Magnetic resonance imaging based finite element modelling of the proximal femur: a short-term in vivo precision study.

Proximal femoral fractures are a serious life-threatening injury with high morbidity and mortality. Magnetic resonance (MR) imaging has potential to non-invasively assess proximal femoral bone strength in vivo through usage of finite element (FE) modelling (a technique referred to as MR-FE). To precisely assess bone strength, knowledge of measurement error associated with different MR-FE outcomes is needed. The objective of this study was to characterize the short-term in vivo precision errors of MR-FE outcomes (e.g., stress, strain, failure loads) of the proximal femur for fall and stance loading configurations using 13 participants (5 males and 8 females; median age: 27 years, range: 21-68), each scanned 3 times. MR-FE models were generated, and mean von Mises stress and strain as well as principal stress and strain were calculated for 3 regions of interest. Similarly, we calculated the failure loads to cause 5% of contiguous elements to fail according to the von Mises yield, Brittle Coulomb-Mohr, normal principal, and Hoffman stress and strain criteria. Precision (root-mean squared coefficient of variation) of the MR-FE outcomes ranged from 3.3% to 11.8% for stress and strain-based mechanical outcomes, and 5.8% to 9.0% for failure loads. These results provide evidence that MR-FE outcomes are a promising non-invasive technique for monitoring femoral strength in vivo.

Determining residual gastric volume in healthy children using ultrasound.

PURPOSE: Fasting guidelines for children recommend restricting clear fluids for one or two hours before a procedure to reduce pulmonary aspiration. Gastric volumes < 1.5 mL·kg-1 do not seem to present an increased risk of pulmonary aspiration. Our aim was to quantify the time to achieve a gastric volume < 1.5 mL·kg-1 after clear fluid ingestion in children. METHODS: We conducted a prospective observational study in healthy volunteers aged 1-14 yr. Participants followed American Society of Anesthesiologists fasting guidelines prior to data collection. Gastric ultrasound (US) was performed in the right lateral decubitus (RLD) position to determine the antral cross-sectional area (CSA). Following baseline measurements, participants consumed 250 mL of a clear fluid. We then performed gastric US at four time intervals: 30, 60, 90, and 120 min. Data were collected following a predictive model for gastric volume estimation using the formula: volume (mL) = -7.8 + (3.5 × RLD CSA) + (0.127) × age (months). RESULTS: We recruited 33 healthy children aged 2-14 yr. The mean gastric volume per weight (mL·kg-1) at baseline was 0.51 mL·kg-1 (95% confidence interval [CI], 0.46 to 0.57). The mean gastric volume was 1.55 mL·kg-1 (95% CI, 1.36 to 1.75) at 30 min, 1.17 mL·kg-1 (95% CI, 1.01 to 1.33) at 60 min, 0.76 mL·kg-1 (95% CI, 0.67 to 0.85) at 90 min, and 0.58 mL·kg-1 (95% CI, 0.52 to 0.65) at 120 min. CONCLUSION: Our results show that total gastric fluid volume was < 1.5 mL·kg-1 after 60 min, suggesting that current fasting guidelines for children could be liberalized.

