Radiology News

Imaging and Insurance: Do the Uninsured Get Less Imaging in Emergency Departments?
On average, Americans without health insurance receive fewer health care services than those with insurance. The specific types of services for which the uninsured face access and utilization deficits are not well understood. The authors describe the use of imaging tests in hospital emergency departments (EDs) by nonelderly patients, comparing uninsured, Medicaid, and non-Medicaid insured individuals. Compared with comparable insured persons, nonelderly uninsured and Medicaid patients received fewer services in the ED (8% and 10%, respectively, P < .01), even after adjustment for level of acuity. These results suggest that insurance status influences how much imaging and the intensity of imaging patients receive. Further research is needed to understand whether insured patients receive unnecessary imaging or if uninsured and Medicaid patients receive too little imaging.

Left Atrial Volume: Comparison of 2D and 3D Transthoracic Echocardiography with ECG-gated CT Angiography
Left atrial volume (LAV) measurement by conventional two-dimensional (2D) transthoracic echocardiography (TTE) may be limited by the geometric model, by suboptimal definition of left atrial endocardium, or by chamber foreshortening. Three-dimensional (3D) TTE is posited to eliminate chamber foreshortening, and LAV measurement by 3D TTE should be more reflective of true LAV. The aim of this study was to compare conventional 2D TTE and newer 3D TTE for measurements of LAV to multidetector computed tomographic (MDCT) measurements using automated chamber reconstruction (ACR). This study shows that LAV is underestimated by both 2D TTE and 3D TTE relative to coronary computed tomographic angiography. Excellent agreement between the ALM and ACR with MDCT imaging suggests that the geometric model plays a negligible role in the underestimation of LAV. Underestimation of LAV by echocardiography is likely related to suboptimal definition of left atrial contour.

Impact of Reduced Patient Life Expectancy on Potential Cancer Risks from Radiologic Imaging
This article sought to quantify the effect of reduced life expectancy on cancer risk by comparing estimated lifetime risks of lung cancer attributable to radiation from commonly used computed tomographic (CT) examinations in patients with and those without cancer or cardiac disease. Patients with decreased life expectancy had decreased radiation-associated cancer risks. For example, for a 70-year-old patient with colon cancer, the estimated reduction in lifetime radiation-associated lung cancer risk was approximately 92% for stage IV disease, versus 8% for stage 0 or I disease. The importance of radiation exposure in determining optimal imaging usage is much reduced for patients with markedly reduced life expectancies: Imaging justification and optimization criteria for patients with substantially reduced life expectancies should not necessarily be the same as for those with normal life expectancies.

Diagnostic value of CT features of the gallbladder in the prediction of gallstone pancreatitis
The aim of this retrospective study was to evaluate the diagnostic value of CT features of the gallbladder in the prediction of gallstone pancreatitis. Eighty-six patients who underwent a diagnostic computed tomography (CT) scan for acute pancreatitis were included. The presence of pericholecystic increased attenuation of the liver parenchyma, GB wall enhancement and thickening, pericholecystic fat strands, stone in the GB or CBD, and diffuse manifestations of pancreatitis achieved statistical significance for differentiation of gallstone induced pancreatitis from non-biliary pancreatitis. The mean values of maximal transverse luminal diameter of GB and CBD were significantly higher in gallstone induced pancreatitis group than non-biliary pancreatitis group.

Non-severe pulmonary embolism: Prognostic CT findings
The goal of this study was to retrospectively evaluate CT cardiovascular parameters and pulmonary artery clot load score as predictors of 3-month mortality in patients with clinically non-severe pulmonary embolism (PE). We included 226 CT positive for PE in hemodynamically stable patients (112 women; mean age 67.1 years ±16.9). CT were independently reviewed by two observers. Results were compared with occurrence of death within 3 months using Cox regression. Twenty-four (10.6%) patients died, for whom 9 were considered to be due to PE. Interobserver agreement was moderate for the shape of interventricular septum (κ=0.41), and for the ratio between the diameters of right and left ventricle (RV/LV) (κ=0.76). Observers found no association between interventricular septum shape and death. A RV/LV diameter ratio >1 was predictive of death (OR, 3.83; p<0.01) only when we also took into account the value of the embolic burden (<40%). In a multivariate model, CT cardiovascular parameters were not associated with death. Concomitant lower limb DVT and comorbid conditions were important predictors of death. In clinically non-severe PE, a RV/LV diameter ratio >1 is predictive of death when the embolic burden is low (<40%).

