The relationship between organ dose and patient size in tube current modulated adult thoracic CT scans

2012 ◽  
Author(s):  
Maryam Khatonabadi ◽  
Di Zhang ◽  
Jeffrey Yang ◽  
John J. DeMarco ◽  
Chris C. Cagnon ◽  
...  
Keyword(s):  
Organ Dose ◽  
Ct Scans ◽  
Thoracic Ct ◽  
Tube Current ◽  
Patient Size ◽  
The Relationship

PACS-based Calculation of Organ Dose to Patients undergoing Chest Computed Tomography with Automatic Tube Current Modulation (Preprint)

2020 ◽  
Author(s):  
Ying Huang ◽  
Yang Yang ◽  
Xin Chen ◽  
Yiming Gao ◽  
Weihai Zhuo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Organ Dose ◽  
Chest Ct ◽  
Ct Scans ◽  
Patient Specific ◽  
Organ Doses ◽  
Chest Computed Tomography ◽  
Tube Current ◽  
Specific Organ ◽  
Patient Size

BACKGROUND CT imaging is one of the most important contributors to medical radiation exposure(1). The frequency of CT scans and radiation doses accepted by patients attracted serious concerns for health physics researchers. The utilization of advanced technology ATCM has the potentials to reduce CT radiation doses while diagnostic image quality is maintained (2-7). As ATCM adjusted tube currents slice by slice it brought challenges to organ dose estimation using conversion factors derived from fixed tube current. Cross-system communication with hospital Picture Archive and Communication System (PACS),made it possible to read massive data automatically like the scanning parameters of each slice in each case. Monte Carlo simulations are probably the most reliable techniques which could be used for accurate dose assessment. [8-11]. However, specific patient model development and specific patient dose simulations are computationally demanding and may require dedicated hardware resources, this limitation constrained its application in large scale investigation. As an alternative method, patient specific organ doses could be calculated using the patient specific scan parameters and the Monte Carlo simulated organ doses with reference human phantom, and then correct the results with patient size factors. Dw is referred as the preferred patient size metric that determined the patient group and affected organ dose. The distance of the pathway traversed by the X-ray beam could provide the best approximation of tissue length traversed during the examination (12, 13),as CT image is a cross-sectional map normalized to the linear attenuation of water (14). The purpose of current study was to establish a method to access patient-specific organ dose associated with ATCM in chest computed tomography (CT) scans by combining Monte Carlo simulation with parameters contracted from clinical CT images of each patient underwent chest CT scan with ATCM. OBJECTIVE To explore a method to access patient-specific organ dose associated with automatic tube current modulation (ATCM) in chest computed tomography (CT) scans based on the information extracted from PACS automatically. METHODS 176cases of chest CT scans were read through cross-system communication with hospital PACS. A total of 8468 images were collected and analyzed automatically using in-house software. The scanning parameters (kVp, tube current, collimation width, etc.) of each CT examination were collected in real time, and a middle CT image of each case was collected for patient size(water equivalent diameter, Dw) calculation. Based on the reference human phantom, organ doses were simulated slice by slice using Monte Carlo method. The patient specific organ doses were calculated by combining tube currents of each patient slice with the simulated results, and doses were revised by correction factors that related to patient size. RESULTS A sum of 8468 slice of tube currents were extracted and analyzed in this study, the average mAs for large size patient group was about 1.6 times to the small size patient group. For organs that covered in the scan range like lung, breast, heart, the dose values were 18.30±2.91mGy, 15.13 ±2.75mGy and 17.87±2.96mGy in small size patients(Dw smaller than 22cm).The dose values of lung, breast, heart, in medium-sized patients (Dw from 22cm to 25cm) were 21.89±4.60mGy, 18.16 ±4.13mGy and 21.46±4.60mGy, while the values were 24.98±4.40mGy, 20.81±3.66mGy and 24.77±4.46mGy respectively in large size patients(Dw larger than 25cm). The organ doses increase with the patient size due to the increase of mAs. CONCLUSIONS The PACS-based method of large batch organ dose calculation to patients undergoing chest CT with ATCM was established. The methods and results may provide guidance to the design and optimization of chest CT protocols with ATCM.

