Two rare cases of circumaortic left renal vein with double retroaortic limbs and its procedural implications

Circumaortic left renal vein with additional retroaortic limb is a rare anatomic variant. We encountered two cases in our practice with additional retroaortic limb draining into hemiazygos and IVC respectively. We focus on discussing the clinical relevance and surgical implications of such variants.

Imaging Update for Hereditary Abdominopelvic Neuroendocrine Neoplasms

ABSTRACT

Neuroendocrine neoplasms have shown a linear increase in incidence and prevalence in recent decades, primarily due to improved cross-sectional imaging, expanded use of endoscopic procedures, and advanced genetic analysis. However, diagnosis of hereditary neuroendocrine tumors is still challenging because of heterogeneity in their presentation, the variety of tumor locations, and multiple associated syndromes. Radiologists should be familiar with the spectrum of these tumors and associated hereditary syndromes. Furthermore, as the assessment of multiple tumor elements such as morphology, biochemical markers, and presence of metastatic disease are essential for the treatment plan, conventional anatomic and functional imaging methods are fundamental in managing and surveilling these cases. Our article illustrates the role of different cross-sectional imaging modalities in diagnosing and managing various hereditary abdominopelvic neuroendocrine tumors.

Quality assurance for magnetic resonance angiography of the chest in patients suspected of pulmonary embolism during iodinated contrast shortage in the emergency department setting

Objectives

COVID-19 lockdowns resulted in a global shortage of iodinated contrast media. Therefore, alternative imaging protocols were devised to evaluate patients arriving to the emergency department (ED) with suspicion of pulmonary embolism (PE). This quality assurance (QA) aims to compare diagnostic potential between alternative magnetic resonance angiography (MRA) protocol over the gold standard computed tomography angiography (CTA) by evaluating MRA imaging quality, scanner type/imaging sequence, and any risk of misdiagnosis in patients with symptoms of PE.

Material and Methods

This retrospective study compromised of 55 patients who arrived to ED and underwent MRA of the chest for suspicion of PE during the months of May to June 2022. Data regarding their chief complaints, imaging sequence, and MRA results were collected. Two fellowship-trained faculty radiologists reviewed the MRA scans of the patients and scored the quality using a Likert scale.

Results

Two patients were positive for PE and 53 patients showed negative results. Regarding the scan quality issues, motion was noted in 80% of the 55 studies that we reviewed. Significant associations (P < 0.009) between Likert scale scores and initial complaint category were found. The characteristic symptoms associated with suspicion of PE, namely, shortness of breath, chest pain, and cough were distributed among the 1 and 2 categories, reflecting the most optimal vessel opacification scores. We found no risk of misdiagnosis after reviewing the electronic medical record for follow-up appointments within 6 months of ED visit.

Conclusion

Patients were screened for PE with MRA as an alternative imaging tool during times of contrast shortage. Further, evaluation of MRA with CTA, side by side, in a larger patient population is required to increase the validity of our QA study.

Beyond squamous cell carcinoma: MRI appearance of uncommon anal neoplasms and mimickers

Anal cancer is an uncommon malignancy. In addition to squamous cell carcinoma, there are a variety of other less common malignancies and benign pathologies that may afflict the anal canal, with which abdominal radiologists should be familiar. Abdominal radiologists should be familiar with the imaging features that can help distinguish different rare anal tumors beyond squamous cell carcinoma and that can aid in diagnosis therefore help steer management. This review discusses these uncommon pathologies with a focus on their imaging appearance, management, and prognosis.

The optimized rectal cancer MRI protocol: choosing the right sequences, sequence parameters, and preparatory strategies

Pelvic MRI plays a critical role in rectal cancer staging and treatment response assessment. Despite a consensus regarding the essential protocol components of a rectal cancer MRI, substantial differences in image quality persist across institutions and vendor software/hardware platforms. In this review, we present image optimization strategies for rectal cancer MRI examinations, including but not limited to preparation strategies, high-resolution T2-weighted imaging, and diffusion-weighted imaging. Our specific recommendations are supported by case studies from multiple institutions. Finally, we describe an ongoing initiative by the Society of Abdominal Radiology's Disease-Focused Panel (DFP) on Rectal and Anal Cancer to create standardized rectal cancer MRI protocols across scanner platforms.

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.

A Multicenter Assessment of Interreader Reliability of LI-RADS Version 2018 for MRI and CT

Background Various limitations have impacted research evaluating reader agreement for Liver Imaging Reporting and Data System (LI-RADS). Purpose To assess reader agreement of LI-RADS in an international multicenter multireader setting using scrollable images. Materials and Methods This retrospective study used deidentified clinical multiphase CT and MRI and reports with at least one untreated observation from six institutions and three countries; only qualifying examinations were submitted. Examination dates were October 2017 to August 2018 at the coordinating center. One untreated observation per examination was randomly selected using observation identifiers, and its clinically assigned features were extracted from the report. The corresponding LI-RADS version 2018 category was computed as a rescored clinical read. Each examination was randomly assigned to two of 43 research readers who independently scored the observation. Agreement for an ordinal modified four-category LI-RADS scale (LR-1, definitely benign; LR-2, probably benign; LR-3, intermediate probability of malignancy; LR-4, probably hepatocellular carcinoma [HCC]; LR-5, definitely HCC; LR-M, probably malignant but not HCC specific; and LR-TIV, tumor in vein) was computed using intraclass correlation coefficients (ICCs). Agreement was also computed for dichotomized malignancy (LR-4, LR-5, LR-M, and LR-TIV), LR-5, and LR-M. Agreement was compared between research-versus-research reads and research-versus-clinical reads. Results The study population consisted of 484 patients (mean age, 62 years ± 10 [SD]; 156 women; 93 CT examinations, 391 MRI examinations). ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68 (95% CI: 0.61, 0.73), 0.63 (95% CI: 0.55, 0.70), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95% CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68 vs 0.62, respectively; P = .03) and for dichotomized malignancy (ICC, 0.63 vs 0.53, respectively; P = .005), but not for LR-5 (P = .14) or LR-M (P = .94). Conclusion There was moderate agreement for LI-RADS version 2018 overall. For some comparisons, research-versus-research reader agreement was higher than research-versus-clinical reader agreement, indicating differences between the clinical and research environments that warrant further study. © RSNA, 2023 Supplemental material is available for this article. See also the editorials by Johnson and Galgano and Smith in this issue.

