Routine Computed Tomography Scan Research Articles

Exploring bone density analysis on routine CT scans as a tool for opportunistic osteoporosis screening

The primary aim of this study was to evaluate computed tomography (CT)-based bone density analysis at the level of thoracic vertebra 12 (Th12) as a screening method for decreased bone density in patients admitted to the intensive care unit (ICU). Interobserver variability was analyzed. Secondary aims were to assess the prevalence of CT-based low bone density upon ICU admission in a cohort of COVID-19 patients and to assess the potential effect of long-term ICU stay on bone density in these patients. Retrospective single-center cohort study. ICU of the Leiden University Medical Center (LUMC), the Netherlands. Patients admitted to the ICU of the LUMC between March 1st, 2020 and February 1st, 2022 with a diagnosis of COVID-19, and a length of ICU stay of ≥ 21 days. In the included patients both baseline chest CT scans (obtained upon ICU admission) and follow-up chest CT scans (obtained ≥ 21 days after ICU admission) were available for analysis. A total of 118 CT scans in 38 patients were analyzed. There was a good interobserver variability, with an overall mean absolute difference (between measurements of three observers) of 9.7 Hounsfield Units (HU) and an intraclass correlation coefficient (ICC) of 0.93 (95% CI 0.88–0.96). The effect of intravenous contrast administration on bone density measurements was small (+ 7.5 HU (95% CI 3.4–11.5 HU)) higher in contrast enhanced CT images compared to non contrast enhanced CT images). Thirty-seven percent of patients had a bone density < 140 HU, suggestive of osteoporosis. No significant difference was found between bone density upon ICU admission and bone density at follow-up (≥ 21 days after ICU admission). Vertebral CT-based bone density analysis using routine CT scans is an easily applicable method to identify ICU patients with decreased bone density, which could enable enrollment in osteoporosis prevention programs. A high prevalence of low bone density was found in our cohort of ICU patients. There were no changes observed in bone density between baseline and follow-up measurements.

Osteoporosis Evaluation and Management in Spine Surgery.

Osteoporosis is a global health problem affecting over 200 million people worldwide and 54 million adults in the United States. Approximately half of all postmenopausal women will have an osteoporosis-related fracture during their lifetime. In the United States, the direct medical cost related to osteoporosis is expected to exceed $25 billion by 2025. Management of osteoporosis in vertebral fractures and elective spine surgery is of the utmost concern, given the high prevalence of osteoporosis in the general population and the increased risk of complication in this population. New pharmacologic treatment options such as anabolic medications and diagnostic tools including Hounsfield unit measurements on routine computed tomography scans are available to orthopaedic and spinal surgeons to help best manage this condition. This review serves as an update to diagnosis, management, and treatment of patients with osteoporosis undergoing spinal surgery.

Prosthetic Graft Migration in Living Donor Liver Transplantation: A Case for Conservative Management?

Abstract A 61-year-old male underwent living donor liver transplantation (LDLT) for decompensated chronic liver disease with hepatocellular carcinoma. The right lobe from the live donor was used as the graft. During implantation, the drainage of the anterior sector of the right lobe graft was through a reconstructed middle hepatic vein using a prosthetic polytetrafluoroethylene (PTFE) graft. Routine follow-up at 6 weeks showed a thrombosed PTFE graft with no clinical, radiological, or biochemical deterioration of the allograft. He was therefore managed conservatively. A routine computed tomography scan at 2 years demonstrated that the PTFE graft had eroded into the duodenum. Given the total absence of symptoms and the risk of complications associated with removing the graft, we decided against any surgical or endoscopic intervention. After a further 3 year period of follow-up, the patient continues to remain well. Enteric erosion of a prosthetic graft following LDLT can be managed without intervention, although long-term consequences are unknown.

Computed Tomography Evaluation of Alumina Ceramic-on-Ceramic Total Hip Arthroplasty With More Than 20 years of Follow-Up: Is a Follow-Up Computed Tomography Scan Necessary?

