Role of multiparametric MRI in long-term surveillance following focal laser ablation of prostate cancer.

OBJECTIVE: Determine the multiparametric magnetic resonance imaging (mpMRI) appearance of the prostate following focal laser ablation (FLA) for PCa and to identify imaging characteristics associated with recurrent disease. METHODS: Retrospective analysis of patients who underwent FLA for low-intermediate risk PCa between 2010 and 2014 was performed. Early (median 4 months) and late mpMRI (median 49 months) follow-up were qualitatively assessed for T2-weighted, dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) appearances and also compared to corresponding PSA values and biopsy results. RESULTS: 55 cancers were treated in 54 men (mean age 61.0 years). Early mpMRI was performed in 30 (54.5%) patients while late follow-up mpMRI in 42 (84%). Ill-defined scarring with and without atrophy at the treatment site were the most common appearances. In patients with paired MRI and biopsy, one of four patients with clinically significant PCa on biopsy (≥GG2 or≥6 mm GG1) showed hyperenhancement or restricted diffusion at early follow-up. At late follow-up, positive biopsies were seen in 5/8 (63%) cases with hyperenhancement and 5/6 (83%) cases with restricted diffusion at the treatment site. PSA change was not associated with biopsy results at either time point. CONCLUSION: mpMRI is able to document the morphological and temporal changes following focal therapy. It has limited ability to detect recurrent disease in early months following treatment. Late-term mpMRI is sensitive at identifying patients with recurrent disease. Small sample size is, however, a limitation of the study. ADVANCES IN KNOWLEDGE: Implementing MRI in follow-up after FT may be useful in predicting residual or recurrent PCa and therefore provide reliable outcome data.

Evaluation of a multiparametric MRI scoring system for histopathologic treatment response following preoperative chemoradiotherapy for rectal cancer.

PURPOSE: To evaluate the performance of a multiparametric (mp) MRI scoring system for assessment of tumour response in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (CRT). METHOD: Fifty-nine consecutive patients with LARC who had rectal MRI before and after CRT followed by surgery were included. Two radiologists retrospectively assessed tumour response using a proposed mpMRI scoring system. Treatment response was classified as complete, near complete, partial or poor. Accuracy, sensitivity, specificity, positive predictive value and negative predictive values were calculated and inter-reader agreements were assessed. Pathologic tumour regression grade (pTRG) was the reference standard. RESULTS: Treatment response was correctly predicted by both readers in 32.2%-40.7% of patients. Overestimation was more common than underestimation. Sensitivity, specificity, PPV and NPV for pathologic complete response (pCR) among both readers was 16.7-33.0 %, 88.7-94.2 %, 14.3-40.0 % and 92.5-94.2 % respectively. Sensitivity and PPV for both readers improved to 56.0-60.0 % and 53.6-66.7 % respectively when complete response and near complete response categories (good responders) were combined. Inter-reader agreement using the scoring system was fair (κ = 0.383). Agreement between mpMRI score and pathological tumour response was poor to fair for both readers (κ = 0.050 to 0.258) but improved when complete and near complete response categories (good responders) were combined (κ = 0.214 to 0.362). CONCLUSIONS: Despite low agreement between radiological tumour response and pTRG, the proposed mpMRI-based scoring system appears useful in identifying good responders who may benefit from nonoperative management strategies.

Quantitative Prostate MRI Analysis Following Fluvastatin Therapy for Localized Prostate Cancer - A Pilot Study.

PURPOSE: To assess the role of multi-parametric MRI (mpMRI) in assessment of tumor response to fluvastatin administered prior to radical prostatectomy. METHODS: Men with MRI-visible, clinically significant prostate cancer and due to be treated with radical prostatectomy were prospectively enrolled. mpMRI was performed at baseline and following 6-7 week of neoadjuvant oral statin therapy (40 mg fluvastatin, twice daily), prior to prostatectomy. MRI assessment included tumor size, T2 relaxation time, ADC value, K-trans (volume transfer constant), Kep (reflux constant), and Ve (fractional volume) parameters at the 2 time points. Initial prostate needle biopsy cores, prior to starting oral statin therapy, corresponding to site of tumor on radical prostatectomy specimens were selected for analysis. The effect of fluvastatin on tumor proliferation (marker Ki67) and on tumor cell apoptosis (marker cleaved Caspase-3, CC3) were analyzed and correlated with MRI findings. RESULTS: Nine men with paired MRI studies were included in the study. Binary histopathological data was available for 6 of the participants. No significant change in tumor size (P = 0.898), T2 relaxation time (P = 0.213), ADC value (P = 0.455), K-trans (P = 0.613), Kep (P = 0.547) or Ve (P = 0.883) between the time of biopsy and prostatectomy were observed. No significant change in tumor proliferation (%Ki67-positive cells, P = 0.766) was observed by immunohistochemistry analysis. However, there was a significant increase in tumor cell apoptosis (%CC3-positive cells, P = 0.047). CONCLUSION: mpMRI techniques may not be sufficiently sensitive to detect the types (or magnitude) of tumor cell changes observed following 6-7 weeks of fluvastatin therapy for prostate cancer.

