Diagnostic strategies in postpartum individuals with suspected venous thromboembolism: A scoping review.

BACKGROUND: The risk of venous thromboembolism (VTE) is increased postpartum and contributes to important morbidity and mortality. While there have been advances in evaluating diagnostic algorithms for suspected VTE during pregnancy, there is limited data for postpartum individuals. OBJECTIVE: We conducted a scoping review to describe and evaluate diagnostic strategies used to investigate suspected VTE in postpartum individuals. METHODS: A comprehensive search strategy was conducted in Ovid MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (January 1, 2000-September 30, 2022) to identify original articles that reported on diagnostic strategies in postpartum individuals with suspected VTE. We extracted demographics, clinical decision rules used, D-dimer and imaging completed, including test performance and VTE outcomes. RESULTS: A total of 13 studies conducted across 11 countries with separate postpartum data were included for 759 individuals with suspected PE (n = 634) or DVT (n = 125), including unpublished data (n = 251). Among those with suspected PE, computed tomography pulmonary angiography was conducted more commonly (n = 522) than ventilation-perfusion scans (n = 69), with PE positivity rates that ranged from 4 %-27.6 % and 0-50 % across studies, respectively. Among 131 postpartum individuals with suspected PE who had a D-dimer measured, only 4.6 % (6/131) had a negative D-dimer test. For postpartum individuals with suspected DVT, the most common diagnostic test was compression ultrasonography (positivity rate 12.2 %-18.6 %). There were limited retrospective data evaluating the clinical decision rules. CONCLUSIONS: There are heterogeneous approaches globally in the diagnosis of suspected postpartum VTE. Limited high-quality data available underscores the need for more robust evidence to inform clinical practice.

Impact of Different Artificial Intelligence User Interfaces on Lung Nodule and Mass Detection on Chest Radiographs.

Purpose: To explore the impact of different user interfaces (UIs) for artificial intelligence (AI) outputs on radiologist performance and user preference in detecting lung nodules and masses on chest radiographs. Materials and Methods: A retrospective paired-reader study with a 4-week washout period was used to evaluate three different AI UIs compared with no AI output. Ten radiologists (eight radiology attending physicians and two trainees) evaluated 140 chest radiographs (81 with histologically confirmed nodules and 59 confirmed as normal with CT), with either no AI or one of three UI outputs: (a) text-only, (b) combined AI confidence score and text, or (c) combined text, AI confidence score, and image overlay. Areas under the receiver operating characteristic curve were calculated to compare radiologist diagnostic performance with each UI with their diagnostic performance without AI. Radiologists reported their UI preference. Results: The area under the receiver operating characteristic curve improved when radiologists used the text-only output compared with no AI (0.87 vs 0.82; P < .001). There was no difference in performance for the combined text and AI confidence score output compared with no AI (0.77 vs 0.82; P = .46) and for the combined text, AI confidence score, and image overlay output compared with no AI (0.80 vs 0.82; P = .66). Eight of the 10 radiologists (80%) preferred the combined text, AI confidence score, and image overlay output over the other two interfaces. Conclusion: Text-only UI output significantly improved radiologist performance compared with no AI in the detection of lung nodules and masses on chest radiographs, but user preference did not correspond with user performance.Keywords: Artificial Intelligence, Chest Radiograph, Conventional Radiography, Lung Nodule, Mass Detection© RSNA, 2023.

Diagnostic imaging for suspected pulmonary embolism during pregnancy and postpartum: A comparative radiation dose study.