BackgroundCeramic-on-ceramic (CoC) bearings have been increasingly used in total hip arthroplasty (THA) because of their superior wear resistance and biocompatibility. However, there is a scarcity of reports on the computed tomography (CT) evaluation of CoC bearings with more than 10 years. The aim of this study was to evaluate the long-term CT results of THA using CoC bearings for more than 20 years of follow-up. We hypothesized that there would be no wear, osteolysis, or ceramic fracture. MethodsBetween November 1997 and June 2003, 956 hips underwent THA using alumina-on-alumina bearings at a tertiary referral hospital. Among them, 107 hips were assessed, all of which underwent a CT examination more than 20 years after the index surgery. The mean age at the time of surgery was 41 years, and a CT scan was performed at an average of 22.0 years postoperatively (range, 20.0 to 25.1). The CT scans were thoroughly assessed for osteolysis, stem notching, and ceramic component fracture. ResultsNo loosening was observed in the acetabular cup or femoral stem. Stem notching was observed in 3 hips (2.8%). In the CT scan taken after a minimum of 20 years of follow-up, 1 case (0.9%) of osteolysis around the cup and 2 cases (1.9%) of osteolysis around the femoral stem were noted. Suspected chip fractures of the ceramic insert were discovered in 4 cases (3.7%). Despite these findings, the patients remained asymptomatic, and no subsequent surgical intervention was needed after close follow-up. ConclusionsRoutine CT examinations for patients who underwent THA using CoC bearings over 20 years ago revealed unexpected findings, such as osteolysis and suspected chip fractures of the ceramic liner. However, routine CT scans may not be universally necessary. The CT evaluation in this cohort should be selectively performed for patients who have relevant clinical symptoms. Level of evidenceLevel III, Therapeutic study.

Accuracy of Phantomless Calibration of Routine Computed Tomography Scans for Opportunistic Osteoporosis Screening in the Spine Clinic.

Diagnostic accuracy study. To establish a simple method of phantomless bone mineral density (BMD) measurement by using preoperative lumbar Computed Tomography (CT) scans, and compare the accuracy of reference tissue combinations to diagnose low BMD against uncalibrated Hounsfield units (HUs). HUs are used as a measure of BMD; however, associations between HU and T-scores vary widely. Quantitative CT (qCT) scans are more accurate, but they require density calibration with an object of known density (phantom), which limits feasibility. As an emerging technique, phantomless (internal) calibration of routine CT scans may provide a good opportunity for screening. Patients who were scheduled to undergo lumbar surgery, with a preoperative CT scan, and a dual-energy x-ray absorptiometry (DXA) scan within six months were included. Four tissues were selected for calibration: subcutaneous adipose (A), erector spinae (ES), psoas (P) and aortic blood (AB). The HUs of these tissues were used in linear regression against ground-truth values. Calibrations were performed by using two different internal tissues at a time to maintain simplicity and in-office applicability.Volumetric bone mineral densities (vBMD) derived from internally calibrated CT scans were analyzed for new threshold values for low bone density. Areas under the curve (AUC) were calculated with 95% confidence intervals (CI). 45 patients were included (M/F=10/35, mean age:63.3). Calibrated vBMDs had stronger correlations with DXA T-scores when compared with HUs, with L2 exhibiting the highest coefficients. Calibration by using A and ES with the threshold of 162mg/cm3 had a sensitivity of 90% in detecting low BMD (AUC=0.671). This novel method allows simple, in-office calibration of routine preoperative CT scans without the use of a phantom. Calibration using adipose and erector spinae with a threshold of 162mg/cm3 is proposed for low bone density screening with high sensitivity (90%). Level III.

3D-Volumetric Shunt Measurement for Detection of High-Risk Esophageal Varices in Liver Cirrhosis.

