Visceral Fat Predicts New-Onset Diabetes After Necrotizing Pancreatitis.

OBJECTIVES: We aimed to estimate the incidence of new-onset diabetes (NOD) and identify risk factors for NOD in patients with necrotizing pancreatitis (NP). METHODS: Necrotizing pancreatitis patients were reviewed for NOD, diagnosed >90 days after acute pancreatitis. Baseline demographics, comorbidities, clinical outcomes, computed tomography (CT) characteristics of necrotic collections, and CT-derived abdominal fat measurements were analyzed to identify predictors for NOD. RESULTS: Among 390 eligible NP patients (66% men; median age, 51 years; interquartile range [IQR], 36-64) with a median follow-up of 400 days (IQR, 105-1074 days), NOD developed in 101 patients (26%) after a median of 216 days (IQR, 92-749 days) from NP. Of the NOD patients, 84% required insulin and 69% developed exocrine pancreatic insufficiency (EPI). Age (odds ratio [OR], 0.98), male sex (OR, 2.7), obesity (OR, 2.1), presence of EPI (OR, 2.7), and diffuse pancreatic necrosis (OR, 2.4) were independent predictors. In a separate multivariable model assessing abdominal fat on CT, visceral fat area (highest quartile) was an independent predictor for NOD (OR, 3.01). CONCLUSIONS: New-onset diabetes was observed in 1 of 4 patients with NP, most within the first year and requiring insulin. Male sex, obesity, diffuse pancreatic necrosis, development of EPI, and high visceral adiposity identified those at highest risk.

Predicting need for intervention in acute necrotizing pancreatitis following discharge- A single center experience in 525 patients.

BACKGROUND AND AIMS: The clinical course of necrotizing pancreatitis (NP) is variable and unpredictable, with some patients managed conservatively, but a significant proportion become symptomatic and needing intervention for drainage and/or necrosectomy. The aim of this study was to identify patients based on baseline clinical and imaging metrics who will likely need intervention and therefore closer follow-up. METHODS: All NP patients managed in our institution between 2010 and 2019 were identified from a prospective database and those who did not undergo intervention during initial hospitalization were followed longitudinally post discharge until clinical and imaging resolution of necrosis. Patients were categorized into a conservative arm or intervention arm (endoscopic/percutaneous/surgical drainage and/or necrosectomy) for criteria defined according to IAP/APA guidelines. Clinical and imaging characteristics during initial presentation were analyzed between the two groups to identify independent predictors for eventual intervention using multivariable logistic regression. A nomogram was designed based on factors that were significant as defined by P value < 0.05. RESULTS: Among 525 patients, 340 who did not meet criteria for intervention during initial admission were included for study and followed for an average 7.4 ± 11.3 months. 140 were managed conservatively and 200 needed intervention (168 within 6 months and 32 after 6 months). Independent predictors of need for eventual intervention were white race [OR 3.43 (1.11-10.62)], transferred status [OR 3.37 (1.81-6.27)], and need for TPN [OR 6.86 (1.63-28.9)], necrotic collection greater than 6 cm [OR 8.66 (4.10-18.32)] and necrotic collection with greater than 75% encapsulation [OR 41.3 (8.29-205.5)]. A prediction model incorporating these factors demonstrated an area under the curve of 0.88. CONCLUSIONS: Majority of NP patients do not need intervention during initial admission but may require drainage/necrosectomy mostly in the first 6 months following discharge. Need for subsequent intervention can be accurately predicted by a combination of clinical and imaging features on index admission.

Hyperechoic Renal Masses: Differentiation of Angiomyolipomas from Renal Cell Carcinomas using Tumor Size and Ultrasound Radiomics.

