Liver Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms.

ABSTRACT: The incidence of neuroendocrine neoplasms (NENs) has gradually increased over the past few decades with the majority of patients presenting with metastases on initial presentation. The liver is the most common site of initial metastatic disease, and the presence of liver metastasis is an independent prognostic factor associated with a negative outcome. Because NENs are heterogenous neoplasms with variable differentiation, grading, and risk of grade transformation over time, accurate diagnosis and management of neuroendocrine liver lesions are both important and challenging. This is particularly so with the multiple liver-directed treatment options available. In this review article, we discuss the diagnosis, treatment, and response evaluation of NEN liver metastases.

Continuing to Thrive in Academic Radiology Despite Decreasing Reimbursement.

Decreasing radiology reimbursement is a major challenge faced by academic radiology practices in the United States. The consequent increased workload from reading more radiological studies can lead to job dissatisfaction, burnout and adverse impact on research, innovation, and education. Thriving successfully in an academic practice despite low reimbursement requires modification of radiology business models and culture of the practice. In this article, we review the financial and operational strategies to mitigate low reimbursement and strategies for thriving in academic radiology without burnout.

Deployed Deep Learning Kidney Segmentation for Polycystic Kidney Disease MRI.

This study develops, validates, and deploys deep learning for automated total kidney volume (TKV) measurement (a marker of disease severity) on T2-weighted MRI studies of autosomal dominant polycystic kidney disease (ADPKD). The model was based on the U-Net architecture with an EfficientNet encoder, developed using 213 abdominal MRI studies in 129 patients with ADPKD. Patients were randomly divided into 70% training, 15% validation, and 15% test sets for model development. Model performance was assessed using Dice similarity coefficient (DSC) and Bland-Altman analysis. External validation in 20 patients from outside institutions demonstrated a DSC of 0.98 (IQR, 0.97-0.99) and a Bland-Altman difference of 2.6% (95% CI: 1.0%, 4.1%). Prospective validation in 53 patients demonstrated a DSC of 0.97 (IQR, 0.94-0.98) and a Bland-Altman difference of 3.6% (95% CI: 2.0%, 5.2%). Last, the efficiency of model-assisted annotation was evaluated on the first 50% of prospective cases (n = 28), with a 51% mean reduction in contouring time (P < .001), from 1724 seconds (95% CI: 1373, 2075) to 723 seconds (95% CI: 555, 892). In conclusion, our deployed artificial intelligence pipeline accurately performs automated segmentation for TKV estimation of polycystic kidneys and reduces expert contouring time. Keywords: Convolutional Neural Network (CNN), Segmentation, Kidney ClinicalTrials.gov identification no.: NCT00792155 Supplemental material is available for this article. © RSNA, 2022.

In-utero Diagnosis of Double Encephalocele - Imaging Features and Review of Literature.

Encephalocele is protrusion of brain parenchyma through a defect in the cranium. It is classified into various types based on the defect location: sincipital (fronto-ethmoidal), basal (trans-sphenoidal, spheno-ethmoidal, trans-ethmoidal, and spheno-orbital), occipital and parietal. Double encephaloceles are very rare with only a handful of cases reported in the literature and most of these cases involved either occipital or sub-occipital region. All, except one, cases of double encephaloceles were diagnosed postnatally. We present a case of double encephalocele with parietal and occipital components diagnosed in utero. To the best of our knowledge, this is the first case of double encephalocele involving the parietal and occipital skull bones diagnosed in-utero.

PI-RADS: what is new and how to use it.

The prostate imaging reporting and data system (PI-RADS) has revolutionized the use of magnetic resonance imaging (MRI) for the management of prostate cancer (PCa). The most recent version 2.1, PI-RADS v2.1, provides specific refinements in the performance, relaxing some recommendations which were not found to be helpful, while reinforcing and clarifying others. The interpretation of T2-weighted imaging (T2WI) in the transition zone (TZ), and the overall assessment of TZ nodules, now allows for a clearer distinction between those which are clearly benign and those which might warrant tissue sampling. Additional changes also resolve discrepancies in T2WI and diffusion-weighted imaging (DWI) of the peripheral zone (PZ). PI-RADS v2.1 is a simpler, more straightforward, and more reproducible method to better communicate between physicians regarding findings on prostate MRI.

