Custom 3-Dimensional Printed Ultrasound-Compatible Vascular Access Models: Training Medical Students for Vascular Access

PurposeTo generate 3-dimensional (3D) printed ultrasound (US)-compatible vascular models (3DPVAM) and test them for noninferiority in training medical students in femoral artery access.Materials and MethodsA 3DPVAM of normal femoral artery (FA) anatomy was developed from an anonymized computerized tomography (CT) examination. Students were randomized to a 3DPVAM or a commercial model (CM) simulation experience (SE) for US-guided FA access. Students completed a pre-SE questionnaire ranking their self-confidence in accessing the artery on a 5-point Likert scale. A standardized SE was administered by interventional radiology faculty or trainees. Students completed a post-SE questionnaire ranking comfort with FA access on a Likert scale. Student questionnaire results from the 3DPVAM group were compared with those from the CM group by using chi-square, Wilcoxon signed-rank, and noninferiority analyses.ResultsTwenty-six and twenty-three students were randomized to 3DPVAM and commercial model training, respectively. A total of 76.9% of 3DPVAM trainees and 82.6% of CM trainees did not feel confident performing FA access prior to the SE. In both groups, training increased student confidence by 2 Likert points (3DPVAM: P < 0.001; CM P < 0.001). The confidence increase in 3DPVAM trainees was noninferior to that in CM trainees (P < 0.001).ConclusionsGeneration of a custom-made 3DPVAM is feasible, producing comparable subjective training outcomes to those of CM. Custom-made 3D-printed training models, including incorporation of more complex anatomical configurations, could be used to instruct medical students in procedural skills.     

Evaluation of Technical Performance of Ultrasound-Guided Procedures through Hand Motion Analysis: An Exploration of Motion Metrics

PurposeTo evaluate the ability of hand motion analysis using conventional and new motion metrics to differentiate between operators of varying levels of experience for central venous access (CVA) and liver biopsy (LB).Materials and MethodsIn the CVA task, 7 interventional radiologists (experts), 10 senior trainees, and 5 junior trainees performed ultrasound-guided CVA on a standardized manikin; 5 trainees were retested after 1 year. In the LB task, 4 radiologists (experts) and 7 trainees biopsied a lesion on a manikin. Conventional motion metrics (path length and task time), a refined metric (translational movements), and new metrics (rotational sum and rotational movements) were calculated.ResultsIn the CVA task, experts outperformed trainees on all metrics (P < .02). Senior trainees required fewer rotational movements (P = .02), translational movements (P = .045), and time (P = .001) than junior trainees. Similarly, on 1-year follow-up, trainees had fewer translational (P = .02) and rotational (P = .003) movements with less task time (P = .003). The path length and rotational sum were not different between junior and senior trainees or for trainees on follow-up. Rotational and translational movements had greater area under the curve values (0.91 and 0.86, respectively) than the rotational sum (0.73) and path length (0.61). In the LB task, experts performed the task with a shorter path length (P = .04), fewer translational (P = .04) and rotational (P = .02) movements, and less time (P < .001) relative to the trainees.ConclusionsHand motion analysis using translational and rotational movements was better at differentiating levels of experience and improvement with training than the conventional metric of path length.     

Results of an American College of Radiology-Society of Interventional Radiology Membership Survey on Exclusive Contracts and the Attitudes of Interventional Radiologists

