An Illustrated Review of the Recent 2019 World Health Organization Classification of Neuroendocrine Neoplasms: A Radiologic and Pathologic Correlation.

ABSTRACT: Recent advances in molecular pathology and an improved understanding of the etiology of neuroendocrine neoplasms (NENs) have given rise to an updated World Health Organization classification. Since gastroenteropancreatic NENs (GEP-NENs) are the most common forms of NENs and their incidence has been increasing constantly, they will be the focus of our attention. Here, we review the findings at the foundation of the new classification system, discuss how it impacts imaging research and radiological practice, and illustrate typical and atypical imaging and pathological findings. Gastroenteropancreatic NENs have a highly variable clinical course, which existing classification schemes based on proliferation rate were unable to fully capture. While well- and poorly differentiated NENs both express neuroendocrine markers, they are fundamentally different diseases, which may show similar proliferation rates. Genetic alterations specific to well-differentiated neuroendocrine tumors graded 1 to 3 and poorly differentiated neuroendocrine cancers of small cell and large-cell subtype have been identified. The new tumor classification places new demands and creates opportunities for radiologists to continue providing the clinically most relevant report and on researchers to design projects, which continue to be clinically applicable.

Estimated Prostate Volume by Semiautomatic Segmentation of MRI Is More Accurately Correlated with Radical Prostatectomy Specimen Weight than the Volume Calculated by Ellipsoid Formula.

INTRODUCTION: Accurate in vivo prostate volume (PV) estimation is important for obtaining prostate-specific antigen density (PSAD) and further predicting clinically significant prostate cancer (csPCa). We aimed to evaluate the accuracy of multiparametric magnetic resonance imaging (mpMRI)-estimated PV compared to both volume and weight of radical prostatectomy (RP). METHODS: We identified 310 PCa patients who underwent RP following combined targeted and systematic biopsy in our institution from September 2019 to February 2021. The MRI PV was determined using a semiautomated segmentation algorithm. RP PV was calculated using the prolate ellipsoid formula (length × width × height × π/6). Formula (prostate weight = [actual weight-3.8 g]/1.05 g/mL) was applied, and the resulting volume was used in further analysis. RESULTS: The median PV from MRI, RP, and RP weight were 39 mL, 38 mL, and 44 mL, respectively. Spearman's rank correlation coefficients (ρ) were 0.841 (MRI PV vs. RP weight), 0.758 (RP PV vs. RP weight), and 0.707 (MRI PV vs. RP PV) (all p < 0.001). Decreased correlation between the MRI PV and RP PV was observed in the larger (more than 55 mL) prostate. The PSAD derived from MRI PV showed most efficient to detect csPCa in RP specimen (57.9% vs. 57.6% vs. 45.4%). CONCLUSION: MRI PV is correlated better with RP weight than calculated RP PV, especially in larger prostate. The high csPCa detection rate in final pathology suggested that PSAD derived from MRI PV can be confidently used in clinical practice.

Harnessing imaging tools to guide immunotherapy trials: summary from the National Cancer Institute Cancer Imaging Steering Committee workshop.

As the immuno-oncology field continues the rapid growth witnessed over the past decade, optimising patient outcomes requires an evolution in the current response-assessment guidelines for phase 2 and 3 immunotherapy clinical trials and clinical care. Additionally, investigational tools-including image analysis of standard-of-care scans (such as CT, magnetic resonance, and PET) with analytics, such as radiomics, functional magnetic resonance agents, and novel molecular-imaging PET agents-offer promising advancements for assessment of immunotherapy. To document current challenges and opportunities and identify next steps in immunotherapy diagnostic imaging, the National Cancer Institute Clinical Imaging Steering Committee convened a meeting with diverse representation among imaging experts and oncologists to generate a comprehensive review of the state of the field.

Simultaneous multislice diffusion-weighted imaging versus standard diffusion-weighted imaging in whole-body PET/MRI.