INTRODUCTION: To compare the radiation dose exposure and diagnostic efficiency of computed tomographic pulmonary angiography (CTPA) and ventilation/perfusion imaging (V/Q) for clinically suspected pulmonary embolism (PE) in pregnant and postpartum women in a tertiary hospital setting. METHODS: A retrospective cohort study of 473 pregnant and postpartum women referred for CTPA or V/Q for clinically suspected PE between January 2013 and December 2018 at a tertiary hospital. Maternal effective radiation dose, breast-absorbed radiation dose and fetal-absorbed dose estimates were calculated. Diagnostic yield was evaluated from radiological findings. RESULTS: Computed tomographic pulmonary angiography (CTPA) was more commonly used for the imaging of suspected PE in pregnant and postpartum populations (51.9% vs. 48.1% and 77.1% vs. 22.9%, respectively). CTPA was associated with higher maternal effective and breast-absorbed doses (maternal effective CTPA 4.7 (±2.9) mSv (millisievert), V/Q 1.7(±0.8) mSv (mean difference 2.93 mSv P < 0.001), and breast-absorbed CTPA 8.0 (±5.2) mGy (milligray), V/Q 0.3 (±0.1) (mean difference 7.67 mGy P < 0.001), respectively). Fetal radiation dose exposure was low. The incidence of positive PE was 5.5%. Indeterminate rates of CTPA and V/Q were 3.0% and 5.5% (P = 0.176), respectively. CONCLUSIONS: Compared to V/Q, CTPA is associated with higher maternal and breast radiation dose; however, modern CT scanners achieve lower radiation doses than historically described. Fetal radiation dose was comparably low. The diagnostic yield of the imaging modalities in pregnant and postpartum women is similar. Revision of guidelines should occur with the advances in CT technology.

Strategies for the Management of Solitary Pulmonary Nodules: A Survey of Patient Preferences.

BACKGROUND: Guideline-based strategies for evaluation of solitary pulmonary nodules are tailored to the likelihood of malignancy. Surveillance, biopsy, and resection are all reasonable approaches in fit individuals when the likelihood of malignancy is intermediate. Given the paucity of data demonstrating superior outcomes and important trade-offs among strategies, guidelines emphasize the importance of eliciting patient preferences and engaging in shared decision making; however, there is little literature on what patient preferences actually are. METHODS: This study conducted a cross-sectional, interview-administered questionnaire survey in 100 adults recruited from a metropolitan teaching hospital (The Royal Melbourne Hospital, Parkville, Victoria, Australia). The questionnaire used a hypothetical scenario designed to elicit patient preferences for different management strategies of solitary pulmonary nodules with a probability of malignancy between 10% and 70%. RESULTS: The mean age of participants was 62 years (range, 45 to 80 years), 56% were male, and 94% were current smokers or ex-smokers. Ninety-four percent completed all questions. At 10% probability of malignancy, 36.3% preferred surveillance, 42.4% preferred needle biopsy, and 21.2% preferred surgical resection. Preference for surgical resection increased to 53.5% and 86.2% when the probability of malignancy was 30% and 70%, respectively. Changes in the diagnostic yield of computed tomography biopsy significantly altered preferences when the probability of malignancy was 10% or 30%. CONCLUSIONS: The majority of participants surveyed expressed a preference for some type of biopsy over observation at all levels of solitary pulmonary nodule probability of malignancy evaluated. In an era of increasing solitary pulmonary nodule detection and patient-centered care, if confirmed in broader studies, these findings have considerable implications for processes of care and resource allocation.

Chest imaging findings in COVID-19-positive patients in an Australian tertiary hospital.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has infected over 215 million individuals worldwide. Chest radiographs (CXR) and computed tomography (CT) have assisted with diagnosis and assessment of COVID-19. Previous reports have described peripheral and lower zone predominant opacities on chest radiographs. Whilst the most common patterns on CT are bilateral, peripheral basal predominant ground glass opacities (Wong et al., Radiology, 296, 2020, E72; Karimian and Azami, Pol J Radiol, 86, 2021, e31). This study describes the imaging findings in an Australian tertiary hospital population. METHODS: COVID-PCR-positive patients who had chest imaging (CXR, CT and ventilation perfusion (V/Q) scans) from January 2020 to August 2020 were included. Distribution, location and pattern of involvement was recorded. Evaluation of the assessors was performed using Fleiss Kappa calculations for review of radiographic findings and qualitative analysis of CT findings. RESULTS: A total of 681 studies (616 CXRs, 59 CTs, 6 V/Q) from 181 patients were reviewed. The most common chest radiograph finding was bilateral lower lobe predominant diffuse opacification and most common CT pattern being ground glass opacities. Of the CT imaging, 33 were CT Pulmonary Angiograms of which five demonstrated acute pulmonary emboli. There was good inter-rater agreement between radiologists in assessment of imaging appearances on CXR (kappa 0.29-0.73) and CT studies. CONCLUSION: A review of imaging in an Australian tertiary hospital demonstrates similar patterns of COVID-19 infection on chest X-ray and CT imaging when compared to the international population.

