Bi-parametric prostate MRI with a recall system for contrast enhanced imaging: Improving accessibility while maintaining quality.

PURPOSE: To review the efficacy of a recall system for bi-parametric non-contrast prostate MRI (bp-MRI). METHODS: A bi-parametric protocol was instituted in July 2020 for all patients who had a prostate MRI requested, excluding those after treatment of prostate cancer, patients with hip prosthesis or pacemaker, and those who lived out-of-town. The protocol consisted of tri-planar T2-weighted and diffusion weighted images (DWI) (b = 50, 800 s/mm2 for ADC map; b = 1,500 s/mm2 acquired separately) in accordance with the Prostate Imaging Reporting & Data system (PI-RADS) v2.1 guidelines. After interpretation of bp-MRI exams, patients with equivocal (PI-RADS 3) lesions in peripheral zone (PZ) or any technical limitations were recalled for contrast administration. RESULTS: Out of 909 bp-MRI scans performed from July 2020 to April 2021, only 52 (5.7 %) were recalled, of which 46 (88.5 %) attended. Amongst these, 41/52 (78.8 %) were recalled for PZ PI-RADS 3 lesions, while the rest of 11 (21.2 %) cases were recalled for technical reasons. Mean time to subsequent recall scan was 11.6 days. On assessment of post-contrast imaging, 29/46 (63 %) cases were upgraded to PI-RADS 4 while 17/46 (37 %) remained PI-RADS 3. This system avoided contrast-agent use in 857 patients, with contrast cost savings of €64,620 (US$68,560) and 214 hours 15 minutes of scanner time was saved. This allowed 255 additional bp-MRI scans to be performed, reducing the waitlist from 1 year to 2-3 weeks. CONCLUSION: A bi-parametric prostate MRI protocol with a robust recall system for contrast administration not only saved time eliminating the marked backlog but was also more cost efficient without compromising the quality of patient care.

Nontargeted Native Renal Biopsy Adequacy: Preintervention Data From a Province-Wide, Multicentre, and Interdepartmental Audit.

Background: Nontargeted renal biopsy is essential to diagnosis, classification, and prognostication of medical renal disease. Inadequate biopsies delay diagnosis, expose the patient to repeated biopsy, and increase costs. Objective: The purpose of this project is to characterize nontargeted renal biopsy specimen adequacy and identify areas for improvement. Design: This project was designed as a clinical audit of specimen adequacy rates of nontargeted renal biopsies from 13 hospitals, as well as a questionnaire of radiology and pathology department staff regarding current practices surrounding renal biopsies. Setting: Retrospective analysis of 2188 adult native renal biopsies was performed from January 1, 2018, to September 9, 2021, across 13 hospitals. Patients: Adult patients with medical renal disease undergoing a nontargeted renal biopsy were included. Methods: Retrospective analysis of 2188 adult native renal biopsies was performed from January 1, 2018, to September 9, 2021, across 13 hospitals. Adequacy was divided into 4 categories based on number of glomeruli received: ideally adequate (≥25 glomeruli), minimally adequate (15-24), suboptimal (<15 and diagnosis rendered), and inadequate (<15 and no diagnosis rendered). Two targets were chosen; target 1, to achieve a combined suboptimal and inadequate rate ≤ 10%, and target 2, to attain an ideally adequate rate ≥80%. Radiology department heads in the province were surveyed on biopsy equipment, technique, technologist support, and feasibility of possible interventions to enhance biopsy adequacy. Pathology department staff were surveyed on their education and experience. Results: Adequacy was as follows: ideally adequate 64.7%, minimally adequate 26.0%, suboptimal 7.9%, and inadequate 1.4%. The province (and 8/13 hospitals) met target 1 for native biopsies (9.3%). Two hospitals achieved target 2 for native biopsies. A key finding was that the 2 hospitals with the lowest target 1 scores did not have a technologist present at biopsy. Limitations: Survey data was used to assess biopsy technique at each hospital, and specific technique for each biopsy was not recorded. As such, a multivariate statistical analysis of specimen adequacy rates was not feasible. Data on complications was not collected. Conclusions: Preintervention the province was at target for limiting inadequate and suboptimal native biopsies. There was a substantial shortfall in the ideally adequate rate from the proposed target. Using insight from survey data, interventions with the greatest expected impact were identified and those that are feasible given limited resources will be implemented to improve sample adequacy. Trial Registration: Not registered.

