Maternal and Fetal Radiation-Induced Cancer Risk From Computed Tomography Pulmonary Angiography During Pregnancy: A Retrospective Cohort Study Across a Multihospital Integrated Health Care Network.

OBJECTIVE: Computed tomography pulmonary angiogram (CTPA) is important to evaluate suspected pulmonary embolism in pregnancy but has maternal/fetal radiation risks. The objective of this study was to estimate maternal and fetal radiation-induced cancer risk from CTPA during pregnancy. METHODS: Simulation modeling via the National Cancer Institute's Radiation Risk Assessment Tool was used to estimate excess cancer risks from 17 organ doses from CTPA during pregnancy, with doses determined by a radiation dose indexing monitoring system. Organ doses were obtained from a radiation dose indexing monitoring system. Maternal and fetal cancer risks per 100,000 were calculated for male and female fetuses and several maternal ages. RESULTS: The 534 CTPA examinations had top 3 maternal organ doses to the breast, lung, and stomach of 17.34, 15.53, and 9.43 mSv, respectively, with a mean uterine dose of 0.21 mSv. The total maternal excess risks of developing cancer per 100,000 were 181, 151, 121, 107, 94.5, 84, and 74.4, respectively, for a 20-, 25-, 30-, 35-, 40-, 45-, and 50-year-old woman undergoing CTPA, compared with baseline cancer risks of 41,408 for 20-year-old patients. The total fetal excess risks of developing cancer per 100,000 were 12.3 and 7.3 for female and male fetuses, respectively, when compared with baseline cancer risks of 41,227 and 48,291. DISCUSSION: Excess risk of developing cancer from CTPA was small relative to baseline cancer risk for pregnant patients and fetuses, decreased for pregnant patients with increasing maternal age, and was greater for female fetuses than male fetuses.

Patient and Fetal Radiation-Induced Malignancy Risk From Imaging For Evaluation of Pulmonary Embolism in Pregnancy.

BACKGROUND: Imaging for diagnosis of suspected pulmonary embolism in pregnancy presents radiation concerns for patient and fetus. OBJECTIVES: Estimate the risks of radiation-induced breast cancer and childhood leukemia from common imaging techniques for the evaluation of suspected pulmonary embolism in pregnancy. METHODS: Breast and uterine absorbed doses for various imaging techniques were input into the National Cancer Institute Radiation Risk Assessment Tool to calculate risk of breast cancer for the patient and childhood leukemia for the fetus. Absorbed doses were obtained by synthesizing data from a recent systematic review and the International Commission on Radiological Protection. Primary outcomes were the estimated excess incidences of breast cancer and childhood leukemia per 100,000 exposures. RESULTS: Baseline incidences of breast cancer for a 30-year-old woman and childhood leukemia for a male fetus were 13,341 and 939, respectively. Excess incidences of breast cancer were 0.003 and 0.275 for a single and two-view chest radiograph, respectively, 9.53 and 20.6 for low- and full-dose computed tomography pulmonary angiography (CTPA), respectively, 0.616 and 2.54 for low- and full-dose perfusion scan, respectively, and 0.732 and 2.66 for low- and full-dose ventilation perfusion scan, respectively. Excess incidences of childhood leukemia were 0.004 and 0.007 for a single and two-view chest radiograph, respectively, 0.069 and 0.490 for low- and full-dose CTPA, respectively, 0.359 and 1.47 for low- and full-dose perfusion scan, respectively, and 0.856 and 1.97 for low- and full-dose ventilation perfusion scan, respectively. CONCLUSION: Excess cancer risks for all techniques were small relative to baseline cancer risks, with CTPA techniques carrying slightly higher risk of breast cancer for the patient and ventilation perfusion techniques a higher risk of childhood leukemia.

Comparison of Guidelines for Evaluation of Suspected Pulmonary Embolism in Pregnancy: A Cost-effectiveness Analysis.

