Tehran University Medical Journal

Background: Since pulmonary angiography is the only non-invasive method for diagnosing pulmonary embolism, the use of radiation reduction methods without affecting the quality of images seems necessary. One of the simplest reasons for unnecessarily increasing of patient exposure is repetitive imaging due to poor image quality. Therefore, it is necessary to identify and eliminate the factors that reduce the image quality, which leads to duplication of imaging or reduced accuracy.  In this study, the reasons for decreasing the image quality of pulmonary computed tomography (CT) angiography were investigated.
Methods: This cross-sectional study was performed over a period of 6 months (May to November 2018) in a university-affiliated hospital. Data of 75 patients suspected of pulmonary embolism who were referred for CT angiography were collected. All CT scans were performed by a 16-slice CT scanner (Lights Speed, GE Healthcare) with fixed imaging parameters including 100 kVp and 100 mA. In order to evaluate the adequacy of pulmonary artery enhancement, the Hounsfield unit (HU) of the main pulmonary artery was measured in the aortic arch, upper, and lower segmental parts. Also, 8 factors affecting the image quality were examined.

Background: The image quality is paramount in interpreting the hepatic dynamic CT scan. A poor quality image results in repeating the procedure, which is very time-consuming for the patient and staff, and besides, it is not cost-efficient. This study intended to determine the correlation between image quality and the Hounsfield unit (HU) of the liver and its vessels in the arterial and venous phase to define the acceptable range of HUs for hepatic CT images.
Methods: The image quality of 146 dynamic CT scans was assessed by qualitative and quantitative methods at Namazi Hospital of Shiraz University of Medical Sciences from September 2019 to August 2021. Two radiologists performed the qualitative evaluation. They categorized the image qualities into three groups; poor, acceptable, and high quality. For quantitative assessment of image quality, the Hounsfield unit of the aorta, hepatic vein, main portal vein, right anterior, right posterior, and left lateral lobe of the liver were evaluated in both arterial and venous phases.

Results: According to the results of the qualitative evaluation of image quality, 59.6%, 17.8%, and 22.6% of triphasic CT scans had good, acceptable, and poor quality, respectively. There was a significant relationship between image quality and Hounsfield units of all ROIs in the arterial phase (P<0.005). Also, a significant relationship was observed between the Hounsfield units of the portal vein right on the anterior and posterior segments of the liver (P<0.03) in the venous phase. Conclusion: In a high quality triphasic CT scan, the Hounsfield unit of different parts in the arterial phase should be as follows: aorta 310±78, portal vein 150±40, hepatic vein 44±7, right posterior and anterior and left lateral segments of liver 77±11, 77±7 and 78±12. Hounsfield units of the portal vein, hepatic vein, and right posterior and anterior segments of the liver in the venous phase should be 155±27, 167±30, 111±19, and 112±16, respectively.

Background: Fine needle aspiration biopsy (FNAB) is usually used to distinguish the malignant and benign nodules. Applying a biopsy needle evokes a sense of fear and pain in the patients. Although some studies refute the usefulness of local anesthesia (LA) prior to fine needle aspiration biopsy, it is still debatable. This prospective cross-sectional study intended to evaluate the effect of LA prior to fine needle aspiration biopsy on pain and anxiety considering nodule size.
Methods: Amongst the patients who were referred to Shiraz Shahid Fagihi Hospital for Thyroid fine needle aspiration biopsy from August 2017 to January 2018, 114 patients participated in this study. LA was performed for 41 patients, and 73 underwent the thyroid nodule fine needle aspiration biopsy without LA. Patients' pain and anxiety were scored using the visual-analog-score and Spielberger anxiety scale. The nodules were categorized into five groups. Pain and anxiety of patients were compared considering their nodule sizes to assess the effects of LA in the reduction of pain and anxiety considering the nodule size.

Results: The patients undergoing LA had a mean age of 44.69 years old and average body mass index (BMI) of 26.7, the patients who performed thyroid nodule fine needle aspiration biopsy without LA had a mean age of 48.17 years old with an average BMI of 26.0. The patients with the maximum nodule size of<10 mm, experienced more pain during the fine needle aspiration biopsy without LA, but there was no significant difference between the S/T-anxiety of these patients. There was no significant difference between the pain and anxiety scores of the patients with larger nodules. Conclusion: The more pain experienced by the patients with the smallest nodules can be attributed to the need for more needle manipulation due to the small nodule size and less precision while piercing the needle into the nodule. Thus, it can be suggested that in patients with a small nodule size, less than 10mm, usage of LA prior to fine needle aspiration biopsy can reduce the pain significantly.

