Classification of pancreatic cystic neoplasms using radiomic feature analysis is equivalent to an experienced academic radiologist: a step toward computer-augmented diagnostics for radiologists.

PURPOSE: A wide array of benign and malignant lesions of the pancreas can be cystic and these cystic lesions can have overlapping imaging appearances. The purpose of this study is to compare the diagnostic accuracy of a radiomics-based pancreatic cyst classifier to an experienced academic radiologist. METHODS: In this IRB-approved retrospective single-institution study, patients with surgically resected pancreatic cysts who underwent preoperative abdominal CT from 2003 to 2016 were identified. Pancreatic cyst(s) and background pancreas were manually segmented, and 488 radiomics features were extracted. Random forest classification based on radiomics features, age, and gender was evaluated with fourfold cross-validation. An academic radiologist blinded to the final pathologic diagnosis reviewed each case and provided the most likely diagnosis. RESULTS: 214 patients were included (64 intraductal papillary mucinous neoplasms, 33 mucinous cystic neoplasms, 60 serous cystadenomas, 24 solid pseudopapillary neoplasms, and 33 cystic neuroendocrine tumors). The radiomics-based machine learning approach showed AUC of 0.940 in pancreatic cyst classification, compared with AUC of 0.895 for the radiologist. CONCLUSION: Radiomics-based machine learning achieved equivalent performance as an experienced academic radiologist in the classification of pancreatic cysts. The high diagnostic accuracy can potentially maximize the efficiency of healthcare utilization by maximizing detection of high-risk lesions.

CT Radiomics-Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma.

OBJECTIVE. Pancreatic ductal adenocarcinoma (PDAC) is often a lethal malignancy with limited preoperative predictors of long-term survival. The purpose of this study was to evaluate the prognostic utility of preoperative CT radiomics features in predicting postoperative survival of patients with PDAC. MATERIALS AND METHODS. A total of 153 patients with surgically resected PDAC who underwent preoperative CT between 2011 and 2017 were retrospectively identified. Demographic, clinical, and survival information was collected from the medical records. Survival time after the surgical resection was used to stratify patients into a low-risk group (survival time > 3 years) and a high-risk group (survival time < 1 year). The 3D volume of the whole pancreatic tumor and background pancreas were manually segmented. A total of 478 radiomics features were extracted from tumors and 11 extra features were computed from pancreas boundaries. The 10 most relevant features were selected by feature reduction. Survival analysis was performed on the basis of clinical parameters both with and without the addition of the selected features. Survival status and time were estimated by a random survival forest algorithm. Concordance index (C-index) was used to evaluate performance of the survival prediction model. RESULTS. The mean age of patients with PDAC was 67 ± 11 (SD) years. The mean tumor size was 3.31 ± 2.55 cm. The 10 most relevant radiomics features showed 82.2% accuracy in the classification of high-risk versus low-risk groups. The C-index of survival prediction with clinical parameters alone was 0.6785. The addition of CT radiomics features improved the C-index to 0.7414. CONCLUSION. Addition of CT radiomics features to standard clinical factors improves survival prediction in patients with PDAC.

Emerging imaging techniques for acute pancreatitis.

Acute pancreatitis (AP) is caused by acute inflammation of the pancreas and adjacent tissue and is a common source of abdominal pain. The current CT and MRI evaluation of AP is mostly based on morphologic features. Recent advances in image acquisition and analysis offer the opportunity to go beyond morphologic features. Advanced MR techniques such as diffusion-weighted imaging, as well as T1 and T2 mapping, can potentially quantify signal changes reflective of underlying tissue abnormalities. Advanced analytic techniques such as radiomics and artificial neural networks (ANNs) offer the promise of uncovering imaging biomarkers that can provide additional classification and prognostic information. The purpose of this article is to review recent advances in imaging acquisition and analytic techniques in the evaluation of AP.

Urinary bladder fistulae and the role of CT cystography: a pictorial review.