A retrospective single-center study was performed to assess the performance of ultrasound image-based texture analysis in differentiating angiomyolipoma (AML) from renal cell carcinoma (RCC) on incidental hyperechoic renal lesions. Ultrasound reports of patients from 2012 to 2017 were queried, and those with a hyperechoic renal mass <5 cm in diameter with further imaging characterization and/or pathological correlation were included. Quantitative texture analysis was performed using a model including 18 texture features. Univariate logistic regression was used to identify texture variables differing significantly between AML and RCC, and the performance of the model was measured using the area under the receiver operating characteristic (ROC) curve. One hundred thirty hyperechoic renal masses in 127 patients characterized as RCCs (25 [19%]) and AMLs (105 [81%]) were included. Size (odds ratio [OR] = 0.12, 95% confidence interval [CI]: 0.04-0.43, p < 0.001) and 4 of 18 texture features, including entropy (OR = 0.09, 95% CI: 0.01-0.81, p = 0.03), gray-level non-uniformity (OR = 0.12, 95% CI: 0.02-0.72, p = 0.02), long-run emphasis (OR = 0.49, 95% CI: 0.27-0.91, p = 0.02) and run-length non-uniformity (OR = 2.18, 95% CI: 1.14-4.16, p = 0.02) were able to differentiate AMLs from RCCs. The area under the ROC curve for the performance of the model, including texture features and size, was 0.945 (p < 0.001). Ultrasound image-based textural analysis enables differentiation of hyperechoic RCCs from AMLs with high accuracy, which improves further when combined with tumor size.

Decreased skeletal muscle density is an independent predictor of mortality in necrotizing pancreatitis- A single tertiary center experience in 507 patients.

BACKGROUND AND AIMS: Necrotizing pancreatitis has a variable clinical course and it is essential to identify determinants associated with high risk of mortality and poor clinical outcomes. The aim of this study is to evaluate the association between CT-assessed body composition parameters such as visceral fat area (VFA), skeletal muscle index (SMI) and skeletal muscle density (SMD) and inpatient mortality in NP patients. Secondary outcomes include organ failure on admission, persistent organ failure, length of stay (LOS), need for ICU admission, need for endoscopic, percutaneous or surgical interventions for NP and 30-day unplanned readmission. METHODS: All NP patients managed at a single center between 2009 and 2019 with a CT scan within a week of admission were included. SMI, SMD and VFA was calculated from CT imaging at the third lumbar vertebra and multivariable analysis was performed after correcting for age, sex, BMI, ASA classification, multi- organ failure on admission to determine independent association with inpatient mortality and secondary outcomes. RESULTS: 507 NP patients [males = 349 (68.8%), median age 53 (IQR 37-65) years were included in this study. The lowest tertile SMD was independently associated with inpatient mortality on multivariable analysis: adjusted OR 3.36 (1.57-7.2), P = 0.002. The lowest SMI tertile and highest VFA tertile were not independently associated with mortality. Lowest tertile SMD was significantly associated with persistent organ failure (OR 2.01, 95% CI 1.34-3.01, p = 0.001), need for percutaneous drainage (OR 1.84, 95% CI 1.21-2.8, p = 0.004), need for ICU admission (OR 2.32, 95% CI 1.59-3.38, p < 0.0001) and LOS. CONCLUSION: Low SMD was independently associated with in-hospital mortality in NP patients and can be usefully incorporated in CT based predictive scoring models as a prognostic marker.

Role of Ultrasound in Complications of Hematopoetic Stem Cell Transplantation.

Hematopoetic stem cell transplantation (HSCT) is an established therapeutic option for both malignant and nonmalignant indications, whose incidence has continued to increase in recent years. Because of its lower cost and lack of radiation exposure, ultrasound examination is often the first-line imaging modality in evaluating patients both before and after HSCT. It is important for radiologists to be aware of sonographic manifestations of the complications that may arise from HSCT. In this study, we will review the basics of HSCT, the role of imaging, and ultrasound examination findings in common and uncommon complications arising from HSCT.

Observer Variability in BI-RADS Ultrasound Features and Its Influence on Computer-Aided Diagnosis of Breast Masses.

OBJECTIVE: Computer classification of sonographic BI-RADS features can aid differentiation of the malignant and benign masses. However, the variability in the diagnosis due to the differences in the observed features between the observations is not known. The goal of this study is to measure the variation in sonographic features between multiple observations and determine the effect of features variation on computer-aided diagnosis of the breast masses. MATERIALS AND METHODS: Ultrasound images of biopsy proven solid breast masses were analyzed in three independent observations for BI-RADS sonographic features. The BI-RADS features from each observation were used with Bayes classifier to determine probability of malignancy. The observer agreement in the sonographic features was measured by kappa coefficient and the difference in the diagnostic performances between observations was determined by the area under the ROC curve, Az, and interclass correlation coefficient. RESULTS: While some features were repeatedly observed, κ = 0.95, other showed a significant variation, κ = 0.16. For all features, combined intra-observer agreement was substantial, κ = 0.77. The agreement, however, decreased steadily to 0.66 and 0.56 as time between the observations increased from 1 to 2 and 3 months, respectively. Despite the variation in features between observations the probabilities of malignancy estimates from Bayes classifier were robust and consistently yielded same level of diagnostic performance, Az was 0.772 - 0.817 for sonographic features alone and 0.828 - 0.849 for sonographic features and age combined. The difference in the performance, ΔAz, between the observations for the two groups was small (0.003 - 0.044) and was not statistically significant (p < 0.05). Interclass correlation coefficient for the observations was 0.822 (CI: 0.787 - 0.853) for BI-RADS sonographic features alone and for those combined with age was 0.833 (CI: 0.800 - 0.862). CONCLUSION: Despite the differences in the BI- RADS sonographic features between different observations, the diagnostic performance of computer-aided analysis for differentiating breast masses did not change. Through continual retraining, the computer-aided analysis provides consistent diagnostic performance independent of the variations in the observed sonographic features.

