Mixed plaque on coronary CT angiography predicts atherosclerotic events in asymptomatic intermediate-risk individuals.

OBJECTIVE: Coronary CT angiography (CCTA) permits both qualitative and quantitative analysis of atherosclerotic plaque and may be a suitable risk modifier in assessing patients at intermediate risk of atherosclerotic cardiovascular disease. We sought to determine the association of plaque components with long-term major adverse cardiovascular events (MACEs) in asymptomatic intermediate-risk patients, compared with conventional coronary artery calcium (CAC) score. METHODS: 100 intermediate-risk patients underwent double-blinded CCTA. Follow-up was conducted at 10 years and data were cross-referenced with the National Death Index. The primary outcome was MACE, which was a composite of death, acute coronary syndrome (ACS), revascularisation and stroke. RESULTS: The median time from CCTA to follow-up was 9.5 years. 83 patients completed follow-up interview and mortality data were available on all 100 patients. MACE occurred in 17 (20.5%) patients, which included 2 (2%) deaths, 8 (10%) ACS, 3 (4%) strokes and 5 (6%) revascularisation procedures. 47 (57%) patients had mixed plaque, which was predictive of MACE (OR 4.68 (95% CI 1.19 to 18.5) p=0.028). The burden of non-calcified and mixed plaque, defined by non-calcified plaque segment stenosis score, was also a predictor of long-term MACE (OR 1.59 (95% CI 1.18 to 2.13) p=0.002). Neither calcified plaque (OR 3.92 (95% CI 0.80 to 19.3)) nor CAC score (OR 1.01 (95% CI 0.999 to 1.02)) was associated with long-term MACE. CONCLUSION: The presence and burden of mixed plaque on CCTA is associated with an increased risk of long-term MACE among asymptomatic intermediate-risk patients and is a superior predictor to CAC score.

Let's settle the controversy-gelfoam is a safe intravascular embolic agent.

OBJECTIVES: A 2021 safety alert restricted endovascular gelfoam use in Australia and resulted in an embargo on gelfoam sales to IR departments. This study aimed to show that gelfoam is safe in a population of trauma patients with pelvic injury, and discuss the basis of the recent controversies. METHODS: Retrospective cohort study between 1 January 2010 and 21 May 2021 of patients who underwent gelfoam embolisation for pelvic arterial haemorrhage. Primary outcome was the rate of adverse events related to intravascular gelfoam administration. RESULTS: Inclusion criteria met in 50 patients, comprising 58% males median age 59.9 years, and median injury severity score 31. There were 0 complications related to gelfoam use and 100% technical success. 35 patients (70%) received a non-targeted embolisation approach. All-cause mortality was observed in 5 patients (10%), unrelated to gelfoam. CONCLUSIONS: Gelfoam is a safe and effective embolic agent in pelvic trauma. Patients are in urgent need of universal on-label registration of endovascular gelfoam products, as it is life-saving in major haemorrhage after trauma. ADVANCES IN KNOWLEDGE: Endovascular gelfoam is mandatory for a high-quality trauma service, and this study shows that it is safe to use intentionally in the endovascular space. Companies should work with interventional radiologists, sharing and collaborating to ensure positive outcomes for patients.

A retrospective observational study assessing mortality after pelvic trauma embolisation.

