Dual Energy Computed Tomography Collagen Material Decomposition for Detection of Lumbar Spine Disc Extrusion and Sequestration: A Comparative Study With Greyscale Computed Tomography.

Purpose: To assess value of dual energy computed tomography (DECT) collagen material decomposition algorithm when combined with standard computed tomography (CT) in detection of lumbar disc extrusion and sequestration. Materials and Methods: Retrospective analysis of all patients with acute low back pain who had a diagnosis of lumbar spine disc extrusion and/or sequestration on Magnetic Resonance Imaging (MRI) (reference standard), and had undergone non-contrast DECT of the lumbar spine within 60 days of the MRI. Age and sex-matched control patients (n = 42) were included. Patients were grouped into standard, grey-scale CT only group and standard CT + DECT tendon images group. Two double-blinded radiologists reviewed both groups for presence of extrusion or sequestration. They also rated their diagnostic confidence on Likert 5-point scale. McNemar Chi-square test was used to compare diagnostic accuracy, unpaired t-test to compare reviewers diagnostic confidence, and Cohen's k (kappa) test for interobserver agreement. Results: The combined group showed higher overall sensitivity (96.6% vs 87.2%), specificity (99% vs 95.4%), and diagnostic accuracy (98.7% vs 94.5%) with a lower false positive rate (1.1% vs 4.6%). McNemar Chi-square test confirmed statistical significance (P = .03 and P = .02 for Reviewers R1 and R2, respectively). The mean diagnostic confidence was also significantly higher on combined group (R1: 3.74 ± 1.1 vs 3.47 ± 1.15 (P < .01) and R2: 3.91 ± 1.15 vs 3.72 ± 1.16 [mean ± SD] (P = .02)). Conclusion: Utilizing MRI as a reference standard, DECT tendon application combined with standard CT increases the sensitivity, specificity, and accuracy of detection of lumbar spine disc extrusion and sequestration, when compared to standard CT alone.

Reducing the Volume of Low-Value Outpatient MRI Joint Examinations in Patients ≥55 Years of Age.

PURPOSE: Magnetic resonance imaging (MRI) is not beneficial in patients with joint pain and concomitant osteoarthritis (OA). We attempt to determine whether evaluation of OA via X-rays can reduce inappropriate MRI and computed tomography (CT) arthrogram use. In our jurisdiction, CT arthrograms are used as surrogate tests because of MRI wait times. MATERIALS AND METHODS: Our intervention required patients ≥55 years of age scheduled for outpatient MRI of the knee/hip/shoulder at an urban hospital to have X-rays (weight bearing when appropriate) from within 1 year. Red flags (ie, neoplasm, infection) were identified for which MRI would be indicated regardless. Through review of radiographs on picture archiving and communication system/digital media and use of the validated Kellgren-Lawrence (KL) OA scale, radiologists assessed the presence and degree of OA. A finding of significant OA (KL > 2) without red flags would preclude MRI. Monthly averages of MRI and CT arthrogram examinations were measured 33 months before and 23 months following introduction of the intervention. RESULTS: The proportion of protocoled MRI requisitions that were avoided was 21%. If extrapolated to the province of British Columbia, 2419 of 11 700 examinations could have been prevented in the past year. The average monthly number of knee/hip/shoulder MRI examinations as a percentage of total MRI examinations decreased from 4.9% to 4.3% (P < .02) following the intervention. The average monthly number of knee/hip/shoulder CT arthrogram examinations decreased from 20.6 to 12.1 (P < .0001). CONCLUSION: We were able to decrease the number of MRI and CT arthrogram examinations in patients ≥55 years of age with joint pain by implementing an evaluation for OA via recent X-ray imaging.

Evaluation of the proximal coronary arteries in suspected pulmonary embolism: diagnostic images in 51% of patients using non-gated, dual-source CT pulmonary angiography.