Background and Objectives: Esophageal varices (EV) and variceal hemorrhages are major causes of mortality in liver cirrhosis patients. Detecting EVs early is crucial for effective management. Computed tomography (CT) scans, commonly performed for various liver-related indications, provide an opportunity for non-invasive EV assessment. However, previous CT studies focused on variceal diameter, neglecting the three-dimensional (3D) nature of varices and shunt vessels. This study aims to evaluate the potential of 3D volumetric shunt-vessel measurements from routine CT scans for detecting high-risk esophageal varices in portal hypertension. Methods: 3D volumetric measurements of esophageal varices were conducted using routine CT scans and compared to endoscopic variceal grading. Receiver operating characteristic (ROC) analyses were performed to determine the optimal cutoff value for identifying high-risk varices based on shunt volume. The study included 142 patients who underwent both esophagogastroduodenoscopy (EGD) and contrast-enhanced CT within six months. Results: The study established a cutoff value for identifying high-risk varices. The CT measurements exhibited a significant correlation with endoscopic EV grading (correlation coefficient r = 0.417, p < 0.001). A CT cutoff value of 2060 mm3 for variceal volume showed a sensitivity of 72.1% and a specificity of 65.5% for detecting high-risk varices during endoscopy. Conclusions: This study demonstrates the feasibility of opportunistically measuring variceal volumes from routine CT scans. CT volumetry for assessing EVs may have prognostic value, especially in cirrhosis patients who are not suitable candidates for endoscopy.

A retrospective cohort study of incidental abdominal aortic aneurysms on routine abdominal computed tomography scans in Te Tairāwhiti (2018-2019).

Ruptured abdominal aortic aneurysm (rAAA) is associated with a high mortality rate which, is especially significant in rural and provincial regions. In Aotearoa New Zealand, Māori experience higher rates of AAA and worse overall medium-term survival following AAA repair. This study aimed to understand the prevalence of incidental AAA on routine abdominal computed tomography (CT) scans over 12 months. A retrospective review of all abdominal CT scans performed on patients ≥50 years at Gisborne Hospital between 1 December 2018-1 December 2019 was performed. A total of 811 scans were reviewed, with 42 incidental AAA detected (5.2%). The majority of incidental AAA were in males aged ≥65 (65.8%), with a higher prevalence for Māori compared to New Zealand European (NZE) (16.2% vs 8.1%, p=0.052). This pattern was also seen in females, aged ≥65 (10.9% in Māori vs 3.8% in NZE, p=0.047). The detection of AAA on routine abdominal CT scans appears to be a useful adjunct in lieu of targeted AAA screening in our region. A high prevalence of incidental AAA (5.2%) over 12 months, with a significantly higher prevalence noted in Māori males and females ≥65 years (16.2% and 10.9%), was observed.

Total Muscle Area and Visceral Adipose Tissue Measurements for Frailty Assessment in TAVR Patients.

Background: Transcatheter aortic valve replacement (TAVR) is a treatment option for severe aortic valve stenosis. Pre-TAVR assessments, extending beyond anatomy, include evaluating frailty. Potential frailty parameters in pre-TAVR computed tomography (CT) scans are not fully explored but could contribute to a comprehensive frailty assessment. The primary objective was to investigate the impact of total muscle area (TMA) and visceral adipose tissue (VAT) as frailty parameters on 5-year all-cause mortality in patients undergoing TAVR. Methods: Between 01/2017 and 12/2018, consecutive TAVR patients undergoing CT scans enabling TMA and VAT measurements were included. Results: A total of 500 patients qualified for combined TMA and VAT analysis. Age was not associated with a higher risk of 5-year mortality (HR 1.02, 95% CI: 0.998-1.049; p = 0.069). Body surface area normalized TMA (nTMA) was significantly associated with 5-year, all-cause mortality (HR 0.927, 95% CI: 0.927-0.997; p = 0.033), while VAT had no effect (HR 1.002, 95% CI: 0.99-1.015; p = 0.7). The effect of nTMA on 5-year, all-cause mortality was gender dependent: the protective effect of higher nTMA was found in male patients (pinteraction: sex × nTMA = 0.007). Conclusions: Normalized total muscle area derived from a routine CT scan before transcatheter aortic valve replacement complements frailty assessment in patients undergoing TAVR.

Postoperative Computed Tomography Scans of Acetabular Fractures Routinely Identify Indications for Revision Surgery.