OBJECTIVE: To compare standard (STD-DWI) single-shot echo-planar imaging DWI and simultaneous multislice (SMS) DWI during whole-body positron emission tomography (PET)/MRI regarding acquisition time, image quality, and lesion detection. METHODS: Eighty-three adults (47 females, 57%), median age of 64 years (IQR 52-71), were prospectively enrolled from August 2018 to March 2020. Inclusion criteria were (a) abdominal or pelvic tumors and (b) PET/MRI referral from a clinician. Patients were excluded if whole-body acquisition of STD-DWI and SMS-DWI sequences was not completed. The evaluated sequences were axial STD-DWI at b-values 50-400-800 s/mm2 and the apparent diffusion coefficient (ADC), and axial SMS-DWI at b-values 50-300-800 s/mm2 and ADC, acquired with a 3-T PET/MRI scanner. Three radiologists rated each sequence's quality on a five-point scale. Lesion detection was quantified using the anatomic MRI sequences and PET as the reference standard. Regression models were constructed to quantify the association between all imaging outcomes/scores and sequence type. RESULTS: The median whole-body STD-DWI acquisition time was 14.8 min (IQR 14.1-16.0) versus 7.0 min (IQR 6.7-7.2) for whole-body SMS-DWI, p < 0.001. SMS-DWI image quality scores were higher than STD-DWI in the abdomen (OR 5.31, 95% CI 2.76-10.22, p < 0.001), but lower in the cervicothoracic junction (OR 0.21, 95% CI 0.10-0.43, p < 0.001). There was no significant difference in the chest, mediastinum, pelvis, and rectum. STD-DWI detected 276/352 (78%) lesions while SMS-DWI located 296/352 (84%, OR 1.46, 95% CI 1.02-2.07, p = 0.038). CONCLUSIONS: In cancer staging and restaging, SMS-DWI abbreviates acquisition while maintaining or improving the diagnostic yield in most anatomic regions. KEY POINTS: • Simultaneous multislice diffusion-weighted imaging enables faster whole-body image acquisition. • Simultaneous multislice diffusion-weighted imaging maintains or improves image quality when compared to single-shot echo-planar diffusion-weighted imaging in most anatomical regions. • Simultaneous multislice diffusion-weighted imaging leads to superior lesion detection.

Transperineal Multiparametric Magnetic Resonance Imaging-Ultrasound Fusion Targeted Prostate Biopsy Combined with Standard Template Improves Prostate Cancer Detection.

PURPOSE: Transperineal (TP) prostate biopsy provides an effective approach to prostate cancer (PCa) detection. Although transrectal targeted biopsy has been well described, the specific advantage of the standard TP template or TP targeted biopsy using multiparametric (mp) magnetic resonance imaging (MRI)-ultrasound (US) fusion remains less understood and without consensus. MATERIALS AND METHODS: We identified all men who underwent a transperineal standard 20-core template in addition to a targeted biopsy with mpMRI-US fusion-guided software from September 2019 to February 2021. We assessed and compared clinical, MRI and biopsy characteristics between standard TP template and fusion targeted biopsies. RESULTS: A total of 301 men underwent TP fusion biopsy during the study period. Target lesions on MRI were sampled with 3 targeted cores per patient (IQR 3-4). The overall cancer detection rate was 74.1% and 63.5% by standard template and targeted biopsy, respectively, of which 52.5% and 59.7% were clinically significant (cs) PCa. Combined csPCa detection rate was 62.2%. Of 176 cases with a cancer diagnosis by both biopsy methods, 18.8% were upgraded with targeted biopsies while 18.2% were upgraded with template biopsies. CONCLUSIONS: In men with suspicious lesions on mpMRI, TP MRI fusion-guided biopsies combined with standard template provide a higher overall cancer detection rate and higher detection rate of csPCa than the standard template or targeted biopsy alone. In the setting of a suspicious mpMRI prostate lesion, targeted plus standard template should be included as part of the TP biopsy procedure.