USPSTF2013 versus PLCOm2012 lung cancer screening eligibility criteria (International Lung Screening Trial): interim analysis of a prospective cohort study.

BACKGROUND: Lung cancer is a major health problem. CT lung screening can reduce lung cancer mortality through early diagnosis by at least 20%. Screening high-risk individuals is most effective. Retrospective analyses suggest that identifying individuals for screening by accurate prediction models is more efficient than using categorical age-smoking criteria, such as the US Preventive Services Task Force (USPSTF) criteria. This study prospectively compared the effectiveness of the USPSTF2013 and PLCOm2012 model eligibility criteria. METHODS: In this prospective cohort study, participants from the International Lung Screening Trial (ILST), aged 55-80 years, who were current or former smokers (ie, had ≥30 pack-years smoking history or ≤15 quit-years since last permanently quitting), and who met USPSTF2013 criteria or a PLCOm2012 risk threshold of at least 1·51% within 6 years of screening, were recruited from nine screening sites in Canada, Australia, Hong Kong, and the UK. After enrolment, patients were assessed with the USPSTF2013 criteria and the PLCOm2012 risk model with a threshold of at least 1·70% at 6 years. Data were collected locally and centralised. Main outcomes were the comparison of lung cancer detection rates and cumulative life expectancies in patients with lung cancer between USPSTF2013 criteria and the PLCOm2012 model. In this Article, we present data from an interim analysis. To estimate the incidence of lung cancers in individuals who were USPSTF2013-negative and had PLCOm2012 of less than 1·51% at 6 years, ever-smokers in the Prostate Lung Colorectal and Ovarian Cancer Screening Trial (PLCO) who met these criteria and their lung cancer incidence were applied to the ILST sample size for the mean follow-up occurring in the ILST. This trial is registered at ClinicalTrials.gov, NCT02871856. Study enrolment is almost complete. FINDINGS: Between June 17, 2015, and Dec 29, 2020, 5819 participants from the International Lung Screening Trial (ILST) were enrolled on the basis of meeting USPSTF2013 criteria or the PLCOm2012 risk threshold of at least 1·51% at 6 years. The same number of individuals was selected for the PLCOm2012 model as for the USPSTF2013 criteria (4540 [78%] of 5819). After a mean follow-up of 2·3 years (SD 1·0), 135 lung cancers occurred in 4540 USPSTF2013-positive participants and 162 in 4540 participants included in the PLCOm2012 of at least 1·70% at 6 years group (cancer sensitivity difference 15·8%, 95% CI 10·7-22·1%; absolute odds ratio 4·00, 95% CI 1·89-9·44; p<0·0001). Compared to USPSTF2013-positive individuals, PLCOm2012-selected participants were older (mean age 65·7 years [SD 5·9] vs 63·3 years [5·7]; p<0·0001), had more comorbidities (median 2 [IQR 1-3] vs 1 [1-2]; p<0·0001), and shorter life expectancy (13·9 years [95% CI 12·8-14·9] vs 14·8 [13·6-16·0] years). Model-based difference in cumulative life expectancies for those diagnosed with lung cancer were higher in those who had PLCOm2012 risk of at least 1·70% at 6 years than individuals who were USPSTF2013-positive (2248·6 years [95% CI 2089·6-2425·9] vs 2000·7 years [1841·2-2160·3]; difference 247·9 years, p=0·015). INTERPRETATION: PLCOm2012 appears to be more efficient than the USPSTF2013 criteria for selecting individuals to enrol into lung cancer screening programmes and should be used for identifying high-risk individuals who benefit from the inclusion in these programmes. FUNDING: Terry Fox Research Institute, The UBC-VGH Hospital Foundation and the BC Cancer Foundation, the Alberta Cancer Foundation, the Australian National Health and Medical Research Council, Cancer Research UK and a consortium of funders, and the Roy Castle Lung Cancer Foundation for the UK Lung Screen Uptake Trial.