Bridging the Gap Between Radiology and Primary Care: Expansion and Sustainability of a Medical Imaging Call Center Model.

OBJECTIVES: The Medical Imaging Call Centre (MICC) was an initiative carried out by a hospital-based academic imaging department with the aim to provide navigational services and radiologist consultations to community-based primary care physicians (PCPs). The strategies used to expand and sustain the initiative over a 3.5-year period after an initial pilot are described. METHODS: The strategy to evolve the MICC had internal and external components. Internally, processes were refined to ensure satisfaction of stakeholders. Externally, a robust engagement strategy focused on recruiting and engaging callers was implemented. Metrics including call volumes, unique callers, and call type were monitored to track utilization and further inform the engagement strategy. A reduction in avoidable use of the emergency department (ED) was determined by tracking pre- and post radiologist consultation decisions reported by callers. RESULTS: During the evaluation period, 2,297 calls were made. There was a 39% increase in the average number of monthly calls in the last 6-month period (61) compared with the first 6 months (44). Call types that involved PCP-to-radiologist communication for patient management consultation also increased over time. A 98% ED avoidance rate (215 of 220) was reported for calls in which PCPs initially indicated that they would be sending their patients to the ED for urgent imaging if the MICC were unavailable. DISCUSSION: The MICC was successful in connecting community-based PCPs with hospital-based subspecialized radiologists. Results indicate that an active engagement strategy is necessary and can lead to changes in patient management that will decrease the burden on other specialists.

Long-Term Impact of Thyroid Biopsy Specialists on Efficiency and Quality of Thyroid Biopsy.

OBJECTIVE: To assess consistency and long-term progress in thyroid biopsy performed by trained sonographers under supervision of a radiologist. METHODS: Trained sonographers started performing thyroid biopsy at our institute in August 2011. The data for this study were extracted from a prospectively maintained database for ultrasound guided thyroid biopsy and included the number of thyroid fine needle aspiration biopsy procedures performed between August 2011 and 2016 and the final cytopathology report as per the Bethesda Classification. For the analysis, the study was divided into two time periods: initial postimplementation period (August 2011 to 2013) and late postimplementation period (2014-2016). RESULTS: In all, 5,538 thyroid biopsies were performed by trained sonographers in the period, 2,561 in the initial implementation period and 2,977 between 2014 and 2016. The unsatisfactory rates dropped from 21% to 10% in the two periods (P < .001), and the proportion of malignant nodules on cytopathology increased from 6% to 7% in the two periods (P = .010). Wait times for thyroid biopsies remained low during the period. CONCLUSION: Sonographers trained to perform ultrasound guided thyroid biopsies provide persistent improved patient care over a long-term period. This reinforces the role of physician extenders in targeted scopes of practice.

Development of nuclear medicine image quality assessment criteria for use in a technologist peer review program.