PurposeTo assess the attitudes of interventional radiologists (IRs) and diagnostic radiologists (DRs) toward exclusive contracts and independently practicing IRs who may request privileges at a hospital where an exclusive contract exists with a different group of radiologists.Materials and MethodsA total of 22,400 survey instruments were distributed to 4,490 IRs and 17,910 DRs in the United States. Statistical evaluation included multivariate ordinal logistic regression analysis with calculation of the odds ratios and forest plots.ResultsCompleted surveys were received from 525 (11.69%) IRs and 401 (2.23%) DRs. Given the low response rate of DRs, data analysis was focused on IRs. Early-career IRs and those in outpatient practices had a more positive attitude toward independent IRs who requested admitting and/or procedural privileges. A supermajority of both IRs and DRs who responded to the survey agreed that the importance of IR to hospital and health system contracts will increase.ConclusionsThis survey identified many interrelated and complex variables that significantly affected the attitudes of IRs in various practice settings toward independent IRs requesting hospital admitting and/or procedural privileges. It will benefit independent IRs seeking admitting privileges to better understand some of the factors that impact the potential willingness of the radiology groups and other IRs with exclusive hospital contracts to work toward mutually beneficial practice paradigms, especially as more clinically oriented IRs complete their training in the new, integrated residency programs.     

Intravascular Ultrasound-Guided Transvenous Biopsy of Abdominal and Pelvic Targets Difficult to Access by Percutaneous Needle Biopsy: Technique and Initial Clinical Experience

PurposeTo report initial clinical experience with intravascular ultrasound (US)-guided transvenous biopsy (TVB) for perivascular target lesions in the abdomen and pelvis using side-viewing phased-array intracardiac echocardiography catheters.Materials and MethodsIn this single-institution, retrospective study, 48 patients underwent 50 intravascular US-guided TVB procedures for targets close to the inferior vena cava or iliac veins deemed difficult to access by conventional percutaneous needle biopsy (PNB). In all procedures, side-viewing phased-array intracardiac echocardiography intravascular US catheters and transjugular liver biopsy sets were inserted through separate jugular or femoral vein access sheaths, and 18-gauge core needle biopsy specimens were obtained under real-time intravascular US guidance. Diagnostic yield, diagnostic accuracy, and complications were analyzed.ResultsIntravascular US-guided TVB was diagnostic of malignancy in 40 of 50 procedures for a diagnostic yield of 80%. There were 5 procedures in which biopsy was correctly negative for malignancy, with a per-procedure diagnostic accuracy of 90% (45/50). Among the 5 false negatives, 2 patients underwent repeat intravascular US-guided TVB, which was diagnostic of malignancy for a per-patient diagnostic accuracy of 94% (45/48). There were 1 (2%) mild, 2 (4%) moderate, and 1 (2%) severe adverse events, with 1 moderate severity adverse event (venous thrombosis) directly attributable to the intravascular US-guided TVB technique.ConclusionsIntravascular US-guided TVB performed on difficult-to-approach perivascular targets in the abdomen and pelvis resulted in a high diagnostic accuracy, similar to accepted thresholds for PNB. Complication rates may be slightly higher but should be weighed relative to the risks of difficult PNB, surgical biopsy, or clinical management without biopsy.     

Direct radiation exposure of the eye lenses in cranial computed tomography and exposure reduction through radiographer training

IntroductionIonizing radiation can cause increased opacity of the lens and later lead to radiation-induced cataract.Therefore, the eye lens should be positioned outside of the direct radiation beam in cranial computed tomography (CCT). If this is not possible, protective measures must be taken, which includes the use of external lens protectors. In this study we assess whether direct radiation exposure of the eyes in CCT can be reduced by trained radiographers and whether the use of eye lens protectors improves after training.MethodsFirst, we evaluated 763 non-enhanced CCT regarding direct radiation exposure of eyeballs and eye lenses and usage of lens shielding. Afterwards, we trained radiographers to avoid radiation exposure of the eyes by head adjustment and protectors and assessed the improvements in a subsequent study of 678 CCT. We tried to identify factors that influenced radiation exposure of the eye lens.ResultsAfter training, frequency of radiation exposure of lenses was significantly reduced by 5.9% (220/763 patients in pre- vs. 155/678 patients in post-training group, p = 0.01). The use of external lens protectors significantly increased after training by 9.8% (37/763 patients in pre- vs. 99/678 patients in post-training group, p < 0.001). The absence of tiltable headrest was a risk factor for increased eye lens radiation exposure in the pre-training group. The presence of cervical spine immobilizer was associated with more frequent radiation exposure of the lenses in the pre- and post-training group.ConclusionsRadiographer training and the use of tiltable headrest lead to reduction of radiation exposure to the eye lens.Implications for practiceRadiographer training is an effective method to reduce eye lens exposure in CCT. The usage of tiltable headrest minimizes the radiation exposure of the lenses.     