INTRODUCTION: Trauma to the pelvic ring and associated haemorrhage represent a management challenge for the multidisciplinary trauma team. In up to 10% of patients, bleeding can be the result of an arterial injury and mortality is reported as high as 89% in this cohort. We aimed to assess the mortality rate after pelvic trauma embolisation and whether earlier embolisation improved mortality. METHODS: Retrospective study at single tertiary trauma and referral centre, between 1 January 2009 and 30 June 2022. All adult patients who received embolisation following pelvic trauma were included. Patients were excluded if angiography was performed but no embolisation performed. RESULTS: During the 13.5-year time period, 175 patients underwent angiography and 28 were excluded, leaving 147 patients in the study. The all-cause mortality rate at 30-days was 11.6% (17 patients). The median time from injury to embolisation was 6.3 h (range 2.8-418.4). On regression analysis, time from injury to embolisation was not associated with mortality (OR 1.01, 95% CI 0.952-1.061). Increasing age (OR 1.20, 95% CI 1.084-1.333) and increasing injury severity score (OR 1.14, 95% CI 1.049-1.247) were positively associated with all-cause 30-day mortality, while non-selective embolisation (OR 0.11, 95% CI 0.013-0.893) was negatively associated. CONCLUSION: The all-cause mortality rate at 30-days in or cohort was very low. In addition, earlier time from injury to embolisation was not positively associated with all-cause 30-day mortality. Nevertheless, minimising this remains a fundamental principle of the management of bleeding in pelvic trauma.

Improving portable low-field MRI image quality through image-to-image translation using paired low- and high-field images.

Low-field portable magnetic resonance imaging (MRI) scanners are more accessible, cost-effective, sustainable with lower carbon emissions than superconducting high-field MRI scanners. However, the images produced have relatively poor image quality, lower signal-to-noise ratio, and limited spatial resolution. This study develops and investigates an image-to-image translation deep learning model, LoHiResGAN, to enhance the quality of low-field (64mT) MRI scans and generate synthetic high-field (3T) MRI scans. We employed a paired dataset comprising T1- and T2-weighted MRI sequences from the 64mT and 3T and compared the performance of the LoHiResGAN model with other state-of-the-art models, including GANs, CycleGAN, U-Net, and cGAN. Our proposed method demonstrates superior performance in terms of image quality metrics, such as normalized root-mean-squared error, structural similarity index measure, peak signal-to-noise ratio, and perception-based image quality evaluator. Additionally, we evaluated the accuracy of brain morphometry measurements for 33 brain regions across the original 3T, 64mT, and synthetic 3T images. The results indicate that the synthetic 3T images created using our proposed LoHiResGAN model significantly improve the image quality of low-field MRI data compared to other methods (GANs, CycleGAN, U-Net, cGAN) and provide more consistent brain morphometry measurements across various brain regions in reference to 3T. Synthetic images generated by our method demonstrated high quality both quantitatively and qualitatively. However, additional research, involving diverse datasets and clinical validation, is necessary to fully understand its applicability for clinical diagnostics, especially in settings where high-field MRI scanners are less accessible.

A rare case of MRI of myxoid hepatocellular adenoma with gadoxetic acid uptake.

This is the first case report of 43-year-old lady with a myxoid hepatic adenoma which demonstrated significant contrast uptake during hepatobiliary phase imaging. This highlights the potential for a missed diagnosis and likely subsequent malignant transformation in a young patient in whom it was initially presumed to be focal nodular hyperplasia with no further surveillance.

The use of whole-body trauma CT should be based on mechanism of injury: A risk analysis of 3920 patients at a tertiary trauma centre.

BACKGROUND: Mechanism of injury (MOI) plays a significant role in a decision to perform whole-body computed tomography (CT) imaging for trauma patients. Various mechanisms have unique patterns of injury and therefore form an important variable in decision making. METHODS: Retrospective cohort study including all patients >18 years old who received a whole-body CT scan between 1 January 2019 and 19 February 2020. The outcomes were divided into CT 'positive' if any internal injuries were detected and CT 'negative' if no internal injuries were detected. The MOI, vital sign parameters, and other relevant clinical examination findings at presentation were recorded. RESULTS: 3920 patients met the inclusion criteria, of which 1591 (40.6%) had a positive CT. The most common MOI was fall from standing height (FFSH), accounting for 23.0%, followed by motor vehicle accident (MVA), accounting for 22.4%. Covariates significantly associated with a positive CT included age, MVA >60 km/h, motor bike, bicycle, or pedestrian accident >30 km/h, prolonged extrication >30 min, fall from height above standing, penetrating chest or abdominal injury, as well as hypotension, neurological deficit, or hypoxia on arrival. FFSH was shown to reduce the risk of a positive CT overall, however, sub-analysis of FFSH in patients >65 years showed a significant association with a positive CT (OR 2.34, p < 0.001) compared to <65 years. CONCLUSIONS: Pre-arrival information including MOI and vital signs have significant impact on identifying subsequent injuries with CT imaging. In high energy trauma, we should consider the need for whole-body CT based on MOI alone regardless of the clinical examination findings. However, for low-energy trauma, including FFSH, in the absence of clinical examination findings which support an internal injury, a screening whole-body CT is unlikely to yield a positive result, particularly in the age group <65yo.

