The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging.

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

Paediatric Thoracic Imaging in Cystic Fibrosis in the Era of Cystic Fibrosis Transmembrane Conductance Regulator Modulation.

Cystic fibrosis (CF) is one of the most common progressive life-shortening genetic conditions worldwide. Ground-breaking translational research has generated therapies that target the primary cystic fibrosis transmembrane conductance regulator (CFTR) defect, known as CFTR modulators. A crucial aspect of paediatric CF disease is the development and progression of irreversible respiratory disease in the absence of clinical symptoms. Accurate thoracic diagnostics have an important role to play in this regard. Chest radiographs are non-specific and insensitive in the context of subtle changes in early CF disease, with computed tomography (CT) providing increased sensitivity. Recent advancements in imaging hardware and software have allowed thoracic CTs to be acquired in paediatric patients at radiation doses approaching that of a chest radiograph. CFTR modulators slow the progression of CF, reduce the frequency of exacerbations and extend life expectancy. In conjunction with advances in CT imaging techniques, low-dose thorax CT will establish a central position in the routine care of children with CF. International guidelines regarding the choice of modality and timing of thoracic imaging in children with CF are lagging behind these rapid technological advances. The continued progress of personalised medicine in the form of CFTR modulators will promote the emergence of personalised radiological diagnostics.

Replacing Plain Radiograph with ultra-low dose CT thorax in cystic fibrosis (CF) in the era of CFTR modulation and its impact on cumulative effective dose.

BACKGROUND: Medical radiation exposure is of increasing concern in patients with cystic fibrosis (PWCF) due to improving life expectancy. We aimed to assess and quantify the cumulative effective dose (CED) in PWCF in the context of CFTR-modulator therapy and the advancement of dose reduction techniques. METHODS: We performed a retrospective observational study in a single University CF centre over a 11-year period. We included PWCF, aged over 18 years who exclusively attended our institution. Relevant clinical data (demographics, transplantation history and modulator status) and radiological data (modality, quantity, and radiation exposure measured as CED) were collected. For those on modulator therapy the quantified imaging and radiation data was dichotomised into pre-and-post therapy periods. RESULTS: The study included 181 patients: 139 on CFTR modulator therapy, 15 transplant recipients and 27 with neither exposure. 82% of patients received <25 mSv over the study period. Mean study duration was 6.9 ± 2.6 years pre-modulation and 4.2 ± 2.6 years post-modulation. Pre-modulation CT contributed 9.6% of total chest imaging (n = 139/1453) and 70.9% of the total CED. Post-modulation CT use increased contributing 42.7% of chest imaging (n = 444/1039) and comprised 75.8% of CED. Annual CED was 1.55 mSv pre and 1.36 mSv post modulation (p = 0.41). Transplant recipients had an annual CED of 64 ± 36.1mSv. CONCLUSION: Chest CT utilisation for PWCF is rising in our institution, replacing chest radiography amidst CFTR-modulation. Despite the increasing use of CT, no significant radiation dose penalty was observed with a reduction in mean annual CED, primarily due to the influence of CT dose reduction strategies.

Uterine Artery Embolisation of Fibroids and the Phenomenon of Post-Embolisation Syndrome: A Systematic Review.

Post-embolisation syndrome (PES) is a prevalent complication that occurs in patients following uterine artery embolisation (UAE) for the treatment of uterine fibroids. The aetiology of PES remains incompletely understood, although postulated to result secondary to tissue infarction resulting in release of inflammatory mediators. We followed PRISMA guidelines and performed a systematic review of studies of PES following UAE from inception to October 2022. Our published protocol was prospectively registered. Our search yielded 54 results. We reviewed 22 full texts, and nine articles were included. Observational studies comprised 6/9 relevant studies, with 5/9 retrospective design. The rate of PES was documented in 5/8 studies (excluding case report) with a reported incidence ranging from 4-34.6%. Five of the nine studies studies postulated that the aetiological basis of PES is inflammatory related. Further research is necessary to advance our understanding of PES to define the biological basis of the syndrome with more certainty and gain a consensus on peri-procedure management to reduce incidence and improve patient outcomes.