Magnetic Resonance (MR) Imaging of Vascular Malformations.

Vascular malformations pose a diagnostic and therapeutic challenge due to the broad differential diagnosis as well as common utilization of inadequate or inaccurate classification systems among healthcare providers. Therapeutic approaches to these lesions vary based on the type, size, and extent of the vascular anomaly, necessitating accurate diagnosis and classification. Magnetic resonance (MR) imaging (MRI) is an effective modality for classifying vascular anomalies due to its ability to delineate the extent and anatomic relationship of the malformation to adjacent structures. In addition to anatomical mapping, the complete evaluation of vascular anomalies includes hemodynamic characterization. Dynamic time-resolved contrast-enhanced MR angiography provides information regarding hemodynamics of vascular anomalies, differentiating high- and low-flow vascular malformations. Radiologists must identify the MRI features of vascular malformations for better diagnosis and classification.

Calcification of the epiglottis presenting as foreign body sensation in the neck.

The epiglottis plays an important role in preventing food of different consistencies from entering the airway during swallowing. Calcification of epiglottis can, potentially, alter and limit its movement causing aspiration amongst other swallowing problems. Isolated calcification of the epiglottis and its clinical presentation remains a poorly understood entity for radiologists as well as clinicians. Therefore, it is important to recognize the imaging features of epiglottic calcification, and it's known clinical presentations to help clinicians with early diagnosis and management.

Subperiosteal Schwannoma of Pelvis- A Rare Case and Review of Literature.

Schwannoma are benign tumours of the nerve sheath. They are commonly found in the soft tissue, but its presence in the bone is extremely rare. We herein present a case of 34-year-old man with two adjacent pelvic subperiosteal schwannomas. Computed Tomography (CT) scan showed osseous pressure erosion and Magnetic Resonance Imaging (MRI) showed two cystic signal intensity lesions, one near superior aspect of right posterior iliac wing and another inferior to it with adjacent cortical pressure erosion. The tumour was excised en bloc and on histopathological examination, the diagnosis was confirmed as subperiosteal schwannoma. To our knowledge, this is the first case report of subperiosteal schwannoma involving the pelvis. When a surface cystic lesion is encountered, subperiosteal schwannoma should be considered as a possible differential diagnosis.

Non-cardiovascular findings in clinical cardiovascular magnetic resonance imaging in children.

BACKGROUND: With increasing use of pediatric cardiovascular MRI, it is important for all imagers to become familiar with the spectrum of non-cardiovascular imaging findings that can be encountered. OBJECTIVE: This study aims to ascertain the prevalence and nature of these findings in pediatric cardiovascular MRIs performed at our institution. MATERIALS AND METHODS: We retrospectively evaluated reports of all cardiovascular MRI studies performed at our institute from January 2008 to October 2012 in patients younger than18 years. Most studies (98%) were jointly interpreted by a pediatric cardiologist and a radiologist. We reviewed the electronic medical records of all cases with non-cardiovascular findings, defined as any imaging finding outside the cardiovascular system. Non-cardiovascular findings were classified into significant and non-significant, based on whether they were known at the time of imaging or they required additional workup or a change in management. RESULTS: In 849 consecutive studies (mean age 9.7 ± 6.3 years), 145 non-cardiovascular findings were found in 140 studies (16.5% of total studies). Overall, 51.0% (74/145) of non-cardiovascular findings were in the abdomen, 30.3% (44/145) were in the chest, and 18.6% (27/145) were in the spine. A total of 19 significant non-cardiovascular findings were observed in 19 studies in individual patients (2.2% of total studies, 47% male, mean age 5.9 ± 6.7 years). Significant non-cardiovascular findings included hepatic adenoma, arterially enhancing focal liver lesions, asplenia, solitary kidney, pelvicaliectasis, renal cystic diseases, gastric distention, adrenal hemorrhage, lung hypoplasia, air space disease, bronchial narrowing, pneumomediastinum and retained surgical sponge. CONCLUSION: Non-cardiovascular findings were seen in 16.5% of cardiovascular MRI studies in children, of which 2.2% were clinically significant findings. Prevalence and nature of these non-cardiovascular findings are different from those reported in adults. Attention to these findings is important during interpretation.