To investigate the utility of postoperative computed tomography (CT) scans in identifying indications for revision surgery after surgical fixation of acetabular fractures. Retrospective cohort study. Urban level 1 trauma center. Patients with surgically treated acetabular fractures with surgical fixation (open reduction and internal fixation or percutaneous fixation) with routine postoperative CT scans. Primary outcome-revision surgery based on postoperative imaging, including intra-articular osteochondral fragments, implant complications, and malreductions. Secondary outcome-quality of reduction on radiographs versus CT scans. One hundred forty-eight patients were included. The revision surgery rate was 15.5% (23/148); indications included malpositioned implants (6.7%, n = 10), malreductions (5.4%, n = 8), and intra-articular loose bodies (3.4%, n = 5). Only 8.7% (2/23) of the indications for revision surgery were identified on postoperative radiographs, with the remainder being identified on CT scans. Revision surgeries were found to be associated with male gender (proportional difference: 19.6%, 95% confidence interval [CI]: 3.4%-29.4%; P = 0.04) and T-type fractures (PD 28.7%; CI, 9.0%-48.9%; P = 0.001). Revision surgery was not found to be associated with age, body mass index, posterior wall fractures, concurrent pelvic ring fractures, or surgical approach. On radiographs, 51.3% (n = 76/148) had anatomic reductions (<2 mm) compared with only 10.2% (n = 15/148) on CT scans. Indications for revision of acetabular fixation surgeries and poor reductions were frequently missed on plain radiography and identified on postoperative CT scans. This suggests that the use of advanced imaging such as intraoperative 3D imaging or postoperative CT scans may be beneficial. Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical parameters for the early detection of complications in patients with blunt hepatic and/or splenic injury undergoing non-operative management.

Complications arising during non-operative management (NOM) of blunt hepatic and/or splenic trauma, particularly in cases of severe injury, are associated with significant morbidity and mortality. Abdominal computed tomography (CT) is the gold standard for the initial detection of complications during NOM. Although many institutions advocate routine in-hospital follow-up scans to improve success rates, others recommend a more selective approach. The use of follow-up CT remains a subject of ongoing debate, with no validated guidelines available regarding the timing, effectiveness, or intervals of follow-up imaging. We aimed to identify the clinical parameters for the early detection of complications in patients with blunt hepatic and/or splenic injury undergoing NOM. This retrospective cohort study included patients with blunt hepatic and/or splenic trauma treated at Songklanagarind Hospital, a level 1 trauma center, from 2013 to 2022. We assessed all patients indicated for non-operative management and examined their clinical parameters and complications. Of 542 patients with blunt hepatic and/or splenic injuries, 315 (58%) were managed non-operatively. High-grade hepatic injuries were significantly associated with complications, as determined through a multivariate logistic regression analysis after adjusting for factors such as contrast blush findings, age, sex, and injury severity score (ISS) (adjusted OR = 7.69, 95% CI 1.59-37.13; p = 0.011). Among the patients with complications (n = 27), 17 (63%) successfully underwent non-operative management. Notably, eight patients presented with clinical symptoms prior to the diagnosis of complications, while only two patients had no clinical symptoms before the diagnosis. Tachycardia, abdominal pain, decreased hematocrit levels, and fever were significant indicators of complications (p < 0.05). Routine CT to detect complications may not be necessary in patients with asymptomatic low-grade blunt hepatic injuries. By contrast, in those with isolated blunt hepatic injuries that are managed non-operatively, high-grade injuries, the presence of a contrast blush on initial imaging, and the patient's age may warrant consideration for routine follow-up CT scans. Clinical symptoms and laboratory observations during NOM, such as tachycardia, abdominal pain, decreased hematocrit levels, and fever, are significantly associated with complications. These symptoms necessitate further management, regardless of the initial injury severity, in patients with blunt hepatic and/or splenic injuries undergoing NOM.

Feasibility of diagnosing osteoporosis using routine computed tomography scans for hip fractures: Correlation with histopathological diagnosis of head and neck regions.