SU-E-I-25: Organ Dose Reduction by Lowering Tube Voltage from 120kVp to 80kVp for Fixed Tube Current Chest CT Scans

2011 ◽  
Vol 38 (6Part4) ◽  
pp. 3401-3401
Author(s):  
M Khatonabadi ◽  
D Zhang ◽  
A Turner ◽  
J DeMarco ◽  
D Cody ◽  
...  
Keyword(s):  
Dose Reduction ◽  
Organ Dose ◽  
Chest Ct ◽  
Ct Scans ◽  
Tube Voltage ◽  
Tube Current

WE-A-218-04: Tube Current Modulation and Patient Size Adjustment for CT Dosimetry Software ImPACT in Thoracic CT Exams

2012 ◽  
Vol 39 (6Part26) ◽  
pp. 3939-3939
Author(s):  
M Khatonabadi ◽  
D Zhang ◽  
C Cagnon ◽  
J DeMarco ◽  
M McNitt-Gray
Keyword(s):  
Tube Current Modulation ◽  
Current Modulation ◽  
Thoracic Ct ◽  
Tube Current ◽  
Patient Size ◽  
Ct Dosimetry ◽  
Size Adjustment

MO-D-134-02: Estimating Organ Dose From CT Scans Performed with Tube Current Modulated Scans

2013 ◽  
Vol 40 (6Part24) ◽  
pp. 402-402
Author(s):  
M Khatonabadi ◽  
G Chu ◽  
D Oria ◽  
C Cagnon ◽  
J DeMarco ◽  
...  
Keyword(s):  
Organ Dose ◽  
Ct Scans ◽  
Tube Current

scholarly journals Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2047
Author(s):  
Nor Azura Muhammad ◽  
Zunaide Kayun ◽  
Hasyma Abu Hassan ◽  
Jeannie Hsiu Ding Wong ◽  
Kwan Hoong Ng ◽  
...  
Keyword(s):  
Image Quality ◽  
Multidetector Ct ◽  
Organ Dose ◽  
Quality Metrics ◽  
Ct Scanner ◽  
Image Quality Metrics ◽  
Tube Current ◽  
Significant Difference ◽  
Noise Ratio ◽  
The Impact

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.

scholarly journals Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

2015 ◽  
Vol 48 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Agnes Araujo Valadares ◽  
Paulo Schiavom Duarte ◽  
Eduardo Bechtloff Woellner ◽  
George Barberio Coura-Filho ◽  
Marcelo Tatit Sapienza ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Lumbar Vertebra ◽  
Ct Scans ◽  
Femoral Diaphysis ◽  
Standardized Uptake Values ◽  
Pet Ct ◽  
Tube Current ◽  
The Mean ◽  
Humeral Diaphysis ◽  
Ct Studies

Objective: To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: The three tube current values yielded similar results for SUV calculation.

scholarly journals The Relationship Between the Width of the Frontal Recess and the Frontal Recess Cells in Japanese Patients

2019 ◽  
Vol 12 ◽  
pp. 117955061988494
Author(s):  
Seiichiro Makihara ◽  
Shin Kariya ◽  
Mitsuhiro Okano ◽  
Tomoyuki Naito ◽  
Kensuke Uraguchi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Frontal Sinus ◽  
Significant Positive Correlation ◽  
Japanese Patients ◽  
Cell Types ◽  
Sinus Surgery ◽  
Ct Scans ◽  
Frontal Sinusitis ◽  
Frontal Recess ◽  
The Relationship

Objective: The agger nasi cell (ANC) is an easily identifiable landmark when approaching the frontal sinus. The success of endoscopic frontal sinus surgery may be influenced by the width of the frontal recess (FR). The aim of this study is to examine the relationship between the FR width and the ANC size in Japanese patients. In addition, the effect of various frontal recess cells (FRCs) on the development of frontal sinusitis has been examined. Materials and methods: Multiplanar computed tomography (CT) scans of the nasal cavities and paranasal sinuses in 95 patients (190 sides) before endoscopic sinus surgery were reviewed. The presence of FRCs, the thickness of the frontal beak (FB), the ANC size, and the anterior-to-posterior (A-P) length of the frontal isthmus (FI) and FR were evaluated in patients with and without frontal sinusitis. Results: The prevalence of the ANC, frontal cell types 1, 2, 3, and 4, frontal bullar cell (FBC), suprabullar cell, supraorbital ethmoid cell, and interfrontal sinus septal cell was 85.3%, 11.6%, 0%, 7.9%, 0%, 25.3%, 45.8%, 16.8%, and 15.3%, respectively. The ANC volume showed a significant positive correlation with the A-P length of the FI and FR. The incidence of frontal sinusitis in the patients with FBCs was significantly higher than that without FBCs. Conclusion: A large ANC offers a greater potential to facilitating the approach to the frontal sinus because of the extensiveness of the FR in Japanese patients. The presence of FBCs may be related to a higher incidence of frontal sinusitis.

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