Intraperitoneal anatomy with the aid of pathologic fluid and gas: An imaging pictorial review

The peritoneum is a large serosal membrane enveloping the abdomen and pelvic organs and forming the peritoneal cavity. This complex relationship forms many named abdominopelvic spaces, which are frequently involved in infectious, inflammatory, neoplastic, and traumatic pathologies. The knowledge of this anatomy is essential to the radiologist to localize and describe the extent of the disease accurately. This manuscript provides a comprehensive pictorial review of the peritoneal anatomy to describe pathologic fluid and gas.

Magnetic resonance imaging radiomic features for recurrent prostate cancer following proton radiation therapy-A pilot study

OBJECTIVE

The role of multiparametric MRI (mp-MRI) for postproton radiation evaluation is unclear. In this pilot study, we characterize the mp-MRI features using the Prostate Imaging-Reporting and Data System (PI-RADS) for recurrent prostate cancer (PCa) following proton radiation therapy.

METHODS

After obtaining IRB approval, we identified 163 consecutive cases who underwent MRI-fusion prostate biopsy at our institution from November 2017 to May 2020. This study evaluated patients with prostate cancer (PCa) with biochemical recurrence following proton radiation. Patients were excluded if they had grossly metastatic disease, metal fragments, implanted devices, or with surgically removed prostates. The mpMRI studies were reviewed in depth and scored by 2 fellowship-trained radiologists. Following MRI-fusion biopsy of lesions of interest (LOI), slides were read by fellowship-trained pathologists.

RESULTS

We found 14 patients with 16 lesions who met the study inclusion criteria. The median age was 69 years (range 57-79) and median time to biochemical recurrence was 7.3 years (range 3-13). On post-treatment imaging, decreases in prostate size and diffusely decreased T2 signal intensity were observed, making the use of apparent diffusion coefficient (ADC) and early enhancement at dynamic contrast enhanced (DCE) imaging often necessary for diagnosis of disease recurrence. We identified a total of 16 lesions with PIRADS scores of 3 or higher. Of these lesions, there were 5 PIRADS 3 lesions (4/5 (80%) without prostate cancer), 7 PIRADS 4-5 lesions (6 (86%) had high risk Pca), and 4 lesions with unassigned PIRADS scores (100% had high risk cancers). Among the MRI variables, diffusion weighted imaging (DWI) heterogeneity had the strongest association with recurrence of PCa (P < 0.001).

CONCLUSIONS

Results of our pilot study showed that the PIRADS scoring system in the postproton radiation therapy setting has some correlations with prostate cancer recurrence; However, the clinical value of these findings are unclear. While definitive PIRADS categorization of lesions demonstrated expected frequency of cancer consistent with the scoring system, all unassigned lesions also harbored malignancy suggesting a cautious approach to PIRADS scoring system in postproton radiation setting. The findings from this study may be validated using a larger cohort.

Magnetic Resonance Imaging Virtual Biopsy of Common Solid Renal Masses-A Pictorial Review

ABSTRACT

The expanded application of radiologic imaging resulted in an increased incidence of renal masses in the recent decade. Clinically, it is difficult to determine the malignant potential of the renal masses, thus resulting in complex management. Image-guided biopsies are the ongoing standard of care to identify molecular variance but are limited by tumor accessibility and heterogeneity. With the evolving importance of individualized cancer therapies, radiomics has displayed promising results in the identification of tumoral mutation status on routine imaging. This article discusses how magnetic resonance imaging features can guide a radiologist toward identifying renal mass characteristics.

Current Update on PET/MRI in Gynecological Malignancies-A Review of the Literature

Early detection of gynecological malignancies is vital for patient management and prolonging the patient's survival. Molecular imaging, such as positron emission tomography (PET)/computed tomography, has been increasingly utilized in gynecological malignancies. PET/magnetic resonance imaging (MRI) enables the assessment of gynecological malignancies by combining the metabolic information of PET with the anatomical and functional information from MRI. This article will review the updated applications of PET/MRI in gynecological malignancies.

Extramural venous invasion: a novel magnetic resonance imaging biomarker for adverse pathology in bladder cancer

Extramural venous invasion (EMVI) recognized on magnetic resonance imaging (MRI) is an unequivocal biomarker for detecting adverse outcomes in rectal cancer: however it has not yet been explored in the area of bladder cancer. In this study, we assessed the feasibility of identifying EMVI findings on MRI in patients with bladder cancer and its avail in identifying adverse pathology. In this single-institution retrospective study, the MRI findings inclusive of EMVI was described in patients with bladder cancer that had available imaging between January 2018 and June 2020. Patient demographic and clinical information were retrieved from our electronic medical records system. Histopathologic features frequently associated with poor outcomes including lymphovascular invasion (LVI), variant histology, muscle invasive bladder cancer (MIBC), and extravesical disease (EV) were compared to MRI-EMVI. A total of 38 patients were enrolled in the study, with a median age of 73 years (range 50-101), 76% were male and 23% were females. EMVI was identified in 23 (62%) patients. There was a significant association between EMVI and MIBC (OR = 5.30, CI = 1.11-25.36; P = 0.036), and extravesical disease (OR = 17.77, CI = 2.37-133; P = 0.005). We found a higher probability of presence of LVI and histologic variant in patients with EMVI. EMVI had a sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of 90%, 73%, 94% and 63% respectively in detecting extravesical disease. Our study suggests, EMVI may be a useful biomarker in bladder cancer imaging, is associated with adverse pathology, and could be potentially integrated in the standard of care with regards to MRI reporting systems. A larger study sample size is further warranted to assess feasibility and applicability.