RéSUMé: OBJECTIF: Les directives de jeûne pour les enfants recommandent de restreindre les liquides clairs pendant une ou deux heures avant une intervention pour réduire l'aspiration pulmonaire. Des volumes gastriques < 1,5 mL·kg−1 ne semblent pas présenter un risque accru d'aspiration pulmonaire. Notre objectif était de quantifier le temps nécessaire pour atteindre un volume gastrique < 1,5 mL·kg−1 après ingestion de liquides clairs chez les enfants. MéTHODE: Nous avons mené une étude observationnelle prospective chez des volontaires en bonne santé âgé·es de 1 à 14 ans. Les participant·es ont suivi les directives de jeûne de l'American Society of Anesthesiologists avant la collecte de données. L'échographie gastrique a été réalisée en décubitus latéral droit (DLD) pour déterminer la section transversale antrale. Après les mesures initiales, les participant·es ont consommé 250 mL d'un liquide clair. Nous avons ensuite réalisé une échographie gastrique à quatre intervalles de temps : 30, 60, 90 et 120 minutes. Les données ont été recueillies selon un modèle prédictif pour l'estimation du volume gastrique à l'aide de la formule : volume (mL) = −7,8 + (3,5 × section transversale antrale en DLD) + (0,127) × âge (mois). RéSULTATS: Nous avons recruté 33 enfants en bonne santé âgé·es de 2 à 14 ans. Le volume gastrique moyen par poids (mL·kg−1) au début de l'intervention était de 0,51 mL·kg−1 (intervalle de confiance [IC] à 95 %, 0,46 à 0,57). Le volume gastrique moyen était de 1,55 mL·kg−1 (IC 95 %, 1,36 à 1,75) à 30 min, 1,17 mL·kg−1 (IC 95 %, 1,01 à 1,33) à 60 min, 0,76 mL·kg−1 (IC 95 %, 0,67 à 0,85) à 90 min, et 0,58 mL·kg−1 (IC 95 %, 0,52 à 0,65) à 120 min. CONCLUSION: Nos résultats montrent que le volume total de liquide gastrique était < 1,5 mL·kg−1 après 60 min, suggérant que les directives actuelles de jeûne pour les enfants pourraient être libéralisées.

Four-Corner Arthrodesis with a Dorsal Locking PEEK Plate: A Retrospective Case Series.

Background Four-corner arthrodesis (4CA) can be performed with a variety of methods. To our knowledge, fewer than 125 cases of 4CA with a locking polyether ether ketone (PEEK) plate have been reported, necessitating further study. Purpose The purpose of this study was to evaluate the radiographic union rate and clinical outcomes in a series of patients who received 4CA with a locking PEEK plate. Methods We re-examined 39 wrists in 37 patients at a mean follow-up of 50 months (median: 52 months, range: 6-128). Patients completed the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), Patient-Rated Wrist Evaluation (PRWE), and participated in measurements of grip strength and range of motion. Anteroposterior, lateral, and oblique radiographs of the operative wrist were examined for union, screw breakage and/or loosening, and lunate change. Results The mean QuickDASH score was 24.4 and the mean PRWE score was 26.5. Mean grip strength was 29.2 kg or 84% of the nonoperative hand. Mean flexion, extension, radial deviation, and ulnar deviation were : 37.2, 28.9, 14.1, and 17.4 degrees, respectively. Eighty-seven percent of wrists achieved union; 8% had nonunion; and5% had indeterminate union. There were seven cases of screw breakage and seven cases of screw loosening (as defined by lucency or bony resorption surrounding screws). Twenty-three percent of wrists required reoperation (four total wrist arthrodesis and five reoperations for other reasons). Conclusion 4CA with a locking PEEK plate has clinical and radiographic outcomes similar to other methods. We observed a high rate of hardware complications. It is unclear whether this implant offers a clear advantage over other methods of fixation used in 4CA. Type of Study/Level of Evidence Level IV, therapeutic study.

Mistakes, Misrepresentation, and Misunderstanding on Applications to a Canadian Diagnostic Radiology Residency Program.

Purpose: Determine the educational background, research publications/presentations experience, and rates of research publication and presentation inaccuracies in applications to a Canadian diagnostic imaging residency program. Method: The education and publication/presentation sections of the Canadian Resident Matching Service form for all applicants to the University of Saskatchewan diagnostic imaging residency program from 2019-20 and 2020-21 were reviewed. Number of advanced degrees (Master's/PhDs), publications, and presentations were recorded. Accuracy of publications listed was confirmed via PubMed-MEDLINE, journal's website, or internet searching. Accuracy of presentations was confirmed via society and residency program websites. Inaccuracies of non-authorship, incorrect authorship order/status (self-promotion or demotion), and nonexistence of article/presentation from a verifiable source were recorded. Result: There were a total of 106 applicants. Thirty (28%) had advanced degrees. There were 230 publications from 61 applicants with inaccuracies in only 5 (2%) of the publications (2 self-promotion, 3 self-demotion). For the 77 publications listed as pending, 25 (31%) were published within 6 months of applications deadlines with 1 non-authorship, 1 self-promotion, and 1 self-demotion. For scientific presentations, there were 467 listed presentations by 91 applicants. Two hundred and twenty-one presentations were from verifiable sources with inaccuracies in 28 (13%) of presentations (9 self-promotion, 9 self-demotion, 1 non-authorship, and 9 non-existence). Conclusion: Despite some uncertainty with scientific articles reported as pending and scientific presentations, radiology residency applicants are accurately representing their published articles with a negligible number of misrepresentations. Canadian radiology residency programs should regard the publication profiles of the applicants with a high level of confidence.