Coronary artery calcium scoring in low risk patients with family history of coronary heart disease: Validation of the SCCT guideline approach in the coronary artery calcium consortium

BackgroundThe Society of Cardiovascular Computed Tomography (SCCT) recommends consideration of coronary artery calcium (CAC) scoring among individuals with a family history (FH) of coronary heart disease (CHD) and atherosclerotic cardiovascular disease (ASCVD) risk <5%. No dedicated study has examined the prognostic significance of CAC scoring among this population.MethodsThe CAC Consortium is a multi-center observational cohort study from four clinical centers linked to long-term follow-up for cause-specific mortality. All CAC scans were physician referred and performed in patients without a history of CHD. Our analysis includes 14,169 patients with ASCVD scores <5% and self-reported FH of CHD.ResultsThis cohort had a mean age of 48.1 (SD 7.4), was 91.3% white, 47.4% female, had an average ASCVD score of 2.3% (SD 1.3), and 59.4% had a CAC = 0. The event rate for all-cause mortality was 1.2 per 1000 person-years, 0.3 per 1000 person-years for CVD-specific mortality, and 0.2 per 1000 person-years for CHD-specific mortality. In multivariable Cox proportional hazard models, those with CAC>100 had a 2.2 (95% CI 1.5–3.3) higher risk of all-cause mortality, 4.3 (95% CI 1.9–9.5) times higher risk of CVD-specific mortality, and a 10.4 (95% CI 3.2–33.7) times higher risk of CHD-specific mortality compared to individuals with CAC = 0. The NNS to detect CAC >100 in this sample was 9.ConclusionIn otherwise low risk patients with FH of CHD, CAC>100 were associated with increased risk of all-cause and CHD mortality with event rates in a range that may benefit with preventive pharmacotherapy. These data strongly support new SCCT recommendations regarding testing of patients with a family history of CHD.     

Beliefs and behaviours of radiographers and other health professionals concerning radiation protection safety in a high-volume Greek public hospital. Development of a new measuring instrument

IntroductionThe use of fluoroscopy-assisted surgical procedures has been increasing recently. The extensive use of fluoroscopy, combined with the lack of knowledge about radiation risks among operating room (OR) personnel (surgeons, anaesthetists, nurses, and radiographers), may lead to misconceptions. The perceptions and beliefs of any health professional concerning radiation protection safety (RPS) may affect their behaviour during surgery, leading to negative outcomes. The aim of this study was to construct a new, original, reliable, and valid instrument to record the beliefs, perceptions, and behaviours of health professionals during surgery, which reflects the established culture of RPS.MethodsA questionnaire was designed, consisting of 95 questions grouped into six coherent sections. The study was performed at a Greek public hospital with a high workload in terms of fluoroscopically guided surgical operations.ResultsIt was distributed among 136 people, and 132 completed questionnaires were collected (response rate 97%). Exploratory factor analysis was performed separately for each scale studied and Cronbach's Alpha reliability analysis was also performed. The reliability of the greater part of the new measurement tool ranged from very good to acceptable.ConclusionThe questionnaire developed in this study is a valid and reliable option for recording health professionals’ perceptions, beliefs, and behaviours concerning the RPS culture.Implications for practiceThis study helps clinical radiographers to understand a possible knowledge gap about RPS and locates the specific fields that the OR personnel misunderstand. It also can support and establish local learning organisations with regular targeted staff training for health professionals, thereby leading to a generally improved RPS culture.     

