Imaging Strategies In Patients Research Articles

A prediction model for lung metastases in patients with indeterminate pulmonary nodules in newly diagnosed colorectal cancer

IntroductionMultidisciplinary teams treating patients with newly diagnosed Colorectal Cancer (CRC) often encounter the appearance of Indeterminate Pulmonary Nodules (IPNs) that warrants follow–up with repetitive medical imaging and anxiety for patients. We determined the incidence of IPNs in patients with newly diagnosed CRC and developed and validated a model for individualized risk prediction of IPNs being lung metastases. Material and methodsNewly diagnosed CRC who underwent surgery between November 2011 to June 2014 were included to create the risk model, developed using both clinical experience and statistical selection. Discrimination and calibration slopes of the risk score were evaluated in an independent temporal validation sample. A nomogram is presented to assist clinicians in estimating an individual risk score. ResultsOut of 2111 CRC patients staged with chest CT, 204 (9.6%) had IPNs and 54/204 (26%) had lung metastases. We identified 4 predictors: “location of primary tumour”, “pathological nodal stage”, “size of the largest nodule” and “extrapulmonary synchronous metastases at diagnosis”. Discrimination of the final model in the validation sample was demonstrated by the difference in mean predicted risk between progressed cases en non-progressed cases (49% versus 21%, p = <0.001). ConclusionA prediction model with 4 clinical risk factors can be used to assist multidisciplinary teams in the prediction of individualized risk of lung metastases and imaging strategy in patients with IPNs and newly diagnosed colorectal cancer. The model performed well in new patients not included in the model development.

Current Imaging Strategies in Patients with Abdominal Aortic Aneurysms.

An abdominal aortic aneurysm (AAA) is defined as a localized dilatation of the abdominal aorta of ≥ 3 cm. With a prevalence of 4-8 %, AAA is one of the most common vascular diseases in Western society. Radiological imaging is an elementary component in the diagnosis, monitoring, and treatment planning of AAA patients. This is a narrative review article on preoperative imaging strategies of AAA, incorporating expert opinions based on the current literature and standard-of-care practices from our own center. Examples are provided to illustrate clinical cases from our institution. Radiological imaging plays a pivotal role in the initial diagnosis and monitoring of patients with AAA. Ultrasound is the mainstay imaging modality for AAA screening and surveillance. Contrast-enhanced CT angiography is currently considered the gold standard for preoperative imaging and image-based treatment planning in AAA repair. New non-contrast MR angiography techniques are robustly applicable and allow precise determination of aortic diameters, which is of critical importance, particularly with regard to current diameter-based surgical treatment guidelines. 3D imaging with multiplanar reformation and automatic centerline positioning enables more accurate assessment of the maximum aortic diameter. Modern imaging techniques such as 4D flow MRI have the potential to further improve individualized risk stratification in patients with AAA. · Ultrasound is the mainstay imaging modality for AAA screening and monitoring. · Contrast-enhanced CT angiography is the gold standard for preoperative imaging in AAA repair. · Non-contrast MR angiography allows for accurate monitoring of aortic diameters in AAA patients. · Measurement of aortic diameters is more accurate with 3D-CT/MRI compared to ultrasound. · Research seeks new quantitative imaging biomarkers for AAA risk stratification, e. g., using 4D flow MRI.

LOw-dose CT Or Lung UltraSonography versus standard of care based-strategies for the diagnosis of pneumonia in the elderly: protocol for a multicentre randomised controlled trial (OCTOPLUS)

IntroductionPneumonia is a leading cause of mortality and a common indication for antibiotic in elderly patients. However, its diagnosis is often inaccurate. We aim to compare the diagnostic accuracy, the...

Palla's sign and the challenge of optimizing the imaging strategy in patients with high pretest probability of pulmonary embolism.

Palla's sign and the challenge of optimizing the imaging strategy in patients with high pretest probability of pulmonary embolism.

Response to: Palla's sign and the challenge of optimizing the imaging strategy in patients with high pretest probability of pulmonary embolism.

Response to: Palla's sign and the challenge of optimizing the imaging strategy in patients with high pretest probability of pulmonary embolism.

Imaging strategies for patients with suspicion of uncomplicated colic pain: diagnostic accuracy and management assessment.

