جستجوی مقالات مرتبط با کلیدواژه "brain computed tomography" در نشریات گروه "پزشکی"

This study aimed to investigate the effect of CAREdose4D on the dose and image quality in Brain Computed Tomography (CT).

Noise, Signal-to-Noise Ratio (SNR), and Contrast-to-Noise Ratio (CNR) for Gray Matter (GM), White Matter (WM), Cerebrospinal Fluid (CSF), and skull bones were investigated in brain CT scans of 60 patients. In addition, a phantom study was conducted to examine the effect of CAREdose 4D on the same subject in the brain, chest, abdomen, and pelvic CT protocols. Volume CT dose index (CTDIvol) and Dose Length Product (DLP) were recorded for each scan. Data were analyzed by T-test and Mann-Whitney statistical test with a significance level of less than 0.05.

The following results were obtained in active and passive modes of CAREdose 4D in brain CT of patients, respectively: CTDIvol, 15.76±3.94 and 16.96±2.14 mGy (p<0.05); DLP, 253.81±84.69 and 252.73±43.26 mGy.cm (p>0.05). There was no significant difference between SNRs and noise of various tissues of the brain (p>0.05) but CNR difference for gray matter, white matter, and cerebrospinal fluid (CSF) was significant (p<0.05). In the phantom study, SNR decreased in the active status of CAREdose 4D for the head in sequential and spiral modes, Chest, abdomen and pelvis by 7%, 84%, 45%, 20%, and 22%, respectively.

CAREdose 4D reduces the dose without having an adverse effect on noise and SNR in brain CT scans. It is recommended newbies and untrained technicians to use CAREdose 4D.

Computed tomography (CT) of the brain is associated with radiation exposure to the lens of the eyes. Therefore, it is necessary to optimize scan settings to keep radiation exposure as low as reasonably achievable without compromising diagnostic image information. The aim of this study was to compare the effectiveness of the five practical techniques for lowering eye radiation exposure and their effects on diagnostic image quality in pediatric brain CT.

The following scan protocols were performed: reference scan, 0.06‑mm Pbeq bismuth shield, 30% globally lowering tube current (GLTC), reducing tube voltage (RTV) from 120 to 90 kVp, gantry tilting, and combination of gantry tilting with bismuth shielding. Radiation measurements were performed using thermoluminescence dosimeters. Objective and subjective image quality was evaluated.

All strategies significantly reduced eye dose, and increased the posterior fossa artifact index and the temporal lobe artifact index, relative to the reference scan. GLTC and RTV increased image noise, leading to a decrease signal‑to‑noise ratio and contrast‑to‑noise ratio. Except for bismuth shielding, subjective image quality was relatively the same as the reference scan.

Gantry tilting may be the most effective method for reducing eye radiation exposure in pediatric brain CT. When the scanner does not support gantry tilting, GLTC might be an alternative.

 For many patients with neurological complaints, a non-enhanced brain computed tomography (CT) scan is the first workup. In some of these patients, there is no pathological finding. Anemia is a condition that can present with neurological symptoms without any imaging findings. The correlation of dural venous sinus density with hemoglobin (Hb) level has been shown in some recent studies.

 This study aimed to propose a strategy to predict the level of Hb and investigate the possibility of underlying anemia based on dural venous sinus density to facilitate treatment.

 The CT scans of selected patients, who were referred to Faghihi Hospital in Shiraz, Iran, from October 2018 until February 2019, were reviewed in this study; the complete blood count (CBC) was measured for cases without any findings. The data of 78 patients, including CBC parameters and the mean Hounsfield unit (HU) in the superior sagittal sinus (SSS), torcula herophili (TH), and transverse sinuses (TS), were also analyzed.

 A relatively strong direct linear correlation was found between the Hb level and HU. The Hb level was calculated based on the following formula: Hb level = 0.2 × SSS HU + 1.2 × sex factor - 0.01 × age (where sex factor is zero for females and one for males). Besides, measurement of the cutoff point for the mean HU of SSS, based on the ROC curve to predict anemia, showed that with SSS HU ≤ 50, anemia could be predicted with 84.62% sensitivity, 75.38% specificity, and 75.64% accuracy in the general population.

 A significant positive correlation was found between the Hb level and the mean HU of dural venous sinuses. Therefore, the level of Hb is predictable based on HU, and differential diagnoses are limited.

Computed Tomography (CT) is a fundamental part of diagnosis of diseases. During CT examinations organs in and out of scanned volume are exposed to ionization radiation. The aim of this study was Estimation Thyroid cancer risk in Patients who Underwent 64 Slice brain and paranasal sinuses CT scan.

with permission from the authors and editor, data related to thyroid dose of 40 patients in Mazyar et al.'s paper was used and by using Biological Effects of Ionizing Radiation (BEIR)VII model thyroid cancer risk was calculated for different ages at exposure in male and female.

In both brain and paranasal sinuses CT, ERR values in female patients were twice as many as those in male patients. At age range from 20 to 40 years, ERR was considerably more than at age range 40-60 years since young patients are more radiosensitive than old patients.

The calculations of ERR indicate that PNS and brain CT increase the theoretical risk of thyroid cancer incidence. Although the ERR values are low, impacts on the thyroid cancer incidence should not be disregarded.

Ubiquitin C-terminal hydrolase-L1 (UCH-L1) is one of the promising candidates, with an accept-able diagnostic value for predicting head computed tomography (CT) scan findings. However, there has beena controversy between studies and still, there is no general overview on this. Therefore, the current system-atic review and meta-analysis attempted to estimate the value of UCH-L1 in predicting intracranial lesions intraumatic brain injury (TBI).

Two independent reviewers screened records from the search of fourdatabases Medline, Embase, Scopus and Web of Science. The data were analyzed in the STATA 14.0 statisticalprogram and the findings were reported as a standardized mean difference (SMD), summary receiver perfor-mance characteristics curve (SROC), sensitivity, specificity, and diagnostic odds ratio with 95% confidence in-terval (95% CI).

Finally, the data of 13 articles were entered into the meta-analysis. The mean serumlevel of UCH-L1 was significantly higher in patients with CT-positive than in TBI patients with CT negative (SMD= 1.67, 95% CI: 1.12 to 2.23, I2 = 98.1%; p <0.0001). The area under the SROC curve for UCH-L1 in the predic-tion of intracranial lesions after mild TBI was 0.83 (95% CI: 0.80 to 0.86). Sensitivity, specificity and diagnosticodds ratio of serum UCH-L1 was 0.97 (95% CI: 0.92 to 0.99), 0.40 (95% CI: 0.30 to 0.51) and 19.37 (95% CI: 7.25to 51.75), respectively. When the analysis was limited to assessing the serum level of UCH-L1 within the first 6hours after mild TBI, its sensitivity and specificity increased to 0.99 (95% CI: 0.94 to 1.0) and 0.44 (95% CI: 0.38to 0.052), respectively. In addition, the diagnostic odds ratio of 6-hour serum level of UCH-L1 in the predictionof intracranial lesions was 680.87 (95% CI: 50.50 to 9197.97).

Moderate level of evidence suggeststhat serum/plasma levels of UCH-L1 have good value in prediction of head CT findings. It was also found thatevaluation of serum/plasma level of UCH-L1 within the first 6 hours following TBI would increase its predictivevalue. However, there is a controversy about the best cutoffs of the UCH-L1.