Making computed tomography safer for patients with Crohn's disease.

Background and aims: Computed tomography (CT), often more accessible than magnetic resonance imaging (MRI), remains widely used though radiation exposure is an obvious disadvantage. We previously showed that modern CT technology can achieve over 70% reduction in radiation-dose without loss of accuracy. Here, we compare low- versus conventional-dose CT in patients with known Crohn's disease to assess clinical confidence and accuracy of the low-dose procedure in the semi-acute setting.Methods: A comparative study of low-dose CT with full iterative reconstruction (IR) versus conventional-dose CT was conducted in 50 consecutive outpatients with Crohn's disease. Clinicians were provided with the low-dose images and reports, whereas conventional-dose images were reviewed after 4 weeks.Results: The clinical question was adequately addressed with low-dose IR imaging in all cases. Complications of Crohn's were detected in 37/50 (74%) with no disagreement between low- and conventional-dose imaging. The effective radiation dose reduction was 76.5% (low-dose mean 2.15 mSv versus conventional-dose CT 6.99 mSv).Conclusion: Low-dose IR CT is safe and accurate for evaluating distribution and complications of known Crohn's disease in the outpatient setting. We propose that low-dose radiation imaging should be adopted as standard-of-care for the evaluation of Crohn's disease and an acceptable alternative to MR particularly in the acute setting. ClinicalTrials.gov: NCT03140306.

The evolving role of radiological imaging in cystic fibrosis.

PURPOSE OF REVIEW: Radiological imaging has a crucial role in pulmonary evaluation in cystic fibrosis (CF), having been shown to be more sensitive than pulmonary function testing at detecting structural lung changes. The present review summarizes the latest published information on established and evolving pulmonary imaging techniques for assessing people with this potentially life-limiting disorder. RECENT FINDINGS: Chest computed tomography (CT) has taken over the predominant role of chest radiography in many centres for the initial assessment and surveillance of CF lung disease. However, several emerging techniques offer a promising means of pulmonary imaging using less ionizing radiation. This is of particular importance given these patients tend to require repeated imaging throughout their lives from a young age. Such techniques include ultra-low-dose CT, tomosynthesis, dynamic radiography and magnetic resonance imaging. In addition, deep-learning algorithms are anticipated to improve diagnostic accuracy. SUMMARY: The recent introduction of triple-combination CF transmembrane regulator therapy has put further emphasis on the need for sensitive methods of monitoring treatment response to allow for early adaptation of treatment regimens in order to limit irreversible lung damage. Further research is needed to establish how emerging imaging techniques can contribute to this safely and effectively.

Body Composition, Inflammation, and 5-Year Outcomes in Colon Cancer.

