Immune checkpoint inhibitors: Assessment of the performance and the agreement of iRECIST, irRC, and irRECIST.

INTRODUCTION: Immunotherapy has become more widely accepted and used by medical oncologists. Radiologists face challenges in assessing tumor response and becoming more involved in the management of treatment. We aimed to assess the agreement between immune-related response criteria (irRC), immune-related RECIST (irRECIST), and immune RECIST (iRECIST) to correlate the response measured by them with overall survival (OS), and to determine the confirmation rate of progressive disease (PD). METHODS: A total of 43 patients (28 men, 15 women; average age = 54.6 ± 15.7 years) treated with immunotherapy were included in this study. Pairwise agreements between iRECIST, irRC, and irRECIST were calculated using Cohen's kappa statistics. The correlation of the criteria-based response and OS was evaluated using the Kaplan-Meier method and log-rank test. A confirmation rate with 95% confidence intervals (CI) was calculated in patients with PD. RESULTS: The kappa values between iRECIST and irRC, iRECIST and irRECIST, and irRC and irRECIST were 0.961 (almost perfect; P < 0.001), 0.961 (almost perfect; P < 0.001), and 0.922 (almost perfect; P < 0.001), respectively. The Kaplan-Meier method and log-rank test showed for each criterion a statistically significant correlation with OS (P < 0.05). The confirmation rates of PD for irRC, irRECIST, and iRECIST were 95% (19/20; 95% CI = 76.4-99.1%), 90% (18/20; 95% CI = 69.9-97.2%), and 90.5% (19/21; 95% CI = 71.1-97.4%), respectively. CONCLUSION: There was an almost perfect and statistically significant agreement between iRECIST, irRC, and irRECIST. The measurements performed with them significantly correlated with the OS; their confirmation rates were similar. iRECIST and irRECIST might be favored over irRC because of their relative ease of use.

State-of-the-art Prostate Imaging.

Prostate cancer is one of the most common cancers in men. In addition to methods such as prostate-specific antigen test, digital rectal examination, and transrectal ultrasonography, magnetic resonance imaging has an important role for accurate and reproducible diagnosis. However, guidance in targeted biopsies and recent use in determining localization for treatment increase its importance. Due to technical difficulties, patient tolerance, and differences in interpretation, the prostate imaging reporting and data system recommends preparations for the patient and magnetic resonance imaging techniques. However, techniques continue to be developed to improve the diagnosis rate and image quality. In our article, patient preparation before imaging and techniques were tried to be discussed in detail. In addition, current approaches in biparametric magnetic resonance imaging and radiomics and new techniques such as T1 and T2 mapping will be mentioned.

The Significance of Preoperative Computed Tomography Features in the Prediction of Overall Survival in Gastric Cancer: A Retrospective Analysis.

Objectives: Computed tomography (CT) is a frequently used modality for staging in the preoperative evaluation of gastric cancer (GC). Our aim was to interpret the importance of preoperative CT features in predicting overall survival (OS) in patients operated for GC. Methods: One hundred and one patients with GC (33 women, 68 men; range of age: 29-82 years, median age: 61 years) who had abdominal CT prior to surgical resection were included in the study retrospectively. Two radiologists evaluated CT scans to record the longest dimension of the tumor, the localization of the lesion, the attenuation values of the tumor in the arterial and venous phases (Hounsfield units), invasion depth of the lesion (T stage), and the number of pathological lymph nodes (LNs) (N stage). Postoperative pathological results including resection (R0, R1), T stage, N stage, grade, and histopathological subtype were documented. All CT-provided results and clinicopathological features associated with OS were analyzed by univariate, multivariate, and receiver operator characteristic analysis. Results: Multivariate analysis revealed that none of the CT features were associated with the OS. After resection, the survival ratio was poor for the R1 and high-grade groups than for the R0 and low-grade groups (p=0.001 and p=0.005, respectively). N stage and the longest dimension of the tumor on CT imaging truly estimated R1 resection status (AUC, 0.697; sensitivity, 63%; and specificity, 88%, and AUC, 0.734; sensitivity, 18%; and specificity, 76%, respectively). Conclusion: R1 resection status is associated with poor OS in GC. CT features, including the tumor's longest dimension and the number of pathological LNs, can predict R1 resection status.