Incidence of Complications from Percutaneous Biopsy in Chronic Liver Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Approaches to liver biopsy have changed over the past decade in patients with chronic liver disease. AIMS: We conducted a systematic review and meta-analysis on the incidence of all complications and technical failure associated with percutaneous liver biopsy. METHODS: We systematically searched PubMed and the Cochrane Library for cohort studies reporting on complications resulting from liver biopsy published between 2010 and 2020. Studies on participants of any age and sex, who underwent any percutaneous biopsy for non-focal liver disease, were selected. All events except mild pain, minor hematoma, vasovagal episodes, fever and fistula were defined as major complications. Random-effect model meta-analyses with and without covariates were performed, to examine the effect of publication year, patient characteristics, outcome collection, and biopsy type on incidences. RESULTS: We identified 30 studies reporting on complications resulting from percutaneous liver biopsy procedures (n = 64,356). Incidence of major complications was 2.44% (95% CI 0.85, 6.75), with mortality at 0.01% (95% CI 0.00, 0.11), hospitalization at 0.65% (95% CI 0.38, 1.11), major bleeding at 0.48% (95% CI 0.22, 1.06), and moderate/severe pain at 0.34% (95% CI 0.08, 1.37). Minor complications at 9.53% (95% CI 3.68, 22.5) were mainly pain at 12.9% (95% CI 5.34, 27.9). Technical failure was high at 0.91% (95% CI 0.27, 3.00). Decreasing patient age significantly increased incidence of hospitalization and major bleeding (P < 0.0001). Hospitalization incidence also significantly increased with disease severity. CONCLUSIONS: Incidence of major (2.4%) and minor (9.5%) complications, and technical failure (0.91%) in percutaneous liver biopsies continues.

PI-RADS: multiparametric MRI in prostate cancer.

Multiparametric MRI of the prostate gland has become the initial evaluation of biopsy naïve men with a clinical suspicion for prostate cancer. PI-RADS 2.1 is a joint initiative and framework for prostate MRI acquisition and reporting, which aims to standardize technique and interpretation across centers. Building upon experience accrued following the introduction of PI-RADS 2.0, version 2.1 provides key updates and important clarifications, although it is intended to be an active document, which continues to be updated. Continued advances in our understanding of prostate cancer and progress in imaging technology will undoubtedly shape future iterations of the reporting system.

PI-RADS Versions 2 and 2.1: Interobserver Agreement and Diagnostic Performance in Peripheral and Transition Zone Lesions Among Six Radiologists.

BACKGROUND. PI-RADS version 2.1 (v2.1) modifications primarily address transition zone (TZ) interpretation. The revisions also impact peripheral zone (PZ) interpretation, which has received less attention. OBJECTIVE. The purpose of this study was to compare interobserver agreement of PI-RADS version 2 (v2) and v2.1 in the prostate PZ and TZ and perform a pilot comparison of their diagnostic performance in the two zones. METHODS. Six radiologists with varying experience retrospectively assessed 80 prostate lesions (40 PZ, 40 TZ) on MRI in separate sessions for PI-RADS v2 and v2.1. Interobserver agreement was assessed using Conger kappa (κ). For 50 lesions with pathology data, average AUC for detecting clinically significant cancer was compared between versions using multireader multicase statistical methods. Error variance and covariance results informed post hoc power analysis. RESULTS. Interobserver agreement for PI-RADS category 4 or greater was higher for version 2.1 (κ = 0.64) than version 2 (κ = 0.51) in the PZ, but similar for version 2 (κ = 0.64) and version 2.1 (κ = 0.60) in the TZ. The PI-RADS v2.1 DWI descriptor "linear/wedge-shaped" had higher agreement than its predecessor version 2 descriptor "indistinct hypointense" (κ = 0.52 vs κ = 0.18) and yielded 14 more true-negative versus five more false-negative interpretations. The ADC signal descriptor "markedly hypointense," for which only version 2.1 provides a specific definition, had lower agreement in version 2.1 (κ = 0.26) than version 2 (κ = 0.52). Modified TZ T2-weighted category 2 descriptors in version 2.1 had fair agreement (κ = 0.21), and agreement for PI-RADS category 2 in the TZ was lower in version 2.1 (κ = 0.31) than version 2 (κ = 0.57). DWI upgraded a TZ lesion category from 2 to 3 in four patients, detecting two additional cancers. Average AUC was not different between versions 2 and 2.1 for the PZ (AUC, 0.81 vs 0.85; p = .24) or the TZ (AUC, 0.69 vs 0.69; p = .94), though among experienced readers AUC was higher for version 2.1 than version 2 for the PZ (0.91 vs 0.82; p = .001). Overall performance comparison had sufficient power (0.8) to detect a 0.085 difference in AUC. CONCLUSION. Interobserver agreement improved using PI-RADS v2.1 in the PZ but not the TZ. Diagnostic performance improved using version 2.1 only in the PZ for experienced readers. Specific version 2.1 modifications yielded mixed results. CLINICAL IMPACT. The impact of PI-RADS v2.1 in the PZ is notable given the emphasis on version 2.1 TZ modifications. The findings suggest areas in which additional modification could further improve interobserver agreement and performance.