Evaluation of subjective anterior disc space widening on trauma cervical spine CT as a potential sign of ligamentous injury.

INTRODUCTION: MRI is commonly accepted as the gold standard imaging technique for identification of isolated discoligamentous injury to the cervical spine. Widening of the anterior disc space (ADW) has been suggested as signs of injury to the anterior longitudinal ligament (ALL). The purpose of this study aimed to assess the accuracy of ADW reported on CT as a sign of ligamentous injury compared. METHODS: The study was performed at a level 1 trauma centre. All patients over a 5-year period from 1 January 2015 to 31 January 2019 who underwent a cervical CT scan for the indication of trauma and who subsequently received a cervical spine MRI during the same admission were included if no fracture was found on the initial CT. Demographic data were collected along with mechanism of injury and time period between CT and MRI. Presence or absence of subjective CT-ADW along with presence or absence of ALL injury on MRI was recorded by retrospective review of the radiology reports. Sensitivity, specificity and positive and negative predictive values were then calculated. RESULTS: Over a 5-year period, 1,305 patients fulfilled the study criteria. CT-ADW had a sensitivity, specificity and positive predictive value of 8.2% (95% CI: 2.7-18.1%), 96.2% (95% CI: 95.3-97.4%) and 10.2% (95% CI: 3.4-22.2%) respectively. CONCLUSION: Subjective CT-ADW is a poor predictor of ALL injury as assessed by MRI and should not be relied upon in isolation to diagnose ligamentous injury of the cervical spine in the setting of trauma.

Retrospective analysis and prospective validation of an AI-based software for intracranial haemorrhage detection at a high-volume trauma centre.

Rapid detection of intracranial haemorrhage (ICH) is crucial for assessing patients with neurological symptoms. Prioritising these urgent scans for reporting presents a challenge for radiologists. Artificial intelligence (AI) offers a solution to enable radiologists to triage urgent scans and reduce reporting errors. This study aims to evaluate the accuracy of an ICH-detection AI software and whether it benefits a high-volume trauma centre in terms of triage and reducing diagnostic errors. A peer review of head CT scans performed prior to the implementation of the AI was conducted to identify the department's current miss-rate. Once implemented, the AI software was validated using CT scans performed over one month, and was reviewed by a neuroradiologist. The turn-around-time was calculated as the time taken from scan completion to report finalisation. 2916 head CT scans and reports were reviewed as part of the audit. The AI software flagged 20 cases that were negative-by-report. Two of these were true-misses that had no follow-up imaging. Both patients were followed up and exhibited no long-term neurological sequelae. For ICH-positive scans, there was an increase in TAT in the total sample (35.6%), and a statistically insignificant decrease in TAT in the emergency (- 5.1%) and outpatient (- 14.2%) cohorts. The AI software was tested on a sample of real-world data from a high-volume Australian centre. The diagnostic accuracy was comparable to that reported in literature. The study demonstrated the institution's low miss-rate and short reporting time, therefore any improvements from the use of AI would be marginal and challenging to measure.

Immune Function After Splenic Artery Embolization for Blunt Trauma: Long-Term Assessment of CD27+ IgM B-Cell Levels.