Contexte: La biopsie rénale non ciblée est essentielle au diagnostic, à la classification et au pronostic d'une néphropathie. Les biopsies inadéquates retardent le diagnostic, exposent le patient à des biopsies répétées et coûtent plus cher au système de santé. Objectif: L'objectif de cette étude était de caractériser l'adéquation des échantillons des biopsies rénales non ciblées et de dégager les domaines d'amélioration. Conception: Cet essai a été conçu comme un audit clinique du taux d'adéquation des échantillons de biopsies rénales non ciblées provenant de 13 hôpitaux. Il comporte également un questionnaire destiné au personnel des services de radiologie et de pathologie portant sur les pratiques actuelles entourant les biopsies rénales. Cadre: Analyze rétrospective de 2 188 biopsies rénales natives réalisées chez des patients adultes dans 13 hôpitaux entre le 1er janvier 2018 et le 9 septembre 2021. Sujets: Ont été inclus les adultes atteints d'une pathologie rénale médicale ayant subi une biopsie rénale non ciblée. Méthodologie: Nous avons procédé à une analyze rétrospective de 2 188 biopsies rénales natives réalisées chez des patients adultes dans 13 hôpitaux entre le 1er janvier 2018 et le 9 septembre 2021. L'adéquation a été classée en 4 catégories en fonction du nombre de glomérules reçus: parfaitement adéquate (25 glomérules et plus), minimalement adéquate (15 à 24 glomérules), sous-optimale (moins de 15 glomérules + diagnostic rendu), inadéquate (moins de 15 glomérules sans diagnostic rendu). Deux objectifs ont été établis: obtenir un taux d'adéquation combiné « sous-optimale + inadéquate ¼ de 10 % ou moins (objectif 1) et obtenir au moins 80 % d'adéquation « parfaite ¼ (objectif 2). Les chefs des services de radiologie de la province ont été interrogés sur l'équipement de biopsie, la technique, le soutien des technologues et la faisabilité des interventions possibles visant à améliorer l'adéquation des biopsies. Le personnel des services de pathologie a été interrogé sur sa formation et son expérience. Résultats: Les taux d'adéquation étaient les suivants: parfaitement adéquate = 64,7 %; minimalement adéquate = 26,0 %; sous-optimale = 7,9 %; inadéquate = 1,4 %. Pour les biopsies natives, avec un taux de 9,3 %, la province (et 8 des 13 hôpitaux) a atteint l'objectif 1. Deux hôpitaux ont atteint l'objectif 2. Une des principales observations a été qu'il n'y avait aucun technologue présent lors de la biopsie dans les deux hôpitaux qui avaient obtenu les moins bons résultats pour l'objectif 1. Limites: Les données de l'enquête ont été utilisées pour évaluer la technique de biopsie dans chaque hôpital; la technique précise utilisée pour chaque biopsie n'a pas été consignée. Par conséquent, il n'était pas possible de réaliser une analyze statistique multivariée des taux d'adéquation des échantillons. Les données sur les complications n'ont pas été recueillies. Conclusion: Avant l'intervention la province atteignait déjà l'objectif de limiter des biopsies natives inadéquates et sous-optimales. Le taux d'adéquation jugé « parfaitement adéquat ¼ était nettement inférieur à l'objectif proposé. Les données de l'enquête ont permis d'identifier les interventions dont l'impact escompté est le plus important; celles qui sont réalisables compte tenu des ressources limitées seront mises en œuvre afin d'améliorer l'adéquation des échantillons.

SBRT for HCC: Overview of technique and treatment response assessment.

