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The nodular thyroid diseas is one of the most common disturbances o the thyroid gland wheras malignant tumors are among the most unusual entities of it. Not only differentiation of these two spectra but also the problems to achieve early diagnosis and treatment, have been a matter of concern, research, and controversy. Two hundred patients were assessed at the Cancer institute of Imam Khomeini Hospital as a retrospective research, considering the aim of evaluating and comparing the results of ultrasound and fine needle aspiration cytology with the postoperative histopathologic report. The ultrosound findings included location, number, size, feature, echogenicity, and presence of calcification; and those of the fine needle aspiration cytology consisted of benign, malignant, and suspicious samples. The cases mentioned as recurrent cancer or metastases of previous thyroid cancer were omitted from the study. In this research we found a sensitivity, specificity, accuracy of 92.3% , 76.4% and 88.1%, respectively , for fine needle aspiration cytology and also showed that the sensitivity and accuracy of fine needle aspiration cytology in diagnosis of malignant lesions of solid nodules was more than in cystic or mixed nodules of thyroid. Moreover, the incidence of false negatives in malignant cases of the studied sample was 7.7% (11/43). This rate was very higher in mixed and cystic lesions compared to benign ones (20% versus 5.7%). According to ultrasound findings, we showed that micro-calcificantion had a significant higher frequency in malignant nodules in comparision with the benign ones (4% in benign lesions versus 35% in malignant ones). The rate of malignancy in solid lesions revealed a significant increment compared to cystic and mixed nodules (P

CT image quality has been affected by many factors such as KVP, ma, exposure time, alogorithm and section thickness. Gantry tilt has the main role in visualization of the temporal bone anatomic structures. In this study, we tried to optimize these factors to determine the best gantry tilt. This study was performed on the human skull phantom and then extended to 15 patients. The phantom was made by inserting a normal human dry skull into a water- filled radiolucent cylindrical container. A lateral scout view was obtained and the OMBL (orbitomeatal baseline) was used as the anatomical landmark.The phantom was scanned in 9, 15 , 30 , 45, 60 , 75, 90,105, 120 degree in relation to OMBL and 24 important anatomical structures were evaluated in each. Kilovoltage of 80, 120, 140 millimeters of 40, 70, 100, 120, 140, 170, 200, 240, exposue time of 2, 2, 4 second , algorithm of smooth, soft, standard, detail, bone adge and section thickness of 1.5, 3,5 millimeter were studied separately. In general, most of the anatomical structures are well demonstrated in 0 or 30 degrees of axial scans and 90 or 105 degrees in coronal scans. The best imaging techniques in Kv=140, Ma=100, S=2 seconds, algorithm of edge or bone, section thickness of 1.5 millimeter for small structures and 3 millineters for greater ones.The best 3-D image is provided by 3 millimeter slice thickness without overlapping but they couldn’t assist in diagnosis of our patient’s diseases. In indirect sagital reformatted images, the greater anatomical structures such as vestibule and cochlea are also shown, but they are recommended due to the slight degradation of the images and some loss of resolution.

Following failure of systemic chemotherapy, transarterial chemoembolization (TACE) is an available method to control unresectable liver metastases from colorectal carcinoma (CRC). The aim of present study was to evaluate the efficacy of chemoembolization for inoperable metastatic liver lesions from CRC. Forty-five CRC patients with liver metastases resistant to systemic chemotherapy were enrolled in our study. For each patient, three session of TACE were conducted with 45 days interval. A combination of mitomycin, doxorubicin, and lipiodol were used for TACE. A tri-phasic computed tomography scan and biochemical laboratory tests were performed for all patients at baseline and 30 days after each TACE. Image analysis included measurement of lesion diameters as well as contrast enhancement. Eleven patients deceased before completing three session and the final analyses were performed on the remaining 34 patients. Evaluation of a total 93 lesions in all patients after chemoembolization sessions revealed a 25.88% reduction in anteroposterior (AP) diameter, 33.92% transverse (T) diameter, and 42.22% in product of APxT diameter of lesions (P<0.001 for all instances). CT scan showed a total disappearance of 33% of lesions and evident reduction in contrast enhancement in 16% of them. There were no changes in contrast enhancement in 51% of lesions. Evaluation of single largest lesion in each patient revealed 57.32% reduction in AP diameter, 59.66% in T diameter, and 62.17% in product of APxT diameters (P<0.001 for all diameters). TACE offers a viable option for CRC patients with unresectable liver metastases by significantly reducing lesion size and contrast enhancement.