Tamar Sella

Extracolonic findings at CT colonography

This review focuses on the detection of extracolonic findings at CT colonography (CTC). Since its introduction, it has been regarded as a promising alternative to conventional colonoscopy for the detection of colorectal polyps and cancers. Unlike conventional colonoscopy and barium enema, CTC allows evaluation not only of the colon but also visualization of the lung bases, the abdomen, and the pelvis. CTC is performed with thin sections (1–5 mm) and small intervals (0.5–2 mm), enabling superb image reconstruction. The ability to evaluate the extracolonic structures can present a clinical dilemma. On the one hand, CTC may incidentally demonstrate asymptomatic malignant diseases or other clinically important conditions, thus possibly reducing morbidity or mortality. On the other hand, CTC may reveal numerous findings of no clinical relevance; this could result in costly additional diagnostic examinations with an increase in morbidity and overall negative impact on patients health. In this article, extracolonic findings at CTC will be reviewed and the potential benefits and disadvantages will be presented.

Age-related changes in CT attenuation of the thymus in children

Background. The CT appearance of the normal and abnormal thymus and its age-related changes have been described. However, there is no information regarding the change in thymus CT attenuation values in children. Objective. The aim of the present study was to evaluate the normal CT attenuation of the thymus in infants and children and discover when the decline begins. Materials and methods. CT attenuation values of the thymus were retrospectively evaluated in 152 children between ages of 1 day and up to 14 years. For each patient the mean value of the CT thymus attenuation was calculated and compared to CT attenuation of the chest wall and cardiac muscles. We also examined the correlation between thymic attenuation, gender, and disease. The statistical analysis used was multivariate linear regression. Results. CT attenuation of the thymus declines with age, beginning only after the 1st year of life. The thymus is more hyperdense than the chest wall and cardiac muscles in infants less than 1 year. The thymus is denser in males than females. In malignant conditions, in infants less than 1 year, thymus CT attenuation is decreased. In older children thymus attenuation was similar to that for the chest wall and cardiac muscles. Conclusion. The decline in thymic CT attenuation with age is consistent with fatty infiltration of the gland. The measurements given in this report can serve as a basis for comparison to determine whether the thymus of a young child is normal or pathological.

A novel functional infrared imaging system coupled with multiparametric computerised analysis for risk assessment of breast cancer

ObjectiveWe evaluated a functional three-dimensional (3D) infrared imaging system (3DIRI) coupled with multiparametric computer analysis for risk assessment of breast cancer. The technique provides objective risk assessment for the presence of a malignant tumour based on automated parameters derived from a clinically known training set.MethodsFollowing institutional review board approval, we recruited 434 women for this prospective multicentre trial, including 256 healthy woman undergoing routine screening mammography with BI-RADS-1 results and 178 women with newly diagnosed breast cancer. This was a two-phase study: an initial training and calibration phase, followed by a two-armed blinded evaluation phase (52 healthy and 66 with breast cancer). 3DIRI data sets were acquired using a non-contact, no radiation system.ResultsThe sensitivity and specificity of functional infrared imaging in providing the correct risk for the presence of breast cancer were 90.9xa0% and 72.5xa0%, respectively. The area under the ROC curve was 86xa0%. Forty-two of the 60 (70xa0%) cancers in women correctly classified by the system as suspicious were smaller than 20xa0mm in size.ConclusionThe preliminary blinded results of this novel technology show sufficient performance of functional infrared imaging in providing risk assessment for breast cancer to warrant further clinical studies.Key Points• 3D functional infrared imaging (3DIRI) provides new metabolic signatures from breast lesions.• 3DIRI offers high sensitivity for risk assessment of breast cancer.• It also has reasonable specificity.• This initial experience warrants further evaluation in larger clinical trials.

Blind spots at oncological CT: lessons learned from PET/CT.

Abstract Improved accuracy in oncological computed tomography (CT) could lead to a decrease in morbidity and improved survival for oncology patients. Visualization of metabolic activity using the glucose analogue [18F]fluorodeoxyglucose (FDG) in combination with the high anatomic resolution of CT in an integrated positron emission tomography (PET)/CT examination has the highest sensitivity and specificity for the detection of primary and metastatic lesions. However, PET/CT costs are high and patient access is limited; thus CT remains the primary imaging modality in oncology patients. We have noted that subtle lesions are more easily detected on CT by radiologists with PET/CT experience. We aimed to provide a brief review of the literature with comparisons of multi-detector computed tomography (MDCT) and PET/CT in primary and metastatic disease with an emphasis on findings that may be overlooked on MDCT in cancer of the breast, lung, colon, and ovaries, and in melanoma, as well as thrombosis in oncology patients. We further reviewed our experience for illustrative comparisons of PET/CT and MDCT studies. Experience in interpreting conventional CT scans alongside PET/CT can help the reader develop an appreciation for the subtle appearance of some lesions on CT that might otherwise be missed. This could improve detection rates, reduce errors, and improve patient management.

Regulation of Cellular Heterogeneity and Rates of Symmetric and Asymmetric Divisions in Triple-Negative Breast Cancer

Differentiation events contribute to phenotypic cellular heterogeneity within tumors and influence disease progression and response to therapy. Here, we dissect mechanisms controlling intratumoral heterogeneity within triple-negative basal-like breast cancers. Tumor cells expressing the cytokeratin K14 possess a differentiation state that is associated with that of normal luminal progenitors, and K14-negative cells are in a state closer to that of mature luminal cells. We show that cells can transition between these states through asymmetric divisions, which produce one K14+ and one K14- daughter cell, and that these asymmetric divisions contribute to the generation of cellular heterogeneity. We identified several regulators that control the proportion of K14+ cells in the population. EZH2 and Notch increase the numbers of K14+ cells and their rates of symmetric divisions, and FOXA1 has an opposing effect. Our findings demonstrate that asymmetric divisions generate differentiation transitions and heterogeneity, and identify pathways that control breast cancer cellular composition.