Various conditions such as inflammation, malignancy, surgical manipulations, and radiation therapy can lead to the development of urinary bladder fistulae. Although many of these fistulae are suspected clinically, imaging plays a major role in confirmation and planning of subsequent treatment. Computed tomography (CT) cystoscopy provides useful details regarding the fistulous track and the anatomy of the region. This article aims to provide a succinct review of bladder fistulae and the role of CT cystography in their management.

Imaging of urinary bladder injury: the role of CT cystography.

Although conventional radiographic cystography has been traditionally considered the reference standard in detecting bladder injuries, computed tomography (CT) cystography has become the initial imaging method of choice in the acute setting. CT cystography has been shown to provide comparable accuracy as conventional cystography, and can be easily performed in conjunction with trauma CT surveys in patients with suspected bladder injuries. Despite increasing enthusiasm toward CT cystography in dealing with patients with suspected bladder injuries, there is little information in this regard in the literature. This article aims to discuss the role of CT cystography in the evaluation of bladder injuries.

Utility of CT Radiomics Features in Differentiation of Pancreatic Ductal Adenocarcinoma From Normal Pancreatic Tissue.

OBJECTIVE. The objective of our study was to determine the utility of radiomics features in differentiating CT cases of pancreatic ductal adenocarcinoma (PDAC) from normal pancreas. MATERIALS AND METHODS. In this retrospective case-control study, 190 patients with PDAC (97 men, 93 women; mean age ± SD, 66 ± 9 years) from 2012 to 2017 and 190 healthy potential renal donors (96 men, 94 women; mean age ± SD, 52 ± 8 years) without known pancreatic disease from 2005 to 2009 were identified from radiology and pathology databases. The 3D volume of the pancreas was manually segmented from the preoperative CT scans by four trained researchers and verified by three abdominal radiologists. Four hundred seventy-eight radiomics features were extracted to express the phenotype of the pancreas. Forty features were selected for analysis because of redundancy of computed features. The dataset was divided into 255 training cases (125 normal control cases and 130 PDAC cases) and 125 validation cases (65 normal control cases and 60 PDAC cases). A random forest classifier was used for binary classification of PDAC versus normal pancreas of control cases. Accuracy, sensitivity, and specificity were calculated. RESULTS. Mean tumor size was 4.1 ± 1.7 (SD) cm. The overall accuracy of the random forest binary classification was 99.2% (124/125), and AUC was 99.9%. All PDAC cases (60/60) were correctly classified. One case from a renal donor was misclassified as PDAC (1/65). The sensitivity was 100%, and specificity was 98.5%. CONCLUSION. Radiomics features extracted from whole pancreas can be used to differentiate between CT cases from patients with PDAC and healthy control subjects with normal pancreas.

The effect of Cobb angle correction on spinal length gain in patients with adolescent idiopathic scoliosis.

The relationship between curve correction and spinal length gain in adolescent idiopathic scoliosis was examined. A total of 102 patients who underwent posterior spinal correction and fusion alone or in combination with anterior spinal correction and fusion (ASF) were studied. The Cobb angle correction, increase in the main thoracic length, T1-L5 spinal length gain, and T1-L5 spinal length gain/Cobb angle correction were reported. The length gain/Cobb angle correction value was not significantly associated with sex, fusion approach, and the number of fused levels. Surgical T1-L5 spinal length gain (mm) equaled (70.20)-(3.51)×(degrees of Cobb angle correction)+(0.08)×(degrees of Cobb angle correction).

Utility of volumetric contrast-enhanced and diffusion-weighted MRI in differentiating between common primary hypervascular liver tumors.