Compare different imaging scenarios in the diagnosis of uncomplicated renal colic due to urolithiasis (URCU). A total of 206 prospectively included patients had been admitted with suspected URCU and had undergone abdominal plain film (APF), US and unenhanced CT after clinical STONE score evaluation. CT was the reference standard. We assessed sensitivity (Se), specificity (Spe) and Youden index for colic pain diagnosis, percentage of patients managed by urologic treatment with stone identified, percentage of alternative diagnoses (AD) and exposure to radiation, according to single imaging approaches, strategies driven by patient characteristics and conditional imaging strategies after APF and US. One hundred (48.5%) patients had a final diagnosis of URCU and 19 underwent urologic treatment. The conditional strategy, i.e. CT in patients who had no stone identified at US, had a perfect sensitivity and specificity. This enabled diagnosis of all stones requiring urology management while decreasing the number of CT exams by 22%. The strategy whereby CT was used when there was neither direct or indirect APF + US finding of colic pain nor alternative diagnoses in patients with a STONE score ≥ 10 had a sensitivity of 0.95 and a specificity of 0.99, identified 84% of stones managed by urologic treatment and decreased the number of CT examinations by 76%. In patients with clinical findings consistent with URCU, the use of ultrasound as first-line imaging modality, with CT restricted to patients with negative US and a STONE score ≥ 10, led to a sensitivity and specificity of above 95%, identified 84% of stones requiring urological management and reduced the number of CT scans needed by fourfold. • For diagnosis, the use of APF + US as first-line imaging, with CT restricted to patients with both a normal APF + US and a STONE score ≥ 10, provides both a sensitivity and specificity superior or equal to 95% and reduces the number of CT scans necessary by fourfold. • For management, the use of APF + US as first-line imaging, with CT restricted to patients with both a normal APF + US and a STONE score ≥ 10, maintains a 84% stone identification rate in urology-treated patients.

OPTimal IMAging strategy in patients suspected of non-traumatic pulmonary disease at the emergency department: chest X-ray or ultra-low-dose chest CT (OPTIMACT) trial\u2014statistical analysis plan

BackgroundA chest X-ray is a standard imaging procedure in the diagnostic work-up of patients suspected of having non-traumatic pulmonary disease. Compared to a chest X-ray, an ultra-low-dose (ULD) chest computed tomography (CT) scan provides substantially more detailed information on pulmonary conditions. To what extent this translates into an improvement in patient outcomes and health care efficiency is yet unknown. The OPTimal IMAging strategy in patients suspected of non-traumatic pulmonary disease at the emergency department: chest X-ray or ultra-low-dose chest CT (OPTIMACT) study is a multicenter, pragmatic, non-inferiority randomized controlled trial designed to evaluate replacement of chest X-ray by ULD chest CT in the diagnostic work-up of such patients, in terms of patient-related health outcomes and costs. During randomly assigned periods of 1 calendar month, either conventional chest X-ray or ULD chest CT scan was used as the imaging strategy. This paper presents in detail the statistical analysis plan of the OPTIMACT trial, developed prior to data analysis.Methods/resultsFunctional health at 28 days is the primary clinical outcome. Functional health at 28 days is measured by the physical component summary scale of the Short Form (SF)-12 questionnaire version 1. Secondary outcomes are mental health (mental component summary scale of the SF-12), length of hospital stay, mortality within 28 days, quality-adjusted life year equivalent during the first 28 days (derived from the EuroQol five-dimension, five-level instrument), correct diagnoses at emergency department discharge as compared to the final post hoc diagnosis at day 28, number of patients in follow-up because of incidental findings on chest X-ray or ULD chest CT, and health care costs.ConclusionsAfter this pragmatic trial we will have precise estimates of the effectiveness of replacing chest X-ray with ULD chest CT in terms of patient-related health outcomes and costs.Trial registrationNetherlands National Trial Register: NTR6163. Registered on 6 December 2016.

