karim ghazikhanlou sani

The breast, being a highly radiosensitive organ, is exposed to scattered radiation during brain computed tomography (CT) scans. This study aims to estimate the lifetime attributable risk (LAR) of female breast cancer resulting from brain CT scans.
90 women participated in this cross-sectional study. The LAR of breast cancer incidence was estimated based on health risks associated with exposure to low levels of ionizing radiation, as per the BEIR VII Phase 2 guidelines. The absorbed dose to the breasts was measured using thermoluminescence dosimeters, and the effective dose was calculated from the dose length product. All brain CT scans were conducted using a 16-slice scanner (SOMATOM EMOTION). Statistical analysis involved the Mann-Whitney test to compare the means of breast dose, effective dose, and LAR at a significance level of 0.05.
The mean age of the participants was 40 ± 22 years, with an age range of 10 to 83 years. The average dose to the breasts without and with shielding was 0.26 ± 0.19 mGy and 0.096 ± 0.13 mGy, respectively (P < 0.05). The effective dose was 0.85 ± 0.35 mSv without shielding and 0.79 ± 0.32 mSv with shielding (P = 0.539). The maximum LAR was 5.41 cases per 100,000 persons aged 10-15 years without shielding. The average LARs were 1.16 and 0.41 breast cancer incidences per 100,000 persons with and without shielding, respectively (P < 0.05).
The LAR of breast cancer in brain CT scans is significant and should not be overlooked. The use of breast shielding can substantially reduce this risk. Therefore, it is recommended to employ radioprotective shields to cover the breasts during this type of scan.

Pulmonary CT angiography (PCTA) is considered a standard method in the diagnosis of pulmonary embolism. In addition to incorrect diagnosis, the poor image quality in this method increases the radiation dose to the patient. This study aimed to investigate the effect of scan direction on image quality and absorbed dose in PTCA.

A total of 126 patients referred for PTCA by a 16-slice CT scanner (Siemens) were examined (63 persons for each scan direction). Two experienced radiologists in the field of CT angiography assessed the images. Volume CT dose index (CTDIvol) and dose length product (DLP) were used to evaluate the patient's dose.

The finding in caudocranial and craniocaudal scan directions was sequential as follows: the appropriate phase of imaging 96.8 and 95.2% (P = 0.73), the possibility of detecting embolism 100% and 98.4% (P = 0.36), the presence of superior vena cava artifact 30.2 and 22.2 percent (P = 0.31), motion artifact caused by breathing in the image 11.1 and 4.3 percent (P = 0.53) and the observation of contrast media in aorta 17.5 and 7.9 percentage was (P = 0.1). The average CTDIvol was 8.63 ± 3.53 and 8.66 ± 2.24 mGy (P = 0.04).

The scan direction does not significantly affect the image quality in PCTA, but the volume CT dose index in the caudocranial direction was lower than the craniocaudal.

This study aimed to compare the image quality and volume dose index of head CT scan between two adaptive statistical iterative reconstructions (ASIR) and the filtered back projection (FBP) algorithms. CT number, noise and signal to noise ratio(SNR) for white matter(WM), gray matter(WM), cerebrospinal fluid(CSF( and skull bone were investigated in brain CT scans of 60 patients. All images were reconstructed by FBP and ASIR 40% algorithms. A water phantom was also used to compare the average CT number; noise, signal-to-noise (SNR), and contrast-to-noise ratio (CNR) between algorithms under different acquisition parameters. Volume computed tomography dose index (CTDIvol) and (dose-length product) DLP were obtained from scanner software. Data were analyzed by T-test and Mann-Whitney statistical test with a significance level of less than 0.05. Image noise of gray matter, CSF and skull bone was significantly lower for ASIR algorithm (P<0.05). The difference in SNR for white matter and gray matter was not significant between the two algorithms but it was higher for CSF and bone for ASIR. In phantom study, Image noise, CTDIvol and DLP in both axial and spiral scan modes were higher for FBP algorithm (P<0.05). In addition, there was no significant difference in SNR and CNR between the two algorithms (P>0.05). ASIR algorithm reduces the dose and image noise in head CT scan compared to the filtered back projection. In addition, using ASIR algorithm the image noise does not increase with lower mA.