Malaria masquerading as relapse of Hodgkin's lymphoma on contrast enhanced (18)F-fluorodeoxyglucose positron emission tomography/computed tomography: A diagnostic dilemma.

(18)Flurodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) is nowadays routinely used in management of lymphoma patients. We here present a case of Hodgkin's lymphoma which showed (18)F-FDG avid splenomegaly on PET/CT done for clinically suspected relapse. Further evaluation by peripheral smear examination revealed malaria. The patient was then started on anti-malarial medications and follow-up PET/CT revealed resolution of hypermetabolic splenomegaly. This report highlights that in endemic regions malaria can cause (18)F-FDG avid splenomegaly and might mimic relapse of lymphoma.

Can hybrid SPECT-CT overcome the limitations associated with poor imaging properties of 131I-MIBG?: Comparison with planar scintigraphy and SPECT in pheochromocytoma.

OBJECTIVE: This study aimed to evaluate the incremental value of (131)I-MIBG hybrid SPECT-CT over planar scintigraphy (PS) and SPECT alone in patients with clinical or biochemical suspicion of pheochromocytoma. METHODS: A total of 126 adrenals of 63 patients (mean [SD] age, 28.6 [15.7] years; male patients, n = 34; female patients, n = 29) with clinical or biochemical suspicion of pheochromocytoma were retrospectively evaluated. All patients had undergone (131)I-MIBG SPECT-CT of adrenal region. The PS, SPECT, and SPECT-CT images were independently evaluated by 2 nuclear medicine physicians with 6 years (R1) and 2 years (R2) experience and in separate sessions 1 week apart. A scoring scale of 1 to 5 was used, in which 1 is definitely abnormal, 2 is probably abnormal, 3 is indeterminate, 4 is probably normal, and 5 is definitely normal. Sensitivity, specificity, predictive values were calculated taking a score 2 or less as abnormal. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Histopathology and/or clinical/imaging follow-up were taken as reference standard. RESULTS: Of the 126 adrenals evaluated, 29 were indeterminate on PS for R1 and 48 for R2, 39 were indeterminate on SPECT for both, and on SPECT-CT, 1 was indeterminate for R1 and 2 for R2. SPECT-CT correctly characterized 28 of 29 indeterminate adrenals on PS and 37 of 39 indeterminate adrenals on SPECT for R1. Similarly, for R2, SPECT-CT correctly characterized 45 of 48 indeterminate adrenals on PS and 33 of 39 indeterminate adrenals on SPECT. On ROC comparison, PS was inferior to SPECT (P = 0.040 for R1; P < 0.001 for R2) and SPECT-CT (P = 0.001 for R1; P < 0.001 for R2) for both the observers. Moreover, SPECT was inferior to SPECT-CT for both the observers (P = 0.017 for R1 and P = 0.001 for R2). Accuracy of SPECT-CT (R1, 97.6%; R2, 97.6%) was higher than PS (R1, 91.2%; R2, 84.1%) and SPECT (R1, 94.4%; R2, 86.5%). Interobserver agreement was highest for SPECT-CT (κ = 0.966) as compared with PS (κ = 0.815) and SPECT (κ = 0.826). CONCLUSIONS: I-MIBG hybrid SPECT-CT shows high sensitivity and specificity for characterizing adrenal lesions in patients with clinical or biochemical suspicion of pheochromocytoma and is superior to PS and SPECT alone. It will be especially useful in countries where (123)I-MIBG is not available.

Carcinoma endometrium: role of 18-FDG PET/CT for detection of suspected recurrence.