P5245Cost-saving diagnosis approach by artificial intelligence tool in patients with suspected coronary artery disease. The co-operative ARTICA registry database

Abstract Background Although coronary tomographic angiography (CTA) has shown promise as a “gatekeeper” to invasive coronary angiography (ICA) in longitudinal cohort studies, it remains unknown whether the strategy of direct initial performance of CTA is cost-effective when compared with selected exercise treadmill testing (ETT) +/− functional cardiac imaging strategies in patients with suspected coronary artery disease (CAD). An innovative artificial intelligence (AI) Decision Support System (DSS) ESC guidelines based has been used at point of care for evaluating subjects with stable chest pain (SCP). Purpose The objective was to verify the cost-saving effect of the robotic AI DSS vs direct CTA by human standard care (SD) for diagnosing CAD in subjects presenting with SCP. Methods From October 2016 over three hospitals, 1017 subjects, 620 males, age 62±11 years, with clinically SCP being referred for CTA by SD received also a same day pre-scan AI DSS administration. All patients did not demonstrate significant CAD at CTA. CTA/ICA, or exercise treadmill test (ETT)/ stress echocardiography (SE), gated myocardial perfusion scintigraphy (gMPS) or Follow up/No tests (FNT) strategies by AI DSS were analyzed and compared to direct CTA SD. Pre-test likelihood (pt-lk) of CAD consider clinical risk factors into the model. Sensitivity and specificity of non-invasive diagnostic tests within our model were based upon a bivariate analysis of data from published multicenter trials. Costs of procedures were calculated by the sum of technical and professional components. Probabilistic sensitivity analysis was conducted to assess the impact of uncertainty in model parameters. Results The direct approach used performing direct CTA strategy by SD in all subjects costed 406.800 €. Costs of each procedure and distribution of AI DSS outputs are shown in the Table. Across the range of pt-lk of CAD, total costs of AI DSS strategy resulted 146.030€ with −65% vs SD approach. AI DSS tests distribution and costs pt-lk (pt/%) FNT (0€) ETT (90€) SE (350€) Stress gated MPS (750€) CCTA (400€) ICA (3.000€) High (29/2.8) 0 0 1 2 0 26 Int (371/36.5) 259 5 51 48 7 1 Low (612/60.7) 595 2 2 0 13 0 Total costs (€) 0 630 18,900.00 37,500.00 8,000.00 81,000.00 Conclusion These results from ARTICA registry seem to demonstrate that AI DSS is extremely cost-saving in subjects with stable chest pain across the whole range of pt-lk of CAD.

Diagnostic imaging in the management of patients with possible cerebral venous thrombosis: a cost-effectiveness analysis.

Imaging is crucial for management of patients with possible cerebral venous thrombosis (CVT). To evaluate the cost-effectiveness of different noninvasive imaging strategies in patients with possible CVT. A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALY) associated with the following imaging strategies: non-contrast CT (NCCT), NCCT plus CT venography (CTV), routine MRI without vascular imaging (R-MRI), and MRI with venography (MRV). The analysis was performed from a US healthcare perspective. Model input was based on best available and most recent evidence, including outcome data from the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Starting age was 37years; both high and low pre-test probabilities of CVT were evaluated. Probabilistic sensitivity analyses (PSA) estimated model uncertainty. In the base-case analysis, NCCT and CTV were dominant over R-MRI and MRV. CTV led to incremental lifetime QALYs compared with NCCT (23.385 QALYs vs. 23.374 QALYs) at slightly higher lifetime costs ($5210 vs. $5057). In PSA, CTV was the strategy with the highest percentage of cost-effective iterations if willingness-to-pay (WTP) thresholds were higher than $13,750/QALY. Complying with contemporary WTP thresholds, CTV was thus identified as the most cost-effective strategy. When the pre-test probability was set to 50%, CTV was also preferred. In patients at the peak age of CVT incidence yet low clinical pre-test probability, diagnostic imaging with CTV is the most cost-effective strategy.

OPTimal IMAging strategy in patients suspected of non-traumatic pulmonary disease at the emergency department: chest X-ray or ultra-low-dose CT (OPTIMACT)\u2014a randomised controlled trial chest X-ray or ultra-low-dose CT at the ED: design and rationale