BACKGROUND: Pulmonary embolism (PE) remains a leading cause of maternal mortality, yet diagnosis remains challenging. International diagnostic guidelines vary significantly in their recommendations, making it difficult to determine an optimal policy for evaluation. RESEARCH QUESTION: Which societal-level diagnostic guidelines for evaluation of suspected PE in pregnancy are an optimal policy in terms of its cost-effectiveness? STUDY DESIGN AND METHODS: We constructed a complex Markov decision model to evaluate the cost-effectiveness of each identified societal guidelines for diagnosis of PE in pregnancy. Our model accounted for risk stratification, empiric treatment, diagnostic testing strategies, as well as short- and long-term effects from PE, treatment with low-molecular-weight heparin, and radiation exposure from advanced imaging. We considered clinical and cost outcomes of each guideline from a US health care system perspective with a lifetime horizon. Clinical effectiveness and costs were measured in time-discounted quality-adjusted life years (QALYs) and US dollars, respectively. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with a willingness-to-pay threshold of $100,000/QALY. One-way, multiway, and probabilistic sensitivity analyses were performed. RESULTS: We identified six international societal-level guidelines. Base-case analysis showed the guideline proposed by the American Thoracic Society and Society of Thoracic Radiology (ATS-STR) yielded the highest health benefits (22.90 QALYs) and was cost-effective, with an ICER of $7,808 over the guidelines proposed by the Australian Society of Thrombosis and Haemostasis and the Society of Obstetric Medicine of Australia and New Zealand (ASTH-SOMANZ). All remaining guidelines were dominated. The ATS-STR guideline-recommended strategy yielded an expected additional 2.7 QALYs/100 patients evaluated over the ASTH-SOMANZ. Conclusions were robust to sensitivity analyses, with the ATS-STR guidelines optimal in 86% of probabilistic sensitivity analysis scenarios. INTERPRETATION: The ATS-STR guidelines for diagnosis of suspected PE in pregnancy are cost-effective and generate better expected health outcomes than guidelines proposed by other medical societies.

CT pulmonary angiography in pregnancy: Specific conversion factors to estimate effective radiation dose from dose length product: A retrospective cross-sectional study across a multi-hospital integrated healthcare network.

PURPOSE: Effective dose describes radiation-related cancer risk from CT scans and is estimated using a readily available conversion factor (k-factor), which varies by body part and study type. To purpose of this study is to determine the specific k-factor for CTPA in pregnant patients and its predictive factors. METHODS: This retrospective cross-sectional study evaluates CTPA in pregnancy across a multihospital integrated healthcare network from January 2012 to April 2017. Patient and CTPA-related data were obtained from the electronic health record and a radiation dose index monitoring system. Each patient's effective dose was determined by patient-specific Monte-Carlo simulation with Cristy phantoms and divided by patient dose-length-product to determine the k-factor. K-factor for pregnant patients was compared to the k-factor for adults of standard physique with a one-sample t-test. Bivariate and multivariable analyses were performed for patient and CT predictors of k-factor. RESULTS: A total of 534 patients were included. The mean k-factor for all patients was 0.0249 (mSv·mGy-1·cm-1), 78% greater than k-factor of 0.014 (p < 0.001) suggested for the general adult population. Multivariable analysis demonstrated lower k-factors with increasing pitch (p = 0.0002), patient size (p < 0.001), and scan length (p < 0.0001). The 120 kVp (p < 0.001) and 140 kVp (p = 0.0028) analyses showed a larger k-factor than 80 and 100 kVp studies combined. CONCLUSIONS: Specific k-factor for CTPA in pregnant patients is greater than the previously used generic chest CT k-factor and should be used to estimate the effective dose for CTPA exams in pregnancy.

Best practices for MRI systematic reviews and meta-analyses.

As defined by the Cochrane Collaboration, a systematic review is a review of evidence with a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant primary research, and to extract and analyze data from the studies that are included in the review. Meta-analysis is a statistical method to combine the results from primary studies that accounts for sample size and variability to provide a summary measure of the studied outcome. Systematic reviews of diagnostic test accuracy present unique methodological and reporting challenges not present in systematic reviews of interventions. This review provides guidance and further resources highlighting current best practices in methodology and reporting of systematic reviews of diagnostic test accuracy, with a specific focus on challenges and opportunities for MRI imaging. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Building Imaging Institutes of Patient Care Outcomes: Imaging as a Nidus for Innovation in Clinical Care, Research, and Education.