The concept of Quality Control (QC) is considered a regular method to control, stabilize, and inspect the function of the diagnostic imaging system. The objective of implementing the QC program is to produce high-quality images by applying a minimum dose of radiation based on the As Low As Reasonably Achievable (ALARA) principle. Therefore, this study aimed to evaluate the status of radiation protection in diagnostic radiology wards of educational hospitals affiliated with Hamadan University of Medical Sciences.

In order to implement the QC programs, standard QC tests were performed for 11 devices at educational hospitals affiliated with Hamadan University of Medical Sciences. A Sweden QC kit called Pirranha was used to carry out the QC tests of X-ray devices, and the dosimetry of controlled areas. Also, the measurement of ambient dose in different places was performed by Graetz dosimeter made in Germany.

Voltage Reproducibility, Exposure time reproducibility, tube outlet Linearity, and tube outlet reproducibility tests in all radiology departments which were in accordance with standard criteria were accepted; however, about 10% of the total filtration resulted in different centers needed to be corrected. In terms of radiation protection, 5% of the centers had problems related to warning signs, dimensions of radiology rooms were not standard at 7% of wards and also required protection was not sufficient at 9 percent. Moreover, there were problems with 12% of radiology centers in terms of dosimetry results and the efficiency of different parts of the radiology device.

QC programs performed by authorized companies are costly. But if these programs are done by qualified physicists in addition to reducing costs, we will see a significant increase in the accuracy and precision of the obtained results.

 Due to high prevalence of urolithiasis, endourologic interventions have increased for the treatment of
patients with urinary stones. During fluoroscopy-guided percutaneous nephrolithotomy (PCNL), the surgeon and the patient are exposed to X-ray and its harmful effects. This study aimed to assess the reduction of the radiation dose received by surgeons and patients after using a new shielding method.

 In this study, the dose of radiation exposure by the surgeon and patient during PCNL
under fluoroscopic procedure with conventional shielding methods was compared to a new shielding method designed by the researcher. For this purpose, shields and lead cones with a thickness of 0.5 mm were used. Also, to evaluate the dose of radiation received by surgeons and patients in different parts of the body, thermoluminescent dosimeters (TLD) were used.

 By using the new shielding method, a 37 ± 2% reduction was found in the dose exposure as compared
to the conventional shielding method. The maximum reduction in radiation dose was specified to the surgeon's
hands, while the lowest reduction in radiation dose was related to the surgeon's thyroid gland. The maximum and minimum reductions in radiation exposure for patients were specified to patients' feet and chest respectively.

 There is a significant difference between the total dose received by the surgeons and the patients
following the use of the new shielding method and the standard shielding method. The new shielding method can
reduce 37 ± 2% of the x-ray received by the patient and the surgeon during fluoroscopy-guided PCNL.

Radiotherapy is a main method for the treatment of breast cancer. This study aimed to measure the absorbed dose of thyroid gland using Gafchromic EBT2 film during breast cancer radiotherapy. In addition, the relationship between the absorbed dose and thyroid hormone levels was evaluated.

Forty‑six breast cancer patients, with the age ranged between 25 and 35 years, undergoing external radiotherapy were studied. The patients were treated with 6 and 18 MV X‑ray beams, and the absorbed thyroid dose was measured by EBT2 film. Thyroid hormone levels, thyroid‑stimulating hormone (TSH), triiodothyronine (T3), and thyroxin (T4), were measured before and after the radiotherapy. Pearson’s, Spearman’s, and Chi‑square tests were performed to evaluate the correlation between the thyroid dose and hormone levels.

The mean thyroid dose was 26 ± 9.45 cGy with the range of 7.85–48.35 cGy. There were not any significant differences at thyroid hormone levels between preradiotherapy and postradiotherapy (P > 0.05). There was a significant relationship between increased thyroid absorbed dose and changes in TSH and T4 levels (P < 0.05), but it was not significant in T3 level (P = 0.1).