Frequent Body CT Scanning of Young Adults: Indications, Outcomes, and Risk for Radiation-Induced Cancer
The aims of this study were to define the magnitude of frequent body CT scanning of young adults and to determine associated patient diagnoses, examination indications, short-term outcomes, and estimated radiation-induced cancer risk. Patients aged 18 to 35 years who underwent chest or abdominopelvic CT between 2003 and 2007 at any of 3 hospitals were identified and categorized by total number of scans per body part as rarely (<5), intermediately (>5 and <15), or frequently (>15) scanned. Medical records of the frequently scanned were reviewed. Cumulative radiation exposure, calculated from typical effective doses, was used to estimate cancer risk. Cancer incidence and mortality were estimated using the Biological Effects of Ionizing Radiation method. This article found that the majority of CT-induced cancers are predicted to result from sporadic rather than frequent scanning. Frequent scanning confers a significant cancer risk but occurs in severely ill patients, a large proportion of who die before any radiation-induced cancer would be a factor in their health.

Can Non-calcified Coronary Artery Plaques Be Detected on Non-contrast CT Calcium Scoring Studies?
Coronary computed tomographic (CT) angiography has been shown to detect noncalcified coronary artery plaque. Depending on tissue composition, noncalcified plaque differs in CT attenuation from blood and epicardial fat. The aim of this study was to determine whether noncalcified plaque can be visually detected on non-contrast-enhanced CT calcium scoring studies. This study found that Noncalcified plaque can be visually detected on calcium scoring studies. Review of calcium scoring studies for features of noncalcified plaque may enhance the identification of patients with more active disease and higher cardiovascular risk.

Subtraction CT Angiography of the Lower Extremities
This article sought to validate the hypothesis that a multisegmented approach during subtraction computed tomography (CT) angiography of the lower extremities can improve bone removal efficiency by suppressing regional motion. It found that bone removal performance and overall MIP image quality can be increased by adopting multisegmented volume subtraction during subtraction CT angiography of the lower extremities.

Sodium bicarbonate for the prevention of contrast induced nephropathy: A meta-analysis of published clinical trials
Contrast induced nephropathy (CIN) is a serious but rare complication following contrast based procedures. Sodium bicarbonate (NaHCO3) has been postulated to prevent CIN by various mechanisms. However, the outcomes following sodium bicarbonate administration to prevent CIN have been inconsistent. A meta-analysis of published randomized clinical trials to determine if the administration of sodium bicarbonate is superior to sodium chloride among patients with chronic renal failure undergoing catheterization and interventional procedures in preventing CIN was performed. This meta-analysis demonstrates that based on currently available randomized trials, the administration of NaHCO3 is superior to the administration of NaCl alone in the prevention of CIN among patients with moderate to severe chronic kidney disease. However, further controlled clinical trials are needed due to significant study heterogeneity and publication bias.

Reconstruction Technique Allows Radiation Dose Reduction in Chest CT
Using adaptive statistical iterative reconstruction (ASIR)-enabled chest CT, acceptable image quality can be achieved at a low radiation dose of 3.5 mGy. Singh and colleagues found in a study of 23 patients that ASIR chest CT images acquired at 40 mAs have lower quantitative image noise (13.5 vs 28.3) than and similar diagnostic confidence to filter back projection (FBP) images. A higher blending factor of 70% ASIR and 30% FBP is needed to reconstruct chest CT images at radiation dose levels of 3.5 mGy to obtain acceptable image noise and diagnostic confidence, the researchers concluded. 

The diagnostic value of diffusion-weighted magnetic resonance imaging in soft tissue abscesses
This article sought to study the diagnostic value of diffusion-weighted imaging (DWI) in soft tissue abscesses. Fifty patients were included in this study who were thought to have soft tissue abscess or cystic lesion as a result of clinical and radiological examinations. Localisations of the lesions were: 1 periorbital, 3 breast, 14 intraabdominal, and 32 intramuscular lesions. After other radiological examinations, DWI was performed. The signal intensity values of the lesions were evaluated qualitatively according to the hyperintensity on b-1000 DWI, using 1.5T MR system. All of the lesions were aspirated after DWI, and detection of pus in the aspiration material was accepted as gold standard for the diagnosis of abscess. The sensitivity and specificity of diffusion-weighted images for detecting soft tissue abscesses were found to be 92% and 80%, respectively. DWI has a high diagnostic value in soft tissue abscesses, and is an important imaging modality that may be used for the differentiation of cysts and abscesses.

Below knee angioplasty in elderly patients: Predictors of major adverse clinical outcomes
The authors of this article attempted to determine predictors of clinical outcome following percutaneous transluminal angioplasty (PTA) in elderly patients with below knee atherosclerotic lesions causing intermittent claudication (IC) or critical limb ischaemia (CLI). IC was improved in 95% at mean 3.4 years (range 0.5–108 months). Successful limb salvage and ulcer healing were seen in 73% with CLI. Most failures were in the CLI group (27% CLI vs. 5% IC), with an amputation rate of 16% for CLI vs. 5% for IC and persistent ulceration in 24% of CLI. Significant independent predictors of MACO were ulceration (hazard ratio 4.02, 95% CI=1.55–10.38) and family history of atherosclerosis.