Traditionally, radiologists have been responsible for the protocol of imaging studies, imaging acquisition, supervision of imaging technologists, and interpretation and reporting of imaging findings. In this article, we outline how radiology needs to change and adapt to a role of providing value-based, integrated health-care delivery. We believe that the way to best serve our specialty and our patients is to undertake a fundamental paradigm shift in how we practice. We describe the need for imaging institutes centered on disease entities (eg, lung cancer, multiple sclerosis) to not only optimize clinical care and patient outcomes, but also spur the development of a new educational focus, which will increase opportunities for medical trainees and other health professionals. These institutes will also serve as unique environments for testing and implementing new technologies and for generating new ideas for research and health-care delivery. We propose that the imaging institutes focus on how imaging practices-including new innovations-improve patient care outcomes within a specific disease framework. These institutes will allow our specialty to lead patient care, provide the necessary infrastructure for state-of-the art-education of trainees, and stimulate innovative and clinically relevant research.

Practical Approaches to Quality Improvement for Radiologists.

Continuous quality improvement is a fundamental attribute of high-performing health care systems. Quality improvement is an essential component of health care, with the current emphasis on adding value. It is also a regulatory requirement, with reimbursements increasingly being linked to practice performance metrics. Practice quality improvement efforts must be demonstrated for credentialing purposes and for certification of radiologists in practice. Continuous quality improvement must occur for radiologists to remain competitive in an increasingly diverse health care market. This review provides an introduction to the main approaches available to undertake practice quality improvement, which will be useful for busy radiologists. Quality improvement plays multiple roles in radiology services, including ensuring and improving patient safety, providing a framework for implementing and improving processes to increase efficiency and reduce waste, analyzing and depicting performance data, monitoring performance and implementing change, enabling personnel assessment and development through continued education, and optimizing customer service and patient outcomes. The quality improvement approaches and underlying principles overlap, which is not surprising given that they all align with good patient care. The application of these principles to radiology practices not only benefits patients but also enhances practice performance through promotion of teamwork and achievement of goals.

Asymmetric expansion of aortic aneurysms on computed tomography imaging.

OBJECTIVE: To investigate whether wall growth during aneurysm development spares the aortic wall between the intercostal or lumbar arteries or, alternatively, is uniform around the circumference. METHODS: Computed tomography scans of 155 patients with aortic aneurysms (40 thoracic, 50 thoracoabdominal, and 65 abdominal) in a single hospital of a large academic institution were retrospectively inspected. Computed tomography studies of 100 control subjects (40 thoracic and 60 abdominal) were also reviewed. In all 255 patients, the ratio of the arc length between the origins of the intercostal or lumbar arteries (interbranch arc length) to the remainder of the aortic residual circumference was calculated. These ratios were compared between all subjects with aneurysms and the controls at each vertebral body level and between those with thoracic or thoracoabdominal or abdominal aneurysms and controls at each vertebral body level. RESULTS: Interbranch arc lengths and residual aortic circumferences were larger in aneurysm patients than in control subjects, but the differences were statistically significant only at T4 and from T8 to L4 (P = .009 to P < .001) and from T4 to L4 (P < .001), respectively. The ratio of interbranch arc length to residual circumference in aneurysmal aortas was significantly smaller than that in controls at 12 out of 13 levels from T4 to L4 (P = .004 to P < .001). There was a statistically significant smaller ratio at 8 out of 9 levels for thoracic aneurysms (P = .006 to P < .001), 12 out of 13 levels for thoracoabdominal aneurysms (P = .008 to P < .001), and 3 out of 4 levels for abdominal aneurysms compared with controls (P = .006 to P < .001). CONCLUSIONS: Wall growth in aortic aneurysms is asymmetric, with greater aneurysmal growth in the anterior aorta wall and relative sparing of the portion of aortic wall between the intercostal or lumbar arteries. The mechanisms effecting this asymmetric growth have not been fully characterized.

Comparative effectiveness of imaging modalities for the diagnosis of upper and lower urinary tract malignancy: a critically appraised topic.