Importance: Obesity, particularly visceral obesity and sarcopenia, are poor prognostic indicators in colon cancer. Objectives: To explore the association between body composition profiles and 5-year colon cancer outcomes and delineate the associated underlying inflammatory processes. Design, Setting, and Participants: This multicenter translational cohort study included patients with nonmetastatic colon cancer who did not have underlying chronic inflammatory disorders and were not receiving anti-inflammatory drugs referred to tertiary cancer centers from 2009 to 2015. Preoperative acute phase proteins (white cell count, C-reactive protein, and albumin), cytokines (interleukin [IL]-1b, IL-2, IL-6, IL-10, interferon γ, and tumor necrosis factor α), vascular endothelial growth factor (VEGF), and cell surface receptor expression levels (CD11b and CD14) were measured. All patients underwent follow-up for at least 5 years. Data were analyzed in December 2020. Exposure: Nonmetastatic colon cancer. Main Outcomes and Measures: The associations of body composition profiles with 5-year cancer recurrence and disease-specific mortality were analyzed using Mantel Cox log-rank test and Kaplan-Meier curves. Results: A total of 28 patients were included (median [interquartile range] age, 67 [58-72] years; 22 [78.6%] men). Low skeletal muscle area (SMA) and high visceral to total fat ratio were associated with poor clinical and oncological outcomes, including increased 5-year recurrence (low SMA: hazard ratio [HR], 2.30 [95% CI, 1.41-2.89]; P = .04; high visceral to total fat ratio: HR, 5.78 [95% CI, 3.66-7.95]; P = .02). High visceral to total fat ratio was associated with increased 5-year disease-specific mortality (HR, 5.92 [95% CI, 4.04-8.00]; P = .02). Patients with low SMA who developed a cancer recurrence, compared with those who did not, had higher C-reactive protein (mean [SD], 31.24 [6.95] mg/dL vs 8.11 [0.58] mg/dL; P = .003), IL-6 (mean [SD], 1.93 [1.16] ng/mL vs 0.88 [0.14] ng/mL; P = .004), VEGF (mean [SD], 310.03 [122.66] ng/mL vs 176.12 [22.94] ng/mL; P = .007), and CD14 (mean [SD], 521.23 [302.02] ng/mL vs 322.07 [98.35] ng/mL; P = .03) expression and lower albumin (mean [SD], 3.8 [0.6] g/dL vs 43.50 [3.69] g/dL; P = .01), IL-2 (mean [SD], 0.45 [0.25] ng/mL vs 0.94 [0.43] ng/mL; P < .001), IL-10 (mean [SD], 8.15 [1.09] ng/mL vs 16.32 [4.43] ng/mL; P = .004), and interferon γ (mean [SD], 2.61 [1.36] ng/mL vs 14.87 [3.43] ng/mL; P = .02) levels. Patients with high visceral to total fat ratio who developed recurrence had higher levels of IL-6 (mean [SD], 5.26 [7.05] ng/mL vs 2.76 [3.11] ng/mL; P = .03) and tumor necrosis factor α (mean [SD], 5.74 [4.53] ng/mL vs 4.50 [1.99] ng/mL; P = .03). Conclusions and Relevance: These findings suggest that low SMA and high visceral to total fat ratio were associated with worse colon cancer outcomes and with increased expression of proinflammatory cytokines and VEGF and inhibition of anti-inflammatory cytokines.

Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus.

BACKGROUND: Cerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS). METHODS: Following ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed. RESULTS: ULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07-0.17, versus 0.25 mSv (0.06-1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS. CONCLUSIONS: At a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

Best Practices: Imaging Strategies for Reduced-Dose Chest CT in the Management of Cystic Fibrosis-Related Lung Disease.

OBJECTIVE. Cystic fibrosis (CF) is a multisystemic life-limiting disorder. The leading cause of morbidity in CF is chronic pulmonary disease. Chest CT is the reference standard for detection of bronchiectasis. Cumulative ionizing radiation limits the use of CT, particularly as treatments improve and life expectancy increases. The purpose of this article is to summarize the evidence on low-dose chest CT and its effect on image quality to determine best practices for imaging in CF. CONCLUSION. Low-dose chest CT is technically feasible, reduces dose, and renders satisfactory image quality. There are few comparison studies of low-dose chest CT and standard chest CT in CF; however, evidence suggests equivalent diagnostic capability. Low-dose chest CT with iterative reconstructive algorithms appears superior to chest radiography and equivalent to standard CT and has potential for early detection of bronchiectasis and infective exacerbations, because clinically significant abnormalities can develop in patients who do not have symptoms. Infection and inflammation remain the primary causes of morbidity requiring early intervention. Research gaps include the benefits of replacing chest radiography with low-dose chest CT in terms of improved diagnostic yield, clinical decision making, and patient outcomes. Longitudinal clinical studies comparing CT with MRI for the monitoring of CF lung disease may better establish the complementary strengths of these imaging modalities.

Computed tomography in cystic fibrosis lung disease: a focus on radiation exposure.