INTRODUCTION/BACKGROUND: A peer learning program includes the process of peer review, which is the act of performing a secondary review of a peer's work using pre-defined criteria. The Technologist Image Quality Assessment Criteria Project (TIQACP) was initiated to develop and evaluate such criteria for use by technologists for assessment of image quality in Nuclear Medicine (NM). METHODS: A NM clinical expert panel was assembled, comprising 14 technologists, radiologists, and educators from five imaging centres and an academic institution with associated medical imaging training programs. Project design was guided by consensus-based methodology that included three phases: (1) image quality assessment criteria development, based on literature search and expert review (2) image quality assessment criteria refinement, based on consensus-building exercises (panel surveys, discussions, ranking exercise, and time trial) (3) external validation performed via a national survey of NM technologists, facilitated by the Canadian Association of Medical Radiation Technologists. RESULTS: The first phase generated 8 key evidence sources, including textbooks, NM journals and guidelines from professional associations that were reviewed by the expert panel leads and led to a preliminary list of 11 criteria. As part of the second phase, the preliminary list was reviewed via online surveys and panel discussions. Preliminary discussions led to an initial expansion of the list to include 18 criteria. This list required an average of 9 min (range: 7-11 min) for review, which was deemed prohibitive by the panel. A ranking exercise identified 'all required anatomy is clearly identified' as the most relevant criteria and 'Image quality demonstrates no breakdown of the radiopharmaceutical' as the least relevant criteria. Panel discussion also highlighted need to eliminate criteria that were not applicable to all settings. These insights led to an updated list of nine criteria organized into four categories. National validation was supported by 47 NM technologists from across Canada. Respondents were in agreement that the criteria reflected the core elements of image quality in NM (94% agree to strongly agree), were familiar (97%) and were relevant to their current practice setting (88%). The final list was thus not changed based on the survey. DISCUSSION/CONCLUSION: The TIQACP utilized an inclusive process that engaged a range of subject matter experts and the broader NM community to ensure buy-in of the final criteria. These criteria have subsequently been embedded in peer review software that has been implemented into a robust peer learning program for technologists designed to promote a culture of continuous improvement and knowledge sharing amongst front-line staff.

Preliminary evaluation of 18F-FDG-PET/MRI for differentiation of serous from nonserous pancreatic cystic neoplasms: a pilot study.

OBJECTIVES: The aim of the study was to evaluate preliminary feasibility of 18F-FDG-PET/MRI in differentiation of pancreatic serous cystic neoplasms (SCNs) from non-SCNs. METHODS: From August 2017 to June 2019, 10 patients (3 men, 7 women; mean age, 63 years) previously diagnosed with pancreatic cystic neoplasm underwent simultaneous 18F-FDG-PET/MRI prospectively on an integrated 3-Tesla hybrid PET/MRI scanner. PET images were analyzed visually and semiquantitatively measuring standardized uptake values (SUV) including lesion SUVmax and SUVmean, lesion to pancreas and lesion to liver SUVmax and SUVmean ratio independent of MRI diagnosis. The reference standard for lesion diagnosis was by MRI features and interval follow-up. RESULTS: Visual assessment of PET images demonstrated uptake in 57% of SCNs. Lesion to liver SUVmax ratio of ≥0.5 showed the highest accuracy (90%) and area under the curve (0.9) followed by lesion SUVmax of ≥1.6 and lesion to pancreas SUVmax ratio of ≥0.77 for diagnosis of SCN. The sensitivity for lesion SUVmax of ≥1.6 was less than two other ones (71 versus 100%). All non-SCNs exhibited SUVmax value less than 1.6 while 33 and 66% demonstrated lesion to liver SUVmax ratio of >0.5 and lesion to pancreas SUVmax ratio of >0.77, respectively. PET/MRI specificity was 67, 100, 67 and 33% through lesion to liver SUVmax ratio, lesion SUVmax, lesion SUVmean and lesion to pancreas SUVmax ratio, respectively, for diagnosis of SCN. CONCLUSION: Preliminary results show that PET/MRI utilization is promising for differentiation of pancreatic SCN from non-SCN lesions. This could reduce need for surveillance imaging or avoidance of unnecessary intervention in pancreatic cystic neoplasms with uncertain diagnoses.

Optimising after-hours workflow of computed tomography orders in the emergency department.

