Ultra-low-dose thoracic CT with model-based iterative reconstruction (MBIR) in cystic fibrosis patients undergoing treatment with cystic fibrosis transmembrane conductance regulators (CFTR).

AIM: To assess the utility of a volumetric low-dose computed tomography (CT) thorax (LDCTT) protocol at a dose equivalent to a posteroanterior (PA) and lateral chest radiograph for surveillance of cystic fibrosis (CF) patients. MATERIALS AND METHODS: A prospective study was undertaken of 19 adult patients with CF that proceeded to LDCTT at 12 and 24 months following initiation of ivacaftor. A previously validated seven-section, low-dose axial CT protocol was used for the 12-month study. A volumetric LDCTT protocol was developed for the 24-month study and reconstructed with hybrid iterative reconstruction (LD-ASIR) and pure iterative reconstruction (model-based IR [LD-MBIR]). Radiation dose was recorded for each scan. Image quality was assessed quantitatively and qualitatively, and disease severity was assessed using a modified Bhalla score. Statistical analysis was performed and p-values of <0.05 were considered statistically significant. RESULTS: Volumetric LD-MBIR studies were acquired at a lower radiation dose than the seven-section studies (0.08 ± 0.01 versus 0.10 ± 0.02 mSv; p=0.02). LD-MBIR and seven-section ASIR images had significantly lower levels of image noise compared with LD-ASIR images (p<0.0001). Diagnostic acceptability scores and depiction of bronchovascular structures were found to be acceptable for axial and coronal LD-MBIR images. LD-MBIR images were superior to LD-ASIR images for all qualitative parameters assessed (p<0.0001). No significant change was observed in mean Bhalla score between 1-year and 2-year studies (p=0.84). CONCLUSIONS: The use of a volumetric LDCTT protocol (reconstructed with pure IR) enabled acquisition of diagnostic quality CT images, which were considered extremely useful for surveillance of CF patients, at a dose equivalent to a PA and lateral chest radiograph.

Clinical and Survival Outcomes Using Percutaneous Cholecystostomy Tube Alone or Subsequent Interval Cholecystectomy to Treat Acute Cholecystitis.

BACKGROUND: Percutaneous cholecystostomy (PCT) is a safe method of gallbladder drainage in the setting of severe or complicated acute cholecystitis (AC), particularly in patients who are high-risk surgical candidates. Small case series suggest that PCT aids resolution of acute cholecystitis in up to 90% of patients. However, reluctance is observed in utilising PCT more frequently, due to concerns that we are committing comorbid patients to an interval surgical procedure for which they may not be suitable. AIM: The aim of this study was to assess the clinical and survival outcomes of PCT use, with particular emphasis on a subgroup of patients who did not proceed to cholecystectomy. METHODS: A retrospective analysis was performed of all patients with severe acute cholecystitis who required PCT insertion in a tertiary referral hospital from 2010 to 2015. Patient demographics and clinical data including systemic inflammatory response (SIRS) scores at presentation, readmissions and clinical and survival outcomes were analysed. Statistical analysis was performed using SPSS v.22 and GraphPad Prism v.7. RESULTS: In total, 157 patients (59% males) with AC underwent PCT insertion during the study period. Median age at presentation was 71 years (range 29-94). A median SIRS score of 3 was noted at presentation. Patients required a median of two cholecystostomy tube changes/replacements (range 1-10) during treatment. Transhepatic tube placement was the preferred approach (69%) with 31% of tubes being placed via transabdominal approach. Only 55% proceeded to interval cholecystectomy. Of the 70 patients treated with PCT alone, their median age was 75 years. In this subgroup, only 12.9% (n = 9) developed recurrent biliary sepsis necessitating readmission following initial resolution of symptoms and tube removal. All episodes of recurrent biliary sepsis presented within 6 months of index presentation, and definitive PCT removal in this group was performed at a median of 3 months. No difference in survival was observed between both groups. CONCLUSION: Almost 90% of patients with AC who are managed definitively with a PCT will recover uneventfully without recurrent sepsis following PCT removal. This is a viable option for older, comorbid patients who are unfit for surgical intervention and is not associated with significantly increased mortality.

Assessment of isocenter alignment during CT colonography: Implications for clinical practice.

INTRODUCTION: Optimization of image quality and patient radiation dose is achieved in part by positioning the patient at the isocenter of the CT gantry. The aim of this study was to establish whether there was increased isocenter misalignment (IM) in CT colonography (CTC) scans by comparing patient position during the prone part of a CTC to patient position during renal stone protocol CT (CT-KUB) and patient position during the supine part of a CTC to patient position during abdominopelvic CT (CT-AP). METHODS: Two hundred and twenty two consecutive outpatient adult CTC studies performed between January and December 2016 were retrospectively analyzed. Automated dose-tracking software was used to quantify IM in the x and y planes. Renal stone CT-KUB (n = 100) and standard CT-AP (n = 100) were used as comparison studies. RESULTS: IM during CTC was significantly greater in the y-axis compared with the x-axis for both prone (p = 0.002) and supine (p < 0.001) scanning. IM was significantly greater during prone CTC compared with CT-KUB (p = 0.008) and during supine CTC compared with CT-AP (p = 0.0001). IM was shown to be slightly greater in studies performed by more experienced radiographers (p = 0.04). IM was not associated with patient age, gender or size (p > 0.05 for all). CONCLUSION: Isocenter misalignment is greater during CT colonography compared with CT-KUB or CT-AP. Strategies for improving patient positioning could include radiographer education and automated patient centering solutions.

The 100 classic papers of pediatric orthopaedic surgery: a bibliometric analysis.

BACKGROUND: Pediatric orthopaedic surgery owes its development to many pioneering individuals, and the studies that these individuals have undertaken form the basis for the clinical decisions made on the modern pediatric orthopaedic service. The aim of our study was to use citation analysis to identify the top 100 papers in pediatric orthopaedic surgery. METHODS: Using the Thomson Reuters Web of Knowledge, we searched for citations of all papers relevant to pediatric orthopaedics. The number of citations, authorship, year of publication, journal of publication, and country and institution of origin were recorded for each paper. RESULTS: The most cited paper was found to be the classic paper from 1963 by Salter and Harris that introduced the now-eponymous classification system for physeal injuries in the skeletally immature patient. The second most cited was Salter's paper describing the widely used osteotomy for the treatment of developmental dysplasia of the hip, and the third most cited was Catterall's description of the natural history of Legg-Calvé-Perthes disease. Most papers originated in the U.S., and most were published in this journal. A number of authors including Salter, Ponseti, Graf, and Loder had more than one paper in the top-100 list. DISCUSSION: This paper's identification of the classic papers of pediatric orthopaedic surgery gives us a unique insight into the development of pediatric orthopaedic surgery in the twentieth and early twenty-first centuries and identifies those individuals who have contributed the most to the body of knowledge used to guide evidence-based clinical decision-making in pediatric orthopaedics today.