Public Awareness of Interventional Radiology: Population-Based Analysis of the Current State of and Pathways for Improvement

PurposeTo evaluate the awareness of interventional radiology (IR) among the public and identify methods for improvement.Materials and MethodsParticipants (N = 1,000) were anonymously surveyed using Amazon’s Mechanical Turk crowdsourcing platform about medical and IR-specific knowledge, preferred methods of acquisition of medical information, and suggestions for improving awareness of IR. The survey consisted of 69 questions, including both Likert Scale and free text questions.ResultsOf the participants, 92% preferred undergoing a minimally invasive procedure over surgery. However, 39.8% recognized IR as a medical specialty, and less than 50% of these participants correctly identified IR as procedurally oriented. Of those who discussed or underwent an IR procedure (n = 113), most were also offered to undergo the procedure performed by a surgeon (n = 66). Furthermore, 71% (n = 20) of those who underwent the procedure performed by a surgeon reported that lack of awareness of IR played a role in their decision. Almost half of the respondents (n = 458) were interested in learning more about IR, particularly the diseases treated and procedures performed (42% and 37%, respectively). Short (<10-minute) educational videos and increased patient education by primary care providers (PCPs) were among the most suggested ways to improve awareness. Regarding the ambiguity of the name “interventional radiology,” most respondents (n = 555) reported this to be true, and “minimally invasive radiologist” was the most preferred alternative (21.18%).ConclusionsLack of awareness of IR may underlie underutilization. When presented with the knowledge that IR improves patient outcomes, minimally invasive procedures by an interventional radiologist are more often desired by the public than surgical options. Educational videos and patient education by PCPs may increase awareness of IR.     

Utilization of and Outcomes Associated with Intravascular Ultrasound during Deep Venous Stent Placement among Medicare Beneficiaries

PurposeTo evaluate temporal trends, practice variation, and associated outcomes with the use of intravascular ultrasound (US) during deep venous stent placement among Medicare beneficiaries.Materials and MethodsAll lower extremity deep venous stent placement procedures performed between January 1, 2017, and December 31, 2019 among Medicare beneficiaries were included. Temporal trends in intravascular US use were stratified by procedural setting and physician specialty. The primary outcome was a composite of 12-month all-cause mortality, all-cause hospitalization, or repeat target vessel intervention. The secondary outcome was a composite of 12-month stent thrombosis, embolization, or restenosis.ResultsAmong the 20,984 deep venous interventions performed during the study period, 15,184 (72.4%) utilized intravascular US. Moderate growth in intravascular US use was observed during the study period in all clinical settings. There was a variation in the use of intravascular US among all operators (median, 77.3% of cases; interquartile range, 20.0%–99.2%). In weighted analyses, intravascular US use during deep venous stent placement was associated with a lower risk of both the primary (adjusted hazard ratio, 0.72; 95% confidence interval [CI], 0.69–0.76; P < .001) and secondary (adjusted hazard ratio, 0.32; 95% CI, 0.27–0.39; P < .001) composite end points.ConclusionsIntravascular US is frequently used during deep venous stent placement among Medicare beneficiaries, with further increase in use from 2017 to 2019. The utilization of intravascular US as part of a procedural strategy was associated with a lower cumulative incidence of adverse outcomes after the procedure, including venous stent thrombosis and embolization.     

Treatment of Arm Swelling in Hemodialysis Patients with Ipsilateral Arteriovenous Access and Central Vein Stenosis: Conversion to the Hemodialysis Reliable Outflow Graft versus Stent Deployment