PURPOSE: This retrospective study reports the frequency and severity of coronary artery motion on dual-source high-pitch (DSHP), conventional pitch single-source (SS), and dual-source dual-energy (DE) CT pulmonary angiography (CTPA) studies. METHODS: Two hundred eighty-eight consecutive patients underwent CTPA scans for suspected pulmonary embolism between September 1, 2013 and January 31, 2014. One hundred ninety-four at DSHP scans, 57 SS scans, and 37 DE scans were analyzed. Coronary arteries were separated into nine segments, and coronary artery motion was qualitatively scored using a scale from 1 to 4 (non-interpretable to diagnostic with no motion artifacts). Signal intensity, noise, and signal to noise ratio (SNR) of the aorta, main pulmonary artery, and paraspinal muscles were also assessed. RESULTS: DSHP CTPA images had significantly less coronary artery motion, with 30.1% of coronary segments being fully evaluable compared to 4.2% of SS segments and 7.9% of DE segments (p < 0.05 for all comparisons). When imaging with DSHP, the proximal coronary arteries were more frequently evaluable than distal coronary arteries (51% versus 11.3%, p < 0.001). Without ECG synchronization and heart rate control, the distal left anterior descending coronary artery and mid right coronary artery remain infrequently interpretable (7% and 9%, respectively) on DSHP images. CONCLUSIONS: DSHP CTPA decreases coronary artery motion artifacts and allows for full evaluation of the proximal coronary arteries in 51% of cases. The study highlights the increasing importance of proximal coronary artery review when interpreting CTPA for acute chest pain.

CCTA in patients with positive troponin and low clinical suspicion for ACS: a useful diagnostic option to exclude obstructive CAD.

PURPOSE: It is uncertain whether patients with elevated troponin and non-classical presentation of acute coronary syndrome (ACS) should receive coronary CT angiography (CCTA). A proportion of these patients will have no coronary artery disease (CAD) and would benefit from non-invasive investigations and expedited discharge. Objectives were to determine most common diagnoses and rate of ACS among patients with positive troponin and low clinical suspicion of ACS who received CCTA. METHODS: IRB approved retrospective analysis of 491 consecutive patients in a level I trauma center ED referred for CCTA between April 4, 2015 to April 2, 2017. Patients were included if there was an elevated troponin (TnI > 0.045 µg/L) and atypical chest pain within 24 h prior to imaging. One hundred one patients met inclusion criteria; 17 excluded due to technical factors or history. Scans performed on dual-source CT. RESULTS: Eighty-four patients (47 men, 37 women) with median TnI of 0.11 ± 0.21 µg/L underwent CCTA 8.20 ± 6.41 h after first elevated Tn. Mean age was 53.2 ± 14.6 years. CCTA demonstrated absence of CAD in 39 patients (46.4%; 20 M, 19 F). CAD < 25% stenosis was observed in 24 (28.6%; 9 M, 15 F). CAD with 25-50% stenosis was observed in seven (8.3%; six M, one F). CAD > 50% stenosis was observed in 11 (13.1%; 9 M, 2 F), and non-diagnostic in three (3.6%, 3 M, 0 F). Forty-six (56.8%) were discharged directly from ED with median stay 15.82 ± 6.41 h. CONCLUSIONS: Use of CCTA in ED patients with elevated troponin and low clinical suspicion for ACS allowed obstructive CAD to be excluded in 83%.

What's new in the hot gallbladder: the evolving radiologic diagnosis and management of acute cholecystitis.

Acute cholecystitis (AC) is a common condition and its incidence is rising. New technologies have advanced the imaging diagnosis of AC, providing more structural and functional information as well as allowing the radiologist to distinguish AC from mimics and identify complications from both the disease and its management. Dual energy CT aids in detecting gallstones and gallbladder wall enhancement, which helps to diagnose AC and identify its complications. Similarly, contrast-enhanced and non-contrast perfusion ultrasound techniques improve detection of abnormal gallbladder wall enhancement. Advances in MR imaging including hepatobiliary contrast agents aid in characterizing post-cholecystectomy complications such as bile leaks. Newer interventional techniques have also expanded the suite of options for minimally invasive management. Lumen apposing metal stents provide more options for conservative treatment in non-surgical candidates and are compared to a standard percutaneous cholecystostomy. Radiologists should be familiar with these advanced imaging methods and intervention techniques and the value they can bring to the diagnosis and management of AC.

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.

Dual-Source Computed Tomography of the Chest in Blunt Thoracic Trauma: Reduced Aortic Motion Using a Novel Temporal Resolution Optimization Method.