SAR user guide to the rectal MR synoptic report (primary staging)

Rectal MR is the key diagnostic exam at initial presentation for rectal cancer patients. It is the primary determinant in establishing clinical stage for the patient and greatly impacts the clinical decision-making process. Consequently, structured reporting for MR is critically important to ensure that all required information is provided to the clinical care team. The SAR initial staging reporting template has been constructed to address these important items, including locoregional extent and factors impacting the surgical approach and management of the patient. Potential outputs to each item are defined, requiring the radiologist to commit to a result. This provides essential information to the surgeon or oncologist to make specific treatment deisions for the patient. The SAR Initial Staging MR reporting template has now been officially adopted by the NAPRC (National Accreditation Program for Rectal Cancer) under the American College of Surgery. With the recent revisions to the reporting template, this user guide has been revamped to improve its practicality and support to the radiologist to complete the structured report. Each line item of the report is supplemented with clinical perspectives, images, and illustrations to help the radiologist understand the potential implications for a given finding. Common errors and pitfalls to avoid are highlighted. Ideally, rectal MR interpretation should not occur in a vacuum but in the context of a multi-disciplinary tumor board to ensure that healthcare providers use common terminology and share a solid understanding of the strengths and weaknesses of MR.

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.

Pancreatic neuroendocrine neoplasms: a 2022 update for radiologists

Pancreatic neuroendocrine neoplasms (PaNENs) are a unique group of pancreatic neoplasms with a wide range of clinical presentations and behaviors. Given their heterogeneous appearance and increasing detection on cross-sectional imaging, it is essential that radiologists understand the variable presentation and distinctions PaNENs display compared to other pancreatic neoplasms. Additionally, some of these neoplasms may be hormonally functional, and it is imperative that radiologists be aware of the common clinical presentations of hormonally active PaNENs. Knowledge of PaNEN pathology and treatments may influence which imaging modality is optimal for each patient. Each imaging modality used for PaNENs has distinct advantages and disadvantages, particularly in different treatment settings. Thus, the focus of this manuscript is to provide an update for the radiologist on PaNEN pathology, imaging, and treatments.

Imaging of neuroendocrine neoplasms of the male GU tract

Male genitourinary neuroendocrine neoplasms (GU-NENs) are rare, without any definite imaging characteristics. The WHO classified neuroendocrine neoplasms in the 2016 classification of the tumors of the urinary tract and genital organs along with other GU tumors; however, no pathologic grading system is available as published for gastroenteropancreatic neuroendocrine neoplasms. Often a multimodality approach using cross-sectional imaging techniques, such as molecular imaging and histopathology are implemented to arrive at the diagnosis. This article provides a review of the pathology and imaging features of the male GU-NENs.

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.

Intraindividual Reliability of Opportunistic Computed Tomography-Assessed Adiposity and Skeletal Muscle among Breast Cancer Patients

Background

Adiposity and skeletal muscle levels assessed on computed tomography (CT) scans are prognostic indicators for patients with breast cancer. However, the intraindividual reliability of temporal changes in body composition assessed on opportunistic CT scans is unclear.

Methods

This retrospective study included 50 patients newly diagnosed with breast cancer who had archived CT scans pre- and postsurgery for breast cancer. The third lumbar CT image was segmented for areas of 3 types of adipose tissues and 5 different densities of skeletal muscles. Mean and percent changes in areas pre- vs postsurgery were compared using Wilcoxon signed rank tests. Intraclass correlation coefficients (ICCs) with 95% confidence intervals were assessed. A 2-sided P less than .05 was considered statistically significant.

Results

Mean (SD) age at diagnosis was 58.3 (12.5) years, and the interval between CT scans was 590.6 (536.8) days. Areas for body composition components were unchanged except for intermuscular adipose tissue (mean change = 1.45 cm², 6.74% increase, P = .008) and very high-density muscle (mean change = −0.37 cm², 11.08% decrease, P = .01) during the interval. There was strong intraindividual reliability in adipose tissue and skeletal muscle areas on pre- vs postsurgery scans overall (ICC = 0.763-0.998) and for scans collected 3 or less years apart (ICC = 0.802-0.999; 42 patients).

Conclusions

Although some body composition components may change after breast cancer surgery, CT scan assessments of body composition were reliable for a 3-year interval including the surgery. These findings inform measurement characteristics of body composition on opportunistic CT scans of patients undergoing surgery for breast cancer.

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.

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.

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.

Abstract 3219: Changes and intra-individual reliability in computed tomography image-assessed adiposity and skeletal muscles areas after breast cancer surgery

Background: Levels of adiposity and skeletal muscles are prognostic indicators in breast cancer patients; however, data are limited on temporal changes in body composition, particularly in different densities of muscles, before and after mastectomy.

Objectives: We examined the change in CT-assessed adipose tissue and different density of skeletal muscle areas using a high-resolution segmentation method in breast cancer patients before and after surgery.

Methods: This study included 50 newly-diagnosed breast cancer patients who had taken CT scans before and after surgery. We analyzed their third lumbar (L3) CT images to measure the areas of adipose tissue and five-level (from very-high-density to very-low-density) skeletal muscle components. We assessed mean and percent changes in areas using paired t-test and calculated the intra-class correlation (ICC).

Results: Patients’ mean age at diagnosis was 58.3 (SD=12.5) years. The mean duration between scans was 591 (SD=537) days. There was a significant decrease in the areas of subcutaneous adipose tissue (mean change= -36.17 cm2, 11.72% decrease, p=0.029), total adipose tissue (mean change= -45.64 cm2, 10.18% decrease, p=0.032), and very-high-density muscle (mean change= -0.37 cm2, 11.08% decrease, p=0.010). The ratio of total adipose tissue and total skeletal muscle decreased from 3.67 to 3.32 after surgery (mean change= -0.36, 9.81% decrease, p=0.061). There was a strong correlation in adipose tissues and skeletal muscle areas of pre-and post-surgery scans taken within 3 years apart (ICC=0.802 to 0.999, all p&lt;0.05), but the correlations were attenuated in scans taken &gt;3 years apart (ICC = -0.055 to 0.738, all p&gt;0.05).

