Background/Objective: Approach to patients with acute right lower quadrant pain remains a clinical dilemma. Decreasing the risk of negative appendectomies is one of the major goals surgery units intend to achieve. This study has been conducted to determine the accuracy of non-contrast focused appendiceal COMPUTED TOMOGRAPHY (CT) in preoperative diagnosis of acute appendicitis. Patients and Methods: During a period of three months, 50 consecutive adult and adolescent patients who were clinically diagnosed as acute appendicitis were included in this study. Focused non-enhanced appendiceal SPIRAL COMPUTED TOMOGRAPHY (CT) was performed for all patients, preoperatively. Two radiologists who were unaware of the surgical findings assessed the CT scans. Results: After the operation and pathologic assessment, eight patients with negative appendectomy were found. The sensitivity of CT was 0.71 and 0.83 according to the interpretations of the first and second radiologists, respectively. Moreover, its specificity was 0.88 and 0.75 according to the first and second radiologists' reports, respectively. Conclusion: In patients with clinically diagnosed acute appendicitis, relying on abdominal CT is not helpful.

Background and Aims: The evaluation of absorbed dose received by patients could give useful information for radiation risk estimation. This study was performed to compare the entrance skin dose received by patients in cone beam COMPUTED TOMOGRAPHY (CBCT), conventional and SPIRAL COMPUTED TOMOGRAPHY (CT).Materials and Methods: In this experimental study, 81 calibrated TLD chips were used. the TLD chips were placed on facial, thyroid and end of sternum skin surface in patients referred for CT of the paranasal sinuses (3 TLD chips for each area) to estimate the absorbed dose received by central part of radiation field, thyroid and out of field areas, respectively. The data were analyzed using one-way ANOVA and Tukey tests.Results: The dose delivered to the center of irradiated field was about 0.79±0.09 mGy in CBCT technique compared with 16.31±3.71 and 18.84±4.12 mGy for SPIRAL and conventional CT, respectively. The received dose by the out of field areas was about 54 percent of central area dose. There was statistical significant relationship between the imaging modalities and absorbed dose received by patients (P=0.016). The least absorbed dose was for CBCT and the greatest dose was for conventional CT imaging technique.Conclusion: The dose delivered to central area of irradiated field in conventional and SPIRAL CT imaging modalities was about 24 times greater than of that in CBCT. Also, the highest received dose was for central area of radiated field and the lowest dose was for the out of field areas.

Introduction: The use of sophisticated radiographic techniques is absolutely necessary in dentistry.The use of these techniques exposes the sensitive organs of head and neck to x-rays. The aim of the present study was to investigate the absorbed dose of the thyroid gland in conventional SPIRAL and SPIRAL COMPUTED TOMOGRAPHY techniques.Materials and Methods: In this experimental study, 10 TLD GR-200 circular dosimeters (Thermoluminans Detector) were used in male RANDO-like phantom (head and neck segment, i.e. the first 10 segments) in order to determine the radiation dose absorbed by the thyroid gland. Then SPIRAL COMPUTED tomographies were provided from the anterior and posterior regions of the maxilla and mandible along with a lateral Scout view as a guide. Conventional SPIRAL tomographies were prepared from the maxilla, mandible and both jaws with a panoramic radiograph as a guide. Data was analyzed using Kruskal-Wallis and Mann-Whitney tests using SPSS 11.5 (a=0.05).Results: The highest and lowest thyroid gland absorbed doses were observed with COMPUTED TOMOGRAPHY of both jaws and conventional SPIRAL TOMOGRAPHY of the anterior maxilla, respectively (5.92±0.01 and 0.79±0.01 mSiv). The mean amount of the absorbed dose by the thyroid gland was lower in the conventional SPIRAL TOMOGRAPHY compared to COMPUTED TOMOGRAPHY. The two techniques revealed significant differences in the absorbed doses except for conventional SPIRAL TOMOGRAPHY in the posterior and anterior regions of the mandible (p value=0.276).Conclusion: According to results of the present study, the absorbed dose of the thyroid gland in the conventional SPIRAL TOMOGRAPHY in different regions of the jaws was less than CT scan techniques. As a result, it appears the use of conventional SPIRAL TOMOGRAPHY is preferred over CT scans in limited regions where three-dimensional and cross-sectional views are required.

Background and Aim: For certain surgical procedures (e.g. placement of implants), an accurate localization of the mandibular canal is of utmost importance to avoid injuries to the neurovascular bundle. The aim of the present study was to evaluate, the accuracy of SPIRAL TOMOGRAPHY for the localization of the mandibular canal.Material and Methods: By means of the cranex tome multifunctional unit (orion corporation Sordex, Finland), tomographic slices were taken at 4 different locations in each posterior mandible segments (distal to the mental foramen). The mandibles were then sectioned at these 4 sites with a specialize designed drill. The following 4 measurements were preformed both on the tomograms (A, B, C and D) and the bone sections (A’, B’, C’ and D’) at the 4 sites.Results: We found an average mean difference of 0.02 mm with a standard deviation of 0.33 mm. The reported data showed that %95.2 of cases are in ±0.5 mm and %98.4 of cases are in ±1 mm (overestimate and underestimate).Conclusion: SPIRAL TOMOGRAPHY using the cranex tome multifunctional x-ray unit provides accurate information and sufficient detail for preoperative planning of implant in the posterior mandible.