Stereotactic body radiation therapy (SBRT) is an emerging locoregional treatment (LRT) modality used in the management of patients with hepatocellular carcinoma (HCC). The decision to treat HCC with LRT is evaluated in a multidisciplinary setting, and the specific LRT chosen depends on the treatment intent, such as bridge-to-transplant, down-staging to transplant, definitive/curative treatment, and/or palliation, as well as underlying patient clinical factors. Accurate assessment of treatment response is necessary in order to guide clinical management in these patients. Patients who undergo LRT need continuous imaging evaluation to assess treatment response and to evaluate for recurrence. Thus, an accurate understanding of expected post-SBRT imaging findings is critical to avoid misinterpreting normal post-treatment changes as local progression or viable tumor. SBRT-treated HCC demonstrates unique imaging findings that differ from HCC treated with other forms of LRT. In particular, SBRT-treated HCC can demonstrate persistent APHE and washout on short-term follow-up imaging. This brief review summarizes current evidence for the use of SBRT for HCC, including patient population, SBRT technique and procedure, tumor response assessment on contrast-enhanced cross-sectional imaging with expected findings, and pitfalls in treatment response evaluation.

MRI of the Prostate With and Without Endorectal Coil at 3 T: Correlation With Whole-Mount Histopathologic Gleason Score.

OBJECTIVE. The purpose of this article is to prospectively compare image quality and diagnostic accuracy of clinically significant prostate cancer with and without endorectal coil (ERC) at 3 T using a combination of T2-weighted and diffusion-weighted MRI. SUBJECTS AND METHODS. Twenty-three patients with biopsy-proven prostate cancer underwent MRI with and without ERC at the same visit. Patients subsequently underwent radical prostatectomy. Specimens were assessed by whole-mount histopathologic examination. Two radiologists reviewed MR images for image quality (5-point scale) and disease using Prostate Imaging Reporting and Data Systems version 2 (PI-RADSv2). Sensitivity, specificity, and area under the ROC curve (AUC) were calculated with and without ERC. Additionally, apparent diffusion coefficient (ADC) was correlated with Gleason score and ADC values of each lesion were compared with and without ERC. RESULTS. Image quality was comparable with and without ERC (3.8 vs 3.5). Twenty-nine cancer foci larger than 0.5 cm in diameter were found in 23 patients on histopathologic examination; 18 tumors had a Gleason score of 7 or greater. Two radiologists recorded AUC for tumors with a Gleason score of 7 or greater as 0.96 and 0.96 with ERC and 0.88 and 0.91 without ERC. All 13 tumors with a Gleason score of 3 + 4 were detected with ERC, but only 9 were detected without ERC. One of five tumors with Gleason scores less than 3 + 4 was missed with and without ERC. ADC significantly correlated with Gleason score. There was no significant difference in the ADC of a lesion on MRI with and without an ERC. CONCLUSION. MRI with and without ERC was equally accurate at showing prostate cancers with Gleason scores of 4 + 3 or greater. However, MRI with ERC was superior at showing cancer with a Gleason score of 3 + 4. There was no significant difference in ADC values between scores acquired with or without an ERC.

A PSA for Radiologists: Pictorial Review of Incidentalomas on Prostate Magnetic Resonance Imaging.

Multiparametric magnetic resonance imaging (MRI) of the prostate is a powerful and increasingly utilized imaging study for the diagnosis, staging, and surveillance of prostate cancer. With greater adoption by clinicians, it is becoming more common for incidental findings to be first detected on prostate MRI. Inadequate description of clinically significant findings may not prompt appropriate patient management, while over-reporting of indolent findings comes at increased patient anxiety, cost of workup, and iatrogenic risk. This review article aims to improve awareness, review pathophysiology, and present key imaging features of incidental findings seen on prostate MRI, ranging from common to rare and from benign to clinically significant.

Virtual monoenergetic reconstruction of contrast-enhanced CT scans of the abdomen and pelvis at 40 keV improves the detection of peritoneal metastatic deposits.