BACKGROUND: Differentiating between hepatocellular carcinoma (HCC), focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) is usually achievable by MRI. However, in some cases with atypical imaging findings accurate diagnosis may be difficult. PURPOSE: To assess the diagnostic value of volumetric contrast-enhanced (CE) and volumetric diffusion-weighted imaging (DWI) in differentiating between HCC, FNH, and HCA. STUDY TYPE: Retrospective. SUBJECTS: In all, 143 patients (206 lesions): 42 HCA (81 lesions), 51 FNH (65 lesions), and 50 HCC (60 lesions). FIELD STRENGTH/SEQUENCE: 1.5T MRI, T1 -T2 WI, DWI. ASSESSMENT: Patients underwent CE-MRI and DWI (b = 0, 750 mm2 /s). Volumetric assessment of lesions' contrast enhancement and apparent diffusion coefficient (ADC) was performed with semiautomatic software after 3D image registration and segmentation by an observer and compared between three lesion groups. The diagnosis of lesions was based on histopathology, typical MRI findings, and/or follow-up. STATISTICAL TESTS: Independent t-test was used to compare parameters between two groups, one-way analysis of variance (ANOVA) between three groups, and receiver operator characteristic curve (ROC) analysis to define under-curve area and optimal cutoff. RESULTS: Mean values (±standard deviation) for HCC, FNH, and HCA, respectively, were: 1) arterial enhancement (%), 40.5 ± 13.2, 88.6 ± 32.6, 69.6 ± 25.1; 2) venous enhancement (%) 72.4 ± 22.1, 95.2 ± 30.9, 80.7 ± 30.6; and 3) ADC (10-6 mm2 /s) 1404.5 ± 168.1, 1413.4 ± 232.1, 1070.1 ± 232.1. ADC was the best differentiator of HCA from FNH (at 1211 × 10-6 mm2 /s; sensitivity 80.4%, specificity 71.7%) and arterial enhancement was the best differentiator of HCC from both HCA (at 48%; sensitivity 80.0%, specificity 80.5%) and FNH (at 52%; sensitivity 85.7%, specificity 85.4%). A combination of arterial enhancement and ADC (at 50% and 1227 × 10-6 mm2 /s) differentiated three types of tumors with high specificity (87.9%). DATA CONCLUSION: Volumetric CE-MRI and volumetric DWI can help to differentiate between HCC, FNH, and HCA. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1080-1090.

Expression of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium: a histopathological study.

Our objective was to examine the expression rates of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium. A total of 94 endometrial frozen sections (carcinoma 48, hyperplasia 21, normal tissue 25) were examined immunohistochemically in terms of the expression rates of p53, Bcl-2 and Bax. All of the specimens in the non-malignant groups were positive for Bax, whereas this rate was 85.4% in the group with malignant specimens (p = .03). Conversely, p53 was expressed only in the cancerous group (77.1%, p < .001). The Bcl-2 expression rate was 54.2% in the cancer group, 76.2% in the group with hyperplasia and 60% in the group containing normal tissue (p = .23). Comparing to the non-malignant specimens, the mean Bcl-2/Bax were significantly higher in the malignant group. In conclusion, Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio might be associated with endometrial carcinoma. Bcl-2, however, plays no significant role in this regard. Impact statement What is already known on this subject? The p53, Bcl-2 and Bax are the three major genes that regulate apoptosis. Some studies have suggested that these genes may play a role in the pathogenesis of endometrial carcinoma. The available reports, however, are old and inconclusive. What do the results of this study add? Comparing immunohistochemically obtained p53, the Bcl-2 and Bax expression rates between normal endometrial tissue, endometrial specimens with endometrial hyperplasia and specimens with carcinoma showed that Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio were associated with malignancy. Using an up-to-date technique to examine the three major regulators of apoptosis at the same time, in a rather large sample size of both normal and abnormal endometrial tissue specimens simultaneously, are the major advantages of the present work. What are the implications of these findings for clinical practice and/or further research? According to our findings, the status of p53, Bcl-2 and Bax expression in the endometrial tissue can be used for risk stratification of endometrial carcinoma for both screening and preventive purposes.

The burden of pure anisometropic amblyopia: a cross-sectional study on 2800 Iranians.