Ordering and protocolling CT scans after-hours from the emergency department (ED) at our institution previously required discussion between the ED physician and radiology resident, which led to workflow inefficiency. Our intervention consisted of creating an electronic list of CT requests that radiology residents would monitor. Radiology protocolled straightforward requests and contacted the ordering physician for more details when required. We aimed to improve workflow efficiency, increase provider satisfaction and reduce CT turnaround time without significantly affecting CT utilisation. Plan-do-study-act cycles were used to plan and evaluate the intervention. The intervention was initiated on weekday evenings and then expanded to weekend hours after an interim analysis. Qualitative outcomes were measured via electronic survey, and quantitative outcomes were collected from administrative data and analysed via control charts and other statistical methods. Survey response was high from ED physicians (76%, n=82/108) and radiology residents (79%, n=30/38). After the intervention, the majority of ED staff and radiology residents perceived improved workflow efficiency (96.3%, 73.3%), radiology residents noted a subjective decrease in disruptions (83.3%) and most ED staff felt that scans were performed more quickly (84.1%). Radiology residents received fewer pages per shift, adjusted for scan volume. There was a reduction in time from order entry to protocol on weekday shifts only, with no statistically significant effect on time from order entry to scan. Segmented regression analysis demonstrated a background increase in utilisation over time (0.7-2.0 CT/100 ED visits/year, p<0.0005), but the intervention itself did not contribute to an overall increase in CT utilisation. In conclusion, our intervention led to improved perceived workflow efficiency and reduced pages. Scans were protocoled more quickly on weekdays, but turnaround times were otherwise not significantly affected by the intervention. Background CT utilisation increased over time, but this increase was not attributable to our intervention.

Cellular fibroepithelial lesions diagnosed on core needle biopsy: Is there any role of clinical-sonography features helping to differentiate fibroadenomas and phyllodes tumor?

OBJECTIVE: The purpose of this study is to determine the role of clinico-sonographic features of breast cellular fibroepithelial lesions (CFELs) diagnosed on core needle biopsy (CNB) in the differentiation between fibroadenoma (FA) and phyllodes. MATERIALS AND METHODS: Results of consecutive women with a CNB showing CFEL from 2005 to 2010 were retrospectively reviewed. Clinical and sonographic findings were compared with surgical outcomes. Chi-square and Fisher's exact tests were used followed by a regression model for statistical analysis. RESULTS: A total of 131 women with 134 CFEL were included in the study; 89 (66%) were FAs and 45 (34%) were phyllodes (32 benign; 13 malignant). Significant predictors of increased risk of phyllodes tumor were patient age equal to or greater than 50 years (P = .021) and lesion size less than 2 cm at sonography (P = .043). No other imaging or clinical features were able to differentiate FA from phyllodes tumors. CONCLUSION: CFEL with a larger size in older women is associated with the surgical pathological result of phyllodes tumor and management should be tailored accordingly. Younger patients with small size nodules might be approached less aggressively, depending on a personalized discussion with the surgeons, taking into account the results obtained in this study.

Assessment of biliary anatomy in potential living liver donors: Added value of gadoxetic acid-enhanced T1 MR Cholangiography (MRC) including utilization of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique in comparison to T2W-MRC.

OBJECTIVES: To assess the added value of gadoxetic-acid-enhanced T1-weighted magnetic resonance Cholangiography (T1W-MRC) including controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-Volumetric Interpolated Breathhold (VIBE) technique compared to T2-weighted MR Cholangiography (T2W-MRC) in depicting biliary anatomy in potential living liver donors. METHODS: Eighty-five potential donors including 34 men with a mean age of 35.6 years (range, 18-55 years) and 51 women with a mean age of 36.7 years (range, 23-57 years), were enrolled in this ethics-approved retrospective study. Image quality for depiction of bile ducts was evaluated by two readers in consensus in 3 separate reading sessions: 1) T2W-MRC alone, 2) T1W-MRC alone (including CAIPI-VIBE and generalized autocalibrating partially parallel acquisitions (GRAPPA)-VIBE techniques, and 3) combined T1W/T2W-MRC. Accuracy of T2W-MRC, T1W-MRC, and combined T1W/T2W-MRC for the identification/classification of the biliary variants was calculated using intraoperative cholangiogram (IOC) as the reference standard. Image quality and reader diagnostic confidence provided by CAIPI-VIBE technique was compared with GRAPPA-VIBE technique. Datasets were compared using the Wilcoxon signed-rank test. RESULTS: Image quality for depiction of the bile ducts was significantly superior in the combined T1W/T2W-MRC group, when compared to each of T2W-MRC and T1W-MRC groups independently (P value = 0.001-0.034). The combination of CAIPI-VIBE and GRAPPA-VIBE was superior compared to each of the sequences individually. The accuracy of T2W-MRC and T1W-MRC was 93% and 91%, respectively. T1W-MRC depicted four biliary variants better than T2W-MRC. Two variants not well seen in T2W-MRC were clearly shown on T1W-MRC. CONCLUSION: Gadoxetic-acid-enhanced T1W-MRC and conventional T2W-MRC techniques are complementary for depiction of biliary variants in potential liver donors and the combination of the two improves the results. The combination of CAIPI-VIBE and GRAPPA-VIBE techniques appear to be complementary for optimal diagnostic yield of T1W-MRC.