PURPOSE: To evaluate the role of virtual monoenergetic imaging (VMI) in the detection of peritoneal metastatic disease in contrast-enhanced computed tomography (CT) of the abdomen and pelvis and to compare this technique to the conventional 120 kV mixed dataset. MATERIALS AND METHODS: Institutional review board approval was obtained with no informed consent required for this retrospective analysis. 43 consecutive patients with histopathologically confirmed peritoneal disease were scanned using a standard protocol on a 128-section dual-source, dual-energy CT system (100/140 keV). Scans were retrospectively reconstructed at VMI energy levels from 40-110 keV in 10 keV increments and were analyzed both quantitatively and qualitatively. CNR values for peritoneal metastatic deposits were recorded using region of interest (ROI) analysis at each energy level for all VMI datasets. Subjective analysis was performed by two independent fellowship-trained readers with combined experience of greater than 15 years. Qualitative parameters included diagnostic acceptability, subjective noise, and contrast resolution and confidence. RESULTS: The contrast-to-noise ratios (CNRs) for peritoneal metastatic deposits at the different VMI energy levels were compared using a one-way ANOVA with Tukey Post Test, and the optimal CNR was observed at 40 keV (p < 0.0001). Qualitative parameters were compared using a Paired T Test. Subjective noise, diagnostic acceptability, and contrast resolution was significantly better on the conventional images, but readers reported increased confidence on VMI at 40 keV (p < 0.001). CONCLUSION: VMI reconstruction of contrast-enhanced dual-energy CT scans of the abdomen and pelvis at 40 keV maximizes the conspicuity of metastatic peritoneal deposits and improves radiologists' diagnostic confidence compared with conventional CT images. We recommend using virtual monoenergetic datasets at 40 keV as a tool for improving the detection of these lesions in routine clinical practice.

Classification of Error in Abdominal Imaging: Pearls and Pitfalls for Radiologists.

Peer review for radiologists plays an important role in identifying contributing factors that can lead to diagnostic errors and patient harm. It is essential that all radiologists be aware of the multifactorial causes of diagnostic error in radiology and the methods available to reduce it. This pictorial review provides readers with an overview of common errors that occur in abdominal radiology and strategies to reduce them. This review aims to make readers more aware of pitfalls in abdominal imaging so that these errors can be avoided in the future. This essay also provides a systematic approach to classifying abdominal imaging errors that will be of value to all radiologists participating in peer review.

Management of Acute Contrast Reactions-Understanding Radiologists' Preparedness and the Efficacy of Simulation-Based Training in Canada.

PURPOSE: Acute radiologic emergencies, primarily severe contrast reactions, are rare but life-threatening events. Given a generalized paucity of formalized or mandated training, studies have shown that radiologists and trainees perform poorly when acutely managing such events. Moreover, skill base, knowledge, and comfort levels precipitously decline over time given the infrequent occurrence of these events during one's daily practice. The primary aim of this study was to assess radiologists' preparedness for managing acute radiologic emergencies and to determine the efficacy of a high-fidelity simulation based training model in an effort to provide a rationale for similar programs to be implemented on a provincial or national level. METHODS: This was a prospective, observational study of radiology residents and attending radiologists throughout the province who were recruited to attend a full-day simulation-based course presenting various cases of acute radiologic emergencies. Participant demographics were collected at the time of commencement of the workshop. Course materials were disseminated 4 weeks prior to the workshop, and a 17-question knowledge quiz was administered before and after the workshop. Likert-type questionnaires were also distributed to survey comfort levels and equipment familiarity. The knowledge quiz and questionnaire were redistributed at 3- and 6-month intervals for acquisition of follow-up data. RESULTS: A total of 14 attending radiologists and 7 residents attended the workshop, with all participants completing the preworkshop questionnaire and 90.5% (19 of 21) completing the post-workshop questionnaire. Participants' principle locations of practice were as follows: academic institutions (50%), community hospitals (36.9%), and private clinics (13.1%). A significant increase in knowledge was demonstrated, with average scores of 10 out of 17 (59%) and 14.5 out of 17 (85%) (P < .001) before and after the workshop, respectively. A significant increase in participants' comfort levels in recognizing acute anaphylactic reactions (3.5; 4.7, P < .001), commencing initial management for acute radiologic emergencies (3.3; 5.0, P < .001), and administering the correct dose for anaphylactic reactions (2.5; 4.8, P < .001) was also demonstrated. Moreover, participants became increasingly familiar with the contents and equipment found within contrast reaction kits (2.8; 3.8, P < .01). Repeat evaluations at 3 and 6 months found an average knowledge test score of 13.8 out of 17 (81%) and 10.8 out of 17 (64%), respectively. Comfort levels were also reassessed in recognizing acute anaphylactic reactions (4.5; 4.1), commencing initial management (4.0; 3.9) and administering the correct dose of medication (4.0; 3.7) at 3- and 6-month intervals. CONCLUSIONS: Acute radiologic emergencies are rare but life-threatening events that require rapid diagnosis and treatment to mitigate associated morbidity and mortality. Simulation-based workshops are a highly efficacious training model to increase knowledge, comfort levels, and equipment familiarity for radiologists and trainees alike; however, retraining at regular intervals is required.