Prediction of carcinogenic human papillomavirus types in cervical cancer from multiparametric magnetic resonance images with machine learning-based radiomics models.

PURPOSE: This study aimed to evaluate the potential of machine learning-based models for predicting carcinogenic human papillomavirus (HPV) oncogene types using radiomics features from magnetic resonance imaging (MRI). METHODS: Pre-treatment MRI images of patients with cervical cancer were collected retrospectively. An HPV DNA oncogene analysis was performed based on cervical biopsy specimens. Radiomics features were extracted from contrast-enhanced T1-weighted images (CE-T1) and T2-weighted images (T2WI). A third feature subset was created as a combined group by concatenating the CE-T1 and T2WI subsets. Feature selection was performed using Pearson's correlation coefficient and wrapper- based sequential-feature selection. Two models were built with each feature subset, using support vector machine (SVM) and logistic regression (LR) classifiers. The models were validated using a five-fold cross-validation technique and compared using Wilcoxon's signed rank and Friedman's tests. RESULTS: Forty-one patients were enrolled in the study (26 were positive for carcinogenic HPV oncogenes, and 15 were negative). A total of 851 features were extracted from each imaging sequence. After feature selection, 5, 17, and 20 features remained in the CE-T1, T2WI, and combined groups, respectively. The SVM models showed 83%, 95%, and 95% accuracy scores, and the LR models revealed 83%, 81%, and 92.5% accuracy scores in the CE-T1, T2WI, and combined groups, respectively. The SVM algorithm performed better than the LR algorithm in the T2WI feature subset (P = 0.005), and the feature sets in the T2WI and the combined group performed better than CE-T1 in the SVM model (P = 0.033 and 0.006, respectively). The combined group feature subset performed better than T2WI in the LR model (P = 0.023). CONCLUSION: Machine learning-based radiomics models based on pre-treatment MRI can detect carcinogenic HPV status with discriminative accuracy.

The Efficiency of Fractional Anisotropy, Apparent Diffusion Coefficient, and Contrast Enhancement Index in Liver Fibrosis Staging.

Objectives: Even though magnetic resonance imaging has been described as the most effective imaging method for the diagnosis of liver fibrosis, an accepted magnetic resonance imaging (MRI) technique is yet to be defined. The aim of this study is to determine the efficiency of MRI in the staging of liver fibrosis. Methods: Patients with chronic hepatitis B infection and had upper abdominal MRI with hepatocyte specific contrast agent were evaluated. Twenty-nine patients that had undergone liver biopsy were included in the study. ADC, FA, and signal intensity values of liver parenchyma were measured by two observers and contrast enhancement index (CEI) was calculated as well. Patients were grouped as early (A) and late fibrosis(B) according to Ishak grading system and then the correlations between the stage and MRI findings were analysed. The intraclass correlation coefficient was used to analyze the inter-rater agreements. ADC, FA, and CEI were compared with Student t-test between early and late fibrosis groups. Pearson's correlation was used to assess the correlation between ADC and FA values. Spearman correlation was used to evaluate the relationship between pathologic fibrosis grade and MRI parameters that were measured. Results: Twenty-two patients were staged as 1 and 2 (group A), seven patients were staged as 3 and above fibrosis(group B). Statistically, there was a strong, negative correlation between the FA values and the degree of fibrosis (r=-0.582, p=0.001). There was no correlation between the CEI and hepatocyte activity index (r=-0.88, p=0.655) and degree of fibrosis (r=0.0001, p=0.997). In terms of FA values, there was a statistically significant difference between two groups (group A=0.429 ± 0.06, group B=0.349 ± 0.06) (p=0.004). Conclusion: Correlation of FA values with fibrosis stage and significant difference in FA values between early-late stage fibrosis patients shows that diffusion tensor imaging can be a promising technique in the staging and follow-up of liver fibrosis.