Conclusion: In this sample of breast cancer patients who have undergone surgery, there was a significant decrease in subcutaneous adipose tissues, total adipose tissues, and very-high-density muscle areas over time. Body composition assessed by CT images is reliable for a 3- year period involving breast cancer surgery. These findings serve as a baseline for prospective studies examining the impact of these changes on breast cancer outcomes.

Keywords: Adipose tissue, skeletal muscle, computed tomography scans, breast cancer, surgery

Citation Format: Livingstone Aduse-Poku, Dheeraj Gopireddy, Mauricio Henandez, Chandana Lall, Joel Divaker, Sara Falzarano, Shahla Masood, Weizhou Zhang, Susmita Datta, Jiang Bian, Ting-Yuan David Cheng. Changes and intra-individual reliability in computed tomography image-assessed adiposity and skeletal muscles areas after breast cancer surgery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3219.

Vulvar Cancer: 2021 Revised FIGO Staging System and the Role of Imaging

Vulvar cancer is a rare gynecological malignancy. It constitutes 5-8% of all gynecologic neoplasms, and squamous cell carcinoma is the most common variant. This article aims to review the etiopathogenesis revised 2021 International Federation of Gynecology and Obstetrics (FIGO) classification and emphasize imaging in the staging of vulvar cancer. The staging has been regulated by FIGO since 1969 and is subjected to multiple revisions. Previous 2009 FIGO classification is limited by the prognostic capability, which prompted the 2021 revisions and issue of a new FIGO classification. Although vulvar cancer can be visualized clinically, imaging plays a crucial role in the staging of the tumor, assessing the tumor extent, and planning the management. In addition, sentinel lymph node biopsy facilitates the histopathological staging of the draining lymph node, thus enabling early detection of tumor metastases and better survival rates.

Ruptured pyomyoma - Rare complication of post-uterine artery embolization: A case report

Leiomyomas, also termed as fibroids, are benign smooth, muscle neoplasms seen in 70–80% of women by the age of 50 years. Uterine artery embolization (UAE) is a minimally invasive procedure that involves cessation of vascular supply to the fibroids, by infusion of gelatinous microspheres into the uterine arteries. Pyomyoma is a suppurative leiomyoma, secondary to infection of necrotic tissue. It is an infrequent complication of uterine artery embolization (UAE). Pyomyoma can lead to sepsis, peritonitis, and respiratory distress syndrome resulting in high morbidity and mortality. Due to its rarity, high suspicion is crucial in the diagnosis, and prompt treatment is recommended to reduce mortality. Ultrasound, computed tomography, and magnetic resonance imaging assist in diagnosis. We present a case of a 44-year-old woman with ruptured pyomyoma, following an UAE intervention. The patient was treated with total abdominal hysterectomy and salpingo-oophorectomy along with peritoneal irrigation and drainage.

Mimics and Pitfalls of Primary Ovarian Malignancy Imaging

The complex anatomy and similarity of imaging features of various pathologies in the pelvis can make accurate radiology interpretation difficult. While prompt recognition of ovarian cancer remains essential, awareness of processes that mimic ovarian tumors can avoid potential misdiagnosis and unnecessary surgery. This article details the female pelvic anatomy and highlights relevant imaging features that mimic extra-ovarian tumors, to help the radiologists accurately build a differential diagnosis of a lesion occupying the adnexa.

Multi-practice survey on MR imaging practice patterns in rectal cancer in the United States

PURPOSE

To investigate practice patterns related to MR technique and structured reporting for MRI of rectal cancer at academic centers and private practice groups in the United States.

METHODS AND MATERIALS

A survey developed by active members of the Society of Abdominal Radiology Rectal and Anal Cancer Disease Focus Panel was sent to 100 private practice and 189 academic radiology groups. The survey asked targeted questions about practice demographics and utilization, technical MR parameters and reporting practices related to MRI of rectal cancer. The results were analyzed using software in an online survey program.

RESULTS

The survey received 47 unique responses from academic (37/47, 78.7%) and private practice (10/47, 21.3%) groups. Most practices report using rectal MR for staging newly diagnosed rectal cancer always (29/47, 61.7%), and less than half always do so for re-staging after neoadjuvant chemoradiation (20/47, 42.6%). Most groups perform between 1 to 5 rectal MR studies for baseline staging per week (32/47, 68.1%) and most groups perform 0 to 2 MR studies for re-staging per week (27/47, 57.4%). Regarding patient preparation and MR technical parameters, there is variability, but a few key points include most practices (27/47, 57.4%) acquire axial T2-weighted images at a slice thickness of 3 mm or less, axial T2-weighted images with 2D acquisition (30/47, 63.8%), a T2-weighted axial oblique sequence through the tumor (43/47, 91.5%), and T2-weighted images without fat suppression (37/47, 78.7%). Equal numbers of groups report using a maximal b-value less than 1000 s/mm² (19/43, 44.2%) and 1000 s/mm² or greater (19/43, 44.2%); the rest were unsure. A substantial portion of respondents do not use intravenous contrast (13/47, 27.7%). Most believe that structured report templates contribute to uniformity of reporting practices (39/47, 83.0%), though there is considerable heterogeneity in usage and included elements.

CONCLUSION

There is considerable technical heterogeneity among respondents' answers and reporting practices in MR for rectal cancer, and most of the groups report reading only a modest number of studies per week. Our findings suggest there may be room for improvement in terms of radiologist education for performance and standardization of clinical practice for MR imaging of rectal cancer.