PURPOSE: The purpose of this study was to evaluate the clinical utility of temporal resolution optimization (TR-Opt), a computed tomography (CT) postprocessing technique, in reducing aortic motion artifacts in blunt thoracic trauma patients. MATERIALS AND METHODS: This was an IRB-approved study of 61 patients with blunt thoracic trauma carried out between February 18 and September 6, 2014; the patients had been imaged using a standardized dual-source high-pitch (DSHP) CT protocol. Image raw data were retrospectively postprocessed using the TR-Opt algorithm (DSHP-TR-Opt) and compared with conventional images (DSHP). Diagnostic ability to confidently identify and exclude potential injuries and qualitative aortic motion artifacts using a 5-point Likert scale (1=absence of motion artifacts; 5=severe motion artifact) was graded by 2 readers at multiple thoracic locations. Signal-to-noise and contrast-to-noise ratios were generated as quantitative indices of image quality. RESULTS: Motion artifacts degrading interpretation and limiting diagnosis of aortic injuries were present in 45% (442/976) of the assessed regions on DSHP. TR-Opt algorithm eliminated motion artifacts in 85% of the motion-degraded areas (375/442), leaving persistent motion artifacts in only 15% (67/442). Motion artifacts were most improved at the interventricular septum (1±1 vs. 3±1), aortic valve (2±1 vs. 4±1.5), and ascending aorta (1±1 vs. 3±2, P<0.005). Mean aorta noise (NAo) was 41.7% higher in the DSHP-TR-Opt images (26.5 vs. 18.7 HU, P<0.0001). CONCLUSIONS: Temporal resolution optimized reconstruction is a raw data-based CT postprocessing technique that can be used to remove the majority of thoracic aortic motion artifacts that commonly degrade interpretation when imaging blunt thoracic trauma patients.

Influence of Artificial Intelligence on Canadian Medical Students' Preference for Radiology Specialty: ANational Survey Study.

RATIONALE AND OBJECTIVES: Artificial intelligence (AI) has the potential to transform the clinical practice of radiology. This study investigated Canadian medical students' perceptions of the impact of AI on radiology, and their influence on the students' preference for radiology specialty. MATERIALS AND METHODS: In March 2018, an anonymous online survey was distributed to students at all 17 Canadian medical schools. RESULTS: Among 322 respondents, 70 students considered radiology as the top specialty choice, and 133 as among the top three choices. Only a minority (29.3%) of respondents agreed AI would replace radiologists in foreseeable future, but a majority (67.7%) agreed AI would reduce the demand for radiologists. Even among first-choice respondents, 48.6% agreed AI caused anxiety when considering the radiology specialty. Furthermore, one-sixth of respondents who would otherwise rank radiology as the first choice would not consider radiology because of the anxiety about AI. Prior significant exposure to radiology and high confidence in understanding of AI were shown to decrease the anxiety level. Interested students valued the opinions of local radiologists, radiology conferences, and journals. Students were most interested in "expert opinions on AI" and "discussing AI in preclinical radiology lectures" to understand the impact of AI. CONCLUSION: Anxiety related to "displacement" (not "replacement") of radiologists by AI discouraged many medical students from considering the radiology specialty. The radiology community should educate medical students about the potential impact of AI, to ensure radiology is perceived as a viable long-term career choice.

Epiploic appendagitis: 7-year experience and relationship with visceral obesity.

PURPOSE: Location, size, and local inflammatory findings in primary epiploic appendagitis (EA) have not been reported outside of small studies. The association between EA and increased adiposity is controversial. The goals of this project are to compare demographics and imaging-based measurements of adiposity between patients with EA and patients with acute abdomen without EA, and to identify CT features of EA. METHODS: A consecutive sample of acute, primary EA (n = 100), and control (acute abdomen; n = 100) was selected retrospectively. Cases of suspected EA were included if they had the characteristic ovoid fatty mass and hyperattenuated ring sign on CT. Abdominal adipose volume (AAV), visceral adipose area (VAA), and subcutaneous adipose area (SAA) were quantified by CT. Location, size, and frequency of coexisting local inflammatory findings in EA patients were recorded. RESULTS: EA had 60% greater AAV, 117% greater VAA, and 35% greater SAA than control subjects (p < 0.0001). Males composed a great proportion of the EA group (67%) than the control group (41%) (p = 0.0002). Inflamed appendage was found in sigmoid colon in 49% of cases, descending colon in 23%, and right colon in 19%. Peritoneal thickening was frequent (76%) and bowel wall thickening was common (47%). Diverticulosis coexisted incidentally in 28%. CONCLUSION: EA is associated with increased abdominal adipose tissue. EA can occur in both sexes at any age, but occurs at age 50 on average and more frequently in males. Patient with EA exhibited central hyperdense dot (79%), peritoneal thickening (76%), and bowel wall thickening (47%).