Lung cancer screening in Australia and New Zealand: the evidence and the challenge.

Lung cancer remains the commonest cause of cancer death in Australia and New Zealand. Targeted screening of individuals at highest risk of lung cancer aims to detect early stage disease, which may be amenable to potentially curative treatment. While current policy recommendations in Australia and New Zealand have acknowledged the efficacy of lung cancer screening in clinical trials, there has been no implementation of national programmes. With the recent release of findings from large international trials, the evidence and experience in lung cancer screening has broadened. This article discusses the latest evidence and implications for Australia and New Zealand.

Correlation of positron emission tomography ventilation-perfusion matching with CT densitometry in severe emphysema.

BACKGROUND: Emphysema severity is frequently measured on CT via densitometry. Correlation with scintigraphic and spirometric functional measures of ventilation or perfusion varies widely, and no prior study has evaluated correlation between densitometry and lobar ventilation/perfusion in patients with severe emphysema. The aim of this study was to evaluate the utility and findings of gallium-68 (68Ga) ventilation/perfusion positron emission tomography-CT (68Ga-VQ/PET-CT) in severe emphysema assessment. METHODS: Fourteen consecutive patients undergoing evaluation for bronchoscopic lung volume reduction between March 2015 and March 2018 underwent 68Ga-VQ/PET-CT assessment for lobar functional lung mapping, in addition to CT densitometry. Correlations between CT densitometry and 68Ga-VQ/PET-CT parameters for individual lobar lung function were sought. RESULTS: CT densitometry assessment of emphysema correlated only weakly (R2 = 0.13) with lobar perfusion and was not correlated with ventilation (R2 = 0.04). Densitometry was moderately (R2 = 0.67) correlated with V/Q units in upper lobes, though poorly reflected physiological function in lower lobes (R2 = 0.19). Emphysema severity, as measured by CT densitometry, was moderately correlated with proportion of normal V/Q units and matched V/Q defects in individual lobes. CONCLUSIONS: Assessment of lobar pulmonary function by 68Ga-VQ/PET-CT provides physiologic information not evident on CT densitometry such as ventilation and perfusion specifics and matched defects. Further research is needed to see if the discordant findings on 68Ga-VQ/PET-CT provide prognostic information or can be used to modify patient management and improve outcomes.

Investigation and diagnostic imaging of suspected pulmonary embolism during pregnancy and the puerperium: A review of the literature.

Pulmonary embolism (PE) is a leading cause of maternal mortality with women at increased risk of PE during pregnancy and the early postpartum period. Clinical assessment of suspected PE during pregnancy is challenging as signs and symptoms associated with PE overlap with physiological changes of pregnancy. Clinical tests and rules commonly used to assess pre-test probability of PE were historically not well validated in the pregnant population. The challenges of clinical assessment in the pregnant and postpartum population result in a lowered threshold for diagnostic imaging. Computed tomographic pulmonary angiography (CTPA) and nuclear medicine lung scintigraphy or ventilation/perfusion (V/Q) scans are the main types of diagnostic imaging for suspected PE. Both methods are associated with small levels of ionising radiation exposure to mother and foetus. Accuracy of the diagnostic imaging tests is paramount. Haemodynamic changes of pregnancy, including increased heart rate, increased blood volume and altered flow velocity in the pulmonary arteries, may influence the quality of imaging. This comprehensive review examines the literature and evidence for the investigation and diagnostic imaging of suspected pulmonary embolism during pregnancy with CTPA and V/Q. Clinical decision-making tools, biomarkers and diagnostic imaging during pregnancy and postpartum will be considered with a focus on diagnostic accuracy and yield, radiation dose exposure (maternal-foetal) and protocol modifications. Current practice guideline recommendations and recent literature on diagnostic pathways are also presented.

Turbulent flow artefact mimicking central pulmonary emboli in pulmonary hypertension: A report of two cases.