PURPOSE: To assess the proportion of pure anisometropic amblyopia in a sample Iranian (white) population. METHODS: A total of 2800 consecutive individuals who presented at a referral eye clinic for any reason were examined for the presence of pure anisometropic amblyopia. Anisometropia was reported when a spherical equivalent refraction difference of at least 1.0 D with or without a cylinder refraction difference of at least 1.0 D was present between the two eyes. Amblyopia was defined as the best-corrected visual acuity of 20/30 or worse or a two-line interocular visual acuity difference between eyes that could not be attributed to any structural ocular pathology or visual pathway abnormality. RESULTS: Subjects were 1528 females and 1272 males with a mean age of 30.25 ± 14.93 years (range, 5-65). Amblyopia was diagnosed in 192 cases (6.9%), significantly more frequent among females (7.9 vs. 5.7%, p = 0.02). Pure anisometropic amblyopia was present in 6.1% of the study population, significantly more common in patients with spherical hyperopic anisometropia (37.7%) compared to patients with spherical myopic anisometropia (21.3%), cylindrical myopic anisometropia (4.1%), and cylindrical hyperopic anisometropia (15%) (p < 0.001). CONCLUSIONS: Pure anisometropic amblyopia is a common finding in Caucasians seeking eye care, particularly when anisometropia is of spherical hyperopic subtype.

The Effect of Concomitant Rib Deformity in Congenital Scoliosis on Spinal Curve Correction After Segmental Pedicle Screw Instrumentation.

STUDY DESIGN: A single-center, prospective study. OBJECTIVE: To investigate the effect of rib anomaly on surgical curve correction outcome in congenital scoliosis. SUMMARY OF BACKGROUND DATA: The presence of rib anomalies may complicate surgical correction of congenital scoliosis. The outcome of surgical correction, however, has not been documented in scoliotic patients with and without rib deformity. METHODS: Percent Cobb angle decrease (CAD) after operation was calculated in 94 patients with congenital scoliosis. Posterior segmental pedicle screw instrumentation (posterior approach) with or without previous anterior spinal release and fusion (anterior approach) was the method of correction. The impact of vertebral anomaly and rib deformity on CAD was examined. RESULTS: Although the type of vertebral anomaly had no significant effect on the mean CAD, it was significantly lower in 56 patients with rib deformity compared with that in the remaining patients without rib deformity (35.14%±15.83% vs. 51.54%±17.82%, P<0.001); particularly in those with complex, unilateral rib abnormalities, and in those with same-level vertebral and rib deformities. Patients' sex and age at the time of operation, rib number abnormality, and the type of operation (ie, posterior-only approach vs. anterior and posterior approach) did not contribute significantly to Cobb angle change after operation. CONCLUSIONS: Concomitant rib deformities, particularly of complex and unilateral types, significantly compromise operative curve correction outcome in congenital scoliosis.

Visibility of Different Intraorbital Foreign Bodies Using Plain Radiography, Computed Tomography, Magnetic Resonance Imaging, and Cone-Beam Computed Tomography: An In Vitro Study.

PURPOSE: The study sought to compare the usefulness of 4 imaging modalities in visualizing various intraorbital foreign bodies (IOFBs) in different sizes. METHODS: Six different materials including metal, wood, plastic, stone, glass. and graphite were cut in cylindrical shapes in 4 sizes (dimensions: 0.5, 1, 2, and 3 mm) and placed intraorbitally in the extraocular space of fresh sheep's head. Four skilled radiologists rated the visibility of the objects individually using plain radiography, spiral computed tomography (CT), magnetic resonance imaging (MRI), and cone-beam computed tomography (CBCT) in accordance with a previously described grading system. RESULTS: Excluding wood, all embedded foreign bodies were best visualized in CT and CBCT images with almost equal accuracies. Wood could only be detected using MRI, and then only when fragments were more than 2 mm in size. There were 3 false-positive MRI reports, suggesting air bubbles as wood IOFBs. CONCLUSIONS: Because of lower cost and using less radiation in comparison with conventional CT, CBCT can be used as the initial imaging technique in cases with suspected IOFBs. Optimal imaging technique for wood IOFBs is yet to be defined.