Classification of retinoblastoma-1 gene mutation with machine learning-based models in bladder cancer.

Purpose: This study aims to evaluate the potential of machine learning algorithms built with radiomics features from computed tomography urography (CTU) images that classify RB1 gene mutation status in bladder cancer. Method: The study enrolled CTU images of 18 patients with and 54 without RB1 mutation from a public database. Image and data preprocessing were performed after data augmentation. Feature selection steps were consisted of filter and wrapper methods. Pearson's correlation analysis was the filter, and a wrapper-based sequential feature selection algorithm was the wrapper. Models with XGBoost, Random Forest (RF), and k-Nearest Neighbors (kNN) algorithms were developed. Performance metrics of the models were calculated. Models' performances were compared by using Friedman's test. Results: 8 features were selected from 851 total extracted features. Accuracy, sensitivity, specificity, precision, recall, F1 measure and AUC were 84%, 80%, 88%, 86%, 80%, 0.83 and 0.84, for XGBoost; 72%, 80%, 65%, 67%, 80%, 0.73 and 0.72 for RF; 66%, 53%, 76%, 67%, 53%, 0.60 and 0.65 for kNN, respectively. XGBoost model had outperformed kNN model in Friedman's test (p = 0.006). Conclusions: Machine learning algorithms with radiomics features from CTU images show promising results in classifying bladder cancer by RB1 mutation status non-invasively.

A Rare Presentation of Extramedullary Hematopoiesis: Perirenal Masses.

Extramedullary hematopoiesis (EMH) is a physiological compensatory mechanism that develops in response to ineffective or insufficient hematopoiesis. Although the liver and spleen are the most common sites, EMH may occur anywhere in the body. Peri-renal involvement in EMH is quite rare and mimics tumoral lesions. To our knowledge, 12 peri-renal EMH cases have been reported in the literature so far.  A 57-year woman was admitted to our hospital with non-specific abdominal pain. She had a history of chronic renal failure. On physical examination, diffuse abdominal tenderness and mild rigidity were detected. Blood tests revealed bicytopenia and elevated acute phase reactants. On non-contrast abdominal computed tomography (CT) scan, two peri-renal mass lesions of 4.5 cm and 4 cm were detected incidentally on the right side. Tumoral lesions were considered in the differential diagnosis, and magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) were performed. Lesions showed mild hypermetabolic activity (SUVmax: 4,68) on PET-CT images. For the definitive diagnosis, an ultrasound-guided core needle biopsy was performed. The histopathological examination was consistent with EMH. This case aims to highlight the peri-renal involvement of EMH, which mimics renal and peri-renal malignancies.

Predictors of malignancy in patients with solitary pulmonary nodules undergoing pulmonary resection.

BACKGROUND: The management of a solitary pulmonary nodule is a challenging issue in pulmonary disease. Although many factors have been defined as predictors for malignancy in solitary pulmonary nodules, the accurate diagnosis can only be established with the permanent histological diagnosis. OBJECTIVE: We tried to clarify the possible predictors of malignancy in solitary pulmonary nodules in patients who had definitive histological diagnosis. METHODS: We made a retrospective study to collect the data of patients with solitary pulmonary nodules who had histological diagnosis either before or after surgery. We made a statistical analysis of both the clinic and radiological features of these nodules with respect to malignancy both in contingency tables and with logistic regression analysis. RESULTS: We had a total of 223 patients with a radiological diagnosis of solitary pulmonary nodule. Age, smoking status and pack years of smoking, maximum standardized uptake value (SUVmax), and radiological features such as solid component, spiculation, pleural tag, lobulation, calcification, and higher density were significant predictors of malignancy in contingency tables. Age, smoking status and smoking (pack/year), SUVmax, and radiological features including spiculation, pleural tag, lobulation, calcification, and higher density were the significant predictors in univariate analysis. However, multivariate analysis revealed only SUVmax greater than 2.5 (p < 0.0001), spiculation (p = 0.009), and age older than 61 years (p = 0.015) as the significant predictors for malignancy. CONCLUSION: Age, SUVmax, and spiculation are the independent predictors of malignancy in patients with solitary pulmonary nodules.