Regarding the results, the thyroid absorbed dose can have an effect on its function. Therefore, the thyroid gland should be considered as an organ at risk in breast cancer radiotherapy.

Normoxic MAGIC-f polymer gels are established dosimeters used for three dimensional dose quantifications in radiotherapy. Nanoparticles with high atomic number such as gold are novel radiosensitizers used to enhance doses delivered to tumors. The aim of this study was to investigate the effect of gold nanoparticles (GNPs) in enhancing percentage depth doses (PDDs) within the MAGIC-f gel exposed to linear accelerator (linac) high energy photon beams. The MAGIC-f gel was fabricated based on its standard composition with some modifications. The PDDs in tubes containing the gel were calculated by using a common Monte Carlo code (Geant4) followed by experimental verifications. Then, GNPs with an average diameter of 15 nm and a concentration of 0.1 mM were embedded in the gel, poured into falcon tubes and irradiated with 18 MeV beams of an Elekta linac. Finally, similar experimental and Monte Carlo (MC) calculations were made to determine the effect of using GNPs on some dosimetric parameters of interest. The results of experimental measurements and simulated MC calculations showed a dose enhancement factor (DEF) of 1.12±0.08 and 1.13±0.04, respectively due to the use of GNPs when exposed to 18 MeV linac energies. The results indicated that the fabricated MAGIC-f gel could be recommended as a suitable tool for three dimensional dosimetric investigations at high energy radiotherapy procedures wherein GNPs are used.

There are critical areas in the mandible that should be considered during implant placement such as inferior alveolar canal, mental foramen, and the root of the adjacent tooth. Two-dimensional images obtained from periapical, panoramic, and conventional tomography are considered in the evaluation of implant placement and bone quality. Cone-beam computed tomography (CBCT) is a new imaging technique, which is superior to other methods from different aspects. Thus, we aimed to compare the accuracy of two different CBCT systems (i.e., Promax 3D and Newtom 3G) in measuring the anatomic distances in the mandible.
In this experimental study, six dry mandibles were used for measuring the width and height of mandible in six areas. Also, caliper was used as the gold standard and the distances were marked by barium sulfate as a radiopaque material. Then, the mandibles were scanned with the two CBCT systems, and the distances were measured by two observers (oral and maxillofacial radiologists) under homogenous conditions by using their respective software. The obtained results were evaluated by multivariate ANOVA and compared with the gold standard.
The accuracy of both CBCT systems (in all the three FOVs) was close to that of collies in measuring the height of mandible. The accuracy of Promax 3D was closer to collies in evaluating bacco-lingual width, and it was more accurate than Newtom 3G (in all the three FOVs; P The results of this study showed that Promax 3D and Newtom 3G techniques (in all the three FOVs) have millimeter precision and are capable of measuring the lengths and widths needed to establish the treatment plan.

Platelet activation and aggregation plays an essential role in the for-mation of coronary artery thrombosis. Nowadays, the Clopidogrel is administered oral-ly as an inhibitor of platelet aggregation. Due to the high price of the original brand of Clopidogrel (Plavix), an Iranian brand of Clopidogrel (Osvix) has been produced. This study was conducted to evaluate the effectiveness, side effects and acceptability of lo-cally available brand of Osvix as anti platelet tablet in coronary artery bypass grafting patients in comparison to the original brand (Plavix) by means of platelet aggregation indexes. This clinical study, was conducted at Heart Center of Ekbatan university Hospital in Hamadan in October 2011 to May 2012. In this study 80 patients undergo-ing coronary artery bypass grafting (CABG) were participated in two independent treatment groups. One group used the Iranian brand of Osvix and other one used the original brand (Plavix) as an inhibitor of platelet aggregation. To evaluate the effective-ness of these two in-inhibiting platelets regimens, blood samples were taken from the patients and platelet aggregation test was performed using Helena Biosiences Europe, PACKS4 aggrigometry system (made in France). Mean platelet-rich plasma amount for the Osvix and Plavix treatment group was 236.260 and 153.290 plt/µl respectively. Results showed a statistically significant difference in the rate of platelet-rich plasma by two above mentioned treatment groups. There was no observed statistical difference in side effects of two studied treatment groups. It must be noted that the effectiveness of Plavix tablet regimen as a platelet aggregation inhibitor in patients undergoing CABG was higher than the Osvix tablet treatment regimen. This study showed the Iranian brand of Clopidogrel (Osvix) is significantly different from the original brand (Plavix) in terms of performance factors in preventing platelet aggregation in patients undergoing coronary artery bypass grafting.