OBJECTIVE: Recurrent carcinoma endometrium has a poor prognosis. However, successful salvage with long-term survival has been achieved after hormone therapy, radical surgery, and radiotherapy/chemotherapy in patients with recurrent disease. Conventional imaging (CI) and tumor marker have limited accuracy for detecting recurrence in these patients. The aim of the present study was to evaluate the role of 18-flurodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) in patients suspected to have recurrence of carcinoma endometrium. METHODS: In this retrospective study, total 101 patients were evaluated. All patients had undergone surgery with/without adjuvant therapy (chemotherapy/radiotherapy/both) for histologically proven carcinoma endometrium. They underwent 18-FDG PET/CT studies for suspected recurrence. Comparable CI (contrast-enhanced CT and/or magnetic resonance imaging) was available for 76 patients. Results of FDG PET/CT were confirmed with clinical/imaging follow-up and/or histopathology. RESULTS: The mean age was 56.9±8.6 years. 18-FDG PET/CT was positive for recurrence in 51 (50.5%) patients and negative in 50 (49.5%). Locoregional disease was observed in 24 patients, metastatic disease was observed in 10, and 17 showed both locoregional and metastatic disease. The sensitivity, specificity, positive and negative predictive values, and accuracy of 18-FDG PET/CT were 88.9%, 93.6%, 94.1%, 88%, and 91%, respectively. 18-FDG PET/CT showed strong positive correlation with final diagnosis based on reference standard (κ 0.823; P=0.0001). Compared to CI, 18-FDG PET/CT has much higher specificity (62% vs. 96.4%), and accuracy (76.3% vs. 92.1%), with comparable sensitivity (85.1% vs. 89.5%). CONCLUSION: 18-FDG PET/CT is a highly sensitive and specific modality for detecting recurrence in post-therapy patients of carcinoma endometrium with suspected recurrence. It performs better than CI.

Role of FDG PET-CT in detecting recurrence in patients with uterine sarcoma: comparison with conventional imaging.

PURPOSE: The purpose of the present study was to evaluate the role of 18F-fluorodeoxyglucose (FDG) PET-CT in detecting recurrent disease in posttherapy patients of uterine sarcoma and compare the same with conventional imaging (CI). METHODS: A total of 15 FDG PET-CT studies were acquired in 12 posttherapy uterine sarcoma patients. The images were evaluated by two experienced nuclear medicine physicians in consensus. Clinical/imaging follow-up (minimum 6 months) and histopathology were taken as the reference standard. All the patients had also undergone CI (CT or MRI or ultrasonography) of the chest, abdomen, and pelvis. The diagnostic accuracy of FDG PET-CT was calculated and compared with that of CI. RESULTS: The median age of the patients was 51.5 years (interquartile range: 47.5-53). Histopathology was leiomyosarcoma in six, carcinosarcoma in five, and endometrial stromal sarcoma in one patient. Six FDG PET-CT studies were carried out for suspected recurrence and nine for posttherapy surveillance. Six FDG PET-CTs were positive and nine were negative for recurrence. The sensitivity, specificity, and accuracy of FDG PET-CT were 85.7, 100, and 93.3%, respectively, on per study-based analysis, and 80, 100, and 83.3% on per lesion-based analysis. PET-CT showed higher sensitivity and specificity compared with CI for both study-based and lesion-based analysis. However, no significant difference was found between FDG PET-CT and CI either in the study-based or in the lesion-based analysis (P not significant). CONCLUSION: FDG PET-CT is a highly sensitive and specific modality for detecting recurrence in posttherapy patients with uterine sarcoma. However, it provides no significant advantage over CI for this purpose.

Imaging thrombus in cancer patients with FDG PET-CT.

The incidence of thrombosis in patients with underlying primary malignancy is high. The thrombus may be the more common venous thromboembolism (VTE) or the rare tumour thrombus. VTE is a common entity in cancer patients and is managed with anticoagulant therapy, while tumour thrombosis requires aggressive multimodality management. Conventional imaging modalities, including ultrasonography, venography, contrast-enhanced computed tomography, and magnetic resonance imaging, are used routinely in such cases. With its increasing use in oncology, more and more such thrombi are encountered on 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT). Accurate characterisation of these lesions is of utmost importance owing to complementary functional information which it provides. FDG PET-CT has been found to be helpful in this context. This pictorial review discusses and illustrates the imaging features of thrombosis on FDG PET-CT.

18F-FDG PET-CT in the diagnosis of tumor thrombus: can it be differentiated from benign thrombus?