Can peritoneal thickening and enhancement be used to determine perforation in patients with acute appendicitis?

BACKGROUND: Acute appendicitis (AA) is a common cause of abdominal pain in developed countries. In patients with suspected AA, computed tomography (CT) is considered as the gold standard with the highest sensitivity and specificity, and it is also an im-portant modality, especially in patients with complicated AA. In this study, we aimed to evaluate age and laboratory findings, as well as specific CT findings in differentiating between perforated and non-perforated appendicitis. METHODS: We retrospectively analyzed 252 patients diagnosed with AA and underwent appendectomy between November 2015 and December 2019 in Somalia Mogadishu Recep Tayyip Erdogan Education and Research Hospital. Patients under 18 years of age and those with no pre-operative CT scans were excluded from the study. The demographic, laboratory, CT findings, and pathological data of all patients were evaluated. RESULTS: This study included 80 patients, 32 (40%) classified as perforated appendicitis (Group-1) and 48 (60%) as non-perforated appendicitis (Group-2). The C-reactive protein value was found to be statistically higher in Group-1 than in Group-2 (177.5±118.9 and 100.2±87.3 mg / L, respectively; p=0.001). The appendix lumen diameter (p=0.002), appendix wall defect (p<0.001), peritoneal thickening and enhancement (p<0.001), ascites (p=0.031), intra-abdominal abscess (p=0.003), jejunal thickening (p=0.019), ileal thick-ening (p=0.008), and ileus (p=0.035) values were significantly higher in Group-1. In the binominal logistic regression analysis performed with statistically significant data, an appendiceal wall defect (OR: 0.069, 95% CI=0.014-0.327, p=0.001) and peritoneal thickening and enhancement (OR: 0.131, 95% CI=0.024-0.714, p=0.019) were identified as independent variables for perforated appendicitis. CONCLUSION: Among CT findings, appendix wall defects and peritoneal thickening and enhancement play an important role in detecting perforation.

Primary Hepatic Angiosarcoma: A Rare and Very Aggressive Liver Tumour.

Primary hepatic angiosarcoma (PHA) is a sporadic and aggressive tumour of the liver that originates from mesenchymal cells and represents less than 2% of all primary liver tumours. It is known to be associated with several environmental and industrial carcinogens; however, in 75% of cases, aetiology remains unclear. Patients generally present with nonspecific symptoms and laboratory findings. Imaging has a limited role in the diagnosis.  We herein present a case of a 52-year-old man with a history of hepatitis B-related cirrhosis who was referred to our hospital for liver transplantation assessment. Magnetic resonance imaging (MRI) revealed two small nodular lesions of 5 and 6 mm in segment IV of the liver, categorised as Liver Imaging Reporting and Data System (LI-RADS) category 3. The patient was discussed at a multidisciplinary tumour meeting, and an MRI follow-up in three months was planned. Three months later, MRI depicted a substantial increase in the lesion size measured 8.5 cm. An ultrasound-guided tru-cut biopsy was performed, and the diagnosis of PHA was confirmed by pathology. In this report, we aim to highlight PHA's MRI features and underline this rare entity's rapid and fatal progression.

Prediction of clinical outcomes of single- and double- bundle anterior cruciate ligament reconstruction techniques using magnetic resonance imaging.