Splenic artery embolization (SAE) plays a critical role in the treatment of high-grade splenic injury not requiring emergent laparotomy. SAE preserves splenic tissue, and growing evidence demonstrates preserved short-term splenic immune function after SAE. However, long-term function is less studied. Patients who underwent SAE for blunt abdominal trauma over a 10-year period were contacted for long-term follow-up. Sixteen participants (sex: women, 10, and men, 6; age: median, 34 years, and range, 18-67 years) were followed up at a median of 7.7 years (range, 4.7-12.8 years) after embolization. Splenic lacerations were of American Association for the Surgery of Trauma grades III to V, and 14 procedures involved proximal embolization. All individuals had measurable levels of IgM memory B cells (median, 14.30 as %B cells), splenic tissue present on ultrasound (median, 122 mL), and no history of severe infection since SAE. In conclusion, this study quantitatively demonstrated that long-term immune function remains after SAE for blunt abdominal trauma based on the IgM memory B cell levels.

Diagnostic accuracy of a commercially available deep-learning algorithm in supine chest radiographs following trauma.

OBJECTIVES: Trauma chest radiographs may contain subtle and time-critical pathology. Artificial intelligence (AI) may aid in accurate reporting, timely identification and worklist prioritisation. However, few AI programs have been externally validated. This study aimed to evaluate the performance of a commercially available deep convolutional neural network - Annalise CXR V1.2 (Annalise.ai) - for detection of traumatic injuries on supine chest radiographs. METHODS: Chest radiographs with a CT performed within 24 h in the setting of trauma were retrospectively identified at a level one adult trauma centre between January 2009 and June 2019. Annalise.ai assessment of the chest radiograph was compared to the radiologist report of the chest radiograph. Contemporaneous CT report was taken as the ground truth. Agreement with CT was measured using Cohen's κ and sensitivity/specificity for both AI and radiologists were calculated. RESULTS: There were 1404 cases identified with a median age of 52 (IQR 33-69) years, 949 males. AI demonstrated superior performance compared to radiologists in identifying pneumothorax (p = 0.007) and segmental collapse (p = 0.012) on chest radiograph. Radiologists performed better than AI for clavicle fracture (p = 0.002), humerus fracture (p < 0.0015) and scapula fracture (p = 0.014). No statistical difference was found for identification of rib fractures and pneumomediastinum. CONCLUSION: The evaluated AI performed comparably to radiologists in interpreting chest radiographs. Further evaluation of this AI program has the potential to enable it to be safely incorporated in clinical processes. ADVANCES IN KNOWLEDGE: Clinically useful AI programs represent promising decision support tools.

A Pilot First-in-Human Study of Embrace, a Polyethylene Glycol-Based Liquid Embolic Agent, in the Embolization of Malignant and Benign Hypervascular Tumors.

PURPOSE: To investigate the safety and efficacy of an aqueous polyethylene glycol-based liquid embolic agent, Embrace Hydrogel Embolic System (HES), in the treatment of benign and malignant hypervascular tumors. MATERIALS AND METHODS: A prospective, single-arm, multicenter study included 8 patients, 5 males and 3 females, with a median age of 58.5 years (30-85 years), who underwent embolization in 8 tumors between October 2019 and May 2020. Technical success was defined as successful delivery of HES to the index vessel, with disappearance of >90% of the targeted vascular enhancement or, for portal vein embolization, occlusion of the portal branches to the liver segments for future resection. The volume of HES administered, ease of use (5 point Likert scale), administration time, and adverse events (AEs) were recorded. Evaluation was performed at 7, 30, and 90 days via clinical assessment and blood testing, and follow-up imaging was performed at 30 days. RESULTS: Eight patients were enrolled, and 10 embolizations were performed in 8 lesions. Tumors included hepatocellular carcinoma (n = 4), renal angiomyolipoma (n = 3), and intrahepatic cholangiocarcinoma (n = 1). Technical success was 100%, and the average ease of use was 3.3 ± 1.0 SD. The HES delivery time was 1-28 minutes (median, 16.5 minutes), and the HES volume injected was 0.4-4.0 mL (median, 1.3 mL). All patients reached 30-day follow-up with imaging, and 6 patients reached 90-day follow-up. There were 3 serious AEs in 2 patients that were unrelated to the embolic agent. CONCLUSION: HES resulted in a 100% embolization technical success rate. The product ease of use was acceptable, and no target vessel recanalization was noted on follow-up imaging at 30 days.

