In patients without selected thromboembolic risk factors, pulmonary embolism (PE) is extremely unlikely and investigation with CT angiography likely unnecessary. In a retrospective study that examined seven major risk factors in patients who underwent CT angiography for suspected PE, Mamlouk and colleagues found that a positive CT angiogram was extremely unlikely—0.95%—for patients with none of the risk factors. The results suggest that unless there is an unusual mitigating circumstance, CT angiography is likely unnecessary in these patients, and triaging risk factors can reduce costs and radiation exposure, the researchers concluded.

Diffuse optical tomography in the near-infrared (NIR) spectrum shows promise for differentiating early-stage breast cancers from benign lesions. In 178 women who underwent US-localized NIR imaging, Zhu and co-workers found a twofold higher total hemoglobin concentration in malignant invasive lesions than in benign lesions. The data from NIR imaging and US yielded high sensitivity, specificity, and negative predictive value for in situ and T1 carcinomas. They concluded that NIR technique with US can provide a safe, quick, noninvasive method that may aid in diagnosis of small indeterminate breast lesions.

A Markov model indicates duplex US with subsequent CT angiography is the most cost-effective approach for assessing patients with recent transient ischemic attack (TIA) or minor ischemic stroke. Tholen et al examined costs, quality-adjusted life-years, incremental cost-effectiveness ratios, and net health benefit in a decision analysis from the societal perspective of US, CT, and MR techniques used individually or in combination. The results suggest that US should be the initial diagnostic test, followed by CT angiography if US findings are positive, with surgery for 70%-99% stenosis; in patients with a high-risk profile, high probability of carotid artery stenosis, or who can undergo surgery without delay, immediate CT angiography and surgery for 50%-99% stenosis is indicated.

A 10-minute scan delay for contrast-enhanced adrenal CT may not allow enough washout time for characterizing adrenal adenomas. In a cohort of 314 patients, Sangwaiya et al found that the 10-minute washout test yielded lower sensitivity than was reported in previous studies. The test's specificity remains acceptable for differentiating adenomatous from nonadenomatous disease, while its sensitivity is insufficient to be useful in routine clinical practice, the researchers concluded.

Scrotal and transrectal US are effective for distinguishing obstructive azoospermia, which may be surgically correctable, from nonobstructive azoospermia. In a study group of 100 men, Du and colleagues found that scrotal and transrectal US yielded high sensitivity, specificity, and accuracy for distinguishing obstructive from nonobstructive azoospermia, and also provided meaningful diagnostic information for etiologic classification of obstructive azoospermia. The information may help guide appropriate clinical and surgical management, the researchers concluded.

Proton-decoupled ³¹P MR spectroscopy can help evaluate severity and treatment response in nonalcoholic liver disease. In a study of 43 patients, Sevastianova and colleagues found that ³¹P MR spectroscopy showed promise in differentiating stages of nonalcoholic fatty liver disease by detecting an increase in signal of nicotinamide adenine dinucleotide phosphate (NADPH), a marker of inflammation and fibrogenesis in the liver. The researchers concluded that ³¹P MR spectroscopy could help to select patients for invasive liver biopsy and possibly replace biopsy in some patients.

In patients with traumatic knee lesions, a virtual noncalcium technique for dual-energy CT can allow bone marrow space assessment by subtracting calcium from cancellous bone, suggesting that bone bruise lesions are potentially detectable with CT. In a study of 21 patients with acute knee trauma, Pache and colleagues found that the technique yielded sensitivity as high as 86.4% and specificity as high as 95.5%. Despite the potentially significant radiation dose increase, dual-energy CT could serve as a useful tool in the diagnostic workup of traumatic knee lesions, the researchers concluded.

In many patients suspected of having primary sclerosing cholangitis, MR cholangiopancreatography (MRCP) is sufficient for diagnosis. In a meta-analysis that included 456 subjects with 623 independent readings, Dave and colleagues found that MRCP yielded high sensitivity and very high specificity for primary sclerosing cholangitis. The researchers concluded that positive MRCP findings can obviate—and avoid the risks involved with—endoscopic retrograde cholangiopancreatography.

For screening mammography, the ability of single reading with CAD versus double reading to enable correct recall of breast cancers varies significantly by lesion type. James and colleagues examined reading regimens of analog film mammograms as part of the UK multicenter Computer Aided Detection Evaluation Trial II (CADET II). They found that readers more ably recalled cancers that appeared as parenchymal deformities with double reading, while they were more adept with single reading and CAD at recalling cancers that appeared as areas of asymmetry. Image readers should be aware of the strengths and weaknesses of each reading regimen to avoid missing the more challenging cancer cases.

MR imaging at 3 T helps identify risk factors in patients with subacute knee symptoms 10 years before the development of osteoarthritis. In a study of 326 patients with a mean 10-year follow-up, Huétink and co-workers found that patients who have had tears of the anterior cruciate ligament or one or both menisci have increased risk of developing features of osteoarthritis. Treatment of meniscal tears—in particular, partial meniscectomy—does not decrease the risk of developing osteoarthritic fractures, the researchers noted.