Cost-effectiveness of immediate total-body CT in patients with severe trauma (REACT-2 trial).

BACKGROUND: The effect of immediate total-body CT (iTBCT) on health economic aspects in patients with severe trauma is an underreported issue. This study determined the cost-effectiveness of iTBCT compared with conventional radiological imaging with selective CT (standard work-up (STWU)) during the initial trauma evaluation. METHODS: In this multicentre RCT, adult patients with a high suspicion of severe injury were randomized in-hospital to iTBCT or STWU. Hospital healthcare costs were determined for the first 6 months after the injury. The probability of iTBCT being cost-effective was calculated for various levels of willingness-to-pay per extra patient alive. RESULTS: A total of 928 Dutch patients with complete clinical follow-up were included. Mean costs of hospital care were €25 809 (95 per cent bias-corrected and accelerated (bca) c.i. €22 617 to €29 137) for the iTBCT group and €26 155 (€23 050 to €29 344) for the STWU group, a difference per patient in favour of iTBCT of €346 (€4987 to €4328) (P = 0.876). Proportions of patients alive at 6 months were not different. The proportion of patients alive without serious morbidity was 61.6 per cent in the iTBCT group versus 66.7 per cent in the STWU group (difference -5.1 per cent; P = 0.104). The probability of iTBCT being cost-effective in keeping patients alive remained below 0.56 for the whole group, but was higher in patients with multiple trauma (0.8-0.9) and in those with traumatic brain injury (more than 0.9). CONCLUSION: Economically, from a hospital healthcare provider perspective, iTBCT should be the diagnostic strategy of first choice in patients with multiple trauma or traumatic brain injury.

Preablation Diagnostic Whole-Body Scan vs Empiric Radioactive Iodine Ablation in Differentiated Thyroid Cancer: Cost-effectiveness Analysis.

OBJECTIVE: To perform a comparative analysis of postthyroidectomy radioactive iodine ablation dosing with or without the implementation of a diagnostic whole-body scan in patients with well-differentiated thyroid cancer. STUDY DESIGN: Decision analysis model. SETTING: Hospital or ambulatory center. METHODS: A decision tree model was created to determine the cost-effectiveness of radioactive iodine ablation dosed with diagnostic whole-body scans versus empiric radioactive iodine ablation in patients with differentiated thyroid cancer undergoing postthyroidectomy ablation. The decision tree was populated with values from the published literature. Costs were represented by 2020 Medicare reimbursement rates (US dollars), and morbidity and survival data were used to calculate quality-adjusted life-years. The incremental cost-effectiveness ratio was the primary outcome. RESULTS: Empiric radioactive iodine dosing was the dominant economic strategy, producing 0.94 more quality-adjusted life-years while costing $1250.07 less than management with a diagnostic whole-body scan. Sensitivity analyses upheld these results except in cases involving a large discrepancy in successful ablation rates between the diagnostic and empiric treatment arms. CONCLUSION: For patients with differentiated thyroid cancer requiring postthyroidectomy ablation, it is more cost-effective to administer radioactive iodine empirically.

Lodox®: the invaluable radiographic solution in the forensic setting.

The benefits of a comparatively inexpensive radiographic system such as the Lodox® scanner in forensic facilities where CT-imaging and radiologist support is not financially viable will be explored. Prodigious caseloads in many under-resourced mortuaries preclude the use of advanced radiological modalities. The aim of this research is to examine the utilization of the Lodox® scanner in one of the busiest mortuaries in South Africa in relation to the nature of the cases scanned and, furthermore, to provide case studies where this imaging modality proved vital in the examination of the deceased and in the approach to the autopsy. The research is a retrospective epidemiological review on the use of the Lodox® scanner at the Salt River Medico-legal Laboratory, Cape Town, South Africa, from 1 January 2017 to 31 December 2017. A total of 3885 cases was admitted to the mortuary; the majority was scanned. A large proportion of cases were male. Ages ranged from foetuses to the elderly. The manner of death in more than a third of the cases was homicide which mainly involved firearm fatalities. This was followed by natural deaths. Pertinent case studies are presented to demonstrate that the use of the Lodox® scanner as an adjunct (or even obviating autopsy) proves to save time and labour and is financially beneficial. In conclusion, the Lodox® scanner is an indispensable tool in mortuaries with heavy caseloads because its use improves quality assurance, saves time, and is cost effective in the examination of both natural and unnatural deaths.