Thoracic computed tomography (CT) is the imaging reference method in the diagnosis, assessment and management of lung disease. In the setting of cystic fibrosis (CF), CT demonstrates increased sensitivity compared with pulmonary function tests and chest radiography, and findings correlate with clinical outcomes. Better understanding of the aetiology of CF lung disease indicates that even asymptomatic infants with CF can have irreversible pulmonary pathology. Surveillance and early diagnosis of lung disease in CF are important to preserve lung parenchyma and to optimise long-term outcomes. CF is associated with increased cumulative radiation exposure due to the requirement for repeated imaging from a young age. Radiation dose optimisation, important for the safe use of CT in children with CF, is best achieved in a team environment where paediatric radiologists work closely with paediatric respiratory physicians, physicists and radiography technicians to achieve the best patient outcomes. Despite the radiation doses incurred, CT remains a vital imaging tool in children with CF. Radiologists with special interests in CT dose optimisation and respiratory disease are key to the appropriate use of CT in paediatric imaging. Paediatric radiologists strive to minimise radiation dose to children whilst providing the best possible assessment of lung disease.

Transbronchial lung cryobiopsy (TBLC) in the diagnosis of interstitial lung disease: experience of first 100 cases performed under conscious sedation with flexible bronchoscope.

BACKGROUND: Diagnosing the aetiology of interstitial lung disease (ILD) may require histology via a surgical lung biopsy (SLB). SLB is associated with significant complications. Transbronchial lung cryobiopsy (TBLC) can provide large, adequate biopsies with fewer complications offering a potential alternative to SLB. AIMS: This study evaluated the safety, diagnostic yield and impact of TBLC on diagnostic certainty in the multidisciplinary diagnosis (MDD) of ILD within routine clinical practice. METHODS: A retrospective study of all TBLC performed in a tertiary institute from March 2014 to December 2016 was performed. Procedures were performed using a flexible bronchoscope and cryoprobe without fluoroscopic guidance. RESULTS: One hundred procedures were performed on 85 patients. A total of 272 cryobiopsies were obtained with a mean biopsy diameter of 5.9 ± 3.2 mm. Ninety-seven percent contained alveolated lung tissue. Diagnosis based against MDD gold standard was confirmed using TBLC in 67.1% of patients and in 72/100 procedures. Three patients proceeded to SLB. The addition of histological information changed the clinic-radiological diagnosis in twelve patients. The most common diagnosis based on clinical-radiologic-pathologic correlation at MDD was idiopathic pulmonary fibrosis (IPF) (51.2%) and hypersensitivity pneumonitis (15.9%). Moderate bleeding occurred in 18% of cases and five patients (5%) developed pneumothorax requiring intervention. Eleven patients required admission, with a mean length of stay of 1.3 ± 0.9 days. CONCLUSION: TBLC aids the diagnosis of ILD in the appropriate patient and may be an acceptable alternative to SLB with fewer complications. Further work on standardizing the procedure is required.

Virtual Mechanical Testing Based on Low-Dose Computed Tomography Scans for Tibial Fracture: A Pilot Study of Prediction of Time to Union and Comparison with Subjective Outcomes Scoring.