HIGH MYOPIA AND DIABETIC RETINOPATHY: A Contralateral Eye Study in Diabetic Patients With High Myopic Anisometropia.

PURPOSE: To examine an association between high myopia and diabetic retinopathy (DR) in diabetic patients with high myopic anisometropia. METHODS: A total of 116 white diabetic patients (232 eyes) with high myopia (spherical equivalent > -5.00 diopters, D) anisometropia (difference ≥ -6 D) were enrolled in this cross-sectional, contralateral eye study. The frequency of DR was compared between the high myopic and the contralateral eyes. RESULTS: Compared with the fellow eyes, DR was significantly less frequent in high myopic side (27.6% vs. 100%, P < 0.001; relative risk, 0.28 with 95% confidence interval of 0.21-0.37). Similar significant trends were found for the incidence of nonproliferative (27.6% vs. 69%, P < 0.001) and proliferative DR (0% vs. 31%, P < 0.001). Diabetic retinopathy was also less severe in the same group. CONCLUSION: Using a contralateral eye study design prevented the influence of potential confounding factors inherent in similar previous case-control studies. On this basis, a protective role for high myopia against DR was established.

Diffusion-weighted magnetic resonance imaging in differentiating acute infectious spondylitis from degenerative Modic type 1 change; the role of b-value, apparent diffusion coefficient, claw sign and amorphous increased signal.

OBJECTIVE: To examine the effect of using different b-values on the utility of diffusion-weighted (DW) MRI in differentiating acute infectious spondylitis from Modic type 1 and the discriminative accuracy of related apparent diffusion coefficient (ADC), claw-sign and amorphous increased signal. METHODS: 43 patients with equivocal diagnosis of acute infectious spondylitis/Modic type 1 by using MR images were prospectively studied. The discriminative accuracy of DW MRI using three b-values of 50, 400, 800 s mm(-2), ADC, claw sign and amorphous increased signal was examined. RESULTS: DW MRI differentiated infectious spondylitis from Modic type 1 change most accurately when a b-value of 800 s mm(-2) was chosen [sensitivity, 91.7%; specificity, 96.8%; positive-predictive value (PPV), 91.7%; negative-predictive value (NPV), 96.8%; and accuracy, 95.3%]. The optimal cut-off ADC value was 1.52 × 10(-3) mm(2) s(-1) (sensitivity, 91.7%; specificity, 100%; PPV, 100%; NPV, 96.9%; and accuracy, 97.7%). Best visualized at a b-value of 50 s mm(-2), claw sign (for degeneration) and amorphous increased signal (for infection) were 100% accurate. CONCLUSION: Should DW MRI be used in differentiating acute infectious spondylitis from degeneration, large b-values are required. With low b-values, however, claw sign and amorphous increased signal are very accurate in this regard. ADVANCES IN KNOWLEDGE: DW MRI using large b-values could be used in differentiating acute infectious spondylitis from Modic type I.

A comparable study of the diagnostic performance of orbital ultrasonography and CBCT in patients with suspected orbital floor fractures.

OBJECTIVES:: To compare the diagnostic performance of ultrasonography and CBCT against CT in detecting orbital floor fractures. METHODS:: A total of 120 orbits with clinical suspicion of isolated orbital floor fractures underwent multislice CT scanning with coronal reconstruction; orbital ultrasonography using a standard machine equipped with a 7- to 10-MHz linear transducer; and CBCT. Patients with severe head and face injuries were not included. The diagnostic performance of ultrasonography and CBCT was reported assuming conventional CT as the imaging method of choice. RESULTS:: According to CT findings, fractures of the floor were present in 39 orbits. The sensitivity, specificity, positive-predictive value and negative-predictive value of ultrasonography in detecting orbital floor fractures were 87.2%, 100%, 100% and 94.2%, respectively. The corresponding values for CBCT were 97.4%, 97.5%, 95.0%, and 98.8%, respectively. Areas under the receiver operator characteristics curves of orbital floor fracture detection were 0.94 for ultrasonography and 0.98 for CBCT. CONCLUSIONS:: When conventional CT cannot be performed in patients with clinically suspected orbital floor fracture and no severe or complex head and face injuries, CBCT could be used in detecting fractures as a reliable surrogate. Because of a lower sensitivity of ultrasonography, however, its use is limited in this regard.