Localising occult prostate cancer metastasis with advanced imaging techniques (LOCATE trial): a prospective cohort, observational diagnostic accuracy trial investigating whole-body magnetic resonance imaging in radio-recurrent prostate cancer.

BACKGROUND: Accurate whole-body staging following biochemical relapse in prostate cancer is vital in determining the optimum disease management. Current imaging guidelines recommend various imaging platforms such as computed tomography (CT), Technetium 99 m (99mTc) bone scan and 18F-choline and recently 68Ga-PSMA positron emission tomography (PET) for the evaluation of the extent of disease. Such approach requires multiple hospital attendances and can be time and resource intensive. Recently, whole-body magnetic resonance imaging (WB-MRI) has been used in a single visit scanning session for several malignancies, including prostate cancer, with promising results, providing similar accuracy compared to the combined conventional imaging techniques. The LOCATE trial aims to investigate the application of WB-MRI for re-staging of patients with biochemical relapse (BCR) following external beam radiotherapy and brachytherapy in patients with prostate cancer. METHODS/DESIGN: The LOCATE trial is a prospective cohort, multi-centre, non-randomised, diagnostic accuracy study comparing WB-MRI and conventional imaging. Eligible patients will undergo WB-MRI in addition to conventional imaging investigations at the time of BCR and will be asked to attend a second WB-MRI exam, 12-months following the initial scan. WB-MRI results will be compared to an enhanced reference standard comprising all the initial, follow-up imaging and non-imaging investigations. The diagnostic performance (sensitivity and specificity analysis) of WB-MRI for re-staging of BCR will be investigated against the enhanced reference standard on a per-patient basis. An economic analysis of WB-MRI compared to conventional imaging pathways will be performed to inform the cost-effectiveness of the WB-MRI imaging pathway. Additionally, an exploratory sub-study will be performed on blood samples and exosome-derived human epidermal growth factor receptor (HER) dimer measurements will be taken to investigate its significance in this cohort. DISCUSSION: The LOCATE trial will compare WB-MRI versus the conventional imaging pathway including its cost-effectiveness, therefore informing the most accurate and efficient imaging pathway. TRIAL REGISTRATION: LOCATE trial was registered on ClinicalTrial.gov on 18th of October 2016 with registration reference number NCT02935816.

An audit of the polytrauma fracture detection rate of clinicians evaluating lodox statscan bodygrams in two South African public sector trauma units.

BACKGROUND: Increasing global demand for specialized radiological investigations has resulted in delayed or non-reporting of plain trauma radiographs by radiologists. This is particularly true in resource-limited environments, where referring clinicians rely largely on their own radiographic interpretation. A wide accuracy range has been documented for non-radiologist reporting of conventional trauma radiographs. The Lodox Statscan whole-body digital X-ray machine is a relatively new technology that poses unique interpretive challenges. The fracture detection rate of trauma clinicians utilizing this modality has not been determined. OBJECTIVE: An audit of the polytrauma fracture detection rate of clinicians evaluating Lodox Statscan bodygrams in two South African public-sector Trauma Units. METHODS: A retrospective descriptive study of imaging data of Cape Town Level 1-equivalent public-sector Trauma Units during March-April 2015. Statscan bodygrams acquired for adult polytrauma triage were reviewed and correlated with follow-up imaging and patient records. Missed fractures were stratified by body part, mechanism of injury and ventilatory support. The fracture detection rate was determined with 95% confidence. The Generalised Fischer Exact Test assessed any association between the fracture site and failure of detection. Specialist orthopaedic review assessed the potential need for surgical management of missed fractures. RESULTS: 227 patients (male = 193, 85%; mean age: 33 years) were included; 195 fractures were demonstrated on the whole-body triage projections. Lower limb fractures predominated (n = 66, 34%). The fracture detection rate was 89% (95% CI = 86-93%), with the site of fracture associated with failure of detection (p = 0.01). Twelve of 21 undetected fractures (57%) involved the elbow or shoulder girdle. All elbow fractures (n = 3, 100%), more than half the shoulder girdle fractures (9/13,69%) and 12% (15/123) of extremity fractures were undetected. One missed fracture (1/21,4.7%) unequivocally required surgical management, while a further 7 (7/21, 33.3%) could potentially have benefitted from surgery, depending on follow-up imaging findings. CONCLUSION: This is the first analysis of the accuracy of bodygram polytrauma fracture detection by clinicians. Particular review of the shoulder girdle, elbow and extremities for subtle fractures, in addition to standardized limb positioning, are recommended for improved diagnostic accuracy in this setting. These findings can inform clinician training courses in this domain.