MRI for the size assessment of pure ductal carcinoma in situ (DCIS)
The authors sought to determine whether MRI assesses the size of ductal carcinomas in situ (DCIS) more accurately than mammography, using the histopathological dimension of the surgical specimen as the reference measurement. This single-center prospective study conducted from March 2007 to July 2008 at the Antoine-Lacassagne Cancer Treatment Center (Nice, France) included 33 patients with a histologically proven DCIS by needle biopsy, who all underwent clinical examination, mammography, and MRI interpreted by an experienced radiologist. Overall MRI appears to assess the size of DCIS better than mammography by limiting the number of under- and over-estimations compared to histopathology findings.

MRI With Mammography Useful for High-Risk Women
When used together with mammography, magnetic resonance imaging (MRI) is a useful screening tool for high-risk women who have undergone chest irradiation, according to research published online Feb. 15 inRadiology. Janice S. Sung, M.D., of the Memorial Sloan-Kettering Cancer Center in New York City, and colleagues conducted a retrospective review of their institution's radiology database, identifying 247 screening breast MRI examinations performed between January 1999 and December 2008 of 91 women with a history of chest irradiation. The researchers reviewed the findings and recommendations for each MRI and the most recent mammogram.

Predictors of Clinical Outcome in Acute Pulmonary Embolism: Correlation of CT Pulmonary Angiography with Clinical, Echocardiography and Laboratory Findings
The aims of this study were to retrospectively evaluate whether computed tomographic (CT) parameters were predictors of in-hospital mortality within 30 days of CT imaging and to compare CT parameters with clinical, echocardiographic, and laboratory findings in patients with acute pulmonary embolism (PE). Thirteen patients (11%) died related to PE within 30 days in the hospital. There were significant differences in the ratio of arterial partial pressure of oxygen to inspired fraction of oxygen and in heart rate between survivors and nonsurvivors (P < .05). No CT or echocardiographic predictor was associated with mortality. The ratio of arterial partial pressure of oxygen to inspired fraction of oxygen and heart rate strongly predicted mortality due to PE. Neither CT pulmonary angiographic variables nor echocardiography could successfully predict in-hospital mortality in patients with acute PE.

Sensitivity of transvaginal ultrasound screening for endometrial cancer in postmenopausal women
Transvaginal ultrasound screening can pick up most cases of endometrial cancer in postmenopausal women before symptoms appear, researchers reported. Such testing could identify more than 80% of cases but would have a false-positive rate of nearly 15%, according to Ian Jacobs, MD, of University College London, and colleagues. The sensitivity and specificity could be improved if the ultrasound screening was restricted to a high-risk population, Jacobs and colleagues reported online inThe Lancet Oncology.

Diagnostic accuracy of 64-slice multidetector CT for detection of in-stent restenosis
This study investigated the diagnostic accuracy of 64-slice multidetector computed tomography (64-CT) for detection of in-stent restenosis (ISR) in an unselected, consecutive patient population. Stent diameter, strut thickness, heart rate and body mass index (BMI) significantly affected image quality. The sensitivity, specificity, positive and negative predictive values of 64-CT for detection of in-stent restenosis were 27%, 95%, 67% and 78%, respectively. It was concluded that the current generation, 64-slice CT, remains limited in its ability to accurately detect in-stent restenosis.

A New Computerized Measurement Approach of Carotid Artery Stenosis on Tomographic Image Sequence
The stenosis degree of carotid artery (CA) can be a critical factor for treatment of cerebrovascular disease and for determining candidate of carotid endarterectomy. Currently, three different measuring methods are applied only on projectional cervical images. These measurement methods introduce several demerits such as a thromboembolic event, and three reference positions provide the different measurement results even on same subject. In addition, projection image could not provide the most severe stenosis position by nature; and the manual measurements also provide the inter-observer and intra-observer variability. Therefore, a computerized measuring scheme is necessary to overcome these drawbacks. This article suggests that the automated approach is recommended to measure the carotid stenosis by using axial image sequence. This technique is not only accurate as possible but also robust, simple to handle, and less time consuming as compared to manual measurements. In addition, a computerized carotid stenosis measuring method is necessary to overcome the drawbacks introduced by using the projectional image and measurement variability of inter-observer, intra-observer.

Increased Epicardial, Pericardial, and Subcutaneous Adipose Tissue Is Associated with the Presence and Severity of Coronary Artery Calcium
Epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), and subcutaneous adipose tissue (SAT) are mediators of metabolic risk and may be involved in the pathogenesis of coronary artery disease. The aim of this study was to investigate the association of visceral and subcutaneous fat depots with the presence and severity of coronary artery calcium (CAC) in asymptomatic individuals. It was found that Increased EAT, PAT, and SAT are associated with the severity of CAC independent of risk factors.

For More Radiology Visit OurRadiology Archives