PurposeTo compare outcomes after conversion of arteriovenous (AV) access to Hemodialysis Reliable Outflow (HeRO) graft vs stent deployment in patients with arm swelling owing to ipsilateral central vein stenosis.Materials and MethodsThis single-center retrospective study comprised 48 patients (19 men, mean age 58 y) with arm swelling ipsilateral to AV access and central vein stenosis over a 13-year period who had clinical follow-up and without prior central stents. Twenty-one patients underwent placement of a HeRO graft with anastomosis of the HeRO graft to the existing graft or fistula, and 27 patients underwent central venous stent deployment. Symptomatic improvement in arm swelling and access patency rates after intervention were ascertained from medical records.ResultsImprovement in swelling within 1 month after HeRO conversion and stent deployment was found in 95% and 89%, respectively (P = .62). Swelling eventually recurred in 16 patients (59%) treated with stents compared with 1 patient (5%) who underwent HeRO conversion (P < .001). Primary access patency was statistically significantly longer after HeRO conversions than stent deployments, with 6- and 12-month primary patency rates of 89% and 72% vs 47% and 11% (P < .001). HeRO conversions also resulted in longer 6- and 12-month secondary access patency rates (95% and 95% vs 79% and 58%, P = .006). Mean number of interventions per 1,000 access days to maintain secondary patency was 2.7 for the HeRO group vs 6.3 for the stent group.ConclusionsAlthough stent deployment and HeRO graft conversion are effective for alleviating arm swelling in the short term in patients receiving hemodialysis with clinically significant arm swelling and functioning AV access, the HeRO graft has more durable results.     

Deep Learning Subtraction Angiography: Improved Generalizability with Transfer Learning

PurposeTo investigate the utility and generalizability of deep learning subtraction angiography (DLSA) for generating synthetic digital subtraction angiography (DSA) images without misalignment artifacts.Materials and MethodsDSA images and native digital angiograms of the cerebral, hepatic, and splenic vasculature, both with and without motion artifacts, were retrospectively collected. Images were divided into a motion-free training set (n = 66 patients, 9,161 images) and a motion artifact–containing test set (n = 22 patients, 3,322 images). Using the motion-free set, the deep neural network pix2pix was trained to produce synthetic DSA images without misalignment artifacts directly from native digital angiograms. After training, the algorithm was tested on digital angiograms of hepatic and splenic vasculature with substantial motion. Four board-certified radiologists evaluated performance via visual assessment using a 5-grade Likert scale. Subgroup analyses were performed to analyze the impact of transfer learning and generalizability to novel vasculature.ResultsCompared with the traditional DSA method, the proposed approach was found to generate synthetic DSA images with significantly fewer background artifacts (a mean rating of 1.9 [95% CI, 1.1–2.6] vs 3.5 [3.5–4.4]; P = .01) without a significant difference in foreground vascular detail (mean rating of 3.1 [2.6–3.5] vs 3.3 [2.8–3.8], P = .19) in both the hepatic and splenic vasculature. Transfer learning significantly improved the quality of generated images (P < .001).ConclusionsDLSA successfully generates synthetic angiograms without misalignment artifacts, is improved through transfer learning, and generalizes reliably to novel vasculature that was not included in the training data.     

Clinical placement challenges associated with radiography education in a low-resource setting: A qualitative exploration of the Ethiopian landscape

IntroductionClinical placements (CP) are of paramount importance in the learning and the acquisition of key competencies in terms of knowledge, skill and professional attributes required for clinical radiography practice. This study explored the challenges faced by radiography students and educators in relation to clinical placement and training in Ethiopia.MethodsA qualitative approach using focus group discussion and interviews were used to explore the experiences of students and educators, respectively, pertaining to challenges encountered in relation to the clinical placement of students across four university affiliated hospitals. Data obtained was analysed using a structured three step framework and the coding approach employed in a thematic analysis.ResultsParticipants comprise of third- and fourth-year undergraduate radiography students (n = 14) and educators [academic faculty (n = 7) and clinical practice educators (n = 8)]. Four main themes were identified, which relate to deficiencies of an existing training curriculum and its implementation strategies, inadequate resource and infrastructure within the CP environments and absence of advanced training opportunities.ConclusionThis research showed that there are many and varied challenges encountered by both students and educators in relation to CP and training of radiography students in Ethiopia. These challenges could potentially affect the future performance of students/practitioners and/or the appropriate application of the core clinical radiography skills and competencies in the world of work.Implications for practiceClinical radiography training in resource-limited settings will require urgent attention and support with modern infrastructure including simulation to augment their clinical development to acceptable standards.     