The aim of this study was to demonstrate the feasibility of diagnosing osteoporosis through routine computed tomography (CT) by assessing the association between the histopathological assessment of femoral head specimens extracted from patients who underwent surgery for intertrochanteric fractures and the Hounsfield unit (HU) measurements derived from preoperative CT scans. Forty-eight patients who presented to our clinic between November 2019 and May 2020 with hip fractures and underwent partial prosthesis fixation were included in this retrospective study. Hounsfield unit measurements were performed on the head and neck regions using dual-energy x-ray absorptiometry (DEXA) and CT scans, respectively. The trabecular ratio per unit area was calculated using the Nikon Imaging Software (NIS-Elements ) program in the pathology laboratory from digitally captured images of the removed head and neck specimens. The mean HU receiver operating characteristic analysis had a sensitivity of 77% and a specificity of 87%, with a cutoff value of 77.68. There was a moderate correlation between the mean trabecular density and the mean HU of the femoral head (P=0.013, r=0.340). Additionally, there was a significant correlation between the mean HU and the T-score of the head, although this correlation was not found with the maximum-minimum HU. Although there was a significant correlation between trabecular density and mean HU, the correlation coefficient indicated a moderate relationship. This relationship was also observed between the inferior sections of the head and the trabecular density and HU (P=.018). However, no significant correlation was found between the T-score and the trabecular structure of the head (P=.977). The results of the present study suggest that conventional CT has the potential to serve as a diagnostic tool for osteoporosis and may offer a more precise and accurate method for evaluating the success of intraosseous implants when compared to T-scores without the need for additional tests or procedures.

Evaluation of deep learning-based quantitative computed tomography for opportunistic osteoporosis screening

To evaluate diagnostic efficacy of deep learning (DL)-based automated bone mineral density (BMD) measurement for opportunistic screening of osteoporosis with routine computed tomography (CT) scans. A DL-based automated quantitative computed tomography (DL-QCT) solution was evaluated with 112 routine clinical CT scans from 84 patients who underwent either chest (N:39), lumbar spine (N:34), or abdominal CT (N:39) scan. The automated BMD measurements (DL-BMD) on L1 and L2 vertebral bodies from DL-QCT were validated with manual BMD (m-BMD) measurement from conventional asynchronous QCT using Pearson’s correlation and intraclass correlation. Receiver operating characteristic curve (ROC) analysis identified the diagnostic ability of DL-BMD for low BMD and osteoporosis, determined by dual-energy X-ray absorptiometry (DXA) and m-BMD. Excellent concordance were seen between m-BMD and DL-BMD in total CT scans (r = 0.961/0.979). The ROC-derived AUC of DL-BMD compared to that of central DXA for the low-BMD and osteoporosis patients was 0.847 and 0.770 respectively. The sensitivity, specificity, and accuracy of DL-BMD compared to central DXA for low BMD were 75.0%, 75.0%, and 75.0%, respectively, and those for osteoporosis were 68.0%, 80.5%, and 77.7%. The AUC of DL-BMD compared to the m-BMD for low BMD and osteoporosis diagnosis were 0.990 and 0.943, respectively. The sensitivity, specificity, and accuracy of DL-BMD compared to m-BMD for low BMD were 95.5%, 93.5%, and 94.6%, and those for osteoporosis were 88.2%, 94.5%, and 92.9%, respectively. DL-BMD exhibited excellent agreement with m-BMD on L1 and L2 vertebrae in the various routine clinical CT scans and had comparable diagnostic performance for detecting the low-BMD and osteoporosis on conventional QCT.

Prognostic value of deep learning-derived body composition in advanced pancreatic cancer—a retrospective multicenter study

Despite the prognostic relevance of cachexia in pancreatic cancer, individual body composition has not been routinely integrated into treatment planning. In this multicenter study, we investigated the prognostic value of sarcopenia and myosteatosis automatically extracted from routine computed tomography (CT) scans of patients with advanced pancreatic ductal adenocarcinoma (PDAC). We retrospectively analyzed clinical imaging data of 601 patients from three German cancer centers. We applied a deep learning approach to assess sarcopenia by the abdominal muscle-to-bone ratio (MBR) and myosteatosis by the ratio of abdominal inter- and intramuscular fat to muscle volume. In the pooled cohort, univariable and multivariable analyses were carried out to analyze the association between body composition markers and overall survival (OS). We analyzed the relationship between body composition markers and laboratory values during the first year of therapy in a subgroup using linear regression analysis adjusted for age, sex, and American Joint Committee on Cancer (AJCC) stage. Deep learning-derived MBR [hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.47-0.77, P < 0.005] and myosteatosis (HR 3.73, 95% CI 1.66-8.39, P < 0.005) were significantly associated with OS in univariable analysis. In multivariable analysis, MBR (P= 0.019) and myosteatosis (P= 0.02) were associated with OS independent of age, sex, and AJCC stage. In a subgroup, MBR and myosteatosis were associated with albumin and C-reactive protein levels after initiation of therapy. Additionally, MBR was also associated with hemoglobin and total protein levels. Our work demonstrates that deep learning can be applied across cancer centers to automatically assess sarcopenia and myosteatosis from routine CT scans. We highlight the prognostic role of our proposed markers and show a strong relationship with protein levels, inflammation, and anemia. In clinical practice, automated body composition analysis holds the potential to further personalize cancer treatment.

