Retrospective case-control study to predict a potential underlying appendiceal tumor in an acute appendicitis context based on a CT-scoring system.

OBJECTIVES: To assess CT signs to discriminate an appendiceal tumor versus a non-tumoral appendix in an acute appendicitis context. METHODS: A 10-year bicentric retrospective case-control study was performed in adults. Patients with a histopathological appendiceal tumor and appendicitis were paired for age and sex with patients with non-tumorous appendicitis (1/3 ratio, respectively). Two senior radiologists blindly analyzed numerous CT findings with final consensus to perform univariate and multivariate statistical analyses. A diagnostic CT scan score was calculated with a bootstrap internal validation. Reproducibility was assessed based on the kappa statistic. RESULTS: A total of 208 patients (51 +/- 21 years; 114 males) were included (52 patients in the tumor group and 156 in the non-tumor group). In the multivariate analysis, an appendicolith and fat stranding were protective factors with OR = 0.2 (p = 0.01) and OR = 0.3 (p = 0.02), respectively, while mural calcifications (OR = 47, p = 0.0001), an appendix mass (OR = 7.1, p = 0.008), a focal asymmetric wall abnormality (OR = 4.9, p = 0, 001), or a ≥ 15 mm diameter (OR = 3.5, p = 0.009) were positive predictive factors of an underlying tumor. Using a ≥1 cut-off, our diagnostic score had an AUC = 0.87 (95 % CI, 0.82-0.93) and a positive likelihood ratio = 13.5 (95 % CI, 6.7-27.1). CONCLUSION: We developed a reliable scoring system based on CT findings, which is highly predictive of an underlying appendiceal neoplasm in an appendicitis context using a ≥1 cut-off.

Breast tomosynthesis: What do we know and where do we stand?

Digital breast tomosynthesis (DBT) is a new imaging technology that addresses the limitation caused by overlapping structures in conventional two-dimensional digital mammography owing to the acquisition of a series of low-dose projection images. This unique technique provides a dual benefit to patients screened for breast cancer. First, DBT increases the cancer detection rate mostly by highlighting architectural distortions and allowing better assessment of masses shape and margins. Second, DBT helps reduce recall rate by discarding asymmetries related to overlapping tissue. However, DBT is not included in the majority of cancer screening programs worldwide. Several issues still need to be addressed such as over-diagnosis and over-treatment, lack of reduction of interval breast cancer, quality control and storage, and radiation dose. In the diagnostic setting, DBT increases the diagnostic accuracy and reduces the number of indeterminate lesions in symptomatic women. Its aforementioned performances regarding asymmetries, masses and architectural distortions allow reducing the number of additional views while working-up a screening-detected lesion. Tumor size is also better assessed at DBT as well as multicentricity, two significant benefits in the staging of breast cancer. Finally, DBT allows a better analysis of scars and helps reduce the rate of indeterminate findings after surgery. Although somewhat limited by high breast density, DBT globally outperforms digital mammography in both screening and diagnostic breast imaging. Additional research is however needed, particularly on relevant screening outcomes. This review describes the main performances of breast DBT in breast cancer screening and diagnosis and the resulting consequences in both settings.

Detection and characterization of focal liver lesions with ultra-low dose computed tomography in neoplastic patients.

PURPOSE: The purpose of this study was to evaluate and compare the diagnostic accuracy of ultra-low dose (ULD) computed tomography (CT) with that of standard dose (STD) CT in the detection and characterization of focal liver lesions in neoplastic patients. MATERIALS AND METHODS: A total of 177 neoplastic patients who underwent two abdominopelvic CT examinations (one with STD and one with ULD protocol) for suspected focal liver lesions were included. There were 103 men and 74 women with a mean age of 64.6±14.4 (SD) (range: 19-93 years). Raw data images were reconstructed with iterative reconstruction. Dose length product (DLP) and effective dose for both protocols were compared. Images were independently evaluated by two radiologists for image-quality, diagnostic quality, and confidence level. RESULTS: DLP for STD and ULD were respectively 215.4±92.0 (SD) mGy·cm (range: 76-599mGy·cm) and 90.7±37.2 (SD) mGy·cm (range: 32-254mGy·cm). Effective dose for STD and ULD CT were 3.2±1.4 (SD) mSv (range: 1.1-9.0mSv) and 1.4±0.6 (SD) mSv (range: 0.5 to 3.8mSv). A significant 58% dose reduction was found between the two protocols (P<0.05). Noise, signal-to-noise ratio and contrast-to-noise ratio were higher with the ULD protocol compared to the STD protocol. No differences in subjective image quality were found between the two protocols. STD CT revealed focal liver lesions in 80 patients and ULD CT in 70 patients (P<0.05). ULD protocol resulted in a sensitivity of 83.8% and a specificity of 96.9% for the diagnosis of focal liver lesions although it was not able to characterize them properly (Se 62.5%). CONCLUSION: STD CT helps detect and characterize focal liver lesions. ULD CT offers good performance to detect focal liver lesions but with lower performances for lesion characterization.