A rapid and nondestructive protocol for whole-mount bone staining of small fish and Xenopus.

Here we propose a new protocol for whole-mount bone staining, which allows the rapid preparation of highly cleared and nondestructive specimens. It only takes 3 days to complete whole procedure for small vertebrates, such as medaka, zebrafish, and Xenopus frogs. In this procedure, we used a newly developed fixative containing formalin, Triton X-100, and potassium hydroxide, which allows the fixation, decolorization, and transparentization of specimens at the same time. A bone staining solution containing alizarin red S with ethylene glycol and a clearing solution containing Tween 20 and potassium hydroxide also contributed the specificity and swiftness of this new system. As expected, although details of the skeletal system could be observed in specimens with high transparency, it was noteworthy that high-resolution fluorescence images acquired using zoom microscopes clearly delineated the shape of each bone. This new procedure would be expected to be widely used as a standard procedure for bone staining in the testing the developmental toxicity of chemicals and in the screening test of knockout or mutant animals.

Whole Body MRI and oncology: recent major advances.

MRI is a very attractive approach for tumour detection and oncological staging with its absence of ionizing radiation, high soft tissue contrast and spatial resolution. Less than 10 years ago the use of Whole Body MRI (WB-MRI) protocols was uncommon due to many limitations, such as the forbidding acquisition times and limited availability. This decade has marked substantial progress in WB-MRI protocols. This very promising technique is rapidly arising from the research world and is becoming a commonly used examination for tumour detection due to recent technological developments and validation of WB-MRI by multiple studies and consensus papers. As a result, WB-MRI is progressively proposed by radiologists as an efficient examination for an expanding range of indications. As the spectrum of its uses becomes wider, radiologists will soon be confronted with the challenges of this technique and be urged to be trained in order to accurately read and report these examinations. The aim of this review is to summarize the validated indications of WB-MRI and present an overview of its most recent advances. This paper will briefly discuss how this examination is performed and which are the recommended sequences along with the future perspectives in the field.

Economic Benefits and Diagnostic Quality of Diffusion-Weighted Magnetic Resonance Imaging for Primary Lung Cancer.

This paper focuses on the latest research of diffusion-weighted magnetic resonance imaging (DWI), and deals with economic benefits, diagnostic benefits, and prospects of DWI for lung cancer. The medical cost of a magnetic resonance imaging (MRI) is 81%-84% cheaper than that of 18-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT). DWI is reported to be useful for differential diagnosis of malignancy or benignity for neoplasm in various organs. Diagnostic efficacy by DWI for pulmonary nodules and masses and the evaluation of N factor and M factor in lung cancer are equivalent to or more than that of FDG-PET/CT. The diagnostic capability of whole-body DWI (WB-DWI) for the staging of clinically operable lung cancers is equivalent to that of FDG-PET/CT and brain MRI, and WB-DWI is now becoming a more main stream procedure. Although the diagnostic performance of DWI for lung cancer may be equivalent to that of FDG-PET/CT, prospective randomized controlled trial for comparison of diagnostic efficacy between FDG-PET/CT and DWI for lung cancer is necessary for an accurate comparison. DWI may have an advantage in the aspect of the cost and diagnostic efficacy in lung cancer management.

PET/MRI-knocking on the doors of the rich and famous.

Since 2010 the portfolio of positron emission tomography (PET)-based imaging has been expanded by industry with the introduction of combined whole-body PET/MRI systems with the intent of merging PET-based molecular imaging with the strengths of MRI. PET/MRI has created a lot of hype in the scientific community but comparatively little traction in the clinic. The first years of whole-body PET/MRI were used to address inherent technical challenges; however, it is now time to make use of the full potential of this integrated imaging modality. This opinion piece highlights the continuing challenges for the clinical adoption of PET/MRI and cautions against putting too much emphasis on comparisons with clinical PET/CT. In order for PET/MRI to enter clinical practice, cross-specialty co-operation must be pursued with rigour and use-case scenarios must be propagated, following long-awaited expansion of reimbursement strategies and protocol standardization.