BackgroundChest X-ray has been the standard imaging method for patients suspected of non-traumatic pulmonary disease at the emergency department (ED) for years. Recently, ultra-low-dose chest computed tomography (ULD chest CT) has been introduced, which provides substantially more detailed information on pulmonary conditions that may cause pulmonary disease, with a dose in the order of chest X-ray (0.1 vs. 0.05 mSv). The OPTimal IMAging strategy in patients suspected of non-traumatic pulmonary disease at the emergency department: chest X-ray or CT (OPTIMACT) study is a randomized trial designed to evaluate the effectiveness of replacing chest X-ray for ULD chest CT in the diagnostic work-up of patients suspected of non-traumatic pulmonary disease at the ED.MethodsTwo thousand four hundred patients presenting at the ED with pulmonary complaints and suspected of non-traumatic pulmonary disease will be enrolled in this multicenter, pragmatic, randomized trial. During randomly assigned periods of one calendar month, either conventional chest X-ray or ULD chest CT scan will be used as the imaging strategy. Randomization will rely on computer-generated blocks of 2 months to control for seasonal effects. Chest X-ray and ULD chest CT will be performed in a standardized way, after obtaining the clinical history and performing physical examination and initial laboratory tests. The primary outcome measure is functional health at 28 days. Secondary outcome measures are mental health, length of hospital stay, mortality within 28 days, quality-adjusted life years (QALYs) during the first 28 days, correct diagnoses at ED discharge as compared to the final post hoc diagnosis, and number of patients in follow-up because of incidental findings on chest X-ray or ULD chest CT. In an economic evaluation, we will estimate total health care costs during the first 28 days.DiscussionThis pragmatic trial will clarify the effects of replacing chest X-ray by ULD chest CT in daily practice, in terms of patient-related health outcomes and costs, in the diagnostic work-up of patients suspected of non-traumatic pulmonary disease at the ED.Trial registrationThe OPTIMACT trial is registered in the Netherlands National Trial Register under number NTR6163. The date of registration is December 6, 2016.

Different Imaging Strategies in Patients With Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis.

This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed tomographic angiography (CTA), magnetic resonance imaging, nonenhanced CT, or duplex ultrasound with intravenous (IV) thrombolysis being administered after positive findings. The analysis was performed from the societal perspective based on US recommendations. Input parameters were derived from the literature. Costs were obtained from United States costing sources and published literature. Outcomes were lifetime costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios, and net monetary benefits, with a willingness-to-pay threshold of $80,000 per QALY. The strategy with the highest net monetary benefit was considered the most cost-effective. Extensive deterministic and probabilistic sensitivity analyses were performed to explore the effect of varying parameter values. In the reference case analysis, CTA dominated all other imaging strategies. CTA yielded 0.02 QALYs more than magnetic resonance imaging and 0.04 QALYs more than duplex ultrasound followed by CTA. At a willingness-to-pay threshold of $80,000 per QALY, CTA yielded the highest net monetary benefits. The probability that CTA is cost-effective was 96% at a willingness-to-pay threshold of $80,000/QALY. Sensitivity analyses showed that duplex ultrasound was cost-effective only for a prior probability of ≤0.02 and that these results were only minimally influenced by duplex ultrasound sensitivity and specificity. Nonenhanced CT and magnetic resonance imaging never became the most cost-effective strategy. Our results suggest that CTA in patients with possible basilar artery occlusion is cost-effective.

Cost analysis favours SPECT over PET and CTA for evaluation of coronary artery disease: the SPARC study.

