Absorbed dose and image quality in examinations of the colon with digital and analogue techniques

Purpose: Image quality and the absorbed dose to the patient are issues of primary interest in the change-over from the conventional analogue technique to the digital technique in the examination of the colon by means of fluoroscopy. the aim of this study was to compare the incident radiation and to evaluate the image quality in two different X-ray equipment types, one digital and one analogue Material and Methods: A kerma-area product meter was used to measure the incident radiation to the patient. Both fluoroscopy and total-examination times were measured as was the number of images. an evaluation of image quality was made and statistically analysed Results and Conclusion: No significant difference in the irradiation dose was observed between the two techniques. the fluoroscopy time was significantly lower with the conventional technique but the total-examination time decreased by 18% with the digital technique. the total number of images taken was higher with the digital technique (25 images compared to 19) owing to the limited field of the image intensifier. Significantly more noise and less sharpness were observed with the digital system but there was no significant difference in contrast or image quality in the various anatomical structures. Although the change-over to the digital system produced a reduction in sharpness and an increase in noise, and no significant dose saving was measured, the digital system was faster to work with and could well be used for diagnostic purposes

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Pelvis imaging: Achieving dose reduction with different patient positions

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp190818037r ◽

2019 ◽

Vol 34 (4) ◽

pp. 375-383

Author(s):

Anja Resnik ◽

Janez Zibert ◽

Nejc Mekis

Keyword(s):

Image Quality ◽

Effective Dose ◽

Signal To Noise Ratio ◽

Absorbed Dose ◽

Field Size ◽

Optimal Position ◽

Dose Area Product ◽

Significant Difference ◽

Noise Ratio ◽

Area Product

The purpose of this research was to determine how dose area product, effective dose, absorbed doses to specific organs, and image quality changed according to different automatic exposure control positions in pelvis imaging. The research was carried out in two parts. The study was conducted on an anthropomorphic phantom and 200 patients referred to pelvic imaging. We measured the dose area product, field size, height, and mass. Then we calculated the effective dose and absorbed dose for individual organs accordingly. Lateral ionizing cells were first positioned in line with the iliac crests (head towards position) and subsequently, with the femoral neck (head away position). All the images were independently evaluated by three radiologists using ViewDEX and objective image analysis was performed measuring contrast-to-noise ratio and signal-to-noise ratio. We found no significant differences in the Siemens Luminos unit in any of the inspected parameters. However, there was a significant difference in dose area product (37.3 %), effective dose (35.7 %) and average absorbed dose to selected individual organs (36.7 %) when the head away position of the patient was used and the image quality increased. Based on these results, we can propose that the optimal position of the patient regarding the ionizing cells is the head away position.

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New patient-controlled abdominal compression method in radiography: radiation dose and image quality

Acta Radiologica Open ◽

10.1177/2058460118772863 ◽

2018 ◽

Vol 7 (5) ◽

pp. 205846011877286 ◽

Cited By ~ 1

Author(s):

Oili Piippo-Huotari ◽

Eva Norrman ◽

Agneta Anderzén-Carlsson ◽

Håkan Geijer

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Prone Position ◽

Quality Criteria ◽

Abdominal Compression ◽

Radiographic Images ◽

Dose Area Product ◽

Similar Dose ◽

Significant Difference ◽

Area Product

Background The radiation dose for patients can be reduced with many methods and one way is to use abdominal compression. In this study, the radiation dose and image quality for a new patient-controlled compression device were compared with conventional compression and compression in the prone position . Purpose To compare radiation dose and image quality of patient-controlled compression compared with conventional and prone compression in general radiography. Material and Methods An experimental design with quantitative approach. After obtaining the approval of the ethics committee, a consecutive sample of 48 patients was examined with the standard clinical urography protocol. The radiation doses were measured as dose-area product and analyzed with a paired t-test. The image quality was evaluated by visual grading analysis. Four radiologists evaluated each image individually by scoring nine criteria modified from the European quality criteria for diagnostic radiographic images. Results There was no significant difference in radiation dose or image quality between conventional and patient-controlled compression. Prone position resulted in both higher dose and inferior image quality. Conclusion Patient-controlled compression gave similar dose levels as conventional compression and lower than prone compression. Image quality was similar with both patient-controlled and conventional compression and was judged to be better than in the prone position.

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Evaluation of Patient's Dose and Estimate of Cancer Risk in Electrophysiology Studies and Ablation in Cath Lab Center of Afshar Hospital, Yazd, Iran

Journal of Shahid Sadoughi University of Medical Sciences ◽

10.18502/ssu.v27i11.2495 ◽

2020 ◽

Author(s):

Fatollah Bouzarjomehri ◽

Fereshteh Omidvar ◽

Mohammad Hossein Zare ◽

Mashallah Nakhaeine Nejad

Keyword(s):