Comparison of single photon emission computed tomography-computed tomography, computed tomography, single photon emission computed tomography and planar scintigraphy for characterization of isolated skull lesions seen on bone scintigraphy in cancer patients.

PURPOSE: The purpose of this study is to evaluate the added value of single photon emission computed tomography-computed tomography (SPECT-CT) over planar scintigraphy, SPECT and CT alone for characterization of isolated skull lesions in bone scintigraphy (BS) in cancer patients. MATERIALS AND METHODS: A total of 32 cancer patients (age: 39.5 ± 21.9; male: female - 1:1) with 36 isolated skull lesions on planar BS, underwent SPECT-CT of skull. Planar BS, SPECT, CT and SPECT-CT images were evaluated in separate sessions to minimize recall bias. A scoring scale of 1-5 was used, where 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. With receiver operating characteristic analysis area under the curves (AUC) was calculated for each modality. For calculation of sensitivity, specificity and predictive values a Score ≤3 was taken as metastatic. Clinical/imaging follow-up and/or histopathology were taken as reference standard. RESULTS: Of 36 skull lesions 11 lesions each were on frontal, parietal and occipital bone while three lesions were in the temporal bone. Of these 36 lesions, 16 were indeterminate (Score-3) on planar and SPECT, five on CT and none on SPECT-CT. The AUC was largest for SPECT-CT followed by CT, SPECT and planar scintigraphy, respectively. Planar scintigraphy was inferior to SPECT-CT (P = 0.006) and CT (P = 0.012) but not SPECT (P = 0.975). SPECT was also inferior to SPECT-CT (P = 0.007) and CT (P = 0.015). Although no significant difference was found between SPECT-CT and CT (P = 0.469), the former was more specific (100% vs. 94%). CONCLUSION: SPECT-CT is better than planar scintigraphy and SPECT alone for correctly characterizing isolated skull lesions on BS in cancer patients. It is more specific than CT, but provides no significant advantage over CT alone for this purpose.

Linfoma primario del sistema nervioso central con linfomatosis cerebri en un niño inmunocompetente: hallazgos de la MRI y 18F-FDG PET-TC / Primary central nervous system lymphoma with lymphomatosis cerebri in an immunocompetent child: MRI and 18F-FDG PET-CT findings

El linfoma primario del sistema nervioso central (LPSNC) es extremadamente raro en niños inmunocompetentes. Presentamos los hallazgos de la imagen de resonancia magnética (MRI) y de tomografía por emisión de positrones-tomografía computarizada (PET-TC) con 18F-FDG en un niño inmunocompetente de 14 años de edad. En este paciente el LPSNC se asoció con linfomatosis cerebri. Estar familiarizado con los hallazgos de esta rara afectación mejorará la confianza diagnóstica del médico nuclear y evitará un diagnóstico erróneo (AU)

Primary central nervous system lymphoma (PCNSL) is extremely rare in immunocompetent children. We present the magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) findings of such a case in a 14-year old immunocompetent boy. In this patient, PCNSL was associated with lymphomatosis cerebri. Familiarity with the findings of this rare condition will improve the diagnostic confidence of the nuclear radiologist and avoid misdiagnosis (AU)

Primary central nervous system lymphoma with lymphomatosis cerebri in an immunocompetent child: MRI and 18F-FDG PET-CT findings.

Primary central nervous system lymphoma (PCNSL) is extremely rare in immunocompetent children. We present the magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) findings of such a case in a 14-year old immunocompetent boy. In this patient, PCNSL was associated with lymphomatosis cerebri. Familiarity with the findings of this rare condition will improve the diagnostic confidence of the nuclear radiologist and avoid misdiagnosis.

