Assessing the effectiveness of MRI, 18F-fluciclovine PET, SUVmax, and PSA in detecting local recurrence of prostate cancer after prostatectomy.

Purpose: The primary objective of this study was to evaluate the discriminatory utility of magnetic resonance imaging (MRI), 18F-fluciclovine positron emission tomography (PET), maximum standardized uptake value (SUVmax), prostate-specific antigen (PSA), and combinations of these diagnostic modalities for detecting local prostate cancer recurrence in the setting of rising PSA after radical prostatectomy. Material and methods: Patients were characterised for clinical features such as Gleason score, PSA at surgery, PSA at follow-up, follow-up MRI result, follow-up PET result, follow-up SUVmax, and follow-up disease status. The utility of diagnostic parameters for detecting disease recurrence at the prostatectomy bed was assessed using receiver operating characteristics (ROC) analysis to determine the area under the curve (AUC) for each model. Sensitivity, specificity, and positive/negative predictive values were also calculated. Optimal cut-off points for continuous variables were determined based on maximum Youden's J statistics. Results: The study found that MRI had the highest concordance (96%), sensitivity (100%), specificity (91%), positive predictive value (93%), and negative predictive value (100%) among the diagnostic modalities. The AUC for MRI was 0.9545, indicating a high discriminatory ability for detecting prostate cancer local recurrence. When combined, PET and SUVmax (cut-off value of 2.85) showed an improved performance compared to using them individually, with an AUC of 0.8925. Conclusions: The analysis suggests that MRI is the most effective imaging modality for detecting local prostate cancer recurrence, with 18F-fluciclovine PET and SUVmax also showing promising combined results. PSA has moderate discriminatory utility at follow-up but can still provide valuable information in detecting prostate cancer recurrence. Further research and recent references are needed to support these findings.

Diagnostic Approaches to Neuroendocrine Neoplasms of Unknown Primary Site.

ABSTRACT: Neuroendocrine tumors (NETs) are relatively uncommon heterogeneous neoplasms arising from endocrine and neuronal origin cells showing highly variable clinical behavior. By the time these tumors are discovered, up to 14% of patients with histologically proven NETs have metastasis, with the liver as the most frequently affected organ. Sometimes, no known primary site can be identified via routine imaging. Neuroendocrine tumors of unknown origin carry a poorer prognosis (compared with metastatic NETs with a known primary site) because of a lack of tailored surgical intervention and appropriate medical therapy (eg, chemotherapy or targeted therapy). A multimethod approach is frequently used in the trial to accurately determine the primary site for NETs of unknown primary sites and may include clinical, laboratory, radiological, histopathological, and surgical data. New molecular techniques using the genomic approach to identify the molecular signature have shown promising results. Various imaging modalities include ultrasound, computed tomography (CT), dual-energy CT, magnetic resonance imaging, and functional and hybrid imaging (positron emission tomography/CT, positron emission tomography/magnetic resonance imaging); somatostatin receptor imaging with new tracers is frequently used in an attempt for localization of the primary site.

Appendiceal Neuroendocrine Neoplasms: A Comprehensive Review.

ABSTRACT: Appendiceal neuroendocrine neoplasm (NEN) is the most common adult appendiceal malignant tumor, constituting 16% of gastrointestinal NENs. They are versatile tumors with varying morphology, immunohistochemistry, secretory properties, and cancer genomics. They are slow growing and clinically silent, to begin with, or present with features of nonspecific vague abdominal pain. Most acute presentations are attributed clinically to appendicitis, with most cases detected incidentally on pathology after an appendectomy. Approximately 40% of them present clinically with features of hormonal excess, which is likened to the functional secretory nature of their parent cell of origin. The symptoms of carcinoid syndrome render their presence clinically evident. However, slow growing and symptomatically silent in its initial stages, high-grade neuroendocrine tumors and neuroendocrine carcinomas of the appendix are aggressive and usually have hepatic and lymph node metastasis at presentation. This review article focuses on imaging characteristics, World Health Organization histopathological classification and grading, American Joint Committee on Cancer/Union or International Cancer Control, European Neuroendocrine Tumor Society staging, European Neuroendocrine Tumor Society standardized guidelines for reporting, data interpretation, early-stage management protocols, and advanced-stage appendiceal NENs. Guidelines are also set for the follow-up and reassessment. The role of targeted radiotherapy, chemotherapy, and high-dose somatostatin analogs in treating advanced disease are discussed, along with types of ablative therapies and liver transplantation for tumor recurrence. The search for newer location-specific biomarkers in NEN is also summarized. Regarding the varying aggressiveness of the tumor, there is a scope for research in the field, with plenty of data yet to be discovered.