BACKGROUND: Quantitative outcomes assessment remains a persistent challenge in orthopaedic trauma. Although patient-reported outcome measures (PROMs) and radiographic assessments such as Radiographic Union Scale for Tibial Fractures (RUST) scores are frequently used, very little evidence has been presented to support their validity for measuring structural bone formation or biomechanical integrity. METHODS: In this pilot study, a sequential cohort of patients with a tibial shaft fracture were prospectively recruited for observation following standard reamed intramedullary nailing in a level-I trauma center. Follow-up at 6, 12, 18, and 24 weeks included radiographs and completion of PROMs (EuroQol 5-Dimension [EQ-5D] and pain scores). Low-dose computed tomography (CT) scans were also performed at 12 weeks. Scans were reconstructed in 3 dimensions (3D) and subjected to virtual mechanical testing via the finite element method to assess torsional rigidity in the fractured limb relative to that in the intact bone. RESULTS: Patients reported progressive longitudinal improvement in mobility, self-care, activity, and health over time, but the PROMs were not correlated with structural bone healing. RUST scoring showed moderate intrarater agreement (intraclass coefficient [ICC] = 0.727), but the scores at 12 weeks were not correlated with the time to union (R = 0.104, p = 0.193) and were only moderately correlated with callus structural integrity (R = 0.347, p = 0.010). In contrast, patient-specific virtual torsional rigidity (VTR) was significantly correlated with the time to union (R = 0.383, p = 0.005) and clearly differentiated 1 case of delayed union (VTR = 10%, union at 36 weeks) from the cases in the normally healing cohort (VTR > 60%; median union time, 19 weeks) on the basis of CT data alone. CONCLUSIONS: PROMs provide insight into the natural history of the patient experience after tibial fracture but have limited utility as a measure of structural bone healing. RUST scoring, although reproducible, may not reliably predict time to union. In contrast, virtual mechanical testing with low-dose CT scans provides a quantitative and objective structural callus assessment that reliably predicts time to union and may enable early diagnosis of compromised healing. LEVEL OF EVIDENCE: Therapeutic Level IV. Please see Instructions for Authors for a complete description of levels of evidence.

Virtual structural analysis of tibial fracture healing from low-dose clinical CT scans.

Quantitative assessment of bone fracture healing remains a significant challenge in orthopaedic trauma research. Accordingly, we developed a new technique for assessing bone healing using virtual mechano-structural analysis of computed tomography (CT) scans. CT scans from 19 fractured human tibiae at 12 weeks after surgery were segmented and prepared for finite element analysis (FEA). Boundary conditions were applied to the models to simulate a torsion test that is commonly used to access the structural integrity of long bones in animal models of fracture healing. The output of each model was the virtual torsional rigidity (VTR) of the healing zone, normalized to the torsional rigidity of each patient's virtually reconstructed tibia. This provided a structural measure to track the percentage of healing each patient had undergone. Callus morphometric measurements were also collected from the CT scans. Results showed that at 12 weeks post-op, more than 75% of patients achieved a normalized VTR (torsional rigidity relative to uninjured bone) of 85% or above. The predicted intact torsional rigidities compared well with published cadaveric data. Across all patients, callus volume and density were weakly and non-significantly correlated with normalized VTR and time to clinical union. Conversely, normalized VTR was significantly correlated with time to union (R2 = 0.383, p = 0.005). This suggests that fracture scoring methods based on the visual appearance of callus may not accurately predict mechanical integrity. The image-based structural analysis presented here may be a useful technique for assessment of bone healing in orthopaedic trauma research.

Low-Dose Computed Tomography for the Optimization of Radiation Dose Exposure in Patients with Crohn's Disease.

Magnetic resonance imaging (MRI) is the mainstay method for the radiological imaging of the small bowel in patients with inflammatory bowel disease without the use of ionizing radiation. There are circumstances where imaging using ionizing radiation is required, particularly in the acute setting. This usually takes the form of computed tomography (CT). There has been a significant increase in the utilization of computed tomography (CT) for patients with Crohn's disease as patients are frequently diagnosed at a relatively young age and require repeated imaging. Between seven and eleven percent of patients with IBD are exposed to high cumulative effective radiation doses (CEDs) (>35-75 mSv), mostly patients with Crohn's disease (Newnham E 2007, Levi Z 2009, Hou JK 2014, Estay C 2015). This is primarily due to the more widespread and repeated use of CT, which accounts for 77% of radiation dose exposure amongst patients with Crohn's disease (Desmond et al., 2008). Reports of the projected cancer risks from the increasing CT use (Berrington et al., 2007) have led to increased patient awareness regarding the potential health risks from ionizing radiation (Coakley et al., 2011). Our responsibilities as physicians caring for these patients include education regarding radiation risk and, when an investigation that utilizes ionizing radiation is required, to keep radiation doses as low as reasonably achievable: the "ALARA" principle. Recent advances in CT technology have facilitated substantial radiation dose reductions in many clinical settings, and several studies have demonstrated significantly decreased radiation doses in Crohn's disease patients while maintaining diagnostic image quality. However, there is a balance to be struck between reducing radiation exposure and maintaining satisfactory image quality; if radiation dose is reduced excessively, the resulting CT images can be of poor quality and may be nondiagnostic. In this paper, we summarize the available evidence related to imaging of Crohn's disease, radiation exposure, and risk, and we report recent advances in low-dose CT technology that have particular relevance.