Proton vs. photon radiotherapy for MR-guided dose escalation of intraprostatic lesions.

BACKGROUND: Dose escalation has been associated with improved biochemical control for prostate cancer. Focusing the high dose on the MRI-defined intraprostatic lesions (IL) could spare the surrounding organs at risk and hence allow further escalation. We compare treatment efficacy between state-of-the-art focally-boosted proton and photon-based radiotherapy, and investigate possible predictive guidelines regarding individualized treatment prescriptions. MATERIAL AND METHODS: Ten prostate cancer patients with well-defined ILs were selected. Multiparametric MRI was used to delineate ILs, which were transferred to the planning CT via image registration. Pencil beam scanning proton therapy and volumetric modulated arc therapy treatment plans, were created for each patient. Each modality featured 6 plans: (1) moderately hypofractionated dose: 70 Gy to the prostate in 28 fractions, (2)-(6) plan 1 plus additional simultaneous-integrated-boost to ILs to 75.6, 81.2, 86.6, 98 and 112 Gy in 28 fractions. Equivalent dose to 2 Gy-per-fraction (EqD2) was used to calculate tumor control (TCP) and normal tissue complication probabilities (NTCP) for ILs and organs-at-risk. RESULTS: For both modalities, the maximum necessary dose to achieve TCP > 99% was 98 Gy for very high-risk ILs. For lower risk ILs lower doses were sufficient. NTCP was <25% and 35% for protons and photons at the maximum dose escalation, respectively. For the cases and beam characteristics considered, proton therapy was dosimetrically superior when IL was >4 cc or located <2.5 mm from the rectum. CONCLUSION: This work demonstrated the potential role for proton therapy in the setting of prostate focal dose escalation. We propose that anatomical characteristic could be used as criteria to identify patients who would benefit from proton treatment.

Abdominal Imaging Findings in COVID-19: Preliminary Observations.

Background Angiotensin-converting enzyme 2, a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demonstrates its highest surface expression in the lung, small bowel, and vasculature, suggesting abdominal viscera may be susceptible to injury. Purpose To report abdominal imaging findings in patients with coronavirus disease 2019. Materials and Methods In this retrospective cross-sectional study, patients consecutively admitted to a single quaternary care center from March 27 to April 10, 2020, who tested positive for SARS-CoV-2 were included. Abdominal imaging studies performed in these patients were reviewed, and salient findings were recorded. Medical records were reviewed for clinical data. Univariable analysis and logistic regression were performed. Results A total of 412 patients (average age, 57 years; range, 18 to >90 years; 241 men, 171 women) were evaluated. A total of 224 abdominal imaging studies were performed (radiography, n = 137; US, n = 44; CT, n = 42; MRI, n = 1) in 134 patients (33%). Abdominal imaging was associated with age (odds ratio [OR], 1.03 per year of increase; P = .001) and intensive care unit (ICU) admission (OR, 17.3; P < .001). Bowel-wall abnormalities were seen on 31% of CT images (13 of 42) and were associated with ICU admission (OR, 15.5; P = .01). Bowel findings included pneumatosis or portal venous gas, seen on 20% of CT images obtained in patients in the ICU (four of 20). Surgical correlation (n = 4) revealed unusual yellow discoloration of the bowel (n = 3) and bowel infarction (n = 2). Pathologic findings revealed ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Right upper quadrant US examinations were mostly performed because of liver laboratory findings (87%, 32 of 37), and 54% (20 of 37) revealed a dilated sludge-filled gallbladder, suggestive of bile stasis. Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures. Conclusion Bowel abnormalities and gallbladder bile stasis were common findings on abdominal images of patients with coronavirus disease 2019. Patients who underwent laparotomy often had ischemia, possibly due to small-vessel thrombosis. © RSNA, 2020.

Ferumoxytol-Enhanced MR Lymphography for Detection of Metastatic Lymph Nodes in Genitourinary Malignancies: A Prospective Study.