RATIONALE AND OBJECTIVES: The purpose of this study was to critically appraise and compare the diagnostic performance of imaging modalities that are used for the diagnosis of upper and lower/bladder urinary tract cancer, transitional cell carcinoma (TCC). METHODS: A focused clinical question was constructed and the literature was searched using the patient, intervention, comparison, outcome (PICO) method comparing computed tomography (CT) urography, magnetic resonance (MR) urography, excretory urography, and retrograde urography in the detection of TCC of the upper urinary tract. The same methods were used to compare CT cystography, MR cystography, and ultrasonography in the diagnosis of bladder cancer. Retrieved articles were appraised and assigned a level of evidence based on the Oxford University Centre for Evidence-Based Medicine hierarchy of validity for diagnostic studies. RESULTS: The retrieved sensitivity/specificity for the detection of TCC of upper urinary tract for CT urography, MR urography, excretory urography, and retrograde urography were 96%/99%, 69%/97%, 80%/81%, and 96%/96%, respectively. For detecting bladder cancer, the retrieved sensitivity/specificity for CT cystography, MR cystography, and ultrasonography were 94%/98%, 91%/95%, and 78%/96%, respectively. CONCLUSIONS: CT urography is the best imaging technique for confirming or excluding malignancy in the upper urinary tract, whereas CT cystography has the best diagnostic performance for diagnosing bladder cancer.

Aortic branch artery pseudoaneurysms accompanying aortic dissection. Part III: natural history.

PURPOSE: To document the natural history of branch artery pseudoaneurysms (BAPs), which are sequelae of aortic dissection with false lumen thrombosis that have been distinguished anatomically from penetrating ulcers. MATERIALS AND METHODS: Serial computed tomography (CT) scans in 50 patients with at least two CT scans greater than 1 month apart were retrospectively studied. Mean follow-up was 29 months, with longitudinal analyses of 119 BAPs. Changes in BAPs, false lumen thrombosis, and aortic diameter were assessed. RESULTS: No patient had an aortic rupture or other poor outcome. All BAPs eventually disappeared (ie, thrombosed), with 50% thrombosed within 18 months. Aortas were ectatic, with a mean diameter of 36 mm. There was no statistically significant change in total aortic diameters; however, there was a significant increase in true lumen diameters (P < .0001) and a significant decrease in false lumen thickness (P < .0001) at the level of the BAP over time (mean 50% reduction in maximum thickness of thrombosed false lumen). There were no significant associations between BAP thrombosis and vertebral level, presence of more than one BAP, presence of branch artery in communication with the BAP, history of smoking, diabetes mellitus or hypertension, or treatment with ß-blockers, other antihypertensive medication, statins, or anticoagulation therapy. After controlling for other variables, BAPs were less likely to thrombose if an ulcerlike projection was present (P = .003), in men (P = .02), in subjects with hypertension (P = .04), and in older patients (P = .05). CONCLUSIONS: Most BAPs spontaneously thrombose, and associated intramural hematoma regresses/disappears. Isolated BAPs were not associated with poor clinical outcomes.

Pattern of failure after high-dose thoracic radiation for non-small cell lung cancer: the University of Michigan experience.

PURPOSE: Our main purpose is to study the pattern of local failure for patients with non-small cell lung cancer treated with conformal therapy. METHODS: This study included patients who failed locally and a matched group without failures after 3D conformal radiation per a radiation dose-escalation trial. Radiation doses ranged from 65.1 to 102.9 Gy in 2.1 Gy fractions, originally computed using an equivalent path length algorithm. The recurrent gross target volumes (RGTV) were contoured. The original and recurrent planning target volume (PTV and RPTV) were generated by 1 cm uniform expansion from GTV. DVHs and generalized equivalent uniform doses (EUD={Σ i (di ) a }1/a ) were computed. Marginal failures were defined for RGTVs covered by the original 10 to 90 % isodose surfaces. RESULTS: There were no significant differences between the failed and control groups with regard to average original GTV volumes, GTV and PTV doses, and minimum PTV doses. Of the 18 RGTVs, four had marginal failure, 12 failed mostly within, and two failed outside of the original PTV. The mean EUDs were 57.1 Gy (95 % confidence interval (CI) 43.9-70.6) and 47.5 Gy (95 % CI 33.7-61.2), for the RGTVs and RPTVs, respectively, significantly below the prescribed doses (p=0.03). EUDs were less than 60 Gy for 39 % of the RGTVs and 56 % of the RPTVs. CONCLUSIONS: Recurrent tumors had significantly lower doses than the prescribed dose suggesting that some of these failures could have been avoided with modern technology such as 4D CT simulation and image-guided radiation therapy.