Sarcopenia and Post-Operative Morbidity and Mortality in Patients with Gastric Cancer.

PURPOSE: Surgical resection for gastric adenocarcinoma is associated with significant post-operative morbidity and mortality. The aim of this study was to assess the prognostic significance of sarcopenia in patients undergoing resection for gastric adenocarcinoma with respect to post-operative morbidity and survival. MATERIALS AND METHODS: A retrospective analysis was conducted on a cohort of consecutive patients who underwent surgical resection for gastric adenocarcinoma between 2008 and 2014. Patient demographics, radiological parameters, and pathological data were collected. OsiriX software (Pixmeo) was used to measure skeletal muscle area, which was normalized for height to calculate skeletal muscle index. RESULTS: A total of 56 patients (41 male, 15 female; mean age, 68.4 ± 11.9 years) met the inclusion criteria. Of these, 36% (20 of 56) of the patients were sarcopenic pre-operatively. Both sarcopenic and non-sarcopenic patient groups were equally matched with the exception of weight and body mass index (P=0.036 and 0.001, respectively). Sarcopenia was associated with a decreased overall survival (log-rank P=0.003) and was an adverse prognostic predictor of overall survival in multivariate analysis (hazard ratio, 10.915; P=0.001). Sarcopenia was a predictor of serious in-hospital complications in multivariate analysis (odds ratio, 3.508; P=0.042). CONCLUSIONS: In patients undergoing curative resection for gastric cancer, there was a statistically significant association between sarcopenia and both decreased overall survival and serious post-operative complications. The measurement and reporting of skeletal muscle index on pre-operative computed tomography should be considered.

Determination of a suitable low-dose abdominopelvic CT protocol using model-based iterative reconstruction through cadaveric study.

INTRODUCTION: Cadaveric studies provide a means of safely assessing new technologies and optimizing scanning prior to clinical validation. Reducing radiation exposure in a clinical setting can entail incremental dose reductions to avoid missing important clinical findings. The use of cadavers allows assessment of the impact of more substantial dose reductions on image quality. Our aim was to identify a suitable low-dose abdominopelvic CT protocol for subsequent clinical validation. METHODS: Five human cadavers were scanned at one conventional dose and three low-dose settings. All scans were reconstructed using three different reconstruction algorithms: filtered back projection (FBP), hybrid iterative reconstruction (60% FBP and 40% adaptive statistical iterative reconstruction (ASIR40)), and model-based iterative reconstruction (MBIR). Two readers rated the image quality both quantitatively and qualitatively. RESULTS: Model-based iterative reconstruction images had significantly better objective image noise and higher qualitative scores compared with both FBP and ASIR40 images at all dose levels. The greatest absolute noise reduction, between MBIR and FBP, of 34.3 HU (equating to a 68% reduction) was at the lowest dose level. MBIR reduced image noise and improved image quality even in CT images acquired with a mean radiation dose reduction of 62% compared with conventional dose studies reconstructed with ASIR40, with lower levels of objective image noise, superior diagnostic acceptability and contrast resolution, and comparable subjective image noise and streak artefact scores. CONCLUSION: This cadaveric study demonstrates that MBIR reduces image noise and improves image quality in abdominopelvic CT images acquired with dose reductions of up to 62%.

Body composition determinants of radiation dose during abdominopelvic CT.