OBJECTIVE. The objective of our study was to evaluate the utility of ferumoxytol-enhanced MR lymphography (MRL) in detection of metastatic lymph nodes (LNs) in patients with prostate, bladder, and kidney cancer. SUBJECTS AND METHODS. This phase 2 single-institution study enrolled patients with confirmed prostate (arm 1), bladder (arm 2), and kidney (arm 3) cancer and evidence of suspected LN involvement. Participants underwent ferumoxytol-enhanced MRL 24 and 48 hours after IV injection of 7.5 mg Fe/kg of ferumoxytol. A retrospective quantitative analysis was performed to determine the optimal timing for ferumoxytol-enhanced MRL using percentage change in normalized signal intensity (SI) from baseline to 24 and 48 hours after injection, which were estimated using the linear mixed-effects model in which time (24 vs 48 hours), diseases status, and time and disease status interaction were the fixed-effects independent variables. Differences in normalized SI values between subgroups of lesions were estimated by forming fixed-effects contrasts and tested by the Wald test. RESULTS. Thirty-nine patients (n = 30, arm 1; n = 6, arm 2; n = 3, arm 3) (median age, 65 years) with 145 LNs (metastatic, n = 100; benign, n = 45) were included. LN-based sensitivity, specificity, positive predictive value, and negative predictive value of ferumoxytol-enhanced MRL was 98.0%, 64.4%, 86.0%, and 93.5%, respectively. Sensitivity and specificity of ferumoxytol-enhanced MRL did not vary by LN size. Metastatic LNs showed a significantly higher percentage decrease of normalized SI on MRL at 24 hours after ferumoxytol injection than at 48 hours after ferumoxytol injection (p = 0.023), whereas the normalized SI values for nonmetastatic LNs were similar at both imaging time points (p = 0.260). CONCLUSION. Ferumoxytol-enhanced MRL shows high sensitivity in the detection of metastatic LNs in genitourinary cancers independent of LN size. The SI difference between benign and malignant LNs on ferumoxytol-enhanced MRL appears similar 24 and 48 hours after ferumoxytol injection, suggesting that imaging can be performed safely within 1 or 2 days of injection. Although ferumoxytol-enhanced MRL can be useful in settings without an available targeted PET agent, issues of iron overload and repeatability of ferumoxytol-enhanced MRL remain concerns for this method.

Multiparametric Magnetic Resonance Imaging-Ultrasound Fusion Biopsy Improves but Does Not Replace Standard Template Biopsy for the Detection of Prostate Cancer.

PURPOSE: There exists a growing debate as to whether multiparametric magnetic resonance imaging with fusion transrectal ultrasound guided prostate biopsy alone without a standard template biopsy is sufficient to evaluate patients with suspected prostate cancer. Our objective was to describe our experience with fusion targeted prostate biopsy and assess whether it could obviate the need for concomitant standard 12-core template prostate biopsy. MATERIALS AND METHODS: We retrospectively reviewed our prospectively collected database of patients who underwent fusion transrectal ultrasound guided prostate biopsy. All images and lesions were graded according to the Prostate Imaging Reporting and Data System, version 2. All patients underwent targeted biopsy followed by standard 12-core double sextant biopsy within the same session. Clinically significant prostate cancer was defined as Grade Group 2 or greater prostate cancer. RESULTS: A total of 506 patients were included in analysis. Indications were elevated prostate specific antigen with a previous negative prostate biopsy in 46% of cases, prostate cancer on active surveillance in 35%, elevated prostate specific antigen without a prior prostate biopsy in 15% and an isolated abnormal digital rectal examination in 3%. For standard vs fusion prostate biopsy the overall cancer detection rate was 57.7% vs 54.0% (p=0.12) and the clinically significant prostate cancer detection rate was 24.7% vs 30.8% (p=0.001). Of the 185 patients diagnosed with clinically significant prostate cancer 29 (16%) would have been missed if only targeted fusion prostate biopsy had been performed. CONCLUSIONS: Fusion targeted prostate biopsy is associated with a higher detection rate of clinically significant prostate cancer compared to standard double sextant biopsy. However, standard double sextant biopsy should still be performed as part of the routine fusion targeted prostate biopsy procedure to avoid missing a significant proportion of clinically significant prostate cancer.