BACKGROUND: The objective of the study is to compare the clinical results of the single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) repairing techniques using magnetic resonance imaging (MRI). METHODS: Thirty-eight patients were randomized by block randomization into two different groups of ACL reconstruction: DB (n=19) and SB techniques (n=19). MRI evaluation and clinical examination with modified Cincinnati Knee Rating Score and Lysholm knee scores were performed pre-operatively and at the end of a follow-up period of 36 months. RESULTS: No significant differences were found in the ACL angle, posterior cruciate ligament angle, and tibial translation between the DB and the SB groups. Regarding the clinical scores, there were no significant differences between the techniques. As for the correlation of radiologic results with clinical scores in the SB group, there was a strong and significant correlation between the post-operative ACL angle values and the Lysholm clinical score (r=-0.66; p=0.002). CONCLUSION: The post-operative ACL angle can predict the degree of clinical recovery in patients undergoing SB ACL reconstruction.

Comparison of MRI and 18F-FDG PET/CT in the Liver Metastases of Gastrointestinal and Pancreaticobiliary Tumors.

OBJECTIVES: To compare the efficacy of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) and magnetic resonance imaging (MRI) in the detection of liver metastases originating from the gastrointestinal system (GIS) and the pancreaticobiliary (PB) system. METHODS: This retrospective study included 42 patients with primary GIS (stomach or colorectal) or PB system malignancies that metastasized to the liver, histopathologically confirmed diagnoses, and MRI and 18F-FDG PET/CT images. The MRI and 18F-FDG PET/CT images were analyzed. Student's t-test was used to compare the two modalities in terms of determining the number of metastases, and Cohen's kappa test was conducted to determine the agreement between the modalities. RESULTS: Twenty-eight (66.7%) of the patients included in this study were male, and the mean age was 60.67±9.4 years. Colon (n=25; 59.5%) and pancreatic (n=7; 16.6%) adenocarcinomas were the most common primary tumors that had metastasized to the liver. MRI detected more metastases in 12 (28.5%) patients, less in seven (16.6%), and an equal number of metastases in 23 (54.7%). No statistically significant difference was observed between the number of metastases detected by MRI and 18F-FDG PET/CT (7.55±7.96 and 6.36±7.28, respectively; p=0.11). There was a moderate agreement between the two modalities (kappa value=0.423). Most of the metastases detected on MRI but not seen on 18F-FDG PET/CT (n=10, 23.8%) were lesions smaller than 10 mm. For the eight (19%) patients with lymph node metastases, the number of metastatic lymph nodes detected by MRI and 18F-FDG PET/CT was similar (12 and 14, respectively, p>0.05). CONCLUSION: MRI can detect small lesions at an early stage, and 18F-FDG PET/CT shows the metabolic activity of lesions; therefore, the combined use of the two modalities can potentially offer a beneficial outcome for patients.

Are radiologists ready to evaluate true response to immunotherapy?

BACKGROUND: Standardized response criteria for evaluating patients radiological imaging have an essential role in oncological management. Immunotherapy, using immune checkpoint inhibitors (ICIs), including drugs targeting cytotoxic T-lymphocyte-associated antigen 4 and programmed cell death protein 1 or its ligand, promise a new role that has demonstrated improvement management in cancers resistant to chemotherapy. This article reviews the literature to understand the most useful response evaluation criteria for optimal patient management under immunotherapy treatment. Areas that warrant further research are described. CONCLUSION: In conclusion, ICIs have become more widely accepted and used by medical oncologists. Radiologists face challenges in assessing tumor response and becoming more involved in the management of treatment. The latest published immune-RECIST criteria can be used in response assessment, but further prospective evaluation is needed with registration clinical trials to be definitively validated.

Liver and pancreas: 'Castor and Pollux' regarding the relationship between hepatic steatosis and pancreas exocrine insufficiency.