CT validation of intraoperative imageless navigation (Naviswiss) for component positioning accuracy in primary total hip arthroplasty in supine patient position: a prospective observational cohort study in a single-surgeon practice

BackgroundThe aim of this study was to report on the validity of the Naviswiss handheld image-free navigation device for accurate intraoperative measurement of THA component positioning, in comparison with the three-dimensional (3D) reconstruction of computed tomography (CT) images as the gold standard.MethodsA series of patients presenting to a single-surgeon clinic with end-stage hip osteoarthritis received primary hip arthroplasty with the anterolateral muscle-sparing surgical approach in the supine position. Imageless navigation was applied during the procedure with bone-mounted trackers applied to the greater trochanter and ASIS. Patients underwent routine CT scans before and after surgery and these were analyzed by using three-dimensional reconstruction to generate cup orientation, offset and leg length changes, which were compared to the intraoperative measurements provided by the navigation system. Estimates of agreement between the intraoperative and image-derived measurements were assessed with and without correction for bias and declared cases with potential measurement issues.ResultsThe mean difference between intraoperative and postoperative CT measurements was within 2° for angular measurements and 2 mm for leg length. Absolute differences for the two indices were between 5° and 4 mm. Mean bias was 1.9°–3.6° underestimation for cup orientation and up to 2 mm overestimation for leg length change, but absolute thresholds of 10° and 10 mm were not exceeded by 95% limits of agreement (LOA), especially after correction for bias. Four cases (12%) were declared intraoperatively for issues with fixation on the greater trochanter. Inclusion of these cases generated acceptable accuracy overall and their omission failed to improve between-case variability in accuracy or LOA for both offset and leg length.ConclusionsThe accuracy of the Naviswiss system applied during primary THA in a supine position and anterolateral surgical approach falls within clinically acceptable recommendations for acetabular cup placement, femoral offset, and length. With refinements to surgical technique to adapt to the navigation hardware, the system could be further improved with regression-based bias correction.Trial registrationRegistered with the Australian New Zealand Clinical Trials Registry (ACTRN12618000317291)

Do Computerized Tomography Scans Change Management in Carpometacarpal Dislocations and Fracture-Dislocations?

Concomitant carpal injuries with dislocations and fracture-dislocations of the carpometacarpal joints (CMCD/FD) are often hard to see on plain radiographs, making advanced imaging a useful diagnostic adjunct. We aim to: (1) characterize bony injury patterns with CMCD/FD; and (2) determine the frequency that preoperative computed tomography (CT) scans change surgical management. A retrospective review was performed of patients who underwent operative fixation of CMCD/FD from 2006 to 2021. X-ray and CT scan diagnoses were reviewed and correlated to intraoperative findings and procedures performed. Statistical analyses were performed to evaluate the frequency in which CT scans changed management and the frequency of new intraoperative diagnoses. Seventy-five patients were identified. All patients had a preoperative x-ray, and 27 patients (36%) additionally had a CT scan. Patients who sustained high-velocity trauma were significantly more likely to obtain a CT scan than patients with low-velocity trauma (P = .019); however, the number of additional diagnoses was not significantly associated with trauma velocity (P = .35). Computed tomography scans significantly increased the number of diagnoses (P < .001) and changed operative management in 58% of cases. Six of the 48 patients (12.5%) that did not receive a CT scan had new intraoperative diagnoses, which changed the procedure for five of these patients. New intraoperative diagnoses were identified significantly more when patients did not have a CT scan (P = .04). Obtaining a CT scan in CMCD/FD patients changed the patient's diagnosis at a significant rate and changed operative management roughly half of the time. The authors recommend routine CT scans be obtained in patients with CMCD/FD.