Background and Objectives: Both 2-dimentional and 3-dimentional computerized tomographies (CT) are useful for measurement of tissue volume and reconstruction of maxillofacial areas. The aim of this study was to compare these two modalities for volumetric measurement of maxillary sinus. Materials and Methods: This study was done on four human skulls obtained from the collections of department of anatomy. Sinus walls were sealed by rose wax and then actual volume of the sinuses were measure by water injection, as our gold standard. This measurement was performed three times for each sinus and the mean values of measurements were calculated. The skulls were also assessed radiologically by two dimensional and three dimensional CT. The results were compared by statistical methods.Results: No significant difference was found between two-dimensional and three dimensional CT measurement with actual sinus volume (P>0.05). The difference between two aforementioned CT methods was also insignificant (P>0.05).Conclusion: Volumetric measurements of maxillary by sinus two-dimensional and three-dimensional reconstructed image methods are reliable and accurate.

Background: Adhesive intestinal obstruction is a common and potentially lethal complication after surgical interventions in the abdomen. Radiologic imaging is the main diagnostic method. Objective: This study aims to analyse the diagnostic value of SPIRAL COMPUTED TOMOGRAPHY with a novel method (n = 54). Material and Methods: In this multidirectional cohort study, we present the data with non-parallel (historical) control. This study included the analysis of results of patients with a diagnosis of intestinal obstruction (n = 54) who were admitted to the surgical departments of the City Clinical Hospitals (Ufa city) from 2013 to 2019; the patients’ examination methods included COMPUTED TOMOGRAPHY with conventional enhancement. The proposed novel enhancement method was implemented by ingesting a mixture containing 50 ml of the contrast Unigexol (300 mg) in 1. 0 L cold mineral carbonated water, and COMPUTED TOMOGRAPHY (CT) was performed during 40 min after ingesting the contrast meal. Further, the patients with suspected obstruction in the colon were administered a pre-prepared contrast enema with a decoction of leaves of smoke-tree (100 g), chamomile flowers (100 g) and calendula flowers (100 g). Additionally, CT was performed. Results: Obstruction was conservatively stopped in 24 (44. 4%) patients of the main group. Remaining 30 (55. 6%) patients from the main group were operated with minimal surgical access in the early stages. Conclusion: Owing to early diagnosis of intestinal obstruction and application of the phytocomposition during the examination, exerting various effects such as antispasmodic, analgesic, disinfectant, bactericidal, cicatrising, choleretic, tanning and decongestant, unnecessary surgical interventions were prevented.

Background: Multislice COMPUTED TOMOGRAPHY (CT) angiography is a robust imaging method for noninvasive assessment of coronary artery diseases، which is associated with high radiation dose. Having knowledge of the various parameters used to estimate the dose plays an important role in increasing the understanding of dose delivered to patients and help operators and technologist to reduce the dose. In this research، the amounts of Weighted COMPUTED TOMOGRAPHY Dose Index (CTDIW) for coronary CT angiography exams were measured in Isfahan city, IranMethods: To calculate the dose، an ionization chamber (Piranha، X-ray Analyzer، RTI Electronics and Sweden) and acrylic body phantom were used. Common conditions of coronary CT angiography used in two centers were applied for this project. Finally, CTDIW of all the scans were calculated using the related formulation.Findings: The amount of mean CTDIW for calcium score exams in Sina and Alzahra hospitals were 0.468±0.190 and 2.354±0.610 mGy, respectively (P = 0.007); and for coronary CT angiography scans in Sina and Alzahra hospitals were 6.221±1.290 and 5.299±0.840 mGy, respectively (P=0.860).Conclusion: CTDIW for the calcium score was significantly different in the two centers، but there was not significant difference in the two centers for coronary CT angiography scans. In this study، the amount of CTDIW was much lower than the measured in other centers. Since scan parameters have an important effect on the dose value، training and precision of technologist result in dose reduction and patient radiation protection.

Introduction: Our aim was to determine the incidence and spectrum of significant alternate or incidental diagnoses established or suggested on SPIRAL COMPUTED TOMOGRAPHY (CT) in a large series of patients with suspected renal colic.Materials and Methods: Records of all patients that had undergone SPIRAL CT (5-mm to 7-mm slice thickness) for acute flank pain during a 5-year period were reviewed. The radiological diagnoses of urinary calculi and obstruction as well as clinical entities not suspected otherwise were analyzed. Results: A total of 4000 CTs had been performed in the evaluation of acute flank pain. Urinary calculi had been identified in 3120 patients (78.0%).There were 398 patients (9.9%) who had an alternate cause of flank pain or an incidentally detected condition on CT. Of these patients, 102 (25.6%) had more than one additional finding. A total of 153 clinical conditions had been identified mimicking flank pain secondary to calculus and obstruction. In 47 patients (1.2%), incidental solid masses had been detected.Conclusion: SPIRAL CT is a valuable technique in the evaluation of acute flank pain with uncertain clinical diagnosis. A wide spectrum of alternate and additional diagnoses including abdominal solid organ tumors and other significant abdominal conditions such as pancreatitis can be established or suggested on SPIRAL CT performed for suspected acute urinary colic.