Repeat CT Performed Within One Month of CT Conducted in the Emergency Department for Abdominal Pain: A Secondary Analysis of Data From a Prospective Multicenter Study.

OBJECTIVE: The purpose of this study is to determine both the frequency of repeat CT performed within 1 month after a patient visits the emergency department (ED) and undergoes CT evaluation for abdominal pain and the frequency of worsened or new CT-based diagnoses. SUBJECTS AND METHODS: Secondary analysis was performed on data collected during a prospective multicenter study. The parent study included patients who underwent CT in the ED for abdominal pain between 2012 and 2014, and these patients constituted the study group of the present analysis. The proportion of patients who underwent (in any setting) repeat abdominal CT within 1 month of the index CT examination was calculated. For each of these patients, results of the index and repeat CT scans were compared by an independent panel and categorized as follows: no change (group 1); same process, improved (group 2); same process, worse (group 3); or different process (group 4). The proportion of patients in groups 1 and 2 versus groups 3 and 4 was calculated, and patient and ED physician characteristics were compared. RESULTS: The parent study included 544 patients (246 of whom were men [45%]; mean patient age, 49.4 years). Of those 544 patients, 53 (10%; 95% CI, 7.5-13%) underwent repeat abdominal CT. Patients' CT comparisons were categorized as follows: group 1 for 43% of patients (23/53), group 2 for 26% (14/53), group 3 for 15% (8/53), and group 4 for 15% (8/53). New or worse findings were present in 30% of patients (16/53) (95% CI, 19-44%). When patients with findings in groups 1 and 2 were compared to patients with findings in groups 3 and 4, no significant difference was noted in patient age (p = 0.25) or sex (p = 0.76), the number of days between scans (p = 0.98), and the diagnostic confidence of the ED physician after the index CT scan was obtained (p = 0.33). CONCLUSION: Short-term, repeat abdominal CT was performed for 10% of patients who underwent CT in the ED for abdominal pain, and it yielded new or worse findings for 30% of those patients.

Noninvasive mapping of pancreatic inflammation in recent-onset type-1 diabetes patients.

The inability to visualize the initiation and progression of type-1 diabetes (T1D) noninvasively in humans is a major research and clinical stumbling block. We describe an advanced, exportable method for imaging the pancreatic inflammation underlying T1D, based on MRI of the clinically approved magnetic nanoparticle (MNP) ferumoxytol. The MNP-MRI approach, which reflects nanoparticle uptake by macrophages in the inflamed pancreatic lesion, has been validated extensively in mouse models of T1D and in a pilot human study. The methodological advances reported here were enabled by extensive optimization of image acquisition at 3T, as well as by the development of improved MRI registration and visualization technologies. A proof-of-principle study on patients recently diagnosed with T1D versus healthy controls yielded two major findings: First, there was a clear difference in whole-pancreas nanoparticle accumulation in patients and controls; second, the patients with T1D exhibited pronounced inter- and intrapancreatic heterogeneity in signal intensity. The ability to generate noninvasive, 3D, high-resolution maps of pancreatic inflammation in autoimmune diabetes should prove invaluable in assessing disease initiation and progression and as an indicator of response to emerging therapies.

Current and potential imaging applications of ferumoxytol for magnetic resonance imaging.

Contrast-enhanced magnetic resonance imaging is a commonly used diagnostic tool. Compared with standard gadolinium-based contrast agents, ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), used as an alternative contrast medium, is feasible in patients with impaired renal function. Other attractive imaging features of i.v. ferumoxytol include a prolonged blood pool phase and delayed intracellular uptake. With its unique pharmacologic, metabolic, and imaging properties, ferumoxytol may play a crucial role in future magnetic resonance imaging of the central nervous system, various organs outside the central nervous system, and the cardiovascular system. Preclinical and clinical studies have demonstrated the overall safety and effectiveness of this novel contrast agent, with rarely occurring anaphylactoid reactions. The purpose of this review is to describe the general and organ-specific properties of ferumoxytol, as well as the advantages and potential pitfalls associated with its use in magnetic resonance imaging. To more fully demonstrate the applications of ferumoxytol throughout the body, an imaging atlas was created and is available online as supplementary material.