Objective. In recent decades many guidelines has been conducted by radiation protection organizations about radiation protection in dentistry. This study aims to evaluate the observance of these guidelines in educational clinics of all dental schools in Iran. Material and methods. In this cross-sectional study a self-administered questionnaire based on National Radiation Protection Board (NRPB) and European Commission guidelines was conducted. The radiology departments of all dental school (18 schools) surveyed in this study. The questionnaire was consisted of 3 sections including intraoral radiography, extraoral radiography and implementation of quality control programs. Results. In the case of the existence of radiation protection facilities (such as lead apron, thyroid shield and lead impacted walls), use of high speed films and existence of automatic processor in dental schools there was a proper condition. The main problem was related to lake of regular quality control and quality assurance programs. Digital radiography systems were employed in none of schools and only used occasionally in research purposes at some of them.Conclusions. This study emphasizes on the need for further consideration of radiation protection principles in dental school, especially on the field of quality control and quality assurance programs.

Sena-Graph syrup has recently been formulated by an Iranian pharmaceutical company for being used in bowel evacuation before radiography, colonoscopy and surgery. This study compares the efficacy, adverse effects and patient compliance of two bowel preparation regimens with castor oil and Sena-Graph syrup in of outpatients for Intravenous Urography (IVU). One hundred and fourteen consecutive outpatients were randomized to receive either the standard bowel preparation with 60 mL of castor oil or the test method with 60 mL of Sena-Graph syrup before IVU examination. Demographic data of patients and their prior bowel preparation experience were collected before the examination. Two radiologists, blinded to the method of bowel preparation, reviewed the radiographs and graded the bowel preparation. The compliance and acceptability of both regimens were assessed by using structured questionnaires filled by the patients. The Numbers, ages, weights and gender distribution of patients and their prior bowel preparation experience in the two groups did not differ significantly. The cleanliness scores for the castor oil and Sena-Graph group were 3.97 ± 0.971 and 4.87 ± 0.917, respectively. The results indicated that Sena-Graph syrup causes a better bowel cleansing compared castor oil. Adverse effects in Sena-Graph groups were significantly lower than the castor oil group. Acceptability of the regimen in patients who used Sena-Graph was higher than the other group. The Sena-Graph regimen is significantly more effective and better tolerated than of Castor oil regimen in bowel cleansing. The incidence and severity of the adverse effects from Castor oil was higher than Sena-Graph.

Application of contrast agents in diagnostic imaging is along with probability of adverse reactions and need to safety observance. In this study, the safety observance in using intravenous contrast media evaluated in four western provinces of Iran. A special questionnaire form was designed based on world standard guidelines and completed by radiology staffs in 40 governmental and private centers in four provinces including Kermanshah, Hamedan, Kordestan and Lorestan. Obtained data was analyzed by independent t and χ 2 tests. The results show in the most centers there are not any uniform and coordinate protocol for using preventive drugs and access to life saving drugs and equipments. The results demonstrate a difference between governmental and private centers in existing of specific protocol for dealing with contrast reactions and also in some equipments and drugs like Canulla or Adrenaline (p =0.001, p = 0.001 and p=0.003 respectively). According to the results, it seems publication of special coordinate guidelines and improvement of equipments are necessary. [ZJRMS, 12(2): 45-48]