There are many ways to perform noninvasive testing in patients with coronary artery disease (CAD), including myocardial perfusion imaging with single-photon emission computed tomography (SPECT), positron-emission tomography (PET), and coronary computed tomography angiography (CTA). Results from series of patients evaluated with single modalities have already been published by many researchers [1–3], but there are few head-to-head comparisons of the outcomes of alternative test strategies [4, 5]. Consequently, the comparative effectiveness of different noninvasive cardiac testing strategies has been difficult to assess. The recently published SPARC registry (Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in Coronary Artery Disease) in JACC by the group of DiCarli et al. (Stanford, CA, USA) was a multicentre study designed to collect standardised clinical data on patients undergoing CTA, PET, or SPECT [6]. The primary purpose of the SPARC study was to evaluate the economic outcomes of using CTA, PET, or SPECT to evaluate patients with suspected CAD. The authors used an observational registry of 1703 patients: 590 patients underwent CTA, 548 patients had PET and 565 patients SPECT for diagnosis of suspected CAD. Patients were followed for 2 years; documented resource use, medical costs for CAD, and clinical outcomes were assessed. The main findings were that costs were significantly lower for SPECT compared with CTA or PET in the evaluation of suspected CAD. SPECT was economically attractive compared with PET, whereas CTA was associated with higher costs and no significant difference in mortality compared with SPECT. More specifically, the authors observed that patients who underwent coronary CTA and PET experienced higher rates of subsequent invasive coronary arteriography (16 % and 15 %, respectively) as compared with patients who underwent SPECT (7 %). The mean total radiation was significantly higher for CTA (15.1 mSV) compared with SPECT (11.7 mSV), both for the initial tests (13 mSV vs. 11 mSV) and for follow-up tests and procedures (2.1 mSV vs. 0.7 mSV). Exposure from follow-up tests and procedures was higher after PET (2.0 mSV) than after SPECT (0.6 mSV). The findings in favour of SPECT are in line with a decision model by Garber and Solomon [7], who compared exercise treadmill testing, stress echocardiography, planar thallium imaging, SPECT, and PET imaging with a strategy of immediate invasive angiography. They found SPECT to be much more cost-effective than PET for noninvasive diagnosis, and SPECT to be a better option than immediate invasive coronary angiography. In terms of outcomes, Shaw et al. [1] found that patients who underwent initial SPECT with selective cardiac catheterisation had lower costs than patients who underwent routine coronary angiography (END study). In the EMPIRE study by Underwood et al. [2] it was demonstrated that strategies using myocardial perfusion imaging were cheaper and equally effective when compared with strategies that did not use myocardial perfusion imaging, both for the cost of diagnosis and for overall 2-year management costs; the 2-year patient outcome was the same. Sharples et al. [8] randomised 898 patients to SPECT, stress echocardiography, magnetic resonance imaging (MRI), or direct invasive coronary angiography, and found SPECT to be as useful as immediate invasive angiography with similar costs. A limitation of the SPARC study is the fact that MRI was not included in the comparative strategies. In addition, as the study started in 2006, in recent years many technological revolutions have taken place for all imaging modalities indicating that studies such as SPARC should be repeated and extended every 5–10 years [9]. Analysis of the current SPARC registry at least suggests that SPECT is the noninvasive imaging procedure of choice to evaluate patients with suspected CAD in terms of subsequent medical costs. SPECT offered the lowest costs over 2 years of follow-up among patients with suspected CAD. The significantly higher costs among patients undergoing CTA or PET were primarily due to higher rates of subsequent invasive cardiac procedures, because there was little difference in initial costs of testing. To conclude, the use of SPECT myocardial perfusion imaging was associated with lower costs over 2 years of follow-up than the use of CTA or PET, primarily because of fewer subsequent invasive procedures. Consequently, SPECT imaging seems to be the preferred imaging strategy in patients with suspected CAD. The value of SPECT imaging has been underscored by several recent reports [10–13]. However, larger and more definitive studies, such as the ongoing PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial (NCT01174550), are needed to assess the value and cost effectiveness of the various noninvasive imaging strategies.

Study of Tomography Of Nephrolithiasis Evaluation (STONE): Methodology, approach and rationale

BackgroundUrolithiasis (kidney stones) is a common reason for Emergency Department (ED) visits, accounting for nearly 1% of all visits in the United States. Computed tomography (CT) has become the most common imaging test for these patients but there are few comparative effectiveness data to support its use in comparison to ultrasound. This paper describes the rationale and methods of STONE (Study of Tomography Of Nephrolithiasis Evaluation), a pragmatic randomized comparative effectiveness trial comparing different imaging strategies for patients with suspected urolithiasis. MethodsSTONE is a multi-center, non-blinded pragmatic randomized comparative effectiveness trial of patients between ages 18 and 75 with suspected nephrolithiasis seen in an ED setting. Patients were randomized to one of three initial imaging examinations: point-of-care ultrasound, ultrasound performed by a radiologist or CT. Participants then received diagnosis and treatment per usual care. The primary aim is to compare the rate of severe SAEs (Serious Adverse Events) between the three arms. In addition, a broad range of secondary outcomes was assessed at baseline and regularly for six months post-baseline using phone, email and mail questionnaires. ResultsExcluding 17 patients who withdrew after randomization, a total of 2759 patients were randomized and completed a baseline questionnaire (n=908, 893 and 958 in the point-of-care ultrasound, radiology ultrasound and radiology CT arms, respectively). Follow-up is complete, and full or partial outcomes were assessed on over 90% of participants. ConclusionsThe detailed methodology of STONE will provide a roadmap for comparative effectiveness studies of diagnostic imaging conducted in an ED setting.