BACKGROUND: Pancreatic exocrine insufficiency (PEI) is found in 30-50% of diabetes mellitus (DM). Insulin resistance is triggering factor in both DM and nonalcoholic fatty liver disease (NAFLD). Therefore, we aimed to investigate frequency of PEI in NAFLD, and relationship of fecal pancreatic elastase (PE) levels with liver histology and pancreatic fat. METHODS: Ninety-seven biopsy proven NAFLD patients and 50 controls were enrolled. Pancreas exocrine functions were measured by PE. Magnetic resonance imaging-estimated proton density fat fraction (MRI-PDFF) was used to quantify fat. RESULTS: NAFLD patients had significantly lower PE levels than controls (297 [204-517] vs. 500 [298-678] µg/g, p < 0.01). PEI (PE < 200 µg/g) ratio of NAFLD patients (22.7%, n = 22) was higher than PEI ratio of controls (6%, n = 3) (p = 0.011). Among diabetic (n = 35) NAFLD patients, 9 (25.7%) exhibited PEI, compared to 13 (21%) of non-diabetics. There was no significant difference in patients with and without DM in terms of PEI (p = 0.592). Among NASH (n = 68) patients 16 (23.5%) exhibited PEI, compared to (20.7%) of non-NASH (p = 0.76). Multiple analysis revealed NAFLD as a predictor of PEI independent of age, sex and DM (OR = 4.892, p = 0,021). Mean pancreas MRI-PDFF was significantly higher in diabetics (13.7% ± 3.6% vs. 8.7% ± 5.1%, p = 0.001). There was no significant pancreas MRI-PDFF difference between NASH and non-NASH (P = 0.95). Mean pancreas MRI-PDFF was significantly higher in patients with PEI (13.7% ± 3.4% vs. 8.9% ± 5.2%, P < 0.01). CONCLUSION: This is the first study demonstrating the high frequency of PEI in NAFLD independent of DM. Moreover, increasing pancreatic steatosis appears to be associated with higher frequency of PEI in NAFLD.

Cardiac Hydatid Cysts: Computed Tomography and Magnetic Resonance Imaging Findings of the 5 Cases.

OBJECTIVE: In this article, we aimed to review the computed tomography (CT) and magnetic resonance imaging (MRI) findings of cardiac hydatid disease. CONCLUSIONS: Regarding the diagnostic work-up of cardiac hydatid disease, CT and MRI are complimentary techniques. Whereas CT effectively depicts wall calcifications, MRI reveals the exact anatomic location and nature of the internal and external structures and is the technique used for the early diagnosis, assessment, and follow-up of patients with cardiac hydatid disease.

Diffusion Weighted MRI for Hepatic Fibrosis: Impact of b-Value.

BACKGROUND: Hepatic fibrosis is a typical complication of chronic liver diseases resulting in cirrhosis that remains a major public health problem worldwide. Liver biopsy is currently the gold standard for diagnosing and staging hepatic fibrosis. Percutaneous liver biopsy; however, is an invasive procedure with risks of complications. Therefore, there is need for alternative non-invasive techniques to assess liver fibrosis and chronic liver diseases. In recent years, MRI techniques, including diffusion weighted imaging (DWI), have been developed for in vivo quantification of liver fibrosis. OBJECTIVES: The purpose of this study is to evaluate the utility of diffusion weighted MRI in the diagnosis and quantification of the degree of hepatic fibrosis and to investigate the influence of b-value. PATIENTS AND METHODS: Twenty-four patients (13 males, 11 females), with a mean age of 46 years (36-73 years) diagnosed as chronic hepatitis and histopathologically proven liver fibrosis and 22 other patients (8 males, 14 females) with no clinical or biochemical findings of liver disease, with a mean age of 51.2 years (32-75 years) were included in the study. All patients with chronic hepatitis underwent percutaneous liver biopsy by an experienced hepatologist without sonographic guidance. The Knodell histology activity index (HAI) for grading of necroinflammatory changes and Metavir scoring system for staging of the liver fibrosis were used to record the severity of the disease. All patients were examined with a 1.5 Tesla MRI system and the patients underwent diffusion weighted imaging (DWI) with a routine hepatic MRI protocol. Different b-values including 250, 500, 750, and 1000 sec/mm (2) were used to calculate apparent diffusion coefficients. RESULTS: We detected decreased apparent diffusion coefficient values in patients with hepatic fibrosis compared to patients without chronic hepatitis and there was a trend toward decrease in hepatic apparent diffusion coefficient values with an increasing degree of fibrosis. CONCLUSIONS: Our findings suggest that hepatic apparent diffusion coefficient measurement with a b-value of 750 sec/mm (2) or greater is useful in accurate quantification of liver fibrosis and necroinflammation.