Simulation study of a D-shape PET scanner for improved sensitivity and reduced cost in whole-body imaging.

Much research effort is being made to increase the sensitivity and improve the imaging performance of positron emission tomography (PET) scanners. Conventionally, sensitivity can be increased by increasing the number of detector rings in the axial direction (but at high cost) or reducing the diameter of the scanner (with the disadvantages of reducing the space for patients and degrading the spatial resolution due to the parallax error). In this study, we proposed a PET scanner with a truncated ring and an array of detectors that can be arranged in a straight line below the bed. We called this system 'D-PET' as it resembles the letter 'D' when it is rotated by 90° in the counterclockwise direction. The basic design idea was to cut the unused space under the patient's bed; this area is usually not in use in clinical diagnosis. We conducted Monte Carlo simulations of the D-PET scanner and compared its performance with a cylindrical PET scanner. The scanners were constructed from 4-layer depth-of-interaction detectors which consisted of a 16 × 16 × 4 LYSO crystal array with dimensions of 2.85 × 2.85 × 5 mm3. The results showed that the D-PET had an increase in sensitivity and peak-NECR of 30% and 18%, respectively. The D-PET had low noise in the reconstructed images throughout the field-of-view compared to the cylindrical PET. These were achieved while keeping sufficient space for the patient, and also without a severe effect on the spatial resolution. Furthermore, the number of detectors (and hence the cost) of the D-PET scanner was reduced by 12% compared to the cylindrical PET scanner.

Introduction of a pan-scan protocol for blunt trauma activations: what are the consequences?

STUDY OBJECTIVE: The aim of this study is to determine if the introduction of a pan-scan protocol during the initial assessment for blunt trauma activations would affect missed injuries, incidental findings, treatment times, radiation exposure, and cost. METHODS: A 6-month prospective study was performed on patients with blunt trauma at a level 1 trauma center. During the last 3 months of the study, a pan-scan protocol was introduced to the trauma assessment. Categorical data were analyzed by Fisher exact test and continuous data were analyzed by Mann-Whitney nonparametric test. RESULTS: There were a total of 220 patients in the pre-pan-scan period and 206 patients during the pan-scan period. There was no significant difference in injury severity or mortality between the groups. Introduction of the pan-scan protocol substantially reduced the incidence of missed injuries from 3.2% to 0.5%, the length of stay in the emergency department by 68.2 minutes (95% confidence interval [CI], -134.4 to -2.1), and the mean time to the first operating room visit by 1465 minutes (95% CI, -2519 to -411). In contrast, fixed computed tomographic scan cost increased by $48.1 (95% CI, 32-64.1) per patient; however, total radiology cost per patient decreased by $50 (95% CI, -271.1 to 171.4). In addition, the rate of incidental findings increased by 14.4% and the average radiation exposure per patient was 8.2 mSv (95% CI, 5.0-11.3) greater during the pan-scan period. CONCLUSION: Although there are advantages to whole-body computed tomography, elucidation of the appropriate blunt trauma patient population is warranted when implementing a pan-scan protocol.

A combined time-of-flight and depth-of-interaction detector for total-body positron emission tomography.

PURPOSE: In support of a project to build a total-body PET scanner with an axial field-of-view of 2 m, the authors are developing simple, cost-effective block detectors with combined time-of-flight (TOF) and depth-of-interaction (DOI) capabilities. METHODS: This work focuses on investigating the potential of phosphor-coated crystals with conventional PMT-based block detector readout to provide DOI information while preserving timing resolution. The authors explored a variety of phosphor-coating configurations with single crystals and crystal arrays. Several pulse shape discrimination techniques were investigated, including decay time, delayed charge integration (DCI), and average signal shapes. RESULTS: Pulse shape discrimination based on DCI provided the lowest DOI positioning error: 2 mm DOI positioning error was obtained with single phosphor-coated crystals while 3-3.5 mm DOI error was measured with the block detector module. Minimal timing resolution degradation was observed with single phosphor-coated crystals compared to uncoated crystals, and a timing resolution of 442 ps was obtained with phosphor-coated crystals in the block detector compared to 404 ps without phosphor coating. Flood maps showed a slight degradation in crystal resolvability with phosphor-coated crystals; however, all crystals could be resolved. Energy resolution was degraded by 3%-7% with phosphor-coated crystals compared to uncoated crystals. CONCLUSIONS: These results demonstrate the feasibility of obtaining TOF-DOI capabilities with simple block detector readout using phosphor-coated crystals.