Comparison of [18 F]FDG PET/CT and MRI in the diagnosis of active osteomyelitis

In diagnosing osteomyelitis (OM) both MRI and [18F]FDG PET-CT proved to be accurate modalities. In anticipation of the advent of hybrid PET/MRI scanners we analyzed our patient group to give direction to future imaging strategies in patients with suspected OM. In this retrospective study all patients of a tertiary referral center who underwent both an MRI and a PET for the diagnosis of OM were included. The results of those scans were evaluated using patient's histology, microbiological findings, and clinical/radiological follow-up. Additionally, ROC curve analysis of the SUVmax and the SUVmax ratio on the PET scans was performed. Two imaging strategies were simulated: first MRI followed by PET, or vice versa. Twenty-seven localizations in 26 patients were included. Both MRI and PET were shown to be accurate in our patients for the qualitative detection of OM. A cut-off value for the SUVmax of 3 gave optimal results (a specificity of 90% with a sensitivity of 88%). The SUVmax ratio gave a worse performance. The two simulated imaging strategies showed no difference in the final diagnosis in 20 out of 27 cases. Remarkably, 6 equivocal cases were all correctly diagnosed by the second modality, i.e., PET or MRI. Both MRI and [18F]FDG PET were accurate in diagnosing OM in a tertiary referral hospital population. Simulation of imaging strategies showed that a combined sequential strategy was optimal. It seems preferable to use MRI as a primary imaging tool for uncomplicated unifocal cases, whereas in cases with (possible) multifocal disease or a contraindication for MRI, PET is preferred. This combined sequential strategy looks promising, but needs to be confirmed in a larger prospective study.

21-Year-Old Man With Chest Pain, Respiratory Distress, and Altered Mental Status

21-Year-Old Man With Chest Pain, Respiratory Distress, and Altered Mental Status

Suspected Carotid Artery Stenosis: Cost-effectiveness of CT Angiography in Work-up of Patients with Recent TIA or Minor Ischemic Stroke

To assess the effectiveness and cost-effectiveness of state-of-the-art noninvasive diagnostic imaging strategies in patients with a transient ischemic attack (TIA) or minor stroke who are suspected of having carotid artery stenosis (CAS). All prospectively evaluated patients provided informed consent, and the local ethics committee approved this study. Diagnostic performance, treatment, long-term events, quality of life, and costs resulting from strategies employing duplex ultrasonography (US), computed tomographic (CT) angiography, contrast material-enhanced magnetic resonance (MR) angiography, and combinations of these modalities were modeled in a decision tree and Markov model. Data sources included a prospective diagnostic cohort study, a meta-analysis, and a review of the literature. Outcomes were costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios, and net health benefits (QALY-equivalents), with a willingness-to-pay threshold of euro 50,000 per QALY and a societal perspective. The strategy with the highest net health benefit was considered the most cost effective. Extensive one-way, two-way, and probabilistic sensitivity analyses to explore the effect of varying parameter values were performed. The reference case analysis assumed that patients underwent surgery 2-4 weeks after the first symptoms, and the effect of earlier intervention was explored. The reference case analysis showed that duplex US combined with CT angiography and surgery for 70%-99% stenoses was the most cost-effective strategy, with a net health benefit of 13.587 and 15.542 QALY-equivalents in men and women, respectively. In men, the CT angiography strategy with a 70%-99% cutoff yielded slightly more QALYs, at an incremental cost of euro 71,419 per QALY, compared with duplex US combined with CT angiography. In patients with a high-risk profile, in patients with a high prior probability of disease, and when patients could be treated within 2 weeks after the first symptoms, the CT angiography strategy with surgery for 50%-99% stenoses was the most cost-effective strategy. In diagnosing CAS, duplex US should be the initial test, and, if its results are positive, CT angiography should be performed; patients with 70%-99% stenoses should then undergo carotid endarterectomy. In patients with a high-risk profile, a high probability of CAS, or who can undergo surgery without delay, immediate CT angiography and surgery for 50%-99% stenoses is indicated.