Thoracic Duct Embolization Using Transabdominal Antegrade and Transcervical Retrograde Accesses

PurposeTo evaluate the technical success and clinical outcomes of thoracic duct embolization (TDE) using transabdominal antegrade and transcervical retrograde accesses to treat patients with chyle leak.Materials and MethodsThis study was a retrospective, nonblinded, single-institution chart review of all patients aged 18 years or older over a 6-year time frame who underwent lymphangiography with attempted TDE for iatrogenic or spontaneous chyle leaks using transabdominal antegrade and/or transcervical retrograde accesses.ResultsNinety-nine patients underwent 113 procedures. Eighty-five patients underwent 1 procedure, and 14 patients required 2 procedures. The technical success rate of TDE was 68% (72/106) with transabdominal antegrade access and 44% (15/34) with transcervical retrograde access. The overall technical success rate of TDE, including both the access methods, was 77% (87/113). The most common reasons for transabdominal access failure were small caliber of the cisterna chyli and thoracic duct (TD) occlusion. Five patients were lost to follow-up. Overall clinical success, defined as resolution of the chyle leak, was achieved in 83% (78/94) of the patients. There were 6 Society of Interventional Radiology (SIR) level 1 adverse events (AEs), 5 SIR level 2 AEs, and 2 SIR level 3 AEs. Nontarget embolization occurred in 2 patients.ConclusionsAlthough transcervical retrograde TDE is a challenging procedure, with a lower technical success rate than transabdominal antegrade access, retrograde access improved the technical and clinical success rates of the treatment of chyle leaks in cases of thoracic duct occlusion, small cisterna chyli, and leaks located in the abdomen.     

Quantification of Blood Flow in Dialysis Access Using Custom-Acquisition Protocol and Imaging Methods: A Clinical Validation Study

PurposeTo determine access blood flow (ABF) rate using 2D image sequences acquired with digital subtraction angiography (DSA) and fluoroscopy.Materials and MethodsA total of 23 patients with known or suspected malfunctioning accesses were imaged using 2 filming modes: DSA at 3 or 6 frames/s (F/s), and fluoroscopy at 10 or 15 pulses/s (P/s). ABF rates were quantified using a bolus tracking method based on cross-correlation algorithm and compared with catheter-based thermal dilution (TD) flow measurements. The indicator-dilution curves were fitted with a gamma-variate (GV) curve fitting model to assess the effect on accuracy. Radiation doses were calculated to examine any increased susceptibility to tissue reactions and stochastic effects.ResultsFor DSA images, the absolute percent deviations (mean ± standard error of mean) in computed flow vs TD flow measurements at 3 F/s and 6 F/s were 34% ± 4.5% and 20% ± 4.7%, respectively, without curve fitting, and 31% ± 3.3% and 20% ± 4.1%, respectively, with curve fitting. For fluoroscopic images, the deviations at 10 P/s and 15 P/s were 44% ± 7.3% and 68% ± 10.7%, respectively, without curve fitting and 36% ± 6.4% and 48% ± 7.1%, respectively, with curve fitting. The mean peak skin dose and effective dose at 6 F/s were 3.28 mGy and 75 μSv, respectively.ConclusionsDigital subtraction angiography images obtained at 6 F/s offered the highest accuracy for dialysis access blood flow quantification.     

Endovascular Removal of Thrombus and Right Heart Masses Using the AngioVac System: Results of 234 Patients from the Prospective,Multicenter Registry of AngioVac Procedures in Detail (RAPID)