PET/MRI imaging in neuroendocrine neoplasm.

Molecular imaging plays a vital role in the management of neuroendocrine neoplasms (NENs). Somatostatin receptor (SSTR) PET is critical for evaluating NENs, ascertaining peptide receptor radionuclide therapy (PRRT) eligibility, and treatment response. SSTR-PET/MRI can provide a one-stop-shop multiparametric evaluation of NENs. The acquisition of complementary imaging information in PET/MRI has distinct advantages over PET/CT and MR imaging acquisitions. The purpose of this manuscript is to provide a comprehensive overview of PET/MRI and a current review of recent PET/MRI advances in the diagnosis, staging, treatment, and surveillance of NENs.

Dual-Energy Computed Tomography Applications in the Genitourinary Tract.

By virtue of material differentiation capabilities afforded through dedicated postprocessing algorithms, dual-energy CT (DECT) has been shown to provide benefit in the evaluation of various diseases. In this article, we review the diagnostic use of DECT in the assessment of genitourinary diseases, with emphasis on its role in renal stone characterization, incidental renal and adrenal lesion characterization, retroperitoneal trauma, reduction of radiation, and contrast dose and cost-effectiveness potential. We also discuss future perspectives of the DECT scanning mode, including the use of novel contrast injection strategies and photon-counting detector computed tomography.

Quality assurance for non-contrast CT of the abdomen and pelvis during a period of supply chain disruption leading to iodinated contrast shortage in the emergency department setting.

Objectives: Iodinated contrast media (ICM) shortage crisis due to COVID-19 lockdowns led to a need for alternate imaging protocols consisting of non-contrast computed tomography (CT) for abdominal complaints and related trauma indications in emergency department (ED) settings. This quality assurance study aims to evaluate clinical outcomes of protocol modifications during ICM shortage and identify potential imaging misdiagnosis of acute abdominal complaints and related trauma. Material and Methods: The study included 424 ED patients with abdominal pain, falls, or motor vehicle collision (MVC)-related trauma who had non-contrast CT of the abdomen and pelvis in May 2022. We accessed the initial complaint, order indication, non-contrast CT results, any acute or incidental findings, and any follow-up imaging of the same body region with their results. We evaluated their association utilizing Chi-squared tests. We assessed sensitivity, specificity, and positive/negative predictive values using follow-up scan confirmation. Results: Across initial complaint categories, 72.9% of cases were abdominal pain, and 37.3% received positive findings. Only 22.6% of patients had follow-up imaging. Most confirmed original reports were for abdominal pain. We also found three reports of missed findings. There were significant associations between complaint categories and initial non-contrast CT report results (P < 0.001), as well as initial complaint categories and whether the patient received follow-up imaging or not (P < 0.004). No significant associations were found between follow-up imaging results and initial report confirmation. Non-contrast CT had 94% sensitivity and 100% specificity, with positive and negative predictive values 100% and 94%, respectively. Conclusion: Rate of missed acute diagnoses using non-contrast CT for patients presenting to the ED with acute abdominal complaints or related trauma has been low during the recent shortage, but further investigation would be needed to verify and quantify the implications of not routinely giving oral or intravenous contrast in the ED.

MRI-based nomograms and radiomics in presurgical prediction of extraprostatic extension in prostate cancer: a systematic review.