Imaging of pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas are rare tumors, but their investigation and management are complex and expensive, both in terms of time and resources. a novel prospective study systematically compared different imaging techniques, and the results provide clinicians with valuable help in deciding the appropriate imaging strategy for patients with pheochromocytomas or paragangliomas.

Health-economic evaluation of three imaging strategies in patients with suspected colorectal liver metastases: Gd-EOB-DTPA-enhanced MRI vs. extracellular contrast media-enhanced MRI and 3-phase MDCT in Germany, Italy and Sweden

The purpose of this study was to perform an economic evaluation of hepatocyte-specific Gd-EOB-DTPA enhanced MRI (PV-MRI) compared to extracellular contrast-media-enhanced MRI (ECCM-MRI) and three-phase-MDCT as initial modalities in the work-up of patients with metachronous colorectal liver metastases. The economic evaluation was performed with a decision-tree model designed to estimate all aggregated costs depending on the initial investigation. Probabilities on the need for further imaging to come to a treatment decision were collected through interviews with 13 pairs of each a radiologist and a liver surgeon in Germany, Italy and Sweden. The rate of further imaging needed was 8.6% after initial PV-MRI, 18.5% after ECCM-MRI and 23.5% after MDCT. Considering the cost of all diagnostic work-up, intra-operative treatment changes and unnecessary surgery, a strategy starting with PV-MRI with 959 Euro was cost-saving compared to ECCM-MRI (1,123 Euro) and MDCT (1,044 Euro) in Sweden. In Italy and Germany, PV-MRI was cost-saving compared to ECCM-MRI and had total costs similar to MDCT. In conclusion, our results indicate that PV-MRI can lead to cost savings by improving pre-operative planning and decreasing intra-operative changes. The higher cost of imaging with PV-MRI is offset in such a scenario by lower costs for additional imaging and less intra-operative changes.

A simple MRI protocol in patients with clinically suspected appendicitis: results in 138 patients and effect on outcome of appendectomy

To establish the value of breathhold magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis. Over a 14-month period, 138 patients clinically suspected of having appendicitis were evaluated prospectively with MRI and comprised the study group. Fast turbo spin-echo breathhold T1, T2 and T2 fat suppression sequences were used in coronal and axial planes. The imaging results were recorded separately and subsequently correlated with clinical, radiological and histopathological follow-up. The effect of imaging strategies in patients suspected of appendicitis on hospital resources was calculated. Sixty-two of the 138 patients had a histopathologically proven appendicitis. MRI determined appendicitis in 63 patients, with one examination being false positive. The resulting sensitivity and specificity were 100% and 99%, respectively. MRI showed an alternative diagnosis in 41 of the 75 remaining patients. In 22 of the remaining 34 patients, a normal appendix was depicted with MRI. In two patients, where MRI showed no appendicitis, an alternative diagnosis or normal appendix, an unnecessary appendectomy was performed. The overall effect of using MRI in patients suspected of appendicitis on the use of hospital resources could have been a net saving between 55,746 euros and 72,534 euros. MRI has a high accuracy in detecting and excluding appendicitis, an alternative diagnosis or showing the normal appendix, and can be a valuable and cost-effective tool in the workup of patients clinically suspected of having appendicitis.

Imaging of patients with clinically suspected appendicitis in the Netherlands: conclusions of a survey

The aim of this study was to summarize the extent of variation in imaging strategies in patients clinically suspected of having appendicitis. By means of a written survey, the policies for the imaging management of patients clinically suspected of having appendicitis in the Netherlands were inventoried. A questionnaire was sent to the departments of surgery and radiology of all 105 Dutch hospitals, including the 8 academic medical centres, in March 2006. Questionnaires were returned from 98 hospitals. It was found that, in the work-up of patients suspected of having appendicitis, ultrasound or CT was performed in a minority of hospitals for 50% or more of these patients. In the majority of hospitals, it was carried out for less than 50% of these patients. There is a widespread variability in pre-operative imaging regardless of hospital type. This survey shows that, despite the ubiquitous presence of ultrasound and CT in Dutch hospitals, the pre-operative imaging work-up in patients clinically suspected of having acute appendicitis does not reflect this, being performed in only a minority of patients suspected of having acute appendicitis. Radiologists and surgeons alike should be aware of the positive impact of adjunctive imaging in this group of patients - most importantly lowering the negative appendicectomy rate and also lowering total hospital costs.