Influence of population prevalences on numbers of false positives: an overlooked entity.

BACKGROUND: Disease prevalence alters the number of true positives (TP), true negatives (TN), false negatives (FN), and false positives (FP), even if the sensitivity and specificity of a test stays the same. METHODS AND MATERIALS: We illustrate this using data for the detection of suspected acute pulmonary embolism (PE) from the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II). We chose PE because of the clinical significance of the disease, the low prevalence of PE in the patient population being tested with CTPA with the widespread adoption of CTPA, and the serious clinical consequences of anticoagulation therapy in FP patients. RESULTS: Based on PIOPED II data (sensitivity 83%, specificity 96%), at a disease prevalence of approximately 5%, the number of FP patients is greater than the number of TP patients. Scaled to the US population, at a disease prevalence of 5%, there would be 139,800 FPs and 3,356,200 TNs. Assuming a mortality rate of 0.5% and a 3.0% rate of major bleeding secondary to anticoagulation therapy for well-controlled patients, if all FP patients received anticoagulation, there would be 699 deaths and 4194 major bleeding complications. CONCLUSIONS: At a prevalence of approximately 5% for PE, the number of FPs approaches or is greater than the number of TPs for CTPA for the detection of suspected acute PE. Patients with FP results may receive unnecessary, potentially harmful treatment with anticoagulation therapy. Population prevalence of disease needs to be taken into account along with the diagnostic accuracy of a test, because this may significantly affect downstream patient outcomes.

Breast cancer sentinel node identification and classification after neoadjuvant chemotherapy-systematic review and meta analysis.

RATIONALE AND OBJECTIVES: Breast cancer is the leading cause of mortality in women worldwide. Lymphatic mapping with sentinel node biopsy has the potential to reduce the morbidity associated with breast cancer staging in women after neoadjuvant therapy. MATERIALS AND METHODS: A systematic search of world literature between 1996 and 2007 of sentinel node mapping in patients with early-stage breast carcinoma after chemotherapy was undertaken. Potentially eligible studies were identified using database-specific search strategies incorporating appropriate Boolean combinations of the keywords sentinel node biopsy or sentinel node localization or lymphatic mapping; breast cancer or malignancy or neoplasm; and preoperative or neoadjuvant chemotherapy. The electronic searches were augmented with a manual search of reference lists from identified articles. Successful lymph node mapping, defined as successful identification rate (SIR), and false-negative rate (FNR) was summarized using a bivariate random effects mixed model. The extent of heterogeneity was assessed using the inconsistency statistic. The effect of study level covariates, such as use of immunohistochemistry or dual mapping technique, and individual quality criteria, such as study design or multi-institution participation, on SIR and FNR were analyzed using metaregression. RESULTS: A total of 24 trials of 1799 subjects were reported that met eligibility criteria. All studies identified were published between 2000 and 2007. Lymph node involvement was found in 758 patients (37%) and ranged from 25% to 96% across studies. The proportion of patients who had successful lymph node mapping ranged from 63% to 100%, with 79% of studies reporting a rate of less than 95%. The summary successful identification rate was 0.896 (95% confidence interval [CI] 0.860-0.923) with moderate heterogeneity. The summary FNR was 0.084 (95% CI 0.064-0.109) with no significant heterogeneity. Increasing prevalence of lymph node involvement and same-day mapping and lymph node dissection both significantly reduced the FNR. CONCLUSIONS: The present systematic review demonstrates robust estimates of successful identification rate and false-negative rates of sentinel lymph node mapping and biopsy after neoadjuvant therapy for early-stage breast cancer patients. With a 90% SIR and 8% FNR, this technique is a reliable tool for planning treatment in this population as an alternative to completion axillary lymph node dissection.

Solitary pulmonary nodules and masses: a meta-analysis of the diagnostic utility of alternative imaging tests.