Many artefacts can mimic pulmonary emboli (PE) on CT pulmonary angiography (CTPA), most commonly in the peripheral pulmonary arteries (PA's). We describe flow-related artefact mimicking PE in the central PA's of two patients, both with pulmonary arterial hypertension (PAH). To our knowledge, this is the first report of this PE mimic in the central PA's.

The many faces of lung adenocarcinoma: A pictorial essay.

Lung adenocarcinoma has a spectrum of appearances on CT, many of which mimic non-malignant processes. The general radiologist has a major role in guiding the management of abnormalities detected on chest CT and an awareness of these appearances is vital. We describe the protean imaging manifestations of lung adenocarcinoma.

Ultralow dose CT for follow-up of solid pulmonary nodules: A pilot single-center study using Bland-Altman analysis.

Solid pulmonary nodules are a common finding requiring serial computed tomography (CT) imaging. We sought to explore the detection and measurement accuracy of an ultralow-dose CT (ULDCT) protocol compared with our standard low-dose CT (LDCT) nodule follow-up protocol.In this pragmatic single-center pilot prospective cohort study, patients scheduled for clinically indicated CT surveillance of 1 or more known solid pulmonary nodules >2 mm underwent ULDCT immediately after routine LDCT. The Bland-Altman 95% limits of agreement for diameter and volumetry were calculated.In all, 57 patients underwent 60 imaging episodes, with 170 evaluable nodules. ULDCT detected all known solid pulmonary nodules >2 mm. Bland-Altman analyses demonstrated clinically agreement for both nodule diameter and volume, both of which fell within prespecified limits.This single-center pilot study suggests that ULDCT may be of use in surveillance of known solid pulmonary nodules >2 mm.

Improvement in the prehospital recognition of tension pneumothorax: the effect of a change to paramedic guidelines and education.

INTRODUCTION: An audit of ambulance service clinical records from 2001 to 2002 in Melbourne, Australia revealed 10 patients with tension pneumothorax on arrival at hospital which had been undetected or untreated by paramedics. The clinical practice guideline for paramedic recognition of tension pneumothorax was subsequently changed to emphasise heightened clinical suspicion of a tension pneumothorax in the setting of chest trauma, especially when patients were managed with positive pressure ventilation. This study was undertaken to determine whether the number of undetected or untreated tension pneumothoraces had decreased after the new clinical practice guideline and associated education program; if there were unintended consequences arising from earlier paramedic intervention; and what effect, if any, this change had on subsequent hospital treatment. METHODS: Retrospective case note review of all patients requiring intercostal catheter (ICC) insertion at The Alfred Hospital, Melbourne, Australia, using records from Ambulance Victoria, the Alfred Trauma Registry and the National Coronial Information System. RESULTS: In 2001-2002 paramedics treated 22 patients with suspected tension pneumothorax before transport to the Alfred Hospital. In 2006-2007 this number had increased to 81. There was a decrease from ten to four in the number of unrecognised or untreated tension pneumothoraces between the two time periods. No unintended or adverse consequences of prehospital needle decompression could be found. However, there was an increase in the number of patients who had prehospital needle decompression that needed further treatment for tension pneumothorax on arrival at hospital. This need for further treatment was associated with use of shorter cannulas and unilateral needle decompression by paramedics. CONCLUSION: A small change in clinical practice guidelines, supported by an education and audit program, led to a reduction in unrecognised untreated tension pneumothoraces by paramedics without an increase in complications. Paramedics should be aware that a shorter cannula may fail to reach the pleural space and that both sides of the chest may require decompression.

Immunoselected STRO-3+ mesenchymal precursor cells and restoration of the extracellular matrix of degenerate intervertebral discs.