PIVET-ED: A Prospective, Randomised, Single-Blinded, Sham Controlled Study of Pelvic Vein Embolisation for Treatment of Erectile Dysfunction.

PURPOSE: Erectile Dysfunction (ED) is defined as the inability to obtain or maintain an erection firm enough for satisfactory sexual performance and affects the quality of life of over 50% of men aged over 40 years. Venogenic ED is elucidated as a cause in a subgroup of patients. The study aims to investigate the clinical success, technical success, safety and durability of venous embolisation for management of venogenic ED. METHODS: After providing informed consent, and subsequent to confirmation of venogenic ED by Doppler ultrasound (dUS) and cavernosography, 80 men referred for cavernosography and pelvic vein embolisation, will undergo randomisation by a computer system either to treatment or sham groups. Efficacy will be assessed using dUS and a validated questionnaire, the International Index of Erectile Function (IIEF). Pharmacologic agents used during the trial will be recorded. The primary outcome of PiVET-ED is to establish clinical success at 3 and 6 months post venous embolisation, as defined by end diastolic velocity in the cavernosal artery < 5 cm/s with dUS and by a > 4-point improvement in IIEF. Durability of the embolisation procedure will be assessed annually to 5 years. Quality of life will be assessed at all study time points using the 36-Item Short Form Survey (SF-36). DISCUSSION: The PiVET-ED trial is a prospective, randomised, single-blinded, single centre, sham controlled study, which aims to establish the safety, efficacy and durability of pelvic vein embolisation for the treatment of venogenic erectile dysfunction. CLINICAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12620001023943, 08/10/2020.

Clinical utility of stimulated cholescintigraphy using a standardized Ensure-Plus fatty meal protocol in patients with suspected functional gallbladder disorder: a retrospective study of seven-years clinical experience.

BACKGROUND: The clinical utility of fatty meal stimulated cholescintigraphy particularly using a standardized formulation in patients with suspected functional gallbladder disorder has not been extensively studied. We present our seven-year clinical experience using an Ensure plus protocol. METHODS: A retrospective study was performed on patients undergoing stimulated cholescintigraphy using Ensure Plus for evaluation of suspected functional gallbladder disorder. A gallbladder ejection fraction (GBEF) of <33% was considered abnormal. RESULTS: Of the 173 patients evaluated, 57 (33%) had an abnormal GBEF, 112 (65%) had a normal GBEF and 4 (2%) had no gallbladder visualization. Of the 57 patients with an abnormal GBEF, symptom improvement occurred in 30/31 (97%) who underwent cholecystectomy and in 17/26 (65%) who were managed conservatively (p = 0.003). Of the 112 patients with a normal GBEF, symptom improvement occurred in 8/10 (80%) who underwent cholecystectomy and 74/102 (73%) who were managed conservatively (p = 1.000). In the subgroup of 102 patients with a normal GBEF managed conservatively, those without symptomatic improvement had lower GBEFs compared to those with symptomatic improvement (median GBEF 46% versus 57%, p = 0.019). CONCLUSION: Our retrospective results support a clinical role for stimulated cholescintigraphy using Ensure Plus in the evaluation of patients with suspected functional gallbladder disorder. While an abnormal GBEF predicts good surgical outcome, our results suggest that using an absolute GBEF cut off value of <33% may not apply to all patients and hence GBEF results should only be used as an adjunct in the surgical decision-making process.

Immune function and the role of vaccination after splenic artery embolization for blunt splenic injury.