The purpose was to assess the clinical utility of diagnostic tests for identifying malignancy within a solitary pulmonary nodule (SPN), and to create a nomogram or "look-up" table using clinical data and non-invasive radiology (positive) test results to estimate post-test probability of malignancy. Studies that examined computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT) for the evaluation of SPN. Two reviewers independently abstracted data and assessed study quality. Study-specific and overall positive likelihood ratios (LRs) for each diagnostic test confirming a diagnosis of malignancy and negative LR for each diagnostic test excluding a diagnosis of malignancy within an SPN were calculated. Forty-four of 242 articles were included. Positive LRs for diagnostic tests were: CT 3.91 (95% confidence interval 2.42, 5.40), MRI 4.57 (3.03, 6.1), PET 5.44 (3.56, 7.32) and SPECT 5.16 (4.03, 6.30). Negative LRs were: CT 0.10 (0.03, 0.16), MRI 0.08 (0.03, 0.12), PET 0.06 (0.02, 0.09) and SPECT 0.06 (0.04, 0.08). Differences in performance for all tests were negligible; therefore, the clinician may confidently use any of the four tests presented in further evaluating an SPN. Given the low cost and prevalence of the technology, SPECT appears to be the leading choice for additional testing in SPN evaluation.

Solitary pulmonary nodules: meta-analytic comparison of cross-sectional imaging modalities for diagnosis of malignancy.

PURPOSE: To perform a meta-analysis to estimate the diagnostic accuracy of dynamic contrast material-enhanced computed tomography (CT) and magnetic resonance (MR) imaging, fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and technetium 99m ((99m)Tc) depreotide single photon emission computed tomography (SPECT) for evaluation of solitary pulmonary nodules (SPNs). MATERIALS AND METHODS: Data sources were studies published in PubMed between January 1990 and December 2005. The selected investigations were comparative and noncomparative diagnostic cohort studies to examine the operating characteristics of the four imaging modalities for evaluation of SPNs, involving at least 10 enrolled participants with histologic confirmation and having sufficient data to calculate contingency tables. A random coefficient binary regression model with disease probability conditioned on test results was used to summarize test performance and construct summary receiver operating characteristic (ROC) curves. Sensitivities, specificities, predictive values, diagnostic odds ratios, and areas under the ROC curve were calculated. RESULTS: Forty-four studies--10 dynamic CT, six dynamic MR, 22 FDG PET, and seven (99m)Tc-depreotide SPECT--met the inclusion criteria. (One study was included in both the FDG PET and SPECT groups.) Sensitivities, specificities, positive predictive values, negative predictive values, diagnostic odds ratios, and areas under the ROC curve were, respectively, 0.93 (95% confidence interval [CI]: 0.88, 0.97), 0.76 (95% CI: 0.68, 0.97), 0.80 (95% CI: 0.74, 0.86), 0.95 (95% CI: 0.93, 0.98), 39.91 (95% CI: 1.21, 81.04), and 0.93 (95% CI: 0.81, 0.97) for dynamic CT; 0.94 (95% CI: 0.91, 0.97), 0.79 (95% CI: 0.73, 0.86), 0.86 (95% CI: 0.83, 0.89), 0.93 (95% CI: 0.90, 0.96), 60.59 (95% CI: 5.56, 115.62), and 0.94 (95% CI: 0.83, 0.98) for dynamic MR; 0.95 (95% CI: 0.93, 0.98), 0.82 (95% CI: 0.77, 0.88), 0.91 (95% CI: 0.88, 0.93), 0.90 (95% CI: 0.85, 0.94), 97.31 (95% CI: 6.26, 188.37), and 0.94 (95% CI: 0.83, 0.98) for FDG PET; and 0.95 (95% CI: 0.93, 0.97), 0.82 (95% CI: 0.78, 0.85), 0.90 (95% CI: 0.83, 0.97), 0.91 (95% CI: 0.84, 0.98), 84.50 (95% CI: 34.28, 134.73), and 0.94 (95% CI: 0.83, 0.98) for (99m)Tc-depreotide SPECT. CONCLUSION: Dynamic CT and MR, FDG PET, and (99m)Tc-depreotide SPECT are noninvasive and accurate in distinguishing malignant from benign SPNs; differences among these tests are nonsignificant.

