CT colonography can be used as a primary colorectal screening tool in patients older than 65 years and in those aged 50-65 years. Examining data from the National CT Colonography Trial, which recruited 2600 participants from 15 U.S. medical centers, Johnson et al found no significant difference in the accuracy of CT colonography in depicting large and intermediate-sized adenomatous lesions between participants 65 years or older and those younger than 65 years. The performance estimates are based on a population with predominately average risk and support CT colonography as a primary colorectal cancer screening tool for all eligible patients, the researchers concluded.

Volume doubling times of lung cancers diagnosed in annual repeat rounds of CT screening are similar to those diagnosed in the absence of screening. Using data from the International Early Lung Cancer Action Program, Henschke and colleagues found no significant difference in volume doubling times for cancers detected at screening and those detected with other methods. Because lung cancers manifesting as subsolid nodules on CT scans had significantly longer volume doubling times than those manifesting as solid nodules, work-up and treatment may become more tailored according to nodule consistency, the researchers concluded.

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Hybrid adaptive statistical iterative reconstruction (ASIR) for pediatric chest and abdominal CT imaging significantly reduces radiation dose while maintaining equal or better image quality and lower noise than does conventional filtered back projection (FBP). In a study of 234 children, Singh and colleagues found that a hybrid ASIR enabled 46% radiation dose reduction for pediatric chest CT and 38% reduction for abdominal CT when compared with the FBP technique. Despite substantial radiation dose reduction, ASIR-enabled CT had 14% lower objective noise for abdominal CT and 19% lower noise for chest CT than did corresponding FBP-enabled CT, the researchers concluded. 

On brain MR images of preterm infants, diffuse excessive high signal intensity (DEHSI) was the most common MR finding; however, it was not predictive of adverse neurodevelopmental outcomes at 18-24 months of corrected age. In a study of high-risk preterm infants at near-term-equivalent age, Jeon et al found that subsequent neurodevelopmental outcomes in infants with DEHSI lesions did not differ significantly from outcomes in those without DEHSI, while cystic encephalomalacia and punctate lesions were more significant predictors of cerebral palsy. Because the presence of DEHSI was not related to adverse neurodevelopmental outcomes, it may represent a delayed maturation or a modifiable white matter change rather than overt white matter injury, the researchers concluded.

Because the nerve routes of posterior hepatic plexuses run diagonally, coronal reformatted CT images are useful for evaluating them in patients with extrahepatic bile duct cancer. In a study of 43 patients with surgically resected cancer involving the extrahepatic bile duct, Yamada and colleagues found that the increased attenuation of the fat tissue along the posterior hepatic plexuses was highly suggestive of tumor invasion. Knowledge of the route of the posterior hepatic plexuses in patients with extrahepatic bile duct cancer and multidetector CT findings related to these plexus invasions is helpful in making an accurate diagnosis and selecting the appropriate surgical strategy, the researchers concluded. 

Magnetization transfer ratio (MTR) measurements can be used to monitor the maturation-myelination process in the developing brain and to detect small changes in tissue that are not shown on T1- and T2-weighted MR images. In a study of MR images of 42 preterm neonates with normal-appearing gray matter structures at presentation, Nossin-Manor et al found that MTRs increased linearly with age in the basal ganglia (BG) and thalami. Higher MTRs were seen in the thalami and pons than in the BG, indicating earlier maturation.  Neonates with white matter injury had lower MTRs in the BG than those with normal radiologic findings. During the preterm period, MTR increased while T1 values decreased with age in deep gray matter structures. The researchers concluded that MTR measurements can be used as a tool to identify secondary brain injury manifesting as regional delays in maturation. 

On the basis of a limited number of published studies, the pooled prevalence of colorectal cancer after a CT diagnosis of acute diverticulitis is 2.1%. In a systematic review of literature to find articles in which patients with CT diagnosis of acute diverticulitis underwent surgery, colonoscopy, or barium enema, Sai and colleagues found 10 articles that met the inclusion criteria. Those articles included only 771 such patients; 14 patients were found to have colon cancer. The researchers concluded there are limited data to support the recommendation to perform colonoscopy after a CT diagnosis of acute diverticulitis, and more refined criteria should be developed for recommending colonoscopy. 

Dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) MR imaging features may serve as biomarkers for high-nuclear-grade (HNG) ductal carcinoma in situ (DCIS). In a study of 55 pure DCIS lesions in women who underwent 1.5-T breast MR with both DCE and DW imaging, Rahbar and colleagues found that on DCE images, HNG DCIS lesions on average manifested as larger lesions than did non-HNG lesions. Non-HNG DCIS demonstrated higher DW signal intensity and higher T2 signal intensity. These findings could lead to increased diagnostic confidence from core biopsy sampling and could facilitate more individualized therapies, the researchers concluded.

US-guided percutaneous microwave coagulation (PMC) may be feasible treatment for small invasive breast cancers, with a 95% complete coagulation rate. In a study of 41 patients, Zhou and colleagues found that patient selection, evaluation of the extent of cancer, and position of the antenna were major concerns for complete microwave coagulation, and that patients with ductal carcinoma in situ may not be good candidates for the treatment because of a low complete coagulation rate. Although US-guided PMC of small breast cancer is feasible, larger-scale clinical trials are still needed to validate it for clinical practice, the researchers concluded. 

Volumetric MR-guided high-intensity focused ultrasound (HIFU) ablation with a one-layer strategy is safe and effective for treating large (>10-cm diameter) uterine fibroids. Kim and colleagues used a technique in which all treatment cells were placed in one coronal plane at a depth of half to anterior two-thirds of the anteroposterior dimension of fibroids. The technique was fast enough to treat fibroids larger than 10 cm in diameter and may be an effective nonsurgical therapeutic modality for patients with uterine fibroids that cannot be effectively treated with uterine fibroid embolization or conventional MR-guided HIFU techniques, the researchers concluded.