Correlation between superior humeral head migration and proximal long head of biceps tendon pathology in patients with and without rotator cuff tears using magnetic resonance imaging and radiography.

Background: The biomechanical role of the proximal long head of the biceps tendon (PLHB) in glenohumeral joint stability remains controversial. This retrospective study aims to correlate between humeral head migration and PLHB pathology in patients with and without rotator cuff tendon tears using imaging. Methods: Seventy-nine patients who underwent 3T magnetic resonance imaging of the shoulder were retrospectively reviewed. Imaging findings were documented by a fellowship-trained musculoskeletal radiologist. PLHB tendon diameter change, contour irregularity, and signal intensity change were assessed. Rotator cuff status was given a binary assignment of intact vs. torn. Radiographs were used for measurement of the acromiohumeral distance and a cutoff value of 7 mm was set as a lower limit of normal. Results: In the cohort of 79 shoulders, 41.8% (33/79) of patients had intact PLHB tendon and rotator cuff, 26.6% (21/79) demonstrated isolated PLHB tendon pathology, 13.9% (11/79) demonstrated isolated rotator cuff tears, and 17.7% (14/79) demonstrated concomitant PLHB tendon pathology and rotator cuff tears. Acromiohumeral distance was preserved in 97.0% (32/33) of patients with intact PLHB tendon and rotator cuff, 28.6% (6/21) of patients with isolated PLHB tendon pathology, 81.8% (9/11) of patients with isolated rotator cuff tears, and 14.3% (2/14) of patients with concomitant PLHB tendon pathology and rotator cuff tears (P < .0001). Conclusion: Results of this study have shown that a statistical correlation was present between superior humeral head migration and PLHB tendon pathology with or without rotator cuff tears, compared to rotator cuff pathology alone. Findings suggest that intact PLHB tendon plays an important role in glenohumeral stability.

Early Detection of First Carpometacarpal Joint Osteoarthritis Using Magnetic Resonance Imaging Assessment in Women With High Hypermobility Scores.

OBJECTIVE: The aim of this study was to explore association between hypermobility and osteoarthritis (OA) at the first carpometacarpal (CMC) joint, using magnetic resonance imaging (MRI) to identify early change in women at high risk of developing OA but without yet established diagnoses. METHODS: For this observational study, 33 women (aged 30-50 years) with self-reported history of maternal hand OA but without personal diagnoses of OA were recruited. Participants completed a 5-point hypermobility questionnaire. The 20 participants with 2 or more positive responses were categorized with "high hypermobility scores." The remaining 13 were categorized with "low hypermobility scores." Data collection included functional index, hand pain measure, parity, smoking status, and body mass index. Each participant underwent dominant hand radiographic and MRI examination. Imaging studies were interpreted by assessors blinded to hypermobility score categorization. RESULTS: No significant differences in age, body mass index, parity, functional index, or pain scores were observed between higher and lower hypermobility score groups. Similarly, there were no significant differences between groups for radiographic changes. However, significantly higher proportions of women with higher hypermobility scores were observed on MRI to have abnormalities of trapezium cartilage (75% vs. 38%), metacarpal cartilage (80% vs. 38%), and trapezium bone (70% vs. 31%); p < 0.05 for all. CONCLUSIONS: First CMC joint structural abnormalities were more frequently observed in women with higher hypermobility scores. Identification of early preradiographic changes in this group supports the concept that early-life joint laxity may contribute to future OA predisposition. Magnetic resonance imaging may be a preferred imaging test for detection of early cartilage changes in people at high risk of CMC joint OA.

Presentation at the Canadian Association of Radiologists Annual General Meeting Is Associated With Higher Likelihood of Publication of Canadian Radiology Resident Research Day Presentations.