Response criteria for immunotherapy and the radiologic patterns of immune-related adverse events

Immunotherapy has revolutionized clinical outcomes in both early-stage and advanced-stage malignancies. Immunotherapy has improved patient survival in both solid and hematologic disorders with the potential added benefit of less toxicity compared to conventional cytotoxic chemotherapy. Imaging plays a fundamental role in monitoring treatment response and assessment of immune-related adverse events, e.g. pneumonitis, colitis, etc. Familiarity with the current strategies of immune-related response evaluation and their limitations is essential for radiologists to guide clinicians with their treatment decisions. Radiologists should be aware of the wide spectrum of immune-related adverse events and their various radiological features as well as the patterns of treatment response associated with immunotherapies.

Current update on vaginal malignancies

Primary vaginal cancers are rare and account for 1-3% of all gynecologic malignancies. There are several histological subtypes that affect a wide range of the population. Imaging plays an important role in the diagnosis, staging, and treatment planning of vaginal cancers. This article reviews the relevant anatomy, clinical findings, imaging characteristics, and recent advances in the management of vaginal malignancies.

A Rare Case of Hemorrhagic Giant Adrenal Myelolipoma: Radiographic and Pathologic Correlation

Myelolipomas are rare benign tumors made up of adipose and hematopoietic tissue that commonly occur in the adrenal glands unilaterally. Spontaneous hemorrhage occurs in < 5% of these tumors, and often present as large masses. A 50-year-old male presented with right flank pain that had been growing increasingly worse over a two-week period. Contrast-enhanced Computed Tomography (CT) revealed a large suprarenal 15-cm mass exerting mass effect on the kidney and liver along with possible hemorrhage. T1 fat saturated and T2 non-fat saturated magnetic resonance imaging (MRI) confirmed the diagnosis of a myelolipoma with hemorrhage. The patient was treated with surgical resection of the mass and the follow-up pathology report confirmed a giant hemorrhagic adrenal myelolipoma. Spontaneous hemorrhage of a large myelolipoma measuring 15 cm is a rare entity and the correct imaging needs to be done in order to carry out the appropriate treatment.

MRI and CT bladder segmentation from classical to deep learning based approaches: Current limitations and lessons

Precise determination and assessment of bladder cancer (BC) extent of muscle invasion involvement guides proper risk stratification and personalized therapy selection. In this context, segmentation of both bladder walls and cancer are of pivotal importance, as it provides invaluable information to stage the primary tumor. Hence, multiregion segmentation on patients presenting with symptoms of bladder tumors using deep learning heralds a new level of staging accuracy and prediction of the biologic behavior of the tumor. Nevertheless, despite the success of these models in other medical problems, progress in multiregion bladder segmentation, particularly in MRI and CT modalities, is still at a nascent stage, with just a handful of works tackling a multiregion scenario. Furthermore, most existing approaches systematically follow prior literature in other clinical problems, without casting a doubt on the validity of these methods on bladder segmentation, which may present different challenges. Inspired by this, we provide an in-depth look at bladder cancer segmentation using deep learning models. The critical determinants for accurate differentiation of muscle invasive disease, current status of deep learning based bladder segmentation, lessons and limitations of prior work are highlighted.

Diffusion Weighted Imaging in Unilateral Adrenal Infarction: A Case of Colicky Right Upper Quadrant Pain in a Pregnant Female

Diffusion weighted imaging (DWI) is a magnetic resonance imaging (MRI) non-contrast sequence that can indicate tissue ischemia or infarction. Adrenal infarct may present similarly to biliary or gallbladder pathologies, and the differential diagnosis during emergency work-up can be narrowed utilizing DWI sequences. In this paper, we describe the usefulness of DWI for urgent diagnosis in a case of non-hemorrhagic adrenal infarct of a pregnant female presenting with right upper quadrant pain. Although uncommon, adrenal infarct may occur in patients with hypercoagulability and localizing pain that is unexplained by other imaging modalities. We outline the imaging features of DWI in evaluating adrenal infarct as a safe and time effective application for patients with contraindications to imaging with ionizing radiation.

Spectrum of CT Findings Related to Bowel Adhesions Without Bowel Obstruction: A Comprehensive Imaging Review

Post-operative adhesions can occur following abdominal or pelvic surgery and are a significant cause of morbidity and mortality. Adhesions are an important cause of abdominal complaints, especially chronic abdominal pain, infertility, and bowel obstruction; responsible for an estimated $2.3 billion annual burden in the United States alone. There is a paucity of literature describing CT findings indicative of the presence of adhesions, however, findings suggestive of this entity may be discovered by a discerning eye. Early recognition and diagnosis may be beneficial for reducing consumption of health-care resources related to abdominal complaints. In addition, these findings may impact surgical planning and facilitate recognition of adhesion-related complications, said to be responsible for a significant number of malpractice claims. The following review discusses various CT findings which may indicate the presence of adhesions. These findings may initially be overlooked, but remain valuable as the clinical presentation evolves to become consistent with adhesive disease. Detection of bowel and peritoneal adhesions can be recognized on imaging modalities based on distortion of bowel loops. This pictorial review illustrates the spectrum of findings related to bowel adhesions encountered on computed tomography imaging.

Role of MRI in the Diagnosis of Large Right Adrenal Abscess

Adrenal abscesses are extremely rare occurrences with only scattered case reports reported in the literature. Owing to their rarity, they are not usually considered within the typical differential for cystic adrenal masses discovered on computed tomography (CT) or magnetic resonance imaging (MRI). Accurate and timely diagnosis of these lesions is critical to exclude malignancy and ensure appropriate management. In this case report, we describe a post-traumatic case of adrenal abscess associated with Staphylococcus aureus bacteremia and its differentiation from cystic adrenal masses. Specific emphasis is placed on the imaging features seen on CT and MRI and how these features can be utilized to differentiate it from other adrenal pathologies such as adrenal pseudocyst or cystic adrenocortical neoplasm.