Risk stratification in primary sclerosing cholangitis: comparison of biliary stricture severity on MRCP versus liver stiffness by MR elastography and vibration-controlled transient elastography.

OBJECTIVES: To compare biliary stricture severity on magnetic resonance cholangiopancreatography (MRCP), magnetic resonance elastography (MRE), and vibration-controlled transient elastography (VCTE) liver stiffness (LS) for evaluation of risk stratification and prognostication in primary sclerosing cholangitis (PSC). MATERIALS AND METHODS: Eighty-seven patients (31-61 years; 34 female/53 male) prospectively underwent biochemical testing, VCTE, MRCP, and MRE between January 2014 and July 2016. Correlation between the MRCP grading of PSC based on biliary stricture severity, LS on MRE and VCTE, and the Mayo Risk Score as well as the Amsterdam Oxford Prognostic Index (AOPI) were evaluated and compared. Stricture severity was classified according to previous classification systems based on ERCP. Spearman's correlation and Kruskal-Wallis tests were performed. RESULTS: MRE-LS and intrahepatic stricture severity combined demonstrated higher discriminatory ability among risk categories based on Mayo Risk Score (AUROC = 0.8). MRE-LS alone demonstrated excellent discriminatory ability among risk categories based on AOPI using cutoffs of 1 and 2.7 and was superior to intrahepatic stricture severity (AUROC = 0.9, AUROC = 0.6-0.7). There was a weak correlation between intrahepatic stricture severity and MRE-LS (rho = 0.3; p = 0.011). VCTE-LS values were not correlated with stricture severity and were noncontributory to differentiate patients across risk groups. Intrahepatic stricture severity alone was a poor discriminator of advanced liver fibrosis on MRE (AUROC = 0.7); however, combining intra- and extrahepatic stricture severity and controlling for cholestasis and disease duration improved results (AUROC = 0.9). CONCLUSION: This study demonstrates a significant discriminatory ability of LS values on MRE to distinguish between early to moderate and advanced liver fibrosis. LS values on MRE may add value to risk prognostication and further studies including clinical outcomes are needed. KEY POINTS: • Risk stratification was excellent for liver stiffness measurements on MRE and poor for VCTE and biliary stricture severity. • Risk stratification was further improved when liver stiffness measured on MRE was combined with intrahepatic and extrahepatic stricture severity and indicators of cholestasis were controlled for. • Liver stiffness measurements on MRE correlated with prognostic scores better than measurements performed on VCTE.

Predictive Value of In Vivo MR Spectroscopy With Semilocalization by Adiabatic Selective Refocusing in Differentiating Clear Cell Renal Cell Carcinoma From Other Subtypes.

OBJECTIVE. The purpose of this study is to evaluate the diagnostic value of in vivo MR spectroscopy (MRS) with semilocalization by adiabatic selective refocusing (semi-LASER MRS) in differentiating clear cell renal cell carcinoma (RCC) from the non-clear cell subtype. SUBJECTS AND METHODS. Sixteen patients with biopsy-proven RCC or masses highly suspicious for RCC were prospectively recruited to participate in the study. Single-voxel 1H spectra were acquired using a 3-T MRI system, with a semi-LASER sequence acquired for renal tumors in 14 patients and for healthy renal tissue (control tissue) in 12 patients. Offline processing of the MR spectra was performed. MRI and spectra analysis were performed independently by radiologists who were blinded to the reference histopathologic findings. RESULTS. Semi-LASER MRS was diagnostic for nine of 11 patients (82%) with histopathologically proven clear cell RCC, showing a strong lipid peak in seven patients and a weaker lipid resonance in two others, whereas control spectra showed weakly positive findings in only one patient. MRS findings were negative for lipid resonance in two of three patients (67%) with non-clear cell tumors and were weakly positive in another patient. Semi-LASER MRS had a high sensitivity and positive predictive value of 82% and 90%, respectively, in addition to a specificity of 67%, a negative predictive value of 50%, and overall accuracy of 79% for the detection of clear cell RCC. Lipid resonance was detected by MRS for four of six clear cell RCCs with no intravoxel fat on chemical-shift MRI. CONCLUSION. The preliminary results of the present study show that semi-LASER MRS is promising for the noninvasive discrimination of clear cell RCC from non-clear cell RCC on the basis of detection of lipid resonance and that it provides an incremental yield compared with chemical-shift MRI.