Objective: Determine how many radiology resident research day projects are presented at the Canadian Association of Radiologists Annual Scientific Meeting (CAR ASM) and if presentation at the CAR ASM is associated with increased rates of publication. Methods: A database of radiology resident presentations from 2012 to 2017 research days at seven Canadian radiology programs was utilized. Each presenting resident was searched for in 2011-2019 CAR ASM books of abstracts to identify all CAR ASM presentations both related to and separate from their research day projects. These presentations were matched with resident research day presentations and their publication status. Descriptive statistical analysis and calculation of relative risk (RR) between publication of research day projects and presentation at CAR was performed. Results: 208 residents presented 288 projects at internal research days. 93 of the 208 residents had a total of 195 presentations at CAR (mean .94 +/- 1.91 SD). 36 of the 288 (13%) research day projects were presented at a CAR ASM, of which 18/36 (50%) were published. 83 of the 252 (32%) research day projects not presented at CAR were published. CAR ASM presentation of a research day project was associated with an increased rate of publication (RR 1.537 P=.0396). There was no significant association between research day project publication and unrelated CAR ASM presentations (P=.275). Most research day projects both presented at CAR ASM and published (56%) were in the Canadian Association of Radiologists Journal. Conclusion: CAR ASM presentation of research day projects is associated with an increased rate of publication.

Evaluation of the Modified Barium Swallow Study Conducted With and Without Radiologist Supervision: A Pre- and Post-Observational Study.

PURPOSE: Assess quality metrics of modified barium swallow studies (MBSS) with and without a radiologist present during the procedure. METHODS: Retrospective review of MBSS performed on adult inpatients at a tertiary care hospital 6-months pre- and post-institutional change from having to not having a radiologist present during the examination. FACTORS ASSESSED INCLUDED: fluoroscopy time; study duration; number of cine loops; number of images; efficiency of collimation (using a 5-point scoring system); time to final report; radiologist-speech language pathologist report disagreement; and recalls for inadequate studies. Statistical analysis was via Welch's t-test and a test of proportions for continuous and count data under the normal approximation. RESULTS: 106 and 119 MBSS were analyzed from the radiologist present and radiologist absent periods, respectively. No statistically significant differences were found for: average fluoroscopy time (116.1 s vs. 126.9 s; P = 0.161); study duration (400.4 s vs. 417.3 s; P = 0.453); number of cine loops (9.3 vs. 10.2; P = 0.075); number of images (620.5 vs. 581.1; P = 0.350); or report disagreement. There was improved performance without the radiologist present for collimation (1.92 vs. 1.43; P = 0.003) and fewer non-diagnostic images (6.5 vs. 4.5; P = 0.001). Time to final report was longer with the radiologist absent due to more reports with significant delays. There were no repeated studies because of inadequate technique in either group. CONCLUSION: MBSS performed by technologists without radiologist supervision is not inferior to those performed with radiologist supervision on multiple performance measures. This supports technologist operated MBSS without radiologist supervision, while acknowledging a need to further address radiologist report time delay.

Is Call Karma Real? Resident After-Hours On-Call Imaging at the University of Saskatchewan: An Assessment of Call Volumes Including Inter-Resident Variability.

PURPOSE: Quantify resident caseload during call and determine if there are consistent differences in call volumes for individuals or resident subgroups. METHODS: Accession codes for after-hours computed tomography (CT) cases dictated by residents between July 1, 2012 and January 9, 2017 were reviewed. Case volumes by patient visits and body regions scanned were determined and categorized according to time period, year, and individual resident. Mean shift Relative Value Units (RVUs) were calculated by year. Descriptive statistics, linear mixed modeling, and linear regression determined mean values, differences between residents, associations between independent variables and outcomes, and changes over time. Consistent differences between residents were assessed as a measure of good or bad luck / karma on call. RESULTS: During this time there were 23,032 patients and 30,766 anatomic regions scanned during 1,652 call shifts among 32 residents. Over the whole period, there were on average 10.6 patients and 14.3 body regions scanned on weekday shifts and 22.3 patients and 29.4 body regions scanned during weekend shifts. Annually, the mean number of patients, body regions, and RVUs scanned per shift increased by an average of 0.2 (1%), 0.4 (2%), and 1.2 (5%) (all p < 0.05) respectively in regression models. There was variability in call experiences, but only 1 resident had a disproportionate number of higher volume calls and fewer lower volume shifts than expected. CONCLUSIONS: Annual increases in scan volumes were modest. Although residents' experiences varied, little of this was attributable to consistent personal differences, including luck or call karma.