Imaging on nodal staging of prostate cancer.

Prostate cancer is the second most common cancer in men and is the second highest cause of cancer death in men of all races. Accurate lymph node staging is essential to ensure adequate treatment of prostate cancer. Historically, conventional imaging methods have demonstrated limited sensitivity and specificity in the detection of lymph node metastases. There are many emerging PET tracers that have recently proven to be effective. In addition, the use of ultrasmall iron oxide nanoparticle-enhanced MRI has demonstrated promising results. This review outlines the strengths and limitations of each of the different imaging modalities as well as individual tracers used, including preclinical and clinical agents.

Patterns of Recurrence in Upper Tract Transitional Cell Carcinoma: Imaging Surveillance.

OBJECTIVE: The objective of our study was to evaluate recurrence patterns of upper tract transitional cell carcinomas (UT-TCCs) after radical nephroureterectomy (RNU). MATERIALS AND METHODS: Sixty-eight patients (mean age, 78 years; 34 men and 34 women) with UT-TCC after having undergone RNU from 2001 to 2008 were included in this study. Radiologic examinations and clinical notes were reviewed to record tumor location, tumor morphology, histologic T stages and grades, lymphovascular invasion (LVI) status, and surgical procedures. Five-year imaging and clinical follow-up (2001-2013) findings were noted at 3, 6, 12, 18, 24, 36, 48, 60, and more than 60 months after RNU for recurrence pattern and tumor-free survival. Kaplan-Meier survival curves and Cox regression models were used to assess tumor-free survival and to perform a multivariate analysis. RESULTS: Forty-one postoperative recurrences were noted in 20 patients. The mean time to relapse was 16 months, and time to relapse ranged from 1 to 66 months. Tumor site (multifocal lesions involving both renal collecting system and ureter), tumor morphology (mass), T stage (muscle invasion [T2-T4]), histologic grade (grade 3), and the presence of LVI were identified as risk factors for postoperative recurrence in UT-TCC. T stage was the only independent risk factor. CONCLUSION: Urinary tract, lymph node, liver, bone, and lung recurrences were common in patients with UT-TCC and were detected most frequently at 3-24 months. Tumor site, tumor morphology, T stage, grade, and LVI status were associated with recurrence after RNU. T stage was the only independent predictor of tumor-free survival. Close surveillance for extra-urinary tract recurrences in high-risk groups and a shorter-interval follow-up of the urinary tract in low-risk patients with adjuvant chemotherapy are recommended. Identifying recurrence patterns in UT-TCC can aid in planning an effective tailored imaging surveillance strategy.

High-Resolution 3-T Endorectal Prostate MRI: A Multireader Study of Radiologist Preference and Perceived Interpretive Quality of 2D and 3D T2-Weighted Fast Spin-Echo MR Images.

OBJECTIVE: The goal of this study was to compare the perceived quality of 3-T axial T2-weighted high-resolution 2D and high-resolution 3D fast spin-echo (FSE) endorectal MR images of the prostate. MATERIALS AND METHODS: Six radiologists independently reviewed paired 3-T axial T2-weighted high-resolution 2D and 3D FSE endorectal MR images of the prostates of 85 men in two sessions. In the first session (n = 85), each reader selected his or her preferred images; in the second session (n = 28), they determined their confidence in tumor identification and compared the depiction of the prostatic anatomy, tumor conspicuity, and subjective intrinsic image quality of images. A meta-analysis using a random-effects model, logistic regression, and the paired Wilcoxon rank-sum test were used for statistical analyses. RESULTS: Three readers preferred the 2D acquisition (67-89%), and the other three preferred the 3D images (70-80%). The option for one of the techniques was not associated with any of the predictor variables. The 2D FSE images were significantly sharper than 3D FSE (p < 0.001) and significantly more likely to exhibit other (nonmotion) artifacts (p = 0.002). No other statistically significant differences were found. CONCLUSION: Our results suggest that there are strong individual preferences for the 2D or 3D FSE MR images, but there was a wide variability among radiologists. There were differences in image quality (image sharpness and presence of artifacts not related to motion) but not in the sequences' ability to delineate the glandular anatomy and depict a cancerous tumor.