Glucose dysregulation in patients with iron overload: is there a relationship with quantitative pancreas and liver iron and fat content measured by MRI?

OBJECTIVES: The aim was to investigate the relationship between pancreatic and hepatic iron and fat to glucose metabolism in patients with iron overload and address conflicting results in literature as regards the relationship between pancreas iron and glucose dysregulation. METHODS: We retrospectively evaluated pancreatic and hepatic R2*, fat fraction (FF), liver iron concentration (LIC), and glucose metabolism in 105 patients with iron overload obtained with a multi-echo gradient echo R2* technique and assessed the correlation between pancreatic R2* and FF to glucose dysregulation. RESULTS: There were no significant differences in pancreatic R2*, liver R2*, and FF in patients with iron overload and glucose dysregulation compared to those with normoglycemia (p = 0.435, p = 0.674, and p = 0.976), whereas pancreatic FF was significantly higher, 23.5% vs 16.7% respectively (p = 0.011). Pancreatic FF and R2* demonstrated an area under the curve of 0.666 and 0.571 for discriminating glucose dysregulation. Pancreatic FF of 26.2% yielded specificity and sensitivity of 80% and 45% for prediction of glucose dysregulation. Pancreatic R2* weakly correlated with pancreatic FF, r = 0.388 (p < 0.001), and liver R2*, r = 0.201 (p = 0.033), and showed no correlation with hepatic FF r = -0.013 (p = 0.892) or LIC categories (p = 0.493). CONCLUSION: Pancreatic FF but not pancreatic R2* was associated with glucose dysregulation in patients with iron overload. Prior studies reporting correlation of pancreatic R2* to glucose dysregulation likely relate from inadequate MRI technique or analysis employed, which unlike our study did not perform simultaneous measurements of fat and iron essential to avoid their confounding effects during quantitative analysis. KEY POINTS: • Pancreatic fat fraction, unlike iron, is associated with glucose dysregulation in iron overload. • Simultaneous measurement of pancreatic iron and fat content with MRI is essential to avoid confounding effects of one another during quantitative analysis. • Pancreatic fat fraction could be utilized to predict glucose dysregulation in iron overload states.

Diagnostic performance of 2015 American Thyroid Association guidelines and inter-observer variability in assigning risk category.

OBJECTIVE: To determine the interobserver variability of the 2015 American Thyroid Association (ATA) thyroid guidelines and to evaluate the diagnostic accuracy of the guidelines in detecting thyroid cancer. MATERIALS AND METHODS: Sonographic patterns of 189 thyroid lesions were retrospectively analyzed by two radiologists according to the 2015 guidelines. The risk of malignancy was calculated for each pattern and compared with the published expected risk of malignancy. RESULTS: The observed risk of malignancy for very low suspicion, low suspicion, intermediate suspicion and high suspicion patterns were 2%, 12.7%, 26.3% and 29.8% respectively. Interobserver agreement for final category assignment was moderate (κ 0.518). CONCLUSION: The estimated risk of malignancy in the high suspicion pattern of the 2015 ATA thyroid biopsy guidelines appears to be less than stated. However, this needs further validation in a larger cohort study.

Outcomes of Long-term Interval Rescreening With Low-Dose Computed Tomography for Lung Cancer in Different Risk Cohorts.

INTRODUCTION: We hypothesize that the incidence of screen-detected lung cancer (LC), in participants with previously negative scans, will be highest in the cohort with the highest baseline risk score. METHODS: Individuals with negative baseline screening results from the Princess Margaret International Early Lung Cancer Action Program before 2009 underwent low-dose computed tomography rescreening from 2015 to 2018. Individuals were contacted in order of descending risk, as determined by the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial's PLCOM2012 6-year LC risk-prediction model, and then categorized into three risk cohorts according to their baseline risks. The incidence of LC in each risk cohort was determined and compared. Chi-square testing was used for categorical variables and one-way analysis of variance on ranks was used for continuous variables. RESULTS: Of the 1261 participants we attempted to re-contact, 359 participants returned for a rescreening scan (mean of 7.6 years between scans). Participants were divided into low (<2%), moderate (≥2% to <3.5%), and high baseline risk (≥3.5%) cohorts. On average, those in the high-risk cohort compared to the moderate- and low-risk cohorts were older (66 years versus 62 and 59 years) and had a greater smoking history (54 pack-years versus 47 and 29 pack-years). The incidence of cancer in the high-risk cohort was significantly higher than in the moderate-risk cohort (11% versus 1.7%, p = 0.002). CONCLUSIONS: There was a significantly higher incidence of LC in the high-risk cohort than in the moderate-risk cohort. The cut-point between the high- and moderate-risk was determined to be greater than or equal to 3.5% of the 6-year baseline risk.