PURPOSE: Prediction of extraprostatic extension (EPE) is essential for accurate surgical planning in prostate cancer (PCa). Radiomics based on magnetic resonance imaging (MRI) has shown potential to predict EPE. We aimed to evaluate studies proposing MRI-based nomograms and radiomics for EPE prediction and assess the quality of current radiomics literature. METHODS: We used PubMed, EMBASE, and SCOPUS databases to find related articles using synonyms for MRI radiomics and nomograms to predict EPE. Two co-authors scored the quality of radiomics literature using the Radiomics Quality Score (RQS). Inter-rater agreement was measured using the intraclass correlation coefficient (ICC) from total RQS scores. We analyzed the characteristic s of the studies and used ANOVAs to associate the area under the curve (AUC) to sample size, clinical and imaging variables, and RQS scores. RESULTS: We identified 33 studies-22 nomograms and 11 radiomics analyses. The mean AUC for nomogram articles was 0.783, and no significant associations were found between AUC and sample size, clinical variables, or number of imaging variables. For radiomics articles, there were significant associations between number of lesions and AUC (p < 0.013). The average RQS total score was 15.91/36 (44%). Through the radiomics operation, segmentation of region-of-interest, selection of features, and model building resulted in a broader range of results. The qualities the studies lacked most were phantom tests for scanner variabilities, temporal variability, external validation datasets, prospective designs, cost-effectiveness analysis, and open science. CONCLUSION: Utilizing MRI-based radiomics to predict EPE in PCa patients demonstrates promising outcomes. However, quality improvement and standardization of radiomics workflow are needed.

Comments on "Review of the role of diagnostic modalities and imaging findings in the COVID-19 pandemic".

The present letter to the editor corresponds to the article entitled "Comprehensive literature review on the radiographic findings, imaging modalities, and the role of radiology in the coronavirus disease 2019 (COVID-19) pandemic" by Pal et al, published in World J Radiol. 2021; 13(9): 258-282. With zero to unknown prevalence, COVID-19 has created a heterogeneous and unforeseen situation across the world. Healthcare providers encountered new challenges in image interpretation, characterization, and prognostication of the disease. Pal et al delineated the radiological findings, which would guide the radiologists to identify the early signs of severe infection.

Virtual Non-contrast Imaging in The Abdomen and The Pelvis: An Overview.

Virtual non-contrast (VNC) imaging is a post-processing technique generated from contrast-enhanced scans using dual-energy computed tomography (DECT). It is generated by removing iodine from imaging acquired at multiple energies. Myriad clinical studies have shown its ability to diagnose the various abdominal and pelvic pathologies discussed in the article. VNC is also a problem-solving tool for characterizing incidentally detected lesions ("incidentalomas"), often decreasing the need for additional follow-up imaging. It also obviates the multiphase image acquisitions to evaluate hematuria, hepatic steatosis, aortic endoleaks, and gastrointestinal bleeding by generating image datasets from different tissue attenuation values. The scope of this article is to provide an overview of various applications of VNC imaging obtained by DECT in the abdomen and pelvis.

Dual-Energy Imaging of the Chest.

Dual-energy computed tomography (DECT) is a contemporary development by which the tissue can be characterized beyond conventional computed tomography. It improves tissue differentiation by exploiting the X-ray absorptive property of the tissues. Although still in its early stages, DECT utilization in pulmonary and cardiovascular pathologies is emerging. It includes applications such as pulmonary embolism, pulmonary hypertension, myocardial perfusion, and coronary artery assessment. This article discusses DECT principles and their current and emerging applications in thoracic imaging.

Introducing and Building a Dual-Energy CT Business.

In recent years, there has been increased utilization of Dual-energy CT (DECT) in diagnostic imaging, mainly due to a reduction of effective radiation dose and lower intravenous contrast dose requirement in DECT imaging compared to conventional CT. A comprehensive imaging protocol and teamwork involving technologists and radiologists are needed to successfully implement DECT in clinical practice. At the same time, insight into the direct and indirect expenditures incurred is critical for rendering a cost-effective service to the patient and institution. This paper focuses on introducing the foundations of DECT to the readers and discusses the impediments encountered during the implementation of DECT in clinical practice. Potential solutions to these challenges are also proposed.

Magnetic resonance imaging of bladder pheochromocytomas: a review.