Cost-effectiveness of whole-body bone scans in the pre-liver transplant assessment of patients with hepatocellular carcinoma in Southern Brazil.

BACKGROUND: Bone metastases (BM) are rare in patients with early-stage hepatocellular carcinoma (HCC). In many centers, liver transplantation (LTx) policies require patients with HCC to undergo bone scans (BSs). METHODS: We retrospectively assessed the benefit of BS for patients with a diagnosis of HCC wait-listed for LTx. RESULTS: BS was performed in 259 of 328 patients (78.9%) and was suggestive of BM in only one (0.4%). At follow-up, 276 patients had received LTx, of whom 207 had undergone BS. Histopathological examination of explants failed to confirm the presence of HCC in 20 patients from the BS group. The survival and recurrence rates of the 187 patients with confirmed HCC in the explant who underwent BS as part of pre-LTx assessment and 69 patients who did not undergo BS were compared. The one- and five-yr post-transplant survival rates were 81% and 69%, respectively, in the BS group vs. 78% and 62%, respectively, in patients who did not undergo BS (p = 0.25). The one- and five-yr post-LTx recurrence rates were 4.8% and 10.7%, respectively, in the BS group vs. 2.9% and 10.1%, respectively, in patients who did not undergo BS (p = 0.46). CONCLUSIONS: BS generated expenditures of US$39 296 and was not cost-effective.

Cost-effectiveness analysis of 18F-FDG PET/CT in detecting suspected recurrence or metastasis in well-differentiated thyroid carcinoma patients with negative diagnostic total body scan in Thailand: a decision analysis.

OBJECTIVE: To evaluate cost-effectiveness analysis of 18F-FDG PET/CT to detect tumor recurrence or metastasis in well-differentiated thyroid cancer patients with high Tg but negative TBS in Thailand. MATERIAL AND METHOD: A retrospective literature review of 55 studies published between 1978 and 2010 was done. Decision analysis by TreeAge program showed an evaluation of the most cost-effective treatment and 18F-FDG PET/CT scan in thyroid cancer patients with high Tg but negative TBS. The incremental cost and life years gained associated with seven strategies approached were analyzed by the decision tree model. The first strategy was treatment with empirical high dose 131I therapy. The second to the seventh strategies were using imaging investigations by CT scan of neck and chest, 99mTc MIBI scan, and 18F-FDG PET/CT scan to identify recurrent, persistent, and metastatic lesions before the specific treatment via curative surgery, external radiotherapy, and high dose 131I therapy. All strategies were adopted using hospital perspective and direct medical cost was estimated based on the reference price of Siriraj Hospital. Deterministic sensitivity analysis was conducted to investigate the effect of the cost of PET/CT scan. RESULTS: The strategy using 18F-FDG PET/CT scan to detect recurrence or metastasis and possible curative surgery in operable cases and high dose 131I therapy in inoperable cases gave the highest life years gained of 27.08 with cost of 90,227.61 Baht (2,926.24 US dollars) and acceptable incremental cost effectiveness ratio (ICER) of 6,936.88 Baht (224.98 US dollars) per life year gained when compared to the least costly strategy using 99mTc MIBI scan and additional 18F-FDG PET/CT scan in negative MIBI result. Other strategies were dominated by this PET/CT strategy. Deterministic sensitivity analysis (based on the willingness to pay (WTP) 360,000 Baht (11,675.42 US dollars) showed that the cost of PET/CT scan has no impact on the net health benefit. CONCLUSION: Based on the hospital perspective, the cost-effectiveness of 18F-FDG PET/CT scan in detecting suspected recurrence or metastasis in thyroid carcinoma patients with negative diagnostic TBS but high Tg was first done using 18F-FDG PET/CT scan to identify disease, followed by curative surgery or high dose 131I therapy. Moreover cost of PET/CT scan did not influence the net health benefit. This PET/CT benefit is helpfulfor considering the proper PET/CT use for thyroid cancer in Thailand.

The right scan, for the right patient, at the right time: the reorganization of major trauma service provision in England and its implications for radiologists.