Incidence Rates of Surgery After Knee MRI: Association According to Referring Physician Type and Patient's Age and Sex.

BACKGROUND: The utility of magnetic resonance imaging (MRI) in the primary care setting is uncertain, with a perception that there is less likelihood for surgery after MRI ordered by general practitioners (GPs) when compared with orthopaedic surgeons and sports medicine physicians. Additionally, the influence of patient age and sex on subsequent surgical intervention is currently unknown. PURPOSE/HYPOTHESIS: The purpose of this study was to compare surgical incidence after MRI referrals by orthopaedic surgeons, GPs, and sports medicine physicians, including a subset analysis for GP patients based on type of approval given by the radiologist. The authors also wanted to explore the association of age and sex on subsequent surgical intervention. They hypothesized that surgical incidence after MRI ordered by orthopaedic surgeons and sports medicine physicians would be higher than after MRI ordered by GPs. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Knee MRI referrals by the 3 physician cohorts during May to December 2017 were assessed. For GP patients, the types of approval or recommendation from a radiologist were categorized. Subsequent surgical intervention status was then compared among referral groups up to 2 years after MRI. Associations of age and sex with surgical occurrence were also assessed. Chi-square test, analysis of variance, and univariate/multivariable logistic regression were used for statistical analysis. RESULTS: Overall, 407 referrals were evaluated (GP, n = 173; orthopaedic, n = 176; sports medicine, n = 58). Surgical incidence was not significantly higher for orthopaedic and sports medicine than GP referrals at 3 months (10%, 3%, and 6%, respectively; P = .23), 6 months (20%, 17%, and 15%; P = .49), and 2 years (30%, 35%, and 24%; P = .25). Surgical incidence for GP patients was higher after discussion with a radiologist or when evaluating specific pathology on prior imaging versus less defined reasons (30.4% vs 15.7%, respectively; P = .03). Surgical incidence was lower for older patients (11% vs 31% for >60 years vs all other age groups combined; P = .002), and women were less likely to undergo surgery than men (22% vs 35%, respectively; P = .008). CONCLUSION: Surgical incidence after MRI was likely appropriately lower for older patients. Lower incidence for female patients is of uncertain cause and warrants further study.

Proximal femoral epiphyseal spurs and their association with acetabular labral tears on MRI in symptomatic patients.

OBJECTIVE: Femoral epiphyseal spurs are developmental projections that form at the edge of the physis. Although considered incidental, their association with acetabular labral tears has never been examined. Our aim was to assess the prevalence of femoral epiphyseal spurs in symptomatic patients with mechanical hip pain and explore if they are associated with labral tears on MRI. MATERIALS AND METHODS: Hip MRI scans performed on a Siemens 3 T MRI using femoroacetabular impingement protocol were retrospectively reviewed. All patients were referred by orthopaedic surgeons for mechanical hip pain. Two musculoskeletal radiologists blinded to initial reports evaluated MRI images for the presence of an epiphyseal spur and acetabular labral changes. A consensus was achieved on all cases by the two readers. The association between epiphyseal spurs and labral changes was assessed using Fisher's exact test. RESULTS: A total of 115 patients (178 hip MRI scans) were reviewed; the mean age was 28.8 years (SD 7.1). There were 52 females (45.2%) and 63 males (54.8%). There were 115 hips with labral tears (64.6%). Fourteen hips (7.8%) in ten patients (8.7%) demonstrated epiphyseal spurs and all of them showed labral tears (100%). There was statistically significant association between epiphyseal spurs and labral tears on MRI (p value = 0.0024). CONCLUSION: Femoral epiphyseal spurs were observed in 8.7% of our defined patient population, and all patients with epiphyseal spurs demonstrated labral tears. Epiphyseal spurs should be documented on imaging reports due to their potential association with labral tears. Future research is needed to further delineate and guide management of these entities.