Diffusion tensor imaging of cysts, hemangiomas, and metastases of the liver.

BACKGROUND: Although diffusion-weighted magnetic resonance imaging imaging (DW-MRI) is commonly used to characterize hepatic lesions, the literature is sparse about the use of MR diffusion tensor imaging (DTI) in this regard. By using DTI, one is able to obtain not only apparent diffusion coefficients (ADCs) but also fractional anisotropy (Fa) values. PURPOSE: To evaluate DTI using ADC and Fa values in the imaging of hepatic cysts, hemangiomas, and metastases. MATERIAL AND METHODS: Sixty-six patients with 77 lesions were examined with DTI. There were 32 metastases, 13 cysts, and 32 hemangiomas. Two radiologists performed ADC and Fa measurements. Inter-observer agreement was evaluated using Bland-Altman plots. ADCs and Fa values were correlated using Pearson correlation. The differences were compared using ANOVA and Tukey tests. A ROC analysis was applied; sensitivities and specificities were calculated. RESULTS: The inter-observer agreement was very good. The correlation between ADC and Fa was negative, weak, and significant (r = -0.36). The mean ADC value of cysts (3.30 ± 0.8 × 10(-3) mm(2)/s) was significantly higher than that of hemangiomas (2.23 ± 0.5 × 10(-3) mm(2)/s) and metastases (1.62 ± 0.4 × 10(-3) mm(2)/s). The mean Fa value of cysts (0.2 ± 0.05) was significantly lower than hemangiomas (0.37 ± 0.1) and metastases (0.46 ± 0.1). The Az values for discriminating metastases from benign hepatic lesions for ADC and Fa value were 0.885 and 0.731, respectively. The sensitivity and specificity of ADC and Fa were 87.5% and 84.4%, and 78.1% and 57.8%, respectively. The Az value for discriminating cysts from hemangiomas for Fa was 0.96. The sensitivity and specificity were 90.6% and 92.3%, respectively. CONCLUSION: Fa values may play a supportive role in the imaging of liver lesions. Whereas metastases tend to have low ADCs and high Fa values, cysts have high ADCs and low Fa values and hemangiomas have high ADCs and high Fa values.

Q-elastosonography of solid thyroid nodules: assessment of diagnostic efficacy and interobserver variability in a large patient cohort.

OBJECTIVE: Evaluation of the diagnostic efficacy and interobserver agreement of Q-elastography in the differentiation of benign from malignant thyroid nodules. METHODS: A total of 344 thyroid nodules in 288 patients were examined with grey-scale and colour Doppler ultrasound (CDUS) and Q-elastography by two independent operators. Nodules with hypoechogenicity, poorly defined margins, microcalcifications, and intralesional vascularity were classified as suspicious. Diagnostic performances of CDUS features and Q-elastography for predicting thyroid malignancy were estimated using ROC analysis. Cytology or histopathology was the reference standard. Interobserver agreement in the evaluation of CDUS and Q-elastography was assessed using Cohen's k-statistic. RESULTS: Q-elastography showed excellent diagnostic performance for the prediction of thyroid malignancy, with sensitivity of 93 % and specificity of 92 % for operator 1 (best cutoff at 2.02), and sensitivity of 84 % and specificity of 79 % for operator 2 (best cutoff at 1.86). Performance of Q-elastography was superior to that of CDUS. Reproducibility of the findings was excellent for both Q-elastography and CDUS features as assessed with Cohen's k, which was highest for strain ratio measurements (0.95) and lowest for the echogenicity score (0.83). CONCLUSIONS: Q-elastography showed excellent performance. It is a valid and reproducible diagnostic method as well as a promising tool for identifying suspicious solid thyroid nodules needing cytological assessment and surgery. KEY POINTS: • Elastography is an additional tool for optimal characterisation of malignant thyroid nodules. • The use of semiquantitative elastographic evaluation increases the diagnostic performance, • The interobserver agreement of quantitative elastography can be considered to be good.