Can Chest Computed Tomography Be Replaced by Lung Ultrasonography With or Without Plain Chest Radiography in Pediatric Pneumonia?

PURPOSE: The purpose of this study was to answer the following question: can chest computed tomography (CT) requested by pediatricians be replaced by lung ultrasonography (US) with or without chest radiography in pediatric pneumonia? MATERIALS AND METHODS: A total of 98 children with suspected pneumonia who were referred by pediatricians for CT examinations were prospectively studied. Levels of agreement between CT findings and plain radiography, lung US, and chest radiography plus lung US results were investigated. RESULTS: CT defined pneumonia in 84 patients, among which 26 cases were complicated. κ values between radiography and CT findings were 0.82 in complicated cases, 0.67 in uncomplicated cases, and 0.72 overall. The corresponding values between US and CT findings were 1, 0.52, and 0.62, respectively, and between radiography plus US and CT findings were 1, 0.86, and 0.88, respectively. CONCLUSIONS: CT can be replaced by US when complex effusions are present in children with pneumonia. In case of an ambiguous diagnosis of pediatric pneumonia with or without complex effusions, a combination of chest radiography and US is a reliable surrogate for chest CT.

Normal Values of Spleen Length and Volume: An Ultrasonographic Study in Children.

We aimed to determine normal ultrasonographic limits of spleen length and volume in healthy Caucasian neonates and children. A total of 458 healthy cases (age, 1 d to 15 y; sex, 241 males and 217 females) with normal body measurements were included. Spleen length and volume were obtained ultrasonographically. The two genders were comparable for the mean spleen length and volume. Lower and upper normal limits were tabulated according to age and sex groups. Significant correlations (Pearson r > 0.80; p < 0.001) were present between spleen length/volume and age, height and weight. Two equations were created to estimate spleen length and volume by age. Normal spleen lengths and volumes and their lower and upper limits were obtained ultrasonographically in a large sample of Caucasian pediatric patients.

Intralesional immunotherapy with tuberculin purified protein derivative (PPD) in recalcitrant wart: A randomized, placebo-controlled, double-blind clinical trial including an extra group of candidates for cryotherapy.

BACKGROUND: Due to paucity of randomized clinical trials, intralesional immunotherapy has not been yet accepted as a standard therapeutic method. OBJECTIVE: To examine the efficacy and safety of intralesional immunotherapy with tuberculin purified protein derivative (PPD) for treating recalcitrant wart. METHODS: In this randomized, placebo-controlled, double-blind clinical trial, a total of 69 patients with recalcitrant warts received either intralesional PPD antigen (n = 35) or intralesional saline (n = 34) for six times at 2-week intervals. A third group of candidates for cryotherapy (n = 33) was also included. The decrease in lesion size (good: complete response, intermediate: 50-99% improvement, poor: <50% improvement), adverse effects and recurrence within 6-month follow-up were documented. RESULTS: At the final session, good, intermediate and poor responses were observed in 77.1%, 22.9% and 0% of the PPD patients; 0%, 14.7% and 85.3% of the placebo patients and 18.2%, 33.3% and 48.5% of the cryotherapy patients, respectively (PPD versus placebo: p < 0.001; PPD versus cryotherapy: p < 0.001). No significant complication was seen in the PPD group. The recurrence rate was 8.6%, 5.9% and 24.2% in the PPD, placebo and cryotherapy groups, respectively (p > 0.05). CONCLUSION: Intralesional immunotherapy with PPD antigen is highly effective and safe for treating recalcitrant warts. CLINICAL TRIAL REGISTRATION: IRCT201407089844N3 in the Iranian Registry of Clinical Trials (IRCT).