Meta-analysis: effectiveness of drugs for preventing contrast-induced nephropathy.

BACKGROUND: N-Acetylcysteine, theophylline, and other agents have shown inconsistent results in reducing contrast-induced nephropathy. PURPOSE: To determine the effect of these agents on preventing nephropathy. DATA SOURCES: Relevant randomized, controlled trials were identified by computerized searches in MEDLINE (from 1966 through 3 November 2006), EMBASE (1980 through November 2006), PubMed, Web of Knowledge (Current Contents Connect, Web of Science, BIOSIS Previews, and ISI Proceedings for the latest 5 years), and the Cochrane Library databases (up to November 2006). Databases were searched for studies in English, Spanish, French, Italian, and German. STUDY SELECTION: Randomized, controlled trials that administered N-acetylcysteine, theophylline, fenoldopam, dopamine, iloprost, statin, furosemide, or mannitol to a treatment group; used intravenous iodinated contrast; defined contrast-induced nephropathy explicitly; and reported sufficient data to construct a 2 x 2 table of the primary effect measure. DATA EXTRACTION: Abstracted information included patient characteristics, type of contrast media and dose, periprocedural hydration, definition of contrast-induced nephropathy, and prophylactic agent dose and route. DATA SYNTHESIS: In the 41 studies included, N-acetylcysteine (relative risk, 0.62 [95% CI, 0.44 to 0.88]) and theophylline (relative risk, 0.49 [CI, 0.23 to 1.06]) reduced the risk for contrast-induced nephropathy more than saline alone, whereas furosemide increased it (relative risk, 3.27 [CI, 1.48 to 7.26]). The remaining agents did not significantly affect risk. Significant subgroup heterogeneity was present only for N-acetylcysteine. No publication bias was discerned. LIMITATIONS: All trials evaluated the surrogate end point of contrast-induced nephropathy as the primary outcome. The lack of a statistically significant renoprotective effect of theophylline may result from insufficient data or study heterogeneity. True study quality remains uncertain. CONCLUSION: N-acetylcysteine is more renoprotective than hydration alone. Theophylline may also reduce risk for contrast-induced nephropathy, although the detected association was not significant. Our data support the administration of N-acetylcysteine prophylaxis, particularly in high-risk patients, given its low cost, availability, and few side effects.

The role of multidetector computed tomography angiography for the diagnosis of pulmonary embolism.

From a radiological point of view, computed tomography pulmonary angiography (CTPA) has effectively become the de-facto first-line imaging test for the evaluation of pulmonary embolism (PE), as patients with a high-quality negative CTPA do not require further examination or treatment for suspected PE. We are likely to see further technical developments in CT technology in the near future. These advances will most likely further improve image quality. Several questions or issues remain, including strategies for further imaging when CT is inconclusive or contraindicated, issues regarding radiation exposure, the prevalence of PE in specific populations, best tests and pathways in specific patient groups, including patients with specific comorbidities such as oncology patients or patients with chronic obstructive pulmonary disease. Also, the question whether all PE patients need anticoagulation, the clinical effect of follow-up imaging, and the accuracy of different clinical prediction rules, remains.

Metastatic shoulder liposarcoma to the right ventricle: CT findings.

Metastatic cardiac liposarcoma is rare. A right ventricular liposarcoma metastasis is described in a 46-year-old man, who was admitted with significant shortness of breath and fatigue, and in whom a large lobulated low attenuation mass occupying most of the right ventricular cavity, with extension through the right ventricular apex and a small-to-moderate pericardial effusion was detected by electrocardiogram-gated cardiac computed tomography. The patient had an antecedent history of a left upper arm liposarcoma treated with surgical resection, chemotherapy, and postoperative radiotherapy 3 years earlier. Surgical resection was performed with the majority of the neoplasm removed though; the right ventricular apex and epicardial extension of tumor could not be fully resected. The histopathologic analysis revealed a liposarcoma, similar to the one resected in the left arm 3 years earlier. Electrocardiogram-gated cardiac computed tomography was able to visualize the metastatic tumor within the heart, accurately evaluate cardiac function and allow for prompt surgical treatment that produced relief of symptoms, and assess for further metastatic disease within the thorax.