Bladder pheochromocytomas (PCCs) are rare tumors that account for 0.06% of all bladder tumors and makeup 1% of all PCCs. Most PCCs are functional, and they secrete catecholamines that lead to clinical symptoms such as paroxysmal hypertension, headaches, palpitations, and sweating. However, some are nonfunctional and asymptomatic and are hence difficult to diagnose. Cystoscopy and biopsy should not be performed when bladder PCCs are suspected. They may provoke a hypertensive crisis if preventative antiadrenergic blockers are not administered prior to the procedure. The diagnostic workup begins with obtaining blood or urine catecholamine and catecholamine metabolite values to make a presumptive diagnosis of bladder PCC. Computed tomography (C.T.) and magnetic resonance imaging (MRI) are then used to localize and stage the tumor for surgical resection. MRI, due to its superior soft tissue resolution and the ability to use multiparametric MRI (mpMRI) to differentiate between layers of the bladder wall and from other bladder masses, is the optimal imaging modality to detect extra-adrenal bladder PCCs and determine locoregional staging. Once antiadrenergic medications are given, the tumor is resected, and the diagnosis is confirmed histologically. However, the differential diagnosis of bladder PCC often gets overlooked, leading to surgical resection in the absence of antiadrenergic medications, increasing the chances of a fatal hypertensive crisis. This makes MRI an essential diagnostic tool for staging bladder PCCs before surgery. This review discusses the indications for MRI in bladder PCCs and describes findings from these tumors on various MRI sequences and when to use them. We also discuss how MRI can differentiate bladder PCCs from other bladder neoplasms.

Advances and effectiveness of the immunotherapy after liver transplantation.

Transplant recipients usually have increased chances of graft rejection and graft vs host disease, requiring chronic immunosuppressive therapy. Nonetheless, long-term immunosuppression risks malignancies such as skin cancer, lymphoma, and Kaposi sarcoma. However, there are very few studies that included solid organ transplant recipients while studying the efficacy of immunotherapy. "Immunotherapy after liver transplantation: Where are we now?" is a study, where the authors described the mechanism of action and outcomes of immune checkpoint inhibitors specific to liver transplant recipients. The authors reported the graft rejection rates and the factors contributing to the rejection in the liver transplant recipients.

Pancreatic acinar cell carcinoma: A comprehensive review.

Acinar cell carcinoma (ACC) is a rare pancreatic malignancy with distinctive clinical, molecular, and morphological features. The long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma patients. As there are no significant patient series about ACCs, our understanding of this illness is mainly based on case reports and limited patient series. Surgical resection is the treatment of choice for patients with the disease restricted to one organ; however, with recent breakthroughs in precision medicine, medicines targeting the one-of-a-kind molecular profile of ACC are on the horizon. There are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not possible. As a result of shared genetic alterations, ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal carcinomas. The role of neoadjuvant or adjuvant chemoradiotherapy has not been established. This article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

Prospective study to analyse the efficiency of Acoustic Doppler v/s Colour Duplex Ultrasound in locating perforators for antero-lateral thigh flap in reconstructive head and neck surgery.

INTRODUCTION: The anterolateral thigh (ALT) flap has become the universal workhorse for Head and Neck reconstruction. Being a perforator-based flap, accurate planning by preoperative perforator localisation is clearly beneficial. Acoustic Doppler (AD) and Colour Duplex Ultrasound (CDU) are the most practicable methods of localisation available. We designed a prospective study to analyse the correlation between preoperative localisation (by AD and CDU) and intraoperative findings, factoring in the advantages of using a high frequency probe for CDU. METHODS: Thirty-three consecutive patients were analysed in a prospective, observational study. AD was first used to mark the perforator point and its distance measured from two anatomical landmarks, the Anterior Superior Iliac Spine (ASIS) and the 'Reference line' (a line joining ASIS with the superior patellar border). CDU was then carried out to mark the perforator position with two probes (9 and 14 MHz), and the above distances measured for both points. At surgery, the actual point of perforator entry was separately marked and the same two distances were measured. A note was also made of perforator characteristics such as size and flow rate. RESULTS: In 21/33 cases, there was a close concordance between pre- and intraoperative localisation (complete success). From the remaining 12 cases, the complete absence of perforator was found in one case, a small, unreliable perforator in 2 cases and a site disparity of > 2 cm between true and preop points in 9 cases. CONCLUSION: No significant advantages were found with either a high frequency probe or indeed for CDU over AD. AD is sufficient for effective perforator localisation and should be routinely employed to accurately plan the anterior incision. CDU can be employed in cases where AD is unconvincing.