Iranian Journal of Radiology
Volume:3 Issue: 3, Spring2006

Background/ Radiofrequency ablation (RFA) is emerging as a new therapeutic technique for unresectable hepatic malignancies. We report our experience with the use of this method for the first time in Iran. Patients and Eighteen patients with primary or metastatic hepatic malignancies, which were considered not suitable for surgical resection, were included in our study. RFA was performed via the percutaneous ultrasound–guided method, under general anesthesia, by an interventional radiologist. Patients were followed prospectively with contrast–enhanced CT or ultrasonography, and tumor marker serum levels 1, 3 and 6 months after RFA. RFA was used to treat 26 tumors (diameters of 12-70 mm). These tumors included hepatocellular carcinoma in three cases and metastatic carcinoma in 23 cases. Three patients had complications: two bilomas and one abscess in the right lobe. At follow-ups, tumor recurred at the site of RFA in four tumors, all of which were over 4 cm in diameter. RFA is a procedure with the potential to be safe and effective for treating unre-sectable liver tumors.

Literature review indicates that desmoid tu mors are exceedingly common in familial adenomatous polyposis (FAP), where the comparative risk is 852 times that of the general population. Prior abdominal surgery has been found in as many as 68 % of FAP patients with abdominal desmoid. Fifty-five percent develop these lesions within 5 years of surgery. We de-scribe a 45-year-old pa tient with Gardner''s syndrome complicated by a desmoid tumor 2 years after he had a prophy lactic colectomy.

Background/ Mammographic differentiation of benign lesions from malignancies is a difficult task. We developed an artificial neural network (ANN) as a diagnostic aid in mammography using radiographic features as input. A three-layered ANN was used to differentiate malignant from benign findings in a group of patients with proven breast lesions on the basis of morphological data extracted from conventional mammograms. Our database included 122 patient records on 14qualitative variables. The database was randomly divided into training and validation samples including 82 and 40 patient records, respectively, to construct the ANN and validate its performance. Sensitivity, specificity, accuracy and receiver operating characteristic curve (ROC) analysis for this method and the radiologist were compared. Our results showed that the neural network model was able to correctly classify 30 out of 40 cases presented in the validation sample. Comparing the output with that of the radiologist, showed a reasonable diagnostic accuracy (75%), a moderate specificity (64%) and a relatively high sensitivity (89%). A diagnostic aid was developed that accurately differentiates malignant from benign pattern using radiological features extracted from mammograms.

Background/ To obtaining reference values for intima–media thickness (IMT) of the carotid arteries in the Iranian subjects without any known atherosclerosis risk factors. Patients and A total of 400 subjects (146 male and 254 female, mean age 36.3±14 years in men and 35.9±12 years in women), with normal body mass index and no history or evidence of cardiovascular or peripheral vascular disease, hypertension, diabetes, thyroid diseases or smoking were examined. IMT was measured on a longitudinal ultrasound image of the carotid artery. Mean thickness was evaluated for the right common carotid (RCCA), right internal carotid (RICA), left common carotid (LCCA) and left internal carotid (LICA). The mean value of carotid IMT was 0.38±0.11 in women and 0.41±0.13 in men. For different age groups, the lowest mean thickness was 0.305±0.045, seen in the RCCA among 20–29-year-old cases, and the highest was 0.645±0.125, seen in the LICA of cases over 60. The mean thickness was higher in men than in women, in all four locations (all p values< 0.02 Linear regression models for prediction of IMT by age, were separately done in different groups of anatomical location and gender, and all models’ R2 were higher than 0.5. Mean IMT in RCCA, RICA, LCCA and LICA in both genders and different age dec-ades was lower than many reports, which may be due to ethnic factors or different inclusion criteria. Reference values of carotid IMT increase significantly with age and IMT is higher in men than in women.

A 40-year-old male patient was referred with a history of exertional shortness of breath since a few years ago. Spirometric findings were consistent with a restrictive ventilatory defect. Plain chest radiographs showed sand-like opacities throughout both lungs predominantly in the lower zones. Computerized tomographic scan revealed diffuse bilateral calcified fine nodular pattern. The diagnosis of pulmonary alveolar microlithiasis was confirmed by transbronchial biopsy.

Background/ Normal values for CT orbital measurements, which appear in refer-ence books, may not be applicable to the Iranian population. The purpose of this study was to determine normal values in an Iranian population and compare them with published standards. Patients and Orbital CT scans from adults were studied from March 2003 to June 2005. The scans had been ordered for complaints unrelated to craniofacial and orbital abnormalities, and in all of them, the presence of any pathology of the bones, globe and orbit were excluded. Four hundred CT scans (134 females, 266 males, mean age 36.9±16.7 years) were studied. The normal interorbital distance at the posterior border of the frontal process of the maxilla measured from 1.8 to 3.5 cm (mean 2.30) in men and 1.5 to 3.2 cm (mean 2.17) in women (p<0.01). At the level of orbital equator, the mean interorbital distance was 2.46 cm in women (range 1.7-3.2) and 2.65 cm in men (range 2-3.4) (p<0.01). Compared with the cor-responding values of interorbital standards, all these measurements were smaller. Normal values of orbital measurements are smaller and more varied in Iranian population and these values must be used when interpreting CT scans of the orbit.

We describe a 12-year-old girl with lymphocytic interstitial pneumonia (LIP) with common variable immunodeficiency (CVI). The patient was under closely followed during acute and remission phases, especially in her last year of life. We believe this case is an informative example of LIP in Iran.

Background/ The risks of low-dose ionizing radiation from radiology and nuclear medicine are not clearly determined. Effective dose to population is a very important factor in risk estimation. The study aimed to determine the effective dose from diagnostic radiation medi-cine in a northern province of Iran. Data about various radiologic and nuclear medicine procedures were collected from all radiology and nuclear medicine departments in Mazandaran Province (popu-lation = 2,898,031); and using the standard dosimetry tables, the total dose, dose per examination, and annual effective dose per capita as well as the annual gonadal dose per ca-pita were estimated. 655,730 radiologic examinations in a year’s period, lead to 1.45 mSv, 0.33 mSv and 0.31 mGy as average effective dose per examination, annual average effective dose to member of the public, and annual average gonadal dose per capita, respectively. The frequency of medical radiologic examinations was 2,262 examinations annually per 10,000 members of population. However, the total number of nuclear medicine examinations in the same period was 7074, with 4.37 mSv, 9.6 Sv and 9.8 Gy, as average effective dose per examination, an-nual average effective dose to member of the public and annual average gonadal dose per caput, respectively. The frequency of nuclear medicine examination was 24 examinations annu-ally per 10,000 members of population. The average effective dose per examination was nearly similar to other studies. However, the average annual effective dose and annual average gonadal dose per capita were less than the similar values in other reports, which could be due to lesser number of radiation medicine examinations in the present study.

Angiomyolipoma (AML) is the most common benign renal tumor. It is composed of an abnormal collection of 3 primary components: unusual abdominal blood vessels, clusters of adipocytes and sheets of smooth muscle. CT is the preferred imaging technique for diagnosing and characterizing AMLs. AMLs typically have a benign course, but patients occasionally present with complications, such as sudden pain or hypotension secondary to spontaneous hemorrhage in the tumor. If the patient is symptomatic, the tumor grows rapidly or is >4 cm, angiography and selective arterial embolization or renal-sparing surgical excisions of the tumor are the treatment of choice. Patients with AMLs treated with embolization generally have a favorable outcome.