Using Digital Health to Support Best Practices: Impact of MRI Ordering Guidelines Embedded Within an Electronic Referral Solution.

BACKGROUND: Between 2003 and 2012, the number of MRIs performed in Canada more than doubled to 1.7 million [1]. According to a 2010 Health Council of Canada report nearly 30% of MRIs were inappropriately ordered [2]. The use of diagnostic imaging referral guidelines has been shown to improve the appropriateness of imaging orders [3, 4]. OBJECTIVES: To identify the number of unnecessary pre-consult MRIs ordered for patients with knee pain. As well, the impact that new evidence-based clinical decision support (DS) guidelines embedded within the referral form has had on the number of unnecessary MRIs was investigated. METHODS: This study employed a retrospective design approach. Charts of all knee pain patients over the age of 55 who were referred for consultation to the 5 participating orthopedic surgeons during the study period were reviewed by three medical students. RESULTS: 270 patient charts were included in this study. MRI was ordered for 60 patients with only 56.7% having had a prior X-ray. Of the 60 ordered MRIs, 50 (84%) were considered inappropriate, while only 10 (16%) were appropriate. Our results were compared to previous results of a quality improvement study implemented at the same clinic. A substantial reduction of 12% in the number of pre-consult MRIs and a 5% increase in the number of ordered X-rays before consultation was demonstrated. CONCLUSION: This work highlights the impact of including DS tools within an electronic referral form to support clinical best practices.

The development and validation of magnetic resonance elastography for fibrosis staging in primary sclerosing cholangitis.

OBJECTIVES: To develop and internally validate MR elastography (MRE) quantified liver stiffness (LS) cut-off values for distinguishing early/moderate fibrosis from cirrhosis in primary sclerosing cholangitis (PSC) against non-invasive fibrosis test of vibration-controlled transient elastography (VCTE). METHODS: Sixty-seven patients were enrolled prospectively at a tertiary care centre to undergo MRE and VCTE. MRE-quantified LS was calculated using three region-of-interest (ROI) methods: Trace, Average and Maximum. Each ROI method was compared with the reference standard of VCTE. Internal validation was performed with bootstrapping. Univariable and multivariable linear regression determined independent predictors for MRE-quantified LS and final Mayo Risk Score (MRS). RESULTS: MRE-quantified LS by Trace ROI method had the highest sensitivity [87.5%; 95% confidence interval (CI), 66.0-96.8] and specificity (96.1%; 95%CI, 89.6-99.0) for distinguishing cirrhosis; and was the strongest predictor of final MRS (ß, 0.44; 95% CI, 0.27-0.61). Alkaline phosphatase twice the normal upper limit (ß, 1.55; 95% CI, 0.95-2.17), abnormal bilirubin (ß, 1.27; 95% CI, 0.41-2.14) and thrombocytopaenia (ß, 0.79; 95% CI, 0.12-1.46) were independent predictors of LS. CONCLUSIONS: MRE has a higher correlation with MRS than VCTE; and though MRE is possibly influenced by severe cholestasis and portal hypertension, MRE-quantified LS is an independent predictor of worse MRS. KEY POINTS: • MRE is valid and reliable in assessing cirrhosis in PSC, and MRE-quantified Liver stiffness (LS) score was the strongest predictor of final Mayo Risk Score (MRS). • Trace ROI performs best for distinguishing moderate fibrosis from cirrhosis and has the highest correlation with Mayo Risk Score (MRS). • Cholestasis, hyperbilirubinaemia and portal hypertension may influence MRE LS score.

"I'm Just Guessing These Answers!" An Evaluation of the (In)Accuracy of Patient-Reported Medical History Collected as Part of a Breast Imaging Program.