Contrast-Enhanced Ultrasound of the Liver: Optimizing Technique and Clinical Applications.

OBJECTIVE: The purpose of this article is to review the general principles, technique, and clinical applications of contrast-enhanced ultrasound of the liver. CONCLUSION: Proper technique and optimization of contrast-enhanced ultrasound require a balance between maintaining the integrity of the microbubble contrast agent and preserving the ultrasound signal. Established and emerging applications in the liver include diagnosis of focal lesions, aiding ultrasound-guided intervention, monitoring of therapy, and aiding surgical management.

Screening and Surveillance of Hepatocellular Carcinoma: An Introduction to Ultrasound Liver Imaging Reporting and Data System.

Given the high prevalence, increasing incidence, and significant morbidity and mortality related to hepatocellular carcinoma (HCC), a robust and cost-effective screening and surveillance program is needed. Most societies recommend ultrasound for HCC screening, despite lack of standardization in imaging acquisition, reporting content and language, and follow-up recommendations. The American College of Radiology Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) fills this unmet need by providing standardization in the use of US in at-risk patients. It is anticipated that US LI-RADS will improve the performance of ultrasound for HCC screening and surveillance and unify management recommendations.

A Pictorial Review of Hepatobiliary Magnetic Resonance Imaging With Hepatocyte-Specific Contrast Agents: Uses, Findings, and Pitfalls of Gadoxetate Disodium and Gadobenate Dimeglumine.

Magnetic resonance imaging (MRI) has a well-established role as a highly specific and accurate modality for characterizing benign and malignant focal liver lesions. In particular, contrast-enhanced MRI using hepatocyte-specific contrast agents (HSCAs) improves lesion detection and characterization compared to other imaging modalities and MRI techniques. In this pictorial review, the mechanism of action of gadolinium-based MRI contrast agents, with a focus on HSCAs, is described. The clinical indications, protocols, and emerging uses of the 2 commercially available combined contrast agents available in the United States, gadoxetate disodium and gadobenate dimeglumine, are discussed. The MRI features of these agents are compared with examples of focal hepatic masses, many of which have been obtained within the same patient therefore allowing direct lesion comparison. Finally, the pitfalls in the use of combined contrast agents in liver MRI are highlighted.

Imaging Intra-abdominal Burkitt's Lymphoma: From Discrete Bowel Wall Thickening to Diffuse Soft Tissue Infiltration.

Burkitt's lymphoma is a highly aggressive non-Hodgkin's B-cell lymphoma, which often presents with intra-abdominal involvement. The purpose of this pictorial review is to illustrate the various intra-abdominal imaging findings of Burkitt's lymphoma. Extranodal disease at presentation is common, including involvement of the bowel, stomach, pancreas, spleen, and mesentery.

Virtual monoenergetic reconstruction of contrast-enhanced dual energy CT at 70keV maximizes mural enhancement in acute small bowel obstruction.

PURPOSE: In patients with small bowel obstruction (SBO), it is challenging to detect early ischemia. The purpose of this study is to evaluate the quantitative and qualitative benefits of virtual monoenergetic image (VMI) reconstruction in the assessment of small bowel mural enhancement on dual source dual energy computed tomography (CT) scans of the abdomen. MATERIALS AND METHODS: Institutional review board approval was obtained, for this retrospective analysis. 72 consecutive patients with acute SBO were scanned using a second generation 128-slice dual source, CT system. Images were reconstructed at VMI energy levels from 40 to 110keV in 10keV increments and were analysed quantitatively and qualitatively. Contrast to noise ratios (CNR) and signal to noise ratios (SNR) for mural enhancement were recorded for all VMI datasets and compared to conventional polychromatic images (PCI) at 120kVp. Subjective analysis of mural enhancement on VMI and PCI was performed by 3 blinded readers. RESULTS: Optimal CNR values for small intestinal mural enhancement were observed at 70keV. Qualitative assessment revealed that there was no statistical difference in diagnostic accuracy between VMI and PCI. All readers reported improved confidence when assessing the contrast enhancement on the 70keV VMI dataset and in our series, 2 additional cases of ischemia were identified on this reconstruction. CONCLUSION: Contrast-enhanced dual source dual energy CT with VMI reconstruction at 70keV maximizes the CNR of small bowel mural enhancement and increases the overall diagnostic confidence in assessing mural enhancement in patients with SBO.