OBJECTIVE: The correct diagnosis of tumor thrombosis and its differentiation from benign thrombus can change patient management and prevent unnecessary anticoagulation treatment. This study was aimed at evaluating the role of fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in the diagnosis of tumor thrombosis, and its differentiation from benign thromboembolism. METHODS: We conducted a retrospective review of FDG PET-CT scans of patients who underwent the study for staging/restaging of a known malignancy and had FDG-avid thrombosis. Maximum standardized uptake value (SUV max) of the thrombus, SUV max of tumor (if any), and SUV max of mediastinal blood pool were calculated. PET-CT results were confirmed with clinical follow-up, structural imaging, and histopathology when available. RESULTS: A total of 24 patients (15 male and nine female) with a mean age of 43.8 years (range: 3-72 years; median: 47.5 years) were evaluated. On the basis of structural imaging and clinical follow-up, 10 patients had benign and 14 patients had tumor thrombosis. On FDG PET-CT, uptake in the thrombus was linear in 18 patients and focal in six patients. The most common site of thrombosis was the inferior vena cava. The mean SUV max was 3.2 (range: 2.3-4.6; median: 3.3) in the benign thrombosis group and was 6.0 (range: 2.3-13.8; median: 3.3) in the tumor thrombosis group. The difference in SUV max was significant (P=0.013). On receiver operating characteristic analysis, a cut-off SUV max of 3.63 (sensitivity: 71.4% and specificity: 90%) was obtained to differentiate tumor thrombus from benign thromboembolism. In six patients, FDG PET-CT detected occult vascular thrombosis. CONCLUSION: FDG PET-CT can detect active tumor thrombosis and is helpful in differentiating it from benign thrombus.

Role of FDG PET-CT in recurrent renal cell carcinoma.

AIM: To determine the efficacy of positron emission tomography-computed tomography using F-18 fluoro-deoxy-glucose (F-18 FDG PET-CT) in diagnosing the recurrence of renal cell carcinoma (RCC) in patients treated earlier with partial or radical nephrectomy. METHODS: We assessed 63 patients with suspected recurrent RCC after nephrectomy. PET-CT findings were interpreted as positive if the focal area of FDG uptake in the abdomen or outside the abdomen was more than the surrounding background tissue. The final diagnosis of the recurrence of RCC was based on histological examination and/or clinical follow-up and conventional imaging modalities. RESULTS: A total of 103 PET-CT studies were done in these 63 patients, of which 63 studies were true positive, 30 studies were true negative, seven studies were false negative and remaining three studies were false positive. In 63 true-positive scans, PET-CT showed 109 lesions. Of these, 28 lesions were in the lungs, 21 lesions were at a locoregional site, 21 were in the bones, 12 in the retroperitoneal lymph nodes and 27 at other sites. The sensitivity, specificity and accuracy of PET-CT were 90, 91 and 90%, respectively. CONCLUSION: Our results seem to confirm the useful role of PET-CT in the evaluation of post-surgical recurrence in patients who had undergone radical surgery for RCC.

Intravenous immunoglobulin therapy in autoimmune mucocutaneous blistering diseases: a review of the evidence for its efficacy and safety.

Intravenous immunoglobulin (IVIg) is a biologic agent that is being increasingly used in the treatment of autoimmune and chronic inflammatory disorders. It is approved by the US FDA for the treatment of primary immunodeficiencies, immune thrombocytopenic purpura, Kawasaki disease, bone marrow transplantation in patients aged over 20 years, chronic B-cell lymphocytic leukemia, and pediatric AIDS. IVIg has been used off-label for several diseases, clinical symptoms and syndromes. Our aim was to determine if there is evidence to support the efficacy of IVIg therapy in autoimmune mucocutaneous blistering diseases (AMBDs). We searched the PubMed database for studies on pemphigus and pemphigoid using the following criteria: (i) English language; (ii) minimum of five patients; (iii) diagnosis based on histology and immunopathology; and (iv) statistical analysis of data for comparison of efficacy provided. We evaluated the data and present information on the number of participants in each study, pre-IVIg therapy, indications for the use of IVIg, IVIg protocol (dose and interval) used, concomitant therapies, clinical outcome, follow-up period, and serologic studies. The quality of the evidence presented in this review is at Level A according to the UK National Health Service criteria. Twenty-three studies that were published between May 1999 and April 2010 were identified. One randomized controlled trial was found and all other studies were case series. Data on 260 patients treated with IVIg were analyzed: 191 patients with pemphigus and 69 patients with pemphigoid. Overall, 245 patients showed improvement with IVIg therapy. IVIg demonstrated a corticosteroid-sparing effect. In the studies presented, the incidence of serious adverse effects was not significant. The best available evidence in the literature indicates that IVIg is efficacious and has a good safety profile in the treatment of AMBDs.