The spleen is the most commonly injured solid organ following blunt abdominal trauma. Over recent decades, splenic artery embolization (SAE) has become the mainstay treatment for haemodynamically stable patients with high-grade blunt splenic trauma, with splenectomy the mainstay of treatment for unstable patients. Splenic function is complex but the spleen has an important role in immune function, particularly in protection against encapsulated bacteria. Established evidence suggests that following splenectomy immune function is impaired resulting in increased susceptibility to overwhelming post-splenectomy infection, however, immune function may be preserved following SAE. This review will discuss the current state of the literature on immune function following different treatments of blunt splenic injury, and the controversies surrounding what constitutes a quantitative test of splenic immune function.

CLiP, catheter and line position dataset.

Correct catheter position is crucial to ensuring appropriate function of the catheter and avoid complications. This paper describes a dataset consisting of 50,612 image level and 17,999 manually labelled annotations from 30,083 chest radiographs from the publicly available NIH ChestXRay14 dataset with manually annotated and segmented endotracheal tubes (ETT), nasoenteric tubes (NET) and central venous catheters (CVCs).

Irreversible electroporation versus radiofrequency ablation for hepatocellular carcinoma: a single centre propensity-matched comparison.

BACKGROUND AND AIMS: Irreversible electroporation (IRE) is a relatively new non-thermal ablative method for unresectable hepatocellular carcinoma (HCC). We aimed to compare the longer-term efficacy of IRE to the standard thermal technique of radiofrequency ablation (RFA) in HCC. METHODS: All patients who underwent IRE or RFA for HCC in our centre were identified and demographic and clinical data were analysed up until 1st March, 2020. Local recurrence-free survival (LRFS) was compared between groups after propensity score matching for age, gender, Child-Pugh grade, BCLC stage, lesion size and alpha-fetoprotein (AFP) level. RESULTS: A total of 190 HCC ablations (31 IRE and 159 RFA) were identified. After propensity score matching, we compared 25 IRE procedures (76% males, median age 62.4 years, median tumour size 20 mm) to 96 RFA procedures (84.4% males, median age 64.3 years, median tumour size 18.5 mm). LRFS did not differ between groups, with a 1-, 2- and 5-year LRFS of 80.4% (95% CI 55.8-92.2), 69.1% (95% CI 43.3-84.9) and 44.9% (95% CI 18.9-68.1%), respectively for IRE and 84.8% (95% CI 75.2-90.9), 71.3% (95% CI 58.3-81.0) and 52.1% (95% CI 35.4-66.4%), respectively for RFA (p = .63). There were no major procedure-related complications or deaths in either group. CONCLUSIONS: Whilst IRE remains a relatively novel therapy for HCC cases where standard thermal ablation is contraindicated, the LRFS in our centre is comparable to that of RFA. IRE should therefore be considered as a treatment option in such cases when available before stage-migration to non-curative therapies such as transarterial chemoembolization (TACE).

Radiological assessment of facial fractures: a comparative study between surgeon and radiologist.

BACKGROUND: The authors aimed to examine the differences in CT facial bone interpretation by the faciomaxillary surgeon and the radiologist, in order to improve communication gaps and subsequently, the quality and consistency of patient care. METHODS: This study was conducted at a level I tertiary trauma centre. Patients with facial trauma who were referred to the faciomaxillary unit following a facial CT examination from August 2017 to September 2018 were eligible for inclusion. The inclusion period was extended to 5 years for panfacial trauma patients. All consecutive patients that fulfilled the study inclusion criteria for each type of injury were included in the study (a total of 120 patients assigned to the following six categories: orbits, skull and skull base, zygomaticomaxillary complex, Le Fort pattern, mandible and pan-facial fractures). Faciomaxillary surgeons, blinded to the radiology report, were asked to provide a verbal description of the fractures. The surgical interpretation was compared to the radiology report and further analysed. RESULTS: Of the 120 cases, the same fractures were reported in 43 cases (35.8%). Both types of specialists noted the predominant and clinically relevant fractures in 106 cases (88.3%). The reports did not match in 14 cases (11.7%) and different terminology was used in 76 cases (63.3%), with agreement in 25% (95% CI: 18-34%), partial agreement in 11.7% (95% CI: 5.9-17.4%) and no agreement in 63.3% (95% CI: 54.7-72.0%) cases. CONCLUSION: Radiologists and faciomaxillary surgeons frequently differ in their assessment of facial fractures.