"Renal emergencies: a comprehensive pictorial review with MR imaging"

Superior soft-tissue contrast and high sensitivity of magnetic resonance imaging (MRI) for detecting and characterizing disease may provide an expanded role in acute abdominal and pelvic imaging. Although MRI has traditionally not been exploited in acute care settings, commonly used in biliary obstruction and during pregnancy, there are several conditions in which MRI can go above and beyond other modalities in diagnosis, characterization, and providing functional and prognostic information. In this manuscript, we highlight how MRI can help in further assessment and characterization of acute renal emergencies. Currently, renal emergencies are predominantly evaluated with ultrasound (US) or computed tomography (CT) scanning. US may be limited by various patient factors and technologist experience while CT imaging with intravenous contrast administration can further compromise renal function. With the advent of rapid, robust non-contrast MRI, and magnetic resonance angiography (MRA) imaging studies with short scan times, free-breathing techniques, and lack of ionization radiation, the utility of MRI for renal evaluation might be superior to CT not only in diagnosing an emergent renal process but also by providing functional and prognostic information. This review outlines the clinical manifestations and the key imaging findings for acute renal processes including acute renal infarction, hemorrhage, and renal obstruction, among other entities, to highlight the added value of MRI in evaluating the finer nuances in acute renal emergencies.

Role of precision imaging in esophageal cancer

Esophageal cancer is a major cause of morbidity and mortality worldwide. Recent advancements in the management of esophageal cancer have allowed for earlier detection, improved ability to monitor progression, and superior treatment options. These innovations allow treatment teams to formulate more customized management plans and have led to an increase in patient survival rates. For example, in order for the most effective management plan to be constructed, accurate staging must be performed to determine tumor resectability. This article reviews the multimodality imaging approach involved in making a diagnosis, staging, evaluating treatment response and detecting recurrence in esophageal cancer.

Impact of surgically maximized versus native membranous urethral length on 30-day and long-term pad-free continence after robot-assisted radical prostatectomy

BACKGROUND

Pelvic multiparametric magnetic resonance imaging (mpMRI)-determined membranous urethral length (MUL) and its surgical maximization have been reported to impact early- and long-term pad-free urinary continence after robot-assisted radical prostatectomy (RARP).

OBJECTIVE

The objective of this study was to present evidence (data and video) of important effects on post-RARP continence recovery from both innate mpMRI-assessed and surgical preservation of MUL.

DESIGN SETTING AND PARTICIPANTS

Of 605 men undergoing RARP, 580 with complete follow-up were included: Group 1, prior (N = 355), and Group 2, subsequent (N = 225) to technique change of MUL maximization. Effect of innate, mpMRI-assessed MUL on postoperative continence was assessed.

SURGICAL PROCEDURE

Before technique change, the dorsal venous complex was stapled before transection of the membranous urethra. After the change, the final step of extirpation was transection of the dorsal venous complex and periurethral attachments, thus facilitating surgical maximization of MUL.

MEASUREMENTS

Primary and secondary outcomes for technique change and mpMRI-assessed MUL were both patient-reported 30-day and 1-year pad-free continence after RARP, respectively.

RESULTS

Preoperative prostate-specific antigen, age, and disease aggressiveness were significantly higher in Group 2. After technique change and surgical maximization of MUL, 30-day and 1-year pad-free continence were both significantly improved (p < 0.05). In multivariate analysis, maximization of MUL significantly increased the likelihood of both early- and long-term continence recovery. For men undergoing MUL preservation, mpMRI-assessed MUL>1.4 cm also independently predicted higher 30-day (odds ratio: 4.85, 95% confidence interval: 1.24-18.9) and 1-year continence recovery (odds ratio: 11.26, 95% confidence interval: 1.07-118).

CONCLUSIONS

Prostatic rotation and circumferential release of apical attachments and maximization of MUL improves continence after RARP. Separately, innate MUL>1.4 cm independently increased 30-day and 1-year continence recovery.

PATIENT SUMMARY

Surgeon efforts to maximize MUL during radical prostatectomy are highly encouraged, as maximally preserved MUL likely improves post-RARP continence recovery. In addition, individual patients' mpMRI-assessed MUL (approximately >1.4 cm) independently limits continence recovery.

Angiogenesis in Hepatocellular Carcinoma; Pathophysiology, Targeted Therapy, and Role of Imaging

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide, usually occurring on a background of liver cirrhosis. HCC is a highly vascular tumor in which angiogenesis plays a major role in tumor growth and spread. Tumor-induced angiogenesis is usually related to a complex interplay between multiple factors and pathways, with vascular endothelial growth factor being a major player in angiogenesis. In the past decade, understanding of tumor-induced angiogenesis has led to the emergence of novel anti-angiogenic therapies, which act by reducing neo-angiogenesis, and improving patient survival. Currently, Sorafenib and Lenvatinib are being used as the first-line treatment for advanced unresectable HCC. However, a disadvantage of these agents is the presence of numerous side effects. A major challenge in the management of HCC patients being treated with anti-angiogenic therapy is effective monitoring of treatment response, which decides whether to continue treatment or to seek second-line treatment. Several criteria can be used to assess response to treatment, such as quantitative perfusion on cross-sectional imaging and novel/emerging MRI techniques, including a host of known and emerging biomarkers and radiogenomics. This review addresses the pathophysiology of angiogenesis in HCC, accurate imaging assessment of angiogenesis, monitoring effects of anti-angiogenic therapy to guide future treatment and assessing prognosis.