Hepatocellular Carcinoma Post Embolotherapy: Imaging Appearances and Pitfalls on Computed Tomography and Magnetic Resonance Imaging.

Embolotherapies used in the treatment of hepatocellular carcinoma (HCC) include bland embolization, conventional transarterial chemoembolization (cTACE) using ethiodol as a carrier, TACE with drug-eluting beads and super absorbent polymer microspheres (DEB-TACE), and selective internal radiation therapy (SIRT). Successfully treated HCC lesions undergo coagulation necrosis, and appear as nonenhancing hypoattenuating or hypointense lesions in the embolized region on computed tomography (CT) and magnetic resonance. Residual or recurrent tumours demonstrate arterial enhancement with portal venous phase wash-out of contrast, features characteristic of HCC, in and/or around the embolized area. Certain imaging features that result from the procedure itself may limit assessment of response. In conventional TACE, the high-attenuating retained ethiodized oil may obscure arterially-enhancing tumours and limit detection of residual tumours; thus a noncontrast CT on follow-up imaging is important post-cTACE. Hyperenhancement within or around the treated zone can be seen after cTACE, DEB-TACE, or SIRT due to physiologic inflammatory response and may mimic residual tumour. Recognition of these pitfalls is important in the evaluation embolotherapy response.

Approach to the Solitary Liver Lesion: Imaging and When to Biopsy.

The characterization and management of focal liver lesions is a commonly encountered problem in radiology. While the imaging findings will often be diagnostic, in equivocal cases the decision of how to proceed may be challenging. The primary modalities for liver lesion characterization are multiphase contrast-enhanced computed tomography and magnetic resonance imaging. Most lesions have typical imaging features, and when taken in conjunction with patient demographics and biochemistry the diagnosis can usually be made. Ancillary imaging modalities such as contrast-enhanced ultrasound and hepatobiliary specific contrast agents are also useful. Cirrhotic livers present a challenge due to the spectrum of benign, dysplastic, and malignant nodules that can occur. The report should include information necessary for accurate staging, and published standardized reporting guidelines should be taken into consideration. A decision to proceed to biopsy should be made only after multidisciplinary review of the case. If biopsy is required, fine needle aspiration is usually sufficient, though core needle biopsy may be required in certain circumstances.

Assessing the Gap in Female Authorship in Radiology: Trends Over the Past Two Decades.

PURPOSE: The aim of this study was to retrospectively identify trends in the representation of female authorship in prominent general radiology journals over the past 2 decades. METHODS: A comprehensive search was conducted for all articles published in 1993, 2003, and 2013 in Radiology, the American Journal of Roentgenology (AJR), European Radiology, and Investigative Radiology. The genders of the first and last authors were collected. Chi-square tests were used for statistical analysis, and P values < .05 were considered to indicate statistical significance. RESULTS: A total of 3,786 articles were reviewed. Overall, women constituted 20.0% authorship, 24.7% of first authors, and 15.2% of senior authors. The average overall female first and senior authorship grew from 19.7% to 32.1% and from 13.6% to 19.1%, respectively from 1993 to 2013. Female first authorship grew over the past 2 decades in the journals reviewed, with significant growth in AJR and Radiology (P < .0001). Female first authorship in the individual journals grew from 16.4%-29.1% in 1993, to 29.1%-34.8% in 2013. Female senior authorship also demonstrated growth in the past 2 decades, growing from 4.3%-17.5% in 1993 to 15.5%-23.2% in 2013. There was significant growth in senior female authorship in Radiology (from 12.1% to 19.2%, P = .004) and European Radiology (from 4.3% to 15.5%, P = .0433). Female senior authorship remained significantly lower than first authorship over the past 2 decades (P = .002, P < .001, and P < .0001). CONCLUSIONS: Although women's growth in first authorship in radiology literature is proportional to their growth in the specialty, they continue to remain a minority, especially in senior authorship, and demonstrate similar participation to other medical specialties.