Comparison of the results of computerized tomographic and diffusion-weighted magnetic resonance imaging techniques in inflammatory bowel diseases.

AIM: To compare the findings obtained by computerised tomography (CT) enterography, which uses oral neutral contrast material and non-contrasted diffusion-weighted magnetic resonance imaging (DW-MRI) technique and reveal the diagnostic value of DW-MRI in patients with inflammatory bowel diseases. METHODS: Patients with established or clinically suspect diagnosis of inflammatory bowel disease were included in the study. CT enterography and DW-MRI obtained from the patients were evaluated by a radiologist blinded to the endoscopic and/or histopathological results. Duodenum, jejunum, ileal loops, ascending, transverse, descending colon, sigmoid colon and rectum were evaluated in that order as for general imaging quality, luminal distension and adequate visualization of the intestinal wall. Image qualities of neutral contrast CT-enterography and DW-MRI were compared. RESULTS: The study included 31 patients. Based on statistical analyses, the best correlation between the results of CT-enterography and diffusion-weighted imaging (DWI) were observed in the evaluation of transverse colon, ileum and duodenum in order of decreasing frequency and with an almost perfect compatibility. Radiological findings of sigmoid colon, jejunum and descending colon were completely compatible. However, a moderate degree of compatibility was estimated between radiological findings of rectum and cecum. CONCLUSIONS: Though conventional enteroclysis is the gold standard method among radiological imaging techniques used for the evaluation of inflammatory small intestinal abnormalities, CT enterography and DW-MRI are alternative methods that can be used effectively to obtain useful information.

The diagnostic efficiency of ultrasound in characterization for thyroid nodules: how many criteria are required to predict malignancy?

OBJECTIVE: The purpose of this study was to define the criteria for use in differentiating benign and malignant nodules with the help of the receiver operating characteristic analysis and to increase the objective diagnostic accuracy of ultrasonography. MATERIALS AND METHODS: A total of 363 patients (307 women, 56 men) with 363 nodules (22 malignant and 341 benign nodules) were included in the study. The presence and absence of each US feature of the evaluated nodule - shape taller than wide, irregular margin, hypoechogenicity, microcalcification, and intranodular vascularity - were scored 1 and 0, respectively. The total ultrasound score was obtained by the summing up of each positive ultrasound findings for malignancy. The effect of the total US score in the discrimination of benign and malignant nodules was analysed using ROC analysis. RESULTS: The cut off values of US score at maximum sensitivity and specificity for nodules larger and smaller than one centimeter were two (Az: 0.783) and three (Az: 0.935), respectively. For nodules greater than one centimeter, the calculated diagnostic performances including sensitivity, specificity, positive predictive value and negative predictive value, and accuracy were 62.5%, 91.5%, 30.3%, 97.7%, and 89,9%, respectively. For nodules smaller or equal to one centimeter; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 83.3%, 94.9%, 62.5%, 98.2% and 93.8%, respectively. CONCLUSION: Using ultraound, thyroid nodules can be characterized effectively. The number of the US features used in this distinction varies in respect to the nodule size.