Major trauma services in England are currently undergoing a radical overhaul with the formation of regional trauma networks and designated major trauma centres (MTCs). Radiology is scheduled to play a key role within major trauma care both in terms of 24/7 access to whole body computed tomography (WBCT) and interventional radiology (IR) services, as well as providing immediate expert imaging guidance to the trauma team. This review examines the rationale behind trauma networks, as well as drawing attention to the new Royal College of Radiologists' standards for major trauma imaging. It attempts to address radiologists' understandable concerns about the inappropriate use of WBCT, radiation dose, and intravenous contrast medium risks. Reporting whole-body CT for trauma patients is difficult, covering multiple body regions, with great pressure to provide a rapid and accurate report to the trauma team. The benefits of standardized reports, dual-radiologist reporting, and the use of organ injury severity grading are explored to aid succinct communication of findings and further guide patient management.

A pilot study utilizing whole body 18 F-FDG-PET/CT as a comprehensive screening strategy for occult malignancy in patients with unprovoked venous thromboembolism.

BACKGROUND: Approximately 7-10% of patients with unprovoked VTE will be diagnosed with cancer within 12 months. Although cancer screening has been proposed in these patients, the optimal strategy remains unclear. In a pilot study, we prospectively investigated the use of FDG-PET/CT to screen for occult malignancy in 40 patients with unprovoked VTE. MATERIALS/METHODS: Patients were initially screened for occult malignancy with a focused history, physical, and laboratory evaluation. Patients underwent whole body FDG-PET/CT and were followed for up to two years for a new diagnosis of cancer. The total costs of using FDG-PET/CT as a comprehensive screening strategy were determined using 2010 Medicare reimbursement rates. RESULTS: Completion of FDG-PET/CT imaging was feasible and identified abnormal findings requiring additional evaluations in 62.5% of patients. Occult malignancy was evident in only one patient (cancer incidence 2.5%) and FDG-PET/CT imaging excluded malignancy in the remainder of patients. No patients with a negative FDG-PET/CT were diagnosed with malignancy during an average (±SD) follow-up of 449 (±311) days. The use of FDG-PET/CT to screen for occult malignancy added $59,151 in total costs ($1,479 per patient). The majority of these costs were due to the cost of the FDG-PET/CT ($1,162 per patient or 78.5% of total per-patient costs). CONCLUSIONS: FDG-PET/CT may have utility for excluding occult malignancy in patients with unprovoked VTE. The costs of this comprehensive screening strategy were comparable to other screening approaches. Larger studies are needed to further evaluate the utility and cost-effectiveness of FDG-PET/CT as a cancer screening strategy in patients with unprovoked VTE.

[Costs and role of ultrasound follow-up of polytrauma patients after initial computed tomography]. / Kosten und Stellenwert von Ultraschallverlaufskontrollen bei polytraumatisierten Patienten nach initialer Computertomografie.

PURPOSE: To assess the costs and diagnostic gain of abdominal ultrasound follow-up of polytrauma patients initially examined by whole-body computed tomography (CT). MATERIALS AND METHODS: A total of 176 patients with suspected multiple trauma (126 men, 50 women; age 43.5 ± 17.4 years) were retrospectively analyzed with regard to supplementary and new findings obtained by ultrasound follow-up compared with the results of exploratory FAST (focused assessment with sonography for trauma) at admission and the findings of whole-body CT. A process model was used to document the staff, materials, and total costs of the ultrasound follow-up examinations. RESULTS: FAST yielded 26 abdominal findings (organ injury and/or free intra-abdominal fluid) in 19 patients, while the abdominal scan of whole-body CT revealed 32 findings in 25 patients. FAST had 81 % sensitivity and 100 % specificity. Follow-up ultrasound examinations revealed new findings in 2 of the 25 patients with abdominal injuries detected with initial CT. In the 151 patients without abdominal injuries in the initial CT scan, ultrasound follow-up did not yield any supplementary or new findings. The total costs of an ultrasound follow-up examination were EUR 28.93. The total costs of all follow-up ultrasound examinations performed in the study population were EUR 5658.23. CONCLUSION: Follow-up abdominal ultrasound yields only a low overall diagnostic gain in polytrauma patients in whom initial CT fails to detect any abdominal injuries but incurs high personnel expenses for radiological departments.