Variability of the Positive Predictive Value of PI-RADS for Prostate MRI across 26 Centers: Experience of the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel

Background Prostate MRI is used widely in clinical care for guiding tissue sampling, active surveillance, and staging. The Prostate Imaging Reporting and Data System (PI-RADS) helps provide a standardized probabilistic approach for identifying clinically significant prostate cancer. Despite widespread use, the variability in performance of prostate MRI across practices remains unknown. Purpose To estimate the positive predictive value (PPV) of PI-RADS for the detection of high-grade prostate cancer across imaging centers. Materials and Methods This retrospective cross-sectional study was compliant with the HIPAA. Twenty-six centers with members in the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel submitted data from men with suspected or biopsy-proven untreated prostate cancer. MRI scans were obtained between January 2015 and April 2018. This was followed with targeted biopsy. Only men with at least one MRI lesion assigned a PI-RADS score of 2-5 were included. Outcome was prostate cancer with Gleason score (GS) greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2). A mixed-model logistic regression with institution and individuals as random effects was used to estimate overall PPVs. The variability of observed PPV of PI-RADS across imaging centers was described by using the median and interquartile range. Results The authors evaluated 3449 men (mean age, 65 years ± 8 [standard deviation]) with 5082 lesions. Biopsy results showed 1698 cancers with GS greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2) in 2082 men. Across all centers, the estimated PPV was 35% (95% confidence interval [CI]: 27%, 43%) for a PI-RADS score greater than or equal to 3 and 49% (95% CI: 40%, 58%) for a PI-RADS score greater than or equal to 4. The interquartile ranges of PPV at these same PI-RADS score thresholds were 27%-44% and 27%-48%, respectively. Conclusion The positive predictive value of the Prostate Imaging and Reporting Data System was low and varied widely across centers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Milot in this issue.

Adrenal cortical carcinoma: pathology, genomics, prognosis, imaging features, and mimics with impact on management

Adrenocortical carcinoma (ACC) is a rare tumor with a poor prognosis. Most tumors are either metastatic or locally invasive at the time of diagnosis. Differentiation between ACC and other adrenal masses depends on clinical, biochemical, and imaging factors. This review will discuss the genetics, pathological, and imaging feature of ACC.

Evaluation of a Diuresis Enhanced Non-Contrast Computed Tomography for Kidney Stones Protocol to Maximize Collecting System Distention

Purpose: In urolithiasis patients, preoperative non-contrast computed tomography (NCCT) commonly fails to provide sufficient distention of the renal collecting system to allow reliable preoperative planning for how best to approach a stone. Our objective was to evaluate the effect of a novel protocol, including oral hydration and an oral diuretic, on the distention of the renal collecting system. Patients and Methods: Twenty patients with a prior NCCT, who were scheduled to undergo a subsequent NCCT for urolithiasis assessment, were enrolled. Each patient was instructed to ingest 1 L of water and 20 mg of oral furosemide 30 to 60 minutes before their scan (DRINK [DiuResIs Enhanced Non-contrast Computed Tomography for Kidney Stones] protocol). Patients' prior NCCT scan (non-DRINK) was used for comparison. Three-dimensional (3D) reconstruction of DRINK and non-DRINK NCCT studies was performed to determine the volume and surface area of the collecting system. In addition, three faculty endourologists measured the width of the upper and lower pole infundibula and renal pelvis in the axial, coronal, and sagittal views. Results: Among the 20 patients, 13 completed the DRINK protocol as specified. For these 13 patients, 3D reconstruction of the DRINK study collecting systems showed a 63% and a 36% increase in collecting system volume and surface area, respectively (p = 0.02 and p < 0.01, respectively). Also, measurements of the CT images demonstrated a significant (p < 0.05) increase in the collecting system widths in 67% of measurements. Conclusion: The DRINK protocol significantly increased the visible collecting system volume and surface area; in the majority of cases, the upper and lower pole infundibular widths and the width of the renal pelvis were also expanded.

Rare Treatment for a Rare Tumor: Cryoablation of a Granular Cell Tumor

Background

Granular cell tumors (GCTs) or Abrikossoff's tumors are rare neoplasms known to originate from Schwann cells in the peripheral nervous system. These lesions are usually benign; malignancy only occurs in 1-2% of cases. Surgical resection is the traditional treatment method for GCTs, but it poses several risks and disadvantages related to the surgical incompatibility of the patient, the extended recovery time, and the chance of relapse. Cryoablation is becoming an increasingly favored method of treatment for tumors, both benign and malignant, due to its minimal invasiveness, natural analgesic properties, and ability to stimulate antitumor immunity. Cryoablation may contribute to the prevention of secondary and metastatic tumor growth in cases of malignancy by preserving tumor-associated antigen molecules for recognition by cell-mediated immunity.

Methods

This article describes a novel method for GCT treatment using cryoablation. This technique exposes tumor tissue to extreme cold temperatures, effectively destroying tumor cells by irreversibly compromising their plasma membranes. To our knowledge, this is the first report in the literature of cryoablative techniques being used for GCT.

Results

Cryoablation of this mass was successful with no complications. CT images during the procedure demonstrated circumferential coverage of the entire lesion with no injury to the surrounding tissues.

Conclusion

Cryoablation can be used as an alternative to surgical intervention to treat malignant GCTs. This procedure is minimally invasive, less painful, and potentially effective in promoting antitumor immunity.

Beyond adenocarcinoma: MRI of uncommon rectal neoplasms and mimickers

OBJECTIVE

To provide a review of rare rectal tumors beyond adenocarcinoma.

RESULTS

Rectal cancer is a common malignancy, both in the United States and abroad. In addition to adenocarcinoma, abdominal radiologists will encounter a variety of other less common rectal masses, both benign and malignant neoplasms as well as non-neoplastic mimickers. Familiarity with these conditions and their characteristic features on MRI is useful in clinical practice. In this article, a number of such conditions are discussed, with an emphasis on distinguishing features on MRI of the rectum.

CONCLUSION

Familiarity with the MRI features of rare rectal tumors beyond adenocarcinoma, as well as a small number of non-neoplastic mimics, is important for abdominal imagers to make diagnostic differentials and to assist in treatment planning.