PurposeTo assess device and procedural safety and technical success associated with the use of the AngioVac System to remove vascular thrombi and cardiac masses.Materials and MethodsThe Registry of AngioVac Procedures in Detail (RAPID) study prospectively collected data for 234 patients receiving treatment with AngioVac at 21 sites between March 2016 and August 2019: 84 (35.9%) with caval thromboemboli (CTEs), 113 (48.3%) with right heart masses (RHMs), 20 (8.5%) with catheter-related thrombi (CRTs), and 4 (1.7%) with pulmonary emboli (PEs). Thirteen patients had a combination of procedures during the same admission.ResultsUsing the AngioVac system, 70%–100% thrombus or mass removal was achieved in 73.6% of patients with CTEs, 58.5% of patients with RHMs, 60% of patients with CRTs, and 57.1% of patients with PEs. Extracorporeal bypass time was < 1 hour for 176 (75.2%) procedures. Estimated blood loss was < 250 mL for 179 procedures (76.5%). Mean hemoglobin decreased from 10.4 g/dL ± 2.9 preoperatively to 9.4 g/dL ± 2.6 postoperatively. Transfusions were administered in 59 procedures (25.2%) with 47 transfusions (78.2%) being ≤ 2 U. There were 36 procedure-related complications, including 1 death.ConclusionsThe RAPID registry data demonstrate that the AngioVac System can be safely and effectively used to remove vascular thrombi and cardiac masses across a broad range of patient populations. The limited use of the device to remove pulmonary emboli in the present series precludes recommending the use of the AngioVac device for this indication.     

Safety and Efficacy of a Truncated Deflation Algorithm for Distal Transradial Access

PurposeTo assess safety and efficacy of a modified rapid hemostasis protocol for distal transradial access (TRA).Materials and MethodsA single-center retrospective study of patients undergoing percutaneous image-guided procedures from a distal TRA with rapid deflation hemostasis protocol was performed. Between March 2017 and August 2019, 593 procedures in 434 patients were performed. Mean patient age was 63.5 y (range, 18–94 y).ResultsThe most common procedures were transarterial chemoembolization (218; 36.8%), abdominal and pelvic embolization (116; 19.6%), yttrium-90 mapping (115; 19.4%), yttrium-90 administration (84; 14.2%), and diagnostic angiography (44; 7.4%). Mean (range) values for clotting parameters were international normalized ratio 1.2 (0.9–3.2), partial thromboplastin time 33.5 s (26–44 s), and platelets 23.4 × 10⁹/L (37–552 × 10⁹/L). A hematoma developed in 7 (1.2%) patients. No radial artery occlusions were encountered during follow-up. Nursing intensity was defined as the number of minutes after the procedure required for assessing and managing the access site for bleeding. The mean nursing intensity was 25.1 min (range, 25–40 min).ConclusionsThe rapid deflation hemostasis protocol for distal TRA at the anatomical snuffbox was feasible and safe. No significant difference or association was found between hematoma formation and clotting parameters after the procedure or type of vascular access equipment used.     

A Survey of Interventional Radiologists Regarding the Use of Morbidity and Mortality Conferencing in Departmental Quality Improvement Programs

PurposeTo investigate the degree to which morbidity and mortality (M&M) conferencing is utilized in interventional radiology (IR), identify impediments to its adoption, and assess the experience of those using this tool.Materials and MethodsMembers of the Society of Interventional Radiology (SIR) were offered a 9-question survey of practices and experiences regarding M&M conferencing within their quality assessment (QA) programs.ResultsAmong 604 respondents, 37.8% were university-based practitioners and 60% were from outside of university practices. Of all respondents, 43% reported practicing 100% IR, with 28.5% practicing IR 75%–99% and 11% practicing IR <50% of the time. The use of M&M conferencing was significantly greater in university practices (90.7%) than in nonuniversity practices (37.1%) and among practitioners performing at least 75% IR (71.2%) than among those practicing <75% (28.8%). The conferences were held monthly (66.6%) or more often, and the majority (56%) of the events identified were scored using the SIR severity score. Approximately 20% of M&M conferences were multidisciplinary, shared most commonly with vascular surgery. The reasons cited for not using M&M included the lack of time and the logistical challenges of the process. However, among those who participate in M&M conferences, the QA goals of the conference were met at very high rates.ConclusionsM&M conferencing is well established in university IR programs and among full-time practitioners but much less so elsewhere. For those sites that do not utilize M&M conferencing, there may be a considerable benefit to addressing the obstacles that are limiting their implementation of this tool.     