Influence of tube and patient positioning in thoracoabdominal CT examinations on radiation exposure–towards a better patient positioning

Although iso-centric patient positioning is enormously important in computed tomography (CT), it is complicated in thoracoabdominal imaging by the varying dimensions of the body. Patient positioning can affect the appearance of the patient on the localiser. Positioned too close to the x-ray tube, a patient appears considerably more voluminous. The goal of this study is to assess the difference in radiation exposure of combined chest and abdomen CT scans between scans with prior 0°- and 180°-localisers in conjunction with patient positioning. In this IRB-approved retrospective study, patients who had two routine thoracoabdominal CT scans on the same CT scanner, one with a prior 0°- and one with a prior 180°-localiser, were included. To evaluate the radiation exposure of the thoracoabdominal CT examination regarding the tube position during the localiser, volumetric computed tomography dose index (CTDIvol), size-specific dose estimate (SSDE), patient diameter and positioning within the iso-centre for three positions (heart, abdomen, femur level) were compared with regard to the tube position during the prior localiser. CT examinations of 114 patients were included. Despite similar patient weight and diameter between the two examinations, SSDE and CTDIvol was significantly larger (up to 73%) with 180°-localisers. Patient offset from the iso-centre ranged between −9 mm at the centre slice (abdomen level) to −43 mm at the most caudal slice at the pelvis (femur level), causing a significant magnification (p < 0.001) on 180°-localisers with a subsequent increase of the apparent attenuation. The results of this study emphasise the use of 0°-localisers in thoracoabdominal CTs, since 180°-localisers caused patient magnification with subsequent increase in radiation exposure. The advantage of 180°-localisers, namely reducing the dose in thyroid and breast, is eliminated if the dose of the CT scan increases significantly in the abdomen and pelvis.

The Loss of Temporal Muscle Volume is Associated with Poor Outcome in Patients with Subarachnoid Hemorrhage: An Observational Cohort Study

BackgroundIntensive care unit (ICU) acquired weakness is a major contributor to poor functional outcome of ICU patients. Quantification of temporal muscle volume assessed on routine computed tomography (CT) scans may serve as a biomarker for muscle wasting in patients suffering from acute brain injury.MethodsThis is a retrospective analysis of prospectively collected data. Temporal muscle volume was assessed on head CT scans of consecutive patients with spontaneous subarachnoid hemorrhage within prespecified time frames (on admission, then weekly ± 2 days). Whenever possible, temporal muscle volume was assessed bilaterally and averaged for the analysis. Poor functional outcome was defined as a 3-month modified Rankin Scale Score ≥ 3. Statistical analysis was performed using generalized estimating equations to handle repeated measurements within individuals.ResultsThe analysis comprised 110 patients with a median Hunt & Hess score of 4 (interquartile range 3–5). Median age was 61 (50–70) years, 73 patients (66%) were women. Baseline temporal muscle volume was 18.5 ± 0.78 cm3 and significantly decreased over time (p < 0.001) by a mean of 7.9% per week. Higher disease severity (p = 0.002), hydrocephalus (p = 0.020), pneumonia (p = 0.032), and bloodstream infection (p = 0.015) were associated with more pronounced muscle volume loss. Patients with poor functional outcome had smaller muscle volumes 2 and 3 weeks after subarachnoid hemorrhage compared with those with good outcome (p = 0.025). The maximum muscle volume loss during ICU stay was greater in patients with poor functional outcome (− 32.2% ± 2.5% vs. − 22.7% ± 2.5%, p = 0.008). The hazard ratio for poor functional outcome was 1.027 (95% confidence interval 1.003–1.051) per percent of maximum muscle volume loss.ConclusionsTemporal muscle volume, which is easily assessable on routine head CT scans, progressively decreases during the ICU stay after spontaneous subarachnoid hemorrhage. Because of its association with disease severity and functional outcome, it may serve as a biomarker for muscle wasting and outcome prognostication.

Fracture Risk in Men and Women With Vertebral Fractures Identified Opportunistically on Routine Computed Tomography Scans and Not Treated for Osteoporosis: An Observational Cohort Study.