Research on Research: Publication of Projects Presented at Medical Imaging Research Days Across Canada.

OBJECTIVE: Twenty-one previous studies have shown a mean presentation to publication conversion rates at radiology conferences of 26%. There have been no prior studies on publication of medical imaging residency research presentations. Our objective was to determine how many medical imaging resident research projects presented at internal program research days across Canada go on to publication. METHODS: A list of unique medical imaging resident research presentations given at program research days during the 2012-2013 to 2016-2017 academic years was generated via e-mail contact of programs or review of publicly available data on program websites. Unique resident presentations were identified and publications associated with these presentations were sought via database and Internet searching. The number of publications, publishing journals, and time to publication was determined. RESULTS: Data from 32 research days at 7 programs were assessed. A total of 287 resident presentations were identified. Of these 287 presentations, 99 had associated publications (34% presentation to publication conversation rate), with variation in presentation numbers and publication conversion rates between schools. These 99 presentations were associated with a total of 118 publications in a total of 57 different journals. Time from presentation to publication was calculable for 109 of the 118 articles. Fifteen (14%) were published before research day and 94 (86%) were published after research day with a mean time to publication of 12.3 ± 13.6 months for all articles. CONCLUSIONS: Thirty-four percent of resident research presentations at Canadian medical imaging program research days go on to publication.

Endoclip Magnetic Resonance Imaging Screening: A Local Practice Review.

PURPOSE: Not all endoscopically placed clips (endoclips) are magnetic resonance imaging (MRI) compatible. At many institutions, endoclip screening is part of the pre-MRI screening process. Our objective is to determine the contribution of each step of this endoclip screening protocol in determining a patient's endoclip status at our institution. METHODS: A retrospective review of patients' endoscopic histories on general MRI screening forms for patients scanned during a 40-day period was performed to assess the percentage of patients that require endoclip screening at our institution. Following this, a prospective evaluation of 614 patients' endoclip screening determined the percentage of these patients ultimately exposed to each step in the protocol (exposure), and the percentage of patients whose endoclip status was determined with reasonable certainty by each step (determination). RESULTS: Exposure and determination values for each step were calculated as follows (exposure, determination): verbal interview (100%, 86%), review of past available imaging (14%, 36%), review of endoscopy report (9%, 57%), and new abdominal radiograph (4%, 96%), or CT (0.2%, 100%) for evaluation of potential endoclips. Only 1 patient did not receive MRI because of screening (in situ gastrointestinal endoclip identified). CONCLUSIONS: Verbal interview is invaluable to endoclip screening, clearing 86% of patients with minimal monetary and time investment. Conversely, the limited availability of endoscopy reports and relevant past imaging somewhat restricts the determination rates of these. New imaging (radiograph or computed tomography) is required <5% of the time, and although costly and associated with patient irradiation, has excellent determination rates (above 96%) when needed.

Endoscopic Clip MRI Screening: A Canada-Wide Policy Survey.

OBJECTIVE: Not all endoscopically placed clips are MRI compatible, so screening for endoscopic clips before MRI is recommended. The purpose of this study was to assess endoscopic clip screening practices at Canadian MRI centers, including number of centers that screen, specific screening methods, perceived safety of endoscopic clip models, and practices for dealing with confirmed gastrointestinal endoscopic clips. MATERIALS AND METHODS: A bilingual online survey was distributed to Canadian MRI centers to assess site demographics, endoscopic clip screening practices, safety considerations for different endoscopic clip models, protocols for dealing with patients with endoscopic clips, and the perceived value of screening. One year later, a secondary survey was distributed to the original participants to assess for changes made to screening policy after the initial survey and to assess awareness of any complications arising from the presence of endoscopic clips during MRI. RESULTS: Sixty-seven MRI centers completed the survey (55% response rate). Sixteen centers (24%) did not specifically screen for endoscopic clips, five because they were not aware that endoscopic clips may not be safe for MRI. Fifty-one centers (76%) did screen for endoscopic clips. At least 23% of screeners misclassified the safety of one or more MRI-unsafe clips. As many as 36% of screeners may perform MRI on patients with confirmed gastrointestinal endoscopic clips; 16% reschedule for more than 6 weeks after endoscopy; and 18% limit the field strength to 1.5 T, the safety of which is uncertain. CONCLUSION: Many Canadians are undergoing MRI without screening for endoscopic clips. Although the risks of MRI to patients with endoscopic clips is unclear, the misclassification of some endoscopic clip models and inconsistent protocols for dealing with confirmed endoscopic clips call for further research and unified evidence-based endoscopic clip screening standards.