Utility of (18)F-FDG PET-CT in staging and restaging of patients with malignant salivary gland tumours: a single-institutional experience.

OBJECTIVE: The aim of this study was to evaluate the clinical utility of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) in staging and restaging of patients with malignant primary salivary gland tumours. METHODS: Data pertaining to 30 patients (age: 43.8±16.8 years; male/female: 20/10) with histopathologically proven malignant primary salivary gland tumours who underwent 36 F-FDG PET-CTs were retrospectively analysed. Ten PET-CTs were performed for staging and 26 for restaging. The primary site was the parotid gland in 22 patients, the submandibular gland in seven and the minor salivary gland in one patient. (18)F-FDG PET-CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local disease, nodal disease and distant metastasis. Results were compared with those of conventional imaging modalities [CIM (CT/ultrasound/bone scintigraphy)] when available (n=28). Clinical or imaging follow-up (minimum 6 months) data along with histopathological information (when available) were taken as the reference standard. RESULTS: Overall, 25 PET-CTs were positive and 11 were negative for disease. (18)F-FDG PET-CT showed local disease in 21 patients, nodal disease in 17 and distant metastasis in nine (lungs, four; liver, three; bones, four; and thyroid, one). Twenty-three PET-CTs were true positive, nine were true negative, two were false positive and two were false negative. The overall sensitivity of (18)F-FDG PET-CT was 92%, specificity was 82%, positive predictive value was 92%, negative predictive value was 82% and accuracy was 89%. No significant difference was seen in the accuracy of PET-CT between the staging and restaging groups (100 vs. 85%; P=0.468). In patients for whom comparable CIM data were available (n=28), PET-CT did not show any significant advantage over CIM (P=0.012) but was more specific (71 vs. 43%). CONCLUSION: (18)F-FDG PET-CT shows high accuracy in staging and restaging of patients with malignant primary salivary gland tumours. It is more specific than CIM for this purpose.

Extensive Extranodal Involvement of Rare Sites in Non Hodgkin's Lymphoma Detected on (18)F- FDG PET-CT: A Case Report.

We present a case of a 23 year-old male treated for Hodgkin's lymphoma who developed diffuse large B-cell lymphoma (DLBCL) 8 years after achieving remission. (18)F-fluorodeoxyglucose positron emission tomography computed tomography ((18)F-FDG PET-CT) was done, which revealed extensive extranodal involvement of bilateral atria, bilateral kidneys, ileo-caecal junction and left testis along with mesenteric and retroperitoneal lymph nodal involvement. Renal and cardiac lesions were not detected by contrast-enhanced CT. Simultaneous lymphomatous involvement of rare sites such as heart, kidneys and testis in a single patient has not been reported before.

Magnetic resonance imaging and positron emission tomography-computed tomography evaluation of soft tissue sarcoma with surgical and histopathological correlation.

PURPOSE: The aim of this study was to evaluate the role of positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) in characterization and pre-operative staging of soft-tissue sarcoma (STS) and correlating with operative and histopathological findings. MATERIALS AND METHODS: Twenty patients (age range 16-72 years [mean 44.4 years]) with resectable and STS were included in this prospective study. Pre-operative MRI was carried out in all patients with acquisition of T1W, T2W, and short tau inversion recovery (STIR) sequences in appropriate planes. Contrast enhanced MRI was performed in four patients. Whole body PET-CT was performed in 13 patients. Demographic data, clinical features, pre-operative imaging analysis, operative, and histopathological findings were analyzed using SPSS software version 11.5. RESULTS: The most common histologic type was malignant fibrous histiocytoma (MFH) (30%). Of 18 STSs 20 were high-grade. Agreement existed between MR and operative size. MRI had 100% negative predictive value (NPV) in predicting neurovascular bundle involvement. However, positive predictive value (PPV) was 33%. MRI had PPV of 20% while PET-CT had 50% PPV in detecting lymph node involvement. Overall staging accuracy of MRI was 75% when correlated with surgical and histopathological findings. Combined PET-CT and MRI staging, in 13 patients, was better (92.31%) when compared with staging with MRI (84.62%). Specific diagnosis on image characteristics was correctly suggested in 35% patients. CONCLUSIONS: MRI is the robust modality in local staging of STSs and PET-CT adds greater accuracy to overall staging in combination with MRI.