Role of the sympathetic nervous system in cardiometabolic control: implications for targeted multiorgan neuromodulation approaches.

Sympathetic overdrive plays a key role in the perturbation of cardiometabolic homeostasis. Diet-induced and exercise-induced weight loss remains a key strategy to combat metabolic disorders, but is often difficult to achieve. Current pharmacological approaches result in variable responses in different patient cohorts and long-term efficacy may be limited by medication intolerance and nonadherence. A clinical need exists for complementary therapies to curb the burden of cardiometabolic diseases. One such approach may include interventional sympathetic neuromodulation of organs relevant to cardiometabolic control. The experience from catheter-based renal denervation studies clearly demonstrates the feasibility, safety and efficacy of such an approach. In analogy, denervation of the common hepatic artery is now feasible in humans and may prove to be similarly useful in modulating sympathetic overdrive directed towards the liver, pancreas and duodenum. Such a targeted multiorgan neuromodulation strategy may beneficially influence multiple aspects of the cardiometabolic disease continuum offering a holistic approach.

Weight-Adjusted Contrast Administration in the Computed Tomography Evaluation of Pulmonary Embolism.

INTRODUCTION: Computed tomography pulmonary angiogram (CTPA) is widely considered the gold standard for diagnosis of pulmonary embolism (PE) with previous studies demonstrating high sensitivity and specificity. Despite this, nondiagnostic and indeterminate CTPA rates of 5%-26% remain a concern. As part of a continuing quality assurance program, a new weight-adjusted contrast dose and increased administration rate CTPA protocol was studied with an aim to improve diagnostic accuracy of PE evaluation. METHODS: A total of 2,398 CTPA examinations were reviewed to assess pulmonary arterial enhancement and PE yield in this retrospective study. Between 1 August 2014 and 1 August 2015, 1,133 patients received a fixed-volume (60 mL) contrast dose technique at 4 mL/s (protocol A). A new protocol was then implemented as part of a continuing quality assurance program. Between 15 September 2015 and 15 September 2016, 1,265 patients received a weight-adjusted contrast dose (1 mL/kg) and increased administration rate (5 mL/s) CTPA technique (protocol B). Studies were classed into categories based on quality of study; diagnostic: HU > 211, nondiagnostic: HU < 211 and PE yield; positive, negative, and indeterminate. These variables were compared with cross-sectional surface area to assess the relationship between patient habitus, CTPA diagnostic quality, and PE yield. RESULTS: A weight-adjusted contrast dose and increased administration rate CTPA protocol (protocol B) resulted in a significant increase in mean PA enhancement (P < .0001), 55.23% decrease in nondiagnostic studies and 43.04% decrease in indeterminate studies. Protocol B demonstrated increased positive and negative CTPA rates with decreased indeterminate rates from 12.38% to 7.04%. Comparison with cross-sectional area demonstrated significant increase in proportion of diagnostic studies and reduction in nondiagnostic and indeterminate CTPAs using protocol B in obese patients. CONCLUSIONS: A weight-adjusted contrast dose and increased administration rate CTPA protocol can significantly increase PA enhancement, especially in obese patients, resulting in greater high-quality and fewer nondiagnostic and indeterminate CTPA examinations. A CTPA protocol with a higher rate of conclusive examinations can provide greater confidence in PE evaluation for reporting radiologists and accurate clinical decision-making pathways for referring physicians.