The Effect of Extrinsic Material and Radiation Dose on Model-Based Iterative Reconstruction Chest Computed Tomography Reconstruction Time: A Phantom-Based Study.

OBJECTIVE: Compare effect of extrinsic materials and radiation dose levels on image processing times for model-based iterative reconstruction (MBIR) in computed tomography. METHODS: Chest computed tomography scans were performed on a phantom with three different levels of clothing and medical equipment at three tube current settings to reflect differing radiation doses. Reconstruction time for MBIR was recorded, and objective image quality was assessed via noise within the phantom mediastinum. Reconstruction time and noise were compared between scans, with noise also compared between MBIR and matching filtered back projection (FBP) images. RESULTS: Reconstruction times (minutes:seconds) ranged from 37:31 to 42:24. Times were generally faster with less extrinsic material and prolonged among high-dose scans when materials were present. On both the MBIR and FBP images, noise levels were improved with higher radiation doses, although for MBIR only minimally, and the relative effect of extrinsic materials at a given radiation dose was also minimal. In addition, noise was better with MBIR than FBP reconstruction for all conditions. CONCLUSIONS: Typical MBIR reconstruction times are faster with less extrinsic materials in the scan field of views, and removing extraneous blankets or medical devices could positively affect workflow over the course of the day. In addition, MBIR reconstruction times are also shorter when using lower dose protocols in situations requiring extensive materials.

The role of radiology in the quantification of digital ulnar deviation in rheumatoid arthritis patients.

BACKGROUND: Rheumatoid arthritis (RA) is a common inflammatory polyarthritis, which causes functional digital ulnar deviation (UD). Radiographic and magnetic resonance imaging (MRI) assessment of the hands is essential in RA, but its role in the quantification of UD remains unclear. PURPOSE: To compare UD measurements in RA patients between clinical goniometric assessments versus standardized radiographs and MRI. METHODS: Fifteen RA patients with clinically apparent UD and 11 RA patients without UD underwent a rheumatological examination prior to recruitment to this study. Goniometric measurements for UD at the metacarpophalangeal (MCP) joints were performed by an occupational therapist (OT). Standardized hand radiographs, and MRI studies of the dominant hand using 3T MRI scanner with 16 channel hand/wrist coil were evaluated. Angulation measurements for radiographs and MRI were performed independently by two experienced musculoskeletal radiologists who were blinded to the rheumatologist's, occupational therapist's and each other's assessments. RESULTS: Inter-observer correlation between radiologists was >0.97 for both radiographic and MRI measurements. Correlation between OT goniometric measurements and the imaging-based measurements was limited at 0.496 for radiographs and 0.317 for MRI. Correlation between imaging modalities was 0.513. Compared to OT measurements, radiographic and MRI study measurements significantly underestimate the angulation in RA patients with UD (P < 0.001). CONCLUSIONS: The results of this study demonstrated discordance between radiological and goniometric measurements of digital ulnar angulation at the MCP joints in RA patients. Although imaging plays a key role in understanding structural damage and disease activity in RA, it should be emphasized that radiological measurements underrate joint malalignment.

Knowing the Enemy: Health Care Provider Knowledge of Computed Tomography Radiation Dose and Associated Risks.