Current controversy, confusion, and imprecision in the use and interpretation of rectal MRI

There has been a rapid increase in the utilization of MRI in rectal cancer staging in the USA essentially replacing endorectal ultrasound and mimicking the trend in Europe seen in the 1990s and 2000s. Accompanying this trend, there is a demand, and recognized need, for greater precision and clarification of confusing, misunderstood and poorly understood concepts, facts, statements and nomenclature regarding rectal cancer and the use of pelvic MRI for diagnosis. As such, this Review, part evidence-based and part expert opinion, will attempt to elucidate and clarify several concepts the authors have encountered in 25 years of imaging rectal cancer, focusing on MRI.

Current controversy, confusion, and imprecision in the use and interpretation of rectal MRI

There has been a rapid increase in the utilization of MRI in rectal cancer staging in the USA essentially replacing endorectal ultrasound and mimicking the trend in Europe seen in the 1990s and 2000s. Accompanying this trend, there is a demand, and recognized need, for greater precision and clarification of confusing, misunderstood and poorly understood concepts, facts, statements and nomenclature regarding rectal cancer and the use of pelvic MRI for diagnosis. As such, this Review, part evidence-based and part expert opinion, will attempt to elucidate and clarify several concepts the authors have encountered in 25 years of imaging rectal cancer, focusing on MRI.

Usefulness of CT texture analysis in differentiating benign and malignant renal tumours

AIM

To elucidate visually imperceptible differences between benign and malignant renal tumours using computed tomography texture analysis (CTTA) using filtration histogram based parameters.

MATERIALS AND METHODS

A retrospective study was performed by texture analysis of pretreatment contrast-enhanced CT examinations in 354 histopathologically confirmed renal cell carcinomas (RCCs) and 147 benign renal tumours. A region-of-interest was drawn encompassing the largest cross-section of the tumour on venous phase axial CT. CTTA features of entropy, kurtosis, mean positive pixel density, and skewness at different spatial filters were calculated and compared in an attempt to differentiate benign lesions from malignancy.

RESULTS

Entropy with fine spatial filter was significantly higher in RCC than benign renal tumours (p=0.022). Entropy with fine and medium filters was higher in RCC than lipid-poor angiomyolipoma (p=0.050 and 0.052, respectively). Entropy >5.62 had high specificity of 85.7%, but low sensitivity of 31.3%, respectively, for predicting RCC.

CONCLUSIONS

Differences in entropy were helpful in differentiating RCC from lipid-poor angiomyolipoma, and chromophobe RCC from oncocytoma. This technique may be useful to differentiate lesions that appear equivocal on visual assessment or alter management in poor surgical candidates.

PI-RADS Version 2 Is an Excellent Screening Tool for Clinically Significant Prostate Cancer as Designated by the Validated International Society of Urological Pathology Criteria: A Retrospective Analysis

OBJECTIVES

To assess the utility of multiparametric MRI in detecting clinically significant prostate cancer (csPCa) by comparing PI-RADSv2 scores with International Society of Urological Pathology (ISUP) pathologic grading criteria.

METHODS

Data from 137 patients were retrospectively analyzed. PI-RADSv2 scores were compared with pathologic grade using ISUP criteria. Pathologic grades were divided into clinically significant (groups 3-5) and clinically insignificant lesions (groups 1-2). Chi-squared analysis was performed for to assess correlation.

RESULTS

Sensitivity and specificity of PI-RADSv2 score 3-5 lesions for detecting csPCa was 100% and 18.5%, respectively. Negative predictive value (NPV) is 100% for these lesions. When considering only PI-RADSv2 score 4-5 lesions, sensitivity decreases to 90% and specificity increases to 67.5%, with a NPV of 98.5%. When only PI-RADSv2 score 5 lesions are considered, sensitivity decreases to 50% and specificity increases to 90%, with a NPV of 95%.

CONCLUSIONS

Multiparametric MRI has excellent sensitivity for detecting csPCa. Specificity is poor for PI-RADSv2 score 3 lesions but improves significantly for PI-RADSv2 score 4 and 5 lesions. Overall, mpMRI is an excellent screening tool for csPCa, as designated by the recently validated ISUP criteria.

ADVANCES IN KNOWLEDGE

Multiple limitations of the longstanding Gleason pathologic scoring system have led to the development of new ISUP pathologic criteria, which is more focused on the clinical significance of lesions. There are currently insufficient studies evaluating and validating the ISUP criteria with PIRADS v2 evaluation of the prostate.

CT texture analysis in the differentiation of major renal cell carcinoma subtypes and correlation with Fuhrman grade

OBJECTIVE

CT texture analysis (CTTA) using filtration-histogram-based parameters has been associated with tumor biologic correlates such as glucose metabolism, hypoxia, and tumor angiogenesis. We investigated the utility of these parameters for differentiation of clear cell from papillary renal cancers and prediction of Fuhrman grade.

METHODS

A retrospective study was performed by applying CTTA to pretreatment contrast-enhanced CT scans in 290 patients with 298 histopathologically confirmed renal cell cancers of clear cell and papillary types. The largest cross section of the tumor on portal venous phase axial CT was chosen to draw a region of interest. CTTA comprised of an initial filtration step to extract features of different sizes (fine, medium, coarse spatial scales) followed by texture quantification using histogram analysis.

RESULTS

A significant increase in entropy with fine and medium spatial filters was demonstrated in clear cell RCC (p = 0.047 and 0.033, respectively). Area under the ROC curve of entropy at fine and medium spatial filters was 0.804 and 0.841, respectively. An increased entropy value at coarse filter correlated with high Fuhrman grade tumors (p = 0.01). The other texture parameters were not found to be useful.

CONCLUSION

Entropy, which is a quantitative measure of heterogeneity, is increased in clear cell renal cancers. High entropy is also associated with high-grade renal cancers. This parameter may be considered as a supplementary marker when determining aggressiveness of therapy.

KEY POINTS

• CT texture analysis is easy to perform on contrast-enhanced CT. • CT texture analysis may help to separate different types of renal cancers. • CT texture analysis may enhance individualized treatment of renal cancers.