Evaluation of an Integrated Spectroscopy and Classification Platform for Point-of-Care Core Needle Biopsy Assessment: Performance Characteristics from Ex Vivo Renal Mass Biopsies

PurposeTo evaluate a transmission optical spectroscopy instrument for rapid ex vivo assessment of core needle cancer biopsies (CNBs) at the point of care.Materials and MethodsCNBs from surgically resected renal tumors and nontumor regions were scanned on their sampling trays with a custom spectroscopy instrument. After extracting principal spectral components, machine learning was used to train logistic regression, support vector machines, and random decision forest (RF) classifiers on 80% of randomized and stratified data. The algorithms were evaluated on the remaining 20% of the data set held out during training. Binary classification (tumor/nontumor) was performed based on a decision threshold. Multinomial classification was also performed to differentiate between the subtypes of renal cell carcinoma (RCC) and account for potential confounding effects from fat, blood, and necrotic tissue. Classifiers were compared based on sensitivity, specificity, and positive predictive value (PPV) relative to a histopathologic standard.ResultsA total of 545 CNBs from 102 patients were analyzed, yielding 5,583 spectra after outlier exclusion. At the individual spectra level, the best performing algorithm was RF with sensitivities of 96% and 92% and specificities of 90% and 89%, for the binary and multiclass analyses, respectively. At the full CNB level, RF algorithm also showed the highest sensitivity and specificity (93% and 91%, respectively). For RCC subtypes, the highest sensitivity and PPV were attained for clear cell (93.5%) and chromophobe (98.2%) subtypes, respectively.ConclusionsEx vivo spectroscopy imaging paired with machine learning can accurately characterize renal mass CNB at the time of tissue acquisition.     

Quantification of extracellular volume with cardiac computed tomography in patients with dilated cardiomyopathy

BackgroundCardiac computed tomography (CCT) was recently validated to measure extracellular volume (ECV) in the setting of cardiac amyloidosis, showing good agreement with cardiovascular magnetic resonance (CMR). However, no evidence is available with a whole-heart single source, single energy CT scanner in the clinical context of newly diagnosed left ventricular dysfunction. Therefore, the aim of this study was to test the diagnostic accuracy of ECV_CCT in patients with a recent diagnosis of dilated cardiomyopathy, having ECV_CMR as the reference technique.Methods39 consecutive patients with newly diagnosed dilated cardiomyopathy (LVEF <50%) scheduled for clinically indicated CMR were prospectively enrolled. Myocardial segment evaluability assessment with each technique, agreement between ECV_CMR and ECV_CCT, regression analysis, Bland-Altman analysis and interclass correlation coefficient (ICC) were performed.ResultsMean age of enrolled patients was 62 ​± ​11 years, and mean LVEF at CMR was 35.4 ​± ​10.7%. Overall radiation exposure for ECV estimation was 2.1 ​± ​1.1 ​mSv. Out of 624 myocardial segments available for analysis, 624 (100%) segments were assessable by CCT while 608 (97.4%) were evaluable at CMR. ECV_CCT demonstrated slightly lower values compared to ECV_CMR (all segments, 31.8 ​± ​6.5% vs 33.9 ​± ​8.0%, p ​< ​0.001). At regression analysis, strong correlations were described (all segments, r ​= ​0.819, 95% CI: 0.791 to 0.844). On Bland-Altman analysis, bias between ECV_CMR and ECV_CCT for global analysis was 2.1 (95% CI: −6.8 to 11.1). ICC analysis showed both high intra-observer and inter-observer agreement for ECV_CCT calculation (0.986, 95%CI: 0.983 to 0.988 and 0.966, 95%CI: 0.960 to 0.971, respectively).ConclusionsECV estimation with a whole-heart single source, single energy CT scanner is feasible and accurate. Integration of ECV measurement in a comprehensive CCT evaluation of patients with newly diagnosed dilated cardiomyopathy can be performed with a small increase in overall radiation exposure.