are associated with coronary heart disease, stroke, and mortality. Physical activity prevents cardiovascular disorders, which can be partly mediated through reducing inflammation, including serum CRP levels. The association of different intensities of physical activity, sedentary behaviours, and C-reactive protein (CRP) levels in serum was examined after adjustment for markers of adiposity, including waist-circumference and body mass index (BMI), in a large population-based study. Using data of the SuRFNCD-2007 study, a large national representative population-based study in Iran, the relationship between quantitative CRP concentrations in serum and physical activity was examined in a sample of 3,001 Iranian adults. The global physical activity questionnaire (GPAQ) was used for evaluating the duration and intensity of physical activity. Total physical activity (TPA) was calculated using metabolic equivalents for the intensity of physical activity. Quantitative CRP concentrations in serum were measured with high-sensitivity enzyme immunoassay. The CRP levels in serum significantly correlated with TPA (r=-0.103, p=0.021 in men and r=-0.114, p=0.017 in women), duration of vigorous-intensity activity (r=-0.122, p=0.019 in men and r=-0.109, p=0.026 in women), duration of moderate-intensity activity (r=-0.107, p=0.031 in men and r=-0.118, p=0.020 in women), and duration of sedentary behaviours (r=0.092, p=0.029 in men and r=0.101, p=0.022 in women) after multiple adjustments for age, area of residence, BMI, waist-circumference, smoking, and diabetes mellitus. Physical activity (of both moderate and vigorous intensity) is inversely associated with the quantitative CRP levels in serum, independent of diabetes and body adiposity.

The dual behavior of heat shock protein 70 and asymmetric dimethylarginine in relation to serum CRP levels in type 2 diabetes.

BACKGROUND: Experimental evidence suggests that heat shock proteins (HSP) and asymmetric dimethylarginine (ADMA) are induced in the state of chronic inflammation and stress conditions. They are both inhibitors of nitric oxide synthase (NOS). The aim of this study was to evaluate the correlation between ADMA and HSP70, in patients with type 2 diabetes with respect to serum levels of C reactive protein (CRP). METHODS: We quantified serum HSP70, ADMA and CRP in 80 newly-diagnosed patients with type 2 diabetes plus 80 age-, sex and BMI-matched healthy controls. The patients and controls were also stratified into groups of high and low CRP levels (cut-point: 2.5mg/ml). RESULTS: Patients with type 2 diabetes had significantly higher serum HSP70 (0.52 [0.51-0.66] vs. 0.27 [0.26-0.36], p<0.001), ADMA (0.86 [0.81-0.92] vs. 0.72 [0.71-0.85], p<0.05) and CRP (2.9 [1.7-3.4] vs. 1.6[1.2-2.3], p<0.05) compared with healthy controls. Serum HSP70 and ADMA levels were significantly correlated in patients with high CRP levels (r=0.89, p<0.01), whereas there were no correlation in patients with low CRP (r=-0.37, p=0.07) and controls. This correlation was significant (r=0.77, p<0.001) in patients with high CRP and also in patients with low CRP levels (r=-0.51, p<0.05), after multiple adjustments for LDL and HDL levels. DISCUSSION: We showed that, in a state of high inflammation; serum levels of ADMA parallel the HSP70 levels. However in low inflammation, they are negatively correlated. The duality in HSP70 and ADMA correlation may be related to the duality of NOS function in low and high CRP levels.

Fistula formation between the right and left main bronchus caused by endobronchial tuberculosis.

The prevalence of endobronchial tuberculosis (EBTB) in patients with active tuberculosis is about 10% to 40%. The most common complication of EBTB is bronchial stenosis. Fistula formation by pulmonary tuberculosis is a very rare complication and is most commonly bronchopleural. The authors present a 53-year-old woman presented with chronic cough and abnormality in chest computed tomography scan. According to chest computed tomography scan finding, bronchoscopic study was done and bronchial lavage was obtained. Bronchial lavage was positive for acid fast bacilli. Bronchoscopy showed fistula formation between the right and left main bronchus, a rare manifestation of EBTB. The patient was treated with antituberculosis therapy, and her symptoms improved and radiological findings showed regression of pulmonary lesions.

Diffusion-weighted magnetic resonance imaging for diagnosis of liver fibrosis and inflammation in chronic viral hepatitis: the performance of low or high B values and small or large regions of interest.

OBJECTIVE: To investigate the performance of different b values and regions of interest (ROI) for diagnosing liver fibrosis in patients with chronic viral hepatitis by using diffusion-weighted (DW) magnetic resonance imaging (MRI). METHODS: Eleven healthy participants and 33 patients with viral hepatitis B or C were enrolled. The stage of liver fibrosis and the grade of necroinflammation were determined by using a histologic activity index. Single-shot spin-echo echo-planar DW-MRI was performed in all participants at b values of 0-500, 0-700, and 0-1000 s/mm(2) by using 2 circular small and large ROIs of 100 and 200 mm(2). To evaluate the performance of different b values for determining cirrhosis, the receiver-operating characteristic curves were depicted, and the areas under the curves were compared. RESULTS: The average values of apparent diffusion coefficients significantly decreased with increasing stage or grade categories at all the 3 b values and for both small and large ROIs. The performance at b = 500 s/mm(2) was significantly better than b = 1000 s/mm(2) for determining cirrhosis or bridging fibrosis. The cut point of 153.4 for apparent diffusion coefficient (×10(-5) mm(2)/s) at b = 500 s/mm(2) could determine cirrhosis or bridging fibrosis with a sensitivity of 96% and specificity of 82%. No difference was found between the average apparent diffusion coefficient values of large or small ROIs. Also, there was no difference in performance of large or small ROIs in the diagnosis of liver fibrosis. CONCLUSIONS: This study provided beneficial data for clinical utilisation of DW-MRI in diagnosing liver fibrosis: b = 500 s/mm(2) is better in performance than b = 1000 s/mm(2), and a small ROI of 100 mm(2) is sufficient for determining cirrhosis or bridging fibrosis.