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MR imaging showed higher per-lesion sensitivity than multidetector CT and should be the preferred imaging modality for the diagnosis of HCCs in patients with chronic liver disease.

Low-dose CT was noninferior to standard-dose CT with respect to negative appendectomy rates in young adults with suspected appendicitis. (Funded by GE Healthcare Medical Diagnostics and others; ClinicalTrials.gov number, NCT00913380.).

Purpose: Radiation-induced pulmonary fibrosis (RIPF) is a late side effect of thoracic radiotherapy. The purpose of our study was to gain further insight into the development of RIPF.Experimental Design/Results: Here, we observed that irradiation of mouse lungs induced collagen deposition, particularly around blood vessels, in the early phase of RIPF. Such deposition subsequently became evident throughout the irradiated tissues. Accompanied by the collagen deposition, vascular EndMT (endothelial-to-mesenchymal transition) began to develop in the early phase of RIPF, before the appearance of EMT (epithelial-tomesenchymal transition) of alveolar epithelial (AE) II cells in the substantive fibrotic phase. Concomitant with the EndMT, we detected vascular endothelial cell (EC)-specific hypoxic damage in the irradiated lung tissues. In human pulmonary artery endothelial cells (HPAEC), the radiation-induced EndMT via activation of TGFb-R1/Smad signaling was dependent on HIF1a expression. A novel HIF1a inhibitor, 2-methoxyestradiol (2-ME), inhibited the irradiation-induced EndMT via downregulation of HIF1a-dependent Smad signaling. In vivo, 2-ME inhibited the vascular EndMT, and decreased the collagen deposition associated with RIPF. Furthermore, HIF1a-related EndMT was observed also in human RIPF tissues.Conclusions: We provide the first evidence that an EndMT occurs in RIPF development and that the EndMT may be effectively inhibited by modulating vascular EC-specific hypoxic damage.

Summary In experimental mouse tumors, high-dose irradiation in a single fraction caused progressive increase in tumor cell death in 2 to 5 days. Such delayed tumor cell deaths appeared to be due to radiation-induced deterioration of intratumor microenvironment characterized by profound reduction of blood perfusion and increase in hypoxia. Similar secondary and indirect cell death may play an important role in clinical stereotactic body radiation therapy and stereotactic radiation surgery. Purpose The purpose of this study was to reveal the biological mechanisms underlying stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS). Methods and Materials FSaII fibrosarcomas grown subcutaneously in the hind limbs of C3H mice were irradiated with 10 to 30 Gy of X rays in a single fraction, and the clonogenic cell survival was determined with in vivo—in vitro excision assay immediately or 2 to 5 days after irradiation. The effects of radiation on the intratumor microenvironment were studied using immunohistochemical methods. Results After cells were irradiated with 15 or 20 Gy, cell survival in FSaII tumors declined for 2 to 3 days and began to recover thereafter in some but not all tumors. After irradiation with 30 Gy, cell survival declined continuously for 5 days. Cell survival in some tumors 5 days after 20 to 30 Gy irradiation was 2 to 3 logs less than that immediately after irradiation. Irradiation with 20 Gy markedly reduced blood perfusion, upregulated HIF-1α, and increased carbonic anhydrase-9 expression, indicating that irradiation increased tumor hypoxia. In addition, expression of VEGF also increased in the tumor tissue after 20 Gy irradiation, probably due to the increase in HIF-1α activity. Conclusions Irradiation of FSaII tumors with 15 to 30 Gy in a single dose caused dose-dependent secondary cell death, most likely by causing vascular damage accompanied by deterioration of intratumor microenvironment. Such indirect tumor cell death may play a crucial role in the control of human tumors with SBRT and SRS.

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Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. RSNA, 2017 Online supplemental material is available for this article.

The value of image based texture features as a powerful method to predict prognosis and assist clinical management in cancer patients has been established recently. However, texture analysis using histograms and grey-level co-occurrence matrix in pancreas cancer patients has rarely been reported. We aimed to analyze the association of survival outcomes with texture features in pancreas head cancer patients. Eighty-eight pancreas head cancer patients who underwent preoperative CT images followed by curative resection were included. Texture features using different filter values were obtained. The texture features of average, contrast, correlation, and standard deviation with no filter, and fine to medium filter values as well as the presence of nodal metastasis were significantly different between the recurred (n = 70, 79.5%) and non-recurred group (n = 18, 20.5%). In the multivariate Cox regression analysis, lower standard deviation and contrast and higher correlation with lower average value representing homogenous texture were significantly associated with poorer DFS (disease free survival), along with the presence of lymph node metastasis. Texture parameters from routinely performed pre-operative CT images could be used as an independent imaging tool for predicting the prognosis in pancreas head cancer patients who underwent curative resection.