OBJECTIVES: We designed a prospective study to investigate the in-vivo relationship between abdominal body composition and radiation exposure to determine the strongest body composition predictor of dose length product (DLP) at CT. METHODS: Following institutional review board approval, quantitative analysis was performed prospectively on 239 consecutive patients who underwent abdominopelvic CT. DLP, BMI, volumes of abdominal adipose tissue, muscle, bone and solid organs were recorded. RESULTS: All measured body composition parameters correlated positively with DLP. Linear regression (R2 = 0.77) revealed that total adipose volume was the strongest predictor of radiation exposure [B (95% CI) = 0.027(0.024-0.030), t=23.068, p < 0.001]. Stepwise linear regression using DLP as the dependent and BMI and total adipose tissue as independent variables demonstrated that total adipose tissue is more predictive of DLP than BMI [B (95% CI) = 16.045 (11.337-20.752), t=6.681, p < 0.001]. CONCLUSIONS: The volume of adipose tissue was the strongest predictor of radiation exposure in our cohort. MAIN MESSAGE: • Individual body composition variables correlate with DLP at abdominopelvic CT. • Total abdominal adipose tissue is the strongest predictor of radiation exposure. • Muscle volume is also a significant but weaker predictor of DLP.

CORK Study in Cystic Fibrosis: Sustained Improvements in Ultra-Low-Dose Chest CT Scores After CFTR Modulation With Ivacaftor.

BACKGROUND: Ivacaftor produces significant clinical benefit in patients with cystic fibrosis (CF) with the G551D mutation. Prevalence of this mutation at the Cork CF Centre is 23%. This study assessed the impact of cystic fibrosis transmembrane conductance regulator modulation on multiple modalities of patient assessment. METHODS: Thirty-three patients with the G551D mutation were assessed at baseline and prospectively every 3 months for 1 year after initiation of ivacaftor. Change in ultra-low-dose chest CT scans, blood inflammatory mediators, and the sputum microbiome were assessed. RESULTS: Significant improvements in FEV1, BMI, and sweat chloride levels were observed post-ivacaftor treatment. Improvement in ultra-low-dose CT imaging scores were observed after treatment, with significant mean reductions in total Bhalla score (P < .01), peribronchial thickening (P = .035), and extent of mucous plugging (P < .001). Reductions in circulating inflammatory markers, including interleukin (IL)-1ß, IL-6, and IL-8 were demonstrated. There was a 30% reduction in the relative abundance of Pseudomonas species and an increase in the relative abundance of bacteria associated with more stable community structures. Posttreatment community richness increased significantly (P = .03). CONCLUSIONS: Early and sustained improvements on ultra-low-dose CT scores suggest it may be a useful method of evaluating treatment response. It paralleled improvement in symptoms, circulating inflammatory markers, and changes in the lung microbiota.

An Assessment of the Quality of CT Radiation Dose Information on the Internet.

OBJECTIVES: Our goal was to ascertain the quality of health information related to CT radiation exposure using a simulated Internet search and from incident information that may be available during day-to-day Internet usage. METHODS: We entered 14 terms relating to information on CT dose into the most commonly used Internet search engine and analyzed the first 100 web page results for each. A Rich Search Site (RSS) feed search was also used to evaluate incidental information over a 12-week period in 2014. Each web page was classified as being "completely accurate," "somewhat accurate," or "inaccurate." RESULTS: Of 1,400 web pages, 290 were relevant and accessible. We deemed 12.8% of these pages as inaccurate and 67.2% of pages as completely accurate. The highest proportion of web pages was from media sources, which, along with discussion forums, commercial websites, and blogs, were found to have proportionally the largest amount of inaccurate information. Of 1,943 posts, 136 (7.0%) identified by the RSS were relevant, 9.6% were deemed inaccurate, and only 29.9% were deemed completely accurate. The results of our simulated query highlight the importance of public education regarding Internet usage when researching topics relating to radiation exposure associated with CT.