X-ray computed tomography (CT) requires an optimal compromise between image quality and patient dose. While high image quality is an important requirement in CT, the radiation dose must be kept minimal to protect the patients from ionizing radiation-associated risks. The use of probes based on gold nanoparticles (AuNPs) along with active targeting ligands for specific recognition of cancer cells may be one of the balanced solutions. Herein, we report the effect of folic acid (FA)-modified AuNP as a targeted nanoprobe on the contrast enhancement of CT images as well as its potential for patient dose reduction. For this purpose, nasopharyngeal KB cancer cells overexpressing FA receptors were incubated with AuNPs with and without FA modification and imaged in a CT scanner with the following X-ray tube parameters: peak tube voltage of 130 KVp, and tube current-time products of 60, 90, 120, 160 and 250 mAs. Moreover, in order to estimate the radiation dose to which the patient was exposed during a head CT protocol, the CT dose index (CTDI) value was measured by an X-ray electrometer by changing the tube current-time product. Raising the tube current-time product from 60 to 250 mAs significantly increased the absorbed dose from 18 mGy to 75 mGy. This increase was not associated with a significant enhancement of the image quality of the KB cells. However, an obvious increase in image brightness and CT signal intensity (quantified by Hounsfield units [HU]) were observed in cells exposed to nanoparticles without any increase in the mAs product or radiation dose. Under the same Au concentration, KB cells exposed to FA-modified AuNPs had significantly higher HU and brighter CT images than those of the cells exposed to AuNPs without FA modification. In conclusion, FA-modified AuNP can be considered as a targeted CT nanoprobe with the potential for dose reduction by keeping the required mAs product as low as possible while enhancing image contrast.

The presence of primary or metastatic cancer within a hernia sac is uncommon, which occurs in fewer than 0.5% of all surgically excised sacs (1). This article demonstrates a case of a metastatic pancreatic cancer, one of which presented as an inguinal hernia with fever of unknown origin (FUO). A 44-year-old male presented with a history of FUO and a painful inguinal hernia. Inguinal canal exploration revealed a mass like lesion in the sac without any correlation to abdominopelvic viscera. Postoperative evaluations confirmed moderately differentiated metastatic adenocarcinoma from pancreatic origin.

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Purpose: In this study, we retrospectively evaluated chest Computed Tomography (CT) imaging manifestations of the patients with Coronavirus Disease 2019 (COVID-19) to simplify prompt early diagnosis of disease and speed up needed actions for infected patients. Materials and Methods: Totally, 75 patients who laboratory confirmed COVID-19 pneumonia were enrolled in this study. CT images, demographic and some clinical data of all patients were collected and analyzed retrospectively. Furthermore, for comparison, the patients were divided into two groups as follows: the young and middle-aged group (< 60 years old) and the elderly group (≥ 60 years old). Results: Based on the evaluation of CT images, 33 patients (44%) showed Ground-Glass Opacity (GGO), 15 patients (20%) showed consolidation, 24 patients (32%) showed mixed GGO and consolidation, 2 patients (2.6%) had bronchial wall thickening, 10 patients (13.3%) had a crazy paving sign, 35 patients (46.6%) had air bronchogram and, 7 patients (9.3%) had cavitation and 2 patients (2.6%) had a tree in the bud. CT images of 3 patients (4%) were normal. In terms of out of lung changes, lymphadenopathy was observed in one patient (1.3%), pleural effusion in 12 patients (16%), and pericardial effusion in 2 patients (2.6%). Lesions were found predominantly in the peripheral (57.3%) and the lower lung region (60%). Conclusion: CT images of the COVID-19 patients showed various aspects, mainly GGO, consolidation, mixed GGO and consolidation, and air bronchogram. Lesion distribution was predominantly in lower lung region, bilateral and peripheral. Pleural effusion and multiple lobe involvement were significantly higher in the elderly group than that of the young and middle-aged group.

The aim of the present study is to fabricate a new shield with an optimal combination of copper and bismuth to protect the eyes in the head computed tomography (CT) examinations without compromising image quality. Radiation shields with different compositions were constructed. Computed Tomography Dose Index phantom was used to evaluate the effectiveness of shields in dose reduction and their impact on image quality quantitatively. The shield that caused the least noise in the phantom study was selected for human study. The 10%Bi-90%Cu shield had the least effect on increasing the image noise, and also no remarkable artifact was seen in the CT image of the phantom. The patient study showed that only in 25% of the study group the artifact was observed so that it did not distort the interpretation of the image. It can be concluded that the 10%Bi-90%Cu shield is flexible and durable and would be safely used in the clinic to reduce the eye radiation dose in head CT imaging without compromising image quality.