Background: MRI is the imaging modality of choice for the detection of diabetic pedal osteomyelitis. The aim of this study is to compare the STIR sequence, as the most important fluid-sensitive sequence, with contrast-enhanced images for diagnosing diabetic pedal osteomyelitis.
Methods: Medical images were compared. Moreover, the effect of adding T1W image findings to the STIR sequence was evaluated. This cross sectional study was collected and analyzed at Namazi Hospital, Shiraz University of Medical Sciences, from 20 March 2016 to 22 September 2017.
Results: The final diagnosis of osteomyelitis was confirmed for 47 bones (78%). 13 bones (22%) didn't have osteomyelitis. The specificity of contrast-enhanced and STIR sequences was 92.3% and 53.8%, respectively; whereas the sensitivity of the two sequences was similar (100%). Records of 48 diabetic patients suspected of having pedal osteomyelitis referred to one of the university hospitals, who underwent foot MRI with and without contrast injection, were assessed. Overall, 48 Patient MRIs and 60 separate bony parts were evaluated. Diagnoses were confirmed by clinical correlation. Finally, sensitivity, specificity and diagnostic accuracy of STIR sequence and contrast-enhanced images were compared. Moreover, the effect of addition of T1W image findings to STIR sequence was evaluated.
Conclusion: This study was performed to suggest a pulse sequence that doesn’t need contrast media injection for diagnosing diabetic pedal osteomyelitis since the previous studies showed that gadolinium-based contrast media shouldn’t be applied in patients with renal failure (glomerular filtration rate<30 ml/min/1.73m². According to the results STIR images had the same sensitivity as T1 post-contrast images; therefore, it can be concluded that contrast media injection can be avoided using this pulse sequence. The specificity of the STIR pulse sequence was lower than that of post-contrast images which was due to the lower ability of this pulse sequence to detect secondary symptoms of osteomyelitis such as cortex disruption, sinus path, and abscess. Using the T1 pre-contrast images, specificity and diagnostic accuracy increased. Finally, it can be concluded that MRI without contrast including STIR and pre-contrast T1W images is a reliable modality for the detection of osteomyelitis in suspected diabetic patients who are more prone to renal disorders.

Background: Ultrasound is widely used to detect renal stones. A no-contrast CT scan is the most accurate modality for stone examination. Considering that determining the size of a stone is the main criterion in treatment planning, the purpose of this study was to compare ultrasound and non-contrast CT scans in determining renal stone size.
Methods: In this cross-sectional study, 140 patients were assessed from June to October 2017 at Namazi Hospital of Shiraz University of Medical Sciences. A radiologist compared the CT scans of patients with their ultrasound images. The ultrasound and CT scan results in terms of stone size were assessed. The correlation rate of stone size in ultrasound and CT scans in different subgroups was assessed by categorizing the stone size into three subgroups. The impact of stone location and the CT window on measuring stone size were evaluated.

Results: The mean stone size measured by ultrasound and CT scan was 11.23±5.26 and 9.48±4.7mm, respectively, which was significantly different. The highest rate of correlation was observed in the stones>10mm (81%) and then in 5-10mm (69.3%). The lowest agreement was observed in stones <5mm (37.5%). Conclusion: Using ultrasonography as a screening test or a primary test for detecting the renal stones is recommended. However, considering the importance of a precise assessment of stone size in choosing the treatment method and the limitations of sonography in the evaluation of small stones, a CT scan should be considered as a standard diagnostic tool if there is no contraindication. In CT images, the application of BW might underestimate the stone size in comparison to SW. Considering the results of previous studies, it is better to use magnified BW to assess the stone size on CT scan images. Although the axial view in a CT scan is more routine, for measuring the stone size it is better to use coronal or sagittal views together with axial views.

Background: Developmental disorders in children include a group of problems and limitations in learning and acquiring specific skills of each age group. The term global developmental delay is used to describe developmental disability in children under five years of age, which is in at least two areas of major development. Neuroradiological imaging such as brain MRI provides important information for physicians. The purpose of this study is to determine the role of brain MRI in predicting the clinical outcome of global developmental delay in children.
Methods: In this cross-sectional study, from 79 - from September 2013 to September 2018 at Motahari Clinic of Shiraz University of Medical Sciences, Shiraz Iran - eligible children with developmental disabilities, 37 patient who had brain MRI were selected as a sample and children scores in five ASQ clinical areas and MRI findings were reviewed and compared. Patients suffering from metabolic, genetic, trauma, infection and neoplasms problems and diseases were excluded from the study.

Results: Out of 37 patients studied, 23 were female and 14 were male with a dispersion of three 3 to 60 months of age. 31 of these children had at least one abnormal finding in brain MRI images and the other six were completely normal. In relation to the imaging findings, the highest frequency is related to abnormal head circumference with a prevalence of 54% and the lowest frequency is related to abnormal myelinization with a prevalence of 10.8%. Results of MRI findings correlation with developmental domains demonstrated that Children with white matter disorder on MRI show severe gross motor abnormality (P<0.049) and who had MRI finding of cortical problems suffer from developmental delay in fine motor area. (P<0.001). Conclusion: Considering the mentioned findings; brain MRI can be a useful diagnostic tool in children with developmental delay and also focusing on the developmental area that is more likely to be affected, MRI can help with treatment and rehabilitation process of these children in the future.