INTRODUCTION: Hundreds of thousands of Ontario women receive breast screening imaging each year. The patient's medical history is a vital tool used to personalize breast screening approaches. This study evaluated the accuracy of self-reported medical and imaging history in patients about to receive breast imaging procedures in a large urban Canadian hospital. The patient experience with using a blank screening form vs. a novel prefilled screening form was also evaluated. METHODS AND MATERIALS: The study was conducted in two phases. Phase 1 compared patient-reported information (via the blank screening form) to information previously captured in the Radiology Information and Picture Archiving Communication Systems to assess data accuracy. In phase 2, study questionnaires were used to collect data on the patients' experience with the screening form in two cohorts (between the blank and a novel prefilled screening form). RESULTS: Data accuracy: for mammography (n = 60), 40% of the patients could accurately recall when and where their last mammogram was performed. For breast ultrasound (n = 43) and breast magnetic resonance imaging (n = 20), significantly fewer patients could accurately recall the date their last test was performed (14% and 10%, respectively). Of those who had previous breast surgery (n = 18), 100% were able to recall whether the surgery resulted in a benign or malignant diagnosis, and 61% were able to accurately recall the year they had the breast surgery. PATIENT EXPERIENCE: Of the returned questionnaires, 65 provided feedback on the blank screening form while 55 provided feedback on the prefilled form. Ninety percent preferred to fill out the new prefilled screening form. The themes acknowledged a general improvement in the screening form, a decrease in frustration associated with having to recall their medical history, and the patients felt that the institution better understood their medical history. CONCLUSIONS: The findings of this research indicate that asking patients to complete a blank medical screening form is a highly inaccurate method of gathering that important information. When that information was prefilled for the patient to review and update, patient frustration and stress were decreased, while satisfaction and confidence in the organization were increased.

Enhanced pneumothorax visualization in ICU patients using portable chest radiography.

OBJECTIVE: Pneumothorax development can cause precipitous deterioration in ICU patients, therefore quick and accurate detection is vital. Portable chest radiography is commonly performed to exclude pneumothoraces but is hampered by supine patient position and overlying internal and external material. Also, the initial evaluation of the chest radiograph may be performed by a relatively inexperienced physician. Therefore, a tool that could significantly improve pneumothorax detection on portable radiography would be helpful in patient care. The aim of this study was to evaluate the clinical utility of novel enhancement software for pneumothorax detection in readers with varied clinical experience of detecting/excluding pneumothoraces on portable chest radiographs in ICU patients. SUBJECTS AND METHODS: 206 portable ICU chest radiographs, 103 with pneumothoraces, were processed with and without enhancement software and reviewed by 5 readers who varied in reading experience. Images were grouped for different complexity levels. RESULTS: The mean AUC for pneumothorax detection increased for 4/5 readers from 0.846-0.957 to 0.88-0.971 with a largest improvement for the reader with least experience. No significant change was noted for the reader with the longest reading experience. The image complexity had no impact on the interpretation result. CONCLUSION: Pneumothorax detection improves with novel enhancement software; the largest improvement is seen in less experienced readers.

Importance of Long-term Low-Dose CT Follow-up after Negative Findings at Previous Lung Cancer Screening.

Purpose To assess the incidence of lung cancer in a cohort of patients with negative findings at previous lung cancer screening. Materials and Methods In this prospective cohort study, the authors first identified 4782 individuals who had negative screening results as part of the International Early Lung Cancer Action Program (1993-2005). Subjects were assigned a lung cancer risk score by using a validated risk model. Starting with those at highest risk, subjects were interviewed by phone and invited to undergo low-dose CT between March 2013 and October 2016. Subjects with a diagnosis of lung cancer and those who had died of lung cancer were determined. Descriptive statistics were used to summarize data. The independent samples t test and Fisher exact test were used to compare age, sex, and risk scores. Results A total of 327 study participants were contacted, and 200 subjects participated in this study. The average age was 74 years (range, 57-88 years), and the median time since previous CT was 7 years. The incidence rate of developing lung cancer during the next 6 years was estimated at 5.6%. The period prevalence of lung cancer was 20.8% (new and preexisting lung cancer, 68 of total cohort of 327). The detection rate of low-dose CT was 7% (14 of 200 subjects). Of the 14 screening-detected cancers, 12 were stage I or II. Conclusion High-risk individuals have a high incidence of lung cancer after previous negative lung cancer screening. Early-stage lung cancer can be successfully detected in older high-risk individuals. © RSNA, 2018 Online supplemental material is available for this article.