BACKGROUND: There is ionizing radiation and associated risk from many medical imaging examinations, especially computed tomography (CT). Unfortunately, health care providers often have limited knowledge regarding radiation dose levels and potential risk. RESEARCH OBJECTIVES: To assess knowledge of dose levels and risk among referring physicians, imaging technologists, and radiologists in Saskatoon, Saskatchewan, and to identify potential differences between and within those groups. MATERIALS AND METHODS: A survey was designed and administered to health care professionals. RESULTS: A total of 308 of 328 surveys were completed (91% response rate). Overall 73% of physicians, 97% of radiologists, and 76% of technologists correctly believed that there is a risk for cancer from an abdomen-pelvic CT scan. Although only 18% of physicians, 28% of radiologists, and 22% of technologists selected the most appropriate estimate of abdominal-pelvic CT dose in terms of chest x-ray equivalents, this is similar to other reported studies. Physicians and technologists who use CT were more likely to select the correct dose than those who do not. Most respondents (91% of physicians, 100% of radiologists, and 100% of technologists) felt that pregnant patients should always be informed about radiation dose as a risk. Although frequency of discussing risk decreased with increasing patient age, technologists were more likely to discuss risk at any age. A total of 93% of respondents expressed interest in receiving dose feedback from medical imaging procedures. CONCLUSIONS: Radiologists and technologists generally showed better knowledge than referring physicians. Among physicians and technologists, knowledge was better in those who use CT than those who do not.

Canadian Association of Radiologists Annual Scientific Meetings: How Many Abstracts Go on to Publication?

PURPOSE: To determine the percentage of abstracts presented at the Canadian Association of Radiologists (CAR) annual scientific meetings that go on to publication. METHODS: Records of previous CAR meetings from the years 2005-2011 were obtained. An Internet search was performed to determine which abstracts went on to publication. Abstracts were assessed according to exhibit category (Resident Award Papers), educational institution, publishing journal, and time to publication. RESULTS: Of the 402 abstracts presented, 112 (28%) were published. Overall, an average of 37% of Radiologists-In-Training Presentations, 34% of Scientific Exhibits, and 20% of Educational Exhibits went on to publication. The University of British Columbia and University of Ottawa published the largest number of abstracts (66 and 62, respectively) from the years 2005-2011. The University of Montreal had the largest percentage of abstracts published (42%). The range of publishing journals was wide, but the top publisher was the Canadian Association of Radiologists Journal (27%). Eighty-three percent of abstracts were published within 3 years of being presented. CONCLUSION: In total, 28% of all the abstracts presented at the CAR conferences between 2005 and 2011 were published. Further exploration into the reasons and barriers for abstracts not being published may be a next step in future research.

Radiological errors in the Canadian Journal of Emergency Medicine.

OBJECTIVES: To systematically evaluate the accuracy of text descriptions and labeling of radiologic images published in the Canadian Journal of Emergency Medicine (CJEM). Error detection by radiologists and emergency physicians and the clinical significance and educational value of these errors were assessed. Errors were also correlated with radiologist involvement in publication and imaging modality. METHODS: Thirty-three issues of CJEM were examined from January 2003 to May 2008. Electronic copies of all radiologic images published were obtained with their caption and description from the text. Identifying information was removed to present images in an anonymous fashion. Images were presented to two radiologists who, working in consensus, critically appraised each image and accompanying text. Images were then presented to two emergency department physicians who, working in consensus, critically appraised each image and accompanying text. All images with errors detected by either radiology or emergency physicians were then discussed to determine if errors would have affected clinical management or educational value. The emergency physicians also identified "underlabeled" images where it was felt that further labeling would enhance their educational value. RESULTS: Forty-five articles with 82 images were obtained. At least one error was observed in 18 (40%) articles and 20 (24%) images. Two errors were present in three images, resulting in 23 errors. Of the 23 errors, 17 were image description errors and 6 were labeling errors. Five errors were detected by both radiology and emergency physicians, whereas 15 were detected only by radiologists and 3 were detected only by emergency physicians. Of these errors, 12 (52%) were rated as potentially affecting both clinical management and educational value, 5 (22%) as only affecting educational value, and 6 (26%) as nonsignificant. Radiologists were involved in six articles, including 12 images that contained no errors. There was no official radiologist involvement in 39 articles, including 70 images, 18 (26%) of which contained errors. In addition, 26 images were identified by emergency physicians as potentially benefiting from enhanced labeling to improve educational value. CONCLUSIONS: Radiologic images published in the CJEM are generally of high quality; however, 23 errors were found in 82 images, 18 (78%) of which were rated as potentially affecting clinical management, educational value, or both. Radiologist involvement in the publication process may be of assistance as no errors were seen in articles that included radiologists as authors.