OBJECT: Chronic low-back pain of discal origin is linked strongly to disc degeneration. Current nonsurgical treatments are palliative and fail to restore the disc extracellular matrix. In this study the authors examined the capacity of ovine mesenchymal precursor cells (MPCs) to restore the extracellular matrix of degenerate discs in an ovine model. METHODS: Three adjacent lumbar discs of 24 adult male sheep were injected intradiscally with chondroitinase-ABC (cABC) to initiate disc degeneration. The remaining lumbar discs were used as normal controls. Three months after cABC injection, the L3-4 discs of all animals were injected with either a high dose (4 × 10(6) cells, in 12 sheep) or low dose (0.5 × 10(6) cells, in 12 sheep) of MPCs suspended in hyaluronic acid (HA). The adjacent L4-5 degenerate discs remained untreated; the L5-6 discs were injected with HA only. The animals were euthanized at 3 or 6 months after MPC injections (6 sheep from each group at each time point), and histological sections of the lumbar discs were prepared. Radiographs and MR images were obtained prior to cABC injection (baseline), 3 months after cABC injection (pretreatment), and just prior to necropsy (posttreatment). RESULTS: Injection of cABC decreased the disc height index (DHI) of target discs by 45%-50%, confirming degeneration. Some recovery in DHI was observed 6 months after treatment in all cABC-injected discs, but the DHI increased to within baseline control values only in the MPC-injected discs. This improvement was accompanied by a reduction in MRI degeneration scores. The histopathology scores observed at 3 months posttreatment for the high-dose MPC-injected discs and at 6 months posttreatment for the low-dose MPC-injected discs were significantly different from those of the noninjected and HA-injected discs (p <0.001) but not from the control disc scores. CONCLUSIONS: On the basis of the findings of this study, the authors conclude that the injection of MPCs into degenerate intervertebral discs can contribute to the regeneration of a new extracellular matrix.

Assessing signal intensity change on well-registered images: comparing subtraction, color-encoded subtraction, and parallel display formats.

PURPOSE: To assess the sensitivity, specificity, accuracy, and interobserver reliability of subtraction, color-encoded subtraction, and parallel display formats in assessing signal intensity (SI) differences between well-registered images. MATERIALS AND METHODS: Institutional ethics approval for the study and a waiver of individual patient consent were obtained. Five radiologists graded the severity of fatty liver by using a seven-point scale for four imaging sets created from 179 pairs of dual-echo in- and opposed-phase magnetic resonance images from 179 patients. The four sets contained images displayed in parallel, subtraction images, color-encoded subtraction images, and images from the three previous formats presented together. The order of the images and sets was randomized. Sensitivity and specificity were assessed with the McNemar test. Accuracy was assessed by using three-way analysis of variance, with Tukey post hoc methods used to assess differences between the four formats. Interobserver reliability was assessed by using the Fleiss κ value. RESULTS: Subtraction (P = .016 at a 5% SI difference threshold) and color-encoded subtraction (P = .031 at a 4% SI difference threshold) formats had higher sensitivity than did the parallel format. The accuracy of the subtraction format was superior to that of the parallel format (P < .0001). Interobserver reliability of the subtraction (κ = 0.53) and color-encoded subtraction (κ = 0.39) formats was superior to that of the parallel format (κ = 0.33) (P < .0001 and P = .0085, respectively). CONCLUSION: When images are well registered, subtraction and color-encoded subtraction techniques offer advantages over the traditional parallel presentation format for the assessment of SI differences.

Percutaneous gastrostomy and gastrojejunostomy.

Gastrostomy allows enteral nutrition to continue in patients who are unable to meet their caloric requirements orally. Though the indications for gastrostomy placement are varied, dysphagia secondary to a neurological condition is the most common. These catheters were initially placed surgically, but percutaneous endoscopic placement is now the routine in most centers. Interventional radiologists have been performing this procedure under fluoroscopic guidance for several years with encouraging results. Percutaneous radiological gastrostomy is reported to have a success rate comparable to that of the endoscopic method, with lower morbidity and mortality rates. A further benefit is that it may be performed in patients for whom the endoscopic method would be difficult or dangerous, such as those with head and neck malignancies. One of the main factors currently limiting the use of this procedure is the shortage of interventional radiology facilities and specialists.This article describes a technique for routine percutaneous radiological gastrostomy catheter placement and procedural variations for difficult cases. Indications and contraindications will be discussed, as will complication rates and how these compare with the traditional methods of gastrostomy tube placement.