Vertebral fractures (VFs) have been associated with future fractures, yet few studies have evaluated whether this pertains to VFs available for identification on routine radiological imaging. We sought to evaluate the risk of subsequent fractures in subjects with VF identified opportunistically on computed tomography (CT) scans performed as part of routine clinical practice. From the radiology database of Holbæk Hospital we identified the first CT scan including the thorax and/or abdomen of 2000 consecutive men and women aged 50 years or older, performed from January 1, 2010 onward. The scans were assessed in a blinded approach to identify chest and lumbar VF, and these data linked to national Danish registers. Subjects were excluded if treated with an osteoporosis medication (OM) in the year prior to baseline (date of CT), and the remaining subjects with VF matched on age and sex in 1:2 ratio against subjects with no VF. We found that the risk of major osteoporotic fractures (hip, non-cervical vertebral, humerus, and distal forearm fractures) was higher for subjects with VF than without VF: incidence rates (IRs) were 32.88 and 19.59 fractures per 1000 subject-years, respectively, and the adjusted hazard ratio (HRadj) was 1.72 (95% confidence interval [CI], 1.03-2.86). Subsequent hip fracture IRs were 16.75 and 6.60; HRadj 3.02 (95% CI, 1.39-6.55). There were no significant differences in other fracture outcomes (including a pooled estimate of any subsequent fracture, except face, skull, and fingers: IRs 41.52 and 31.38; HRadj 1.31 [95% CI, 0.85-2.03]). Our findings suggest that subjects undergoing routine CT scans including the chest and/or abdomen are a high risk population in terms of fracture risk. Even within this group, subjects with VF are at higher risk of future major osteoporotic fracture (MOF), in particular hip fracture. Hence, systematic opportunistic screening for VF and subsequent fracture risk management is important to reduce the risk of new fractures. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Routine postoperative computed tomography (CT) scans following acetabulum open reduction internal fixation (ORIF): A survey of orthopaedic traumatologists

ObjectiveThe purpose of this study was to assess the practices related to obtaining postoperative pelvic CT scans following acetabular ORIF and revision surgery rates. DesignA 20-question survey published on the Orthopaedic Trauma Association (OTA) website assessed each surgeon's preference and rationale for or against the routine use of postoperative CT scans for acetabular fractures. ParticipantsFellowship-trained orthopaedic traumatologists. Main outcome measurementsWe examined the percentage of surgeons ordering routine postoperative CT scans, surgeon demographics, and revision surgery rates based on these routine CT scan results. ResultsResponses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 16 surgeons (28%, Group A) routinely ordering them and 41 surgeons (72%, Group B) not ordering them on all patients. No significant difference in surgeon demographics were found between the groups. Majority of Group A report a revision surgery rate of <1% based on the results of the postoperative CT.Group A report routine postoperative scans were obtained to assess reduction, hardware placement, identify intra-articular fragments, and for educational purposes. Group B did not obtain routine postoperative CTs due to the following: unlikely to change postoperative treatment, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with inadequate intraoperative imaging and postoperative neurological changes being the most common indications. ConclusionThe routine use of postoperative CTs following open reduction internal fixation of acetabular fractures is a controversial topic. While we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.

Routine Postoperative Computed Tomography Scans Following Posterior Pelvic Fixation of Pelvic Ring Fractures: A Survey of (OTA) Orthopaedic Traumatologists.

To assess practices related to ordering computed tomography (CT) scans routinely after posterior pelvic ring fixation and revision surgery rates. A 20-question cross-sectional survey. Fellowship-trained orthopaedic traumatologists. (1) Percentage of surgeons ordering a routing postoperative CT after posterior pelvic ring fixation, (2) Revision surgery rates based on routine CT scan results. Responses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 20 surgeons (35%, group A) routinely ordering them and 37 surgeons (65%, group B) not ordering them on all patients. Group A were younger and with less years of experience than those in Group B. Most group A surgeons report a revision surgery rate of <1% based on results of the postoperative CT. Group A report routine postoperative scans were obtained to assess reduction, instrumentation placement, and for educational purposes. Group B did not obtain routine postoperative CTs because of the following: unlikely to change postoperative treatment course, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with postoperative neurological deficit being the most common indication. The routine use of postoperative CTs following posterior fixation of pelvic ring fractures is a controversial topic. Although we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.