Cancer Risk ◽

Effective Dose ◽

Absorbed Dose ◽

Image Intensifier ◽

Time Range ◽

Cross Sectional ◽

Dose Area Product ◽

The Mean ◽

Area Product ◽

Risk Of Cancer

Introduction: Today electrophysiology studies and ablation have been developed due to increasing arrhythmias disorder of heart. In these diagnostic – treatments methods, the use of fluoroscopy can be causes patient radiation dose, therefore evaluation of patient's absorbed dose is necessary to protection of the radiation. The aim of this study was to evaluate the absorbed dose in patients undergoing electrophysiology and cardiac ablation and to estimate their risk of cancer in Yazd Afshar Hospital. Methods: This study was a cross-sectional study. In this study, the mean absorbed dose of referral patients for electrophysiology studies and ablation had been measured in the cat. Lab of Afshar Hospital, Yazd. The dosimeter had been used in this research was KAP meter, the M4 DIAMENTOR made in Germany that was able to measure dose-area product and time of the fluoroscopy. The patient effective dose was calculated by the PCXMC software from dose-area product. Results: The mean dose-area in ablation and electrophysiology studies was respectively 153.34±105.32 and 5.62 14.88 Gy.cm2 and the radiation time range was recorded 3.32 to 68.65 minutes and 1.03 to 6.28 minutes, respectively. The mean effective dose of ablation and electrophysiology studies were respectively 16.38 and 1.65 mSv. The cancer risk per ten thousands of patients, who were under the ablation and electrophysiology examinations were estimated 13 and 1.3 people, respectively. Conclusion: Increasing of patient dose due to ablation in this study relation to the other studies can be due to long old of image intensifier device.

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OPTIMAL COLLIMATION SIGNIFICANTLY IMPROVES LUMBAR SPINE RADIOGRAPHY

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa057 ◽

2020 ◽

Vol 189 (4) ◽

pp. 420-427

Author(s):

Anamaria Pazanin ◽

Damijan Skrk ◽

Jessica C O'Driscoll ◽

Mark F McEntee ◽

Nejc Mekis

Keyword(s):

Lumbar Spine ◽

Image Quality ◽

Absorbed Dose ◽

Field Size ◽

Organ Doses ◽

Dose Area Product ◽

Spine Radiography ◽

Spine Imaging ◽

Radiosensitive Organs ◽

Area Product

Abstract Purpose To determine the influence of optimal collimation during lumbar spine radiography on radiation dose and image quality. Material and methods 110 lumbar spine patients were split into two groups—the first imaged with standard collimation and the second with optimal collimation. Body mass index, image field size, exposure conditions and dose area product were measured. Effective and absorbed organ doses were calculated. Image quality was assessed. Results Optimal collimation reduced the primary field by up to 40%. The effective dose was reduced by 48% for the AP projection, while no differences were found for the LAT projection due to incorrect positioning of the central beam with standard collimation. The absorbed dose to selected radiosensitive organs decreased by 41 and 10% in the AP and LAT projections, respectively. Image quality for the LAT projection improved by 24% and maintained for the AP projection. Conclusion Optimal collimation in lumbar spine imaging significantly influences patient exposure to radiation.

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Comparison of Image Quality and Mean Absorbed Dose to the Breast for Two Mammographic Films

Acta Radiologica ◽

10.1177/028418519303400408 ◽

1993 ◽

Vol 34 (4) ◽

pp. 351-355 ◽

Cited By ~ 1

Author(s):

J. Persliden ◽

V. Fransson ◽

B. Vitak ◽

G. Fagerberg

Keyword(s):

Image Quality ◽

Irradiation Dose ◽

Processing Time ◽

Absorbed Dose ◽

Nonparametric Test ◽

Moving Grid ◽

X Ray ◽

Tube Potential ◽

Significant Difference ◽

The Mean

A film intended for mammography (Kodak SO 155 MRH-1) was tested and compared to one (Kodak SO 177 Ortho M) used earlier. Both films including the cassette could resolve 20 lp/mm. For a processing time of 90 s the new film gave the same overall image quality and irradiation dose to the breast as the old system. If, instead, the processing time was increased to 150 s, a 43% reduction in kerma could be attained with the new film. With a developing temperature of 36°C and 150 s processing time, the noise is clinically acceptable. A nonparametric test showed no significant difference between the 2 films on the 0.01 level. At an X-ray tube potential difference of 25 kV, the mean absorbed dose to a 4.5-cm-thick breast was reduced from 1.7 mGy with the old combination to 1.0 mGy with the new one. The measurements were made with a moving grid.

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Assessment of extracranial-intracranial bypass in Moyamoya disease using 3T time-of-flight MR angiography: Comparison with CT angiography

VASA ◽

10.1024/0301-1526/a000363 ◽

2014 ◽

Vol 43 (4) ◽

pp. 278-283 ◽

Cited By ~ 8

Author(s):

Qian Chen ◽

Rongfeng Qi ◽

Xiaoqing Cheng ◽

Changsheng Zhou ◽

Song Luo ◽

...

Keyword(s):

Image Quality ◽

Moyamoya Disease ◽

Mr Angiography ◽

Time Of Flight ◽

Consecutive Series ◽

Tof Mra ◽

Bypass Patency ◽

Significant Difference ◽

Contrast Technique ◽

Vessel Integrity

Background: To evaluate the value of time-of-flight MR angiography (TOF MRA) for the assessment of extracranial-intracranial (EC-IC) bypass in Moyamoya disease in comparison with computed tomography angiography (CTA). Patients and methods: A consecutive series of 23 patients with Moyamoya disease were analyzed retrospectively. Twenty three patients underwent 25 procedures of extracranial-intracranial bypass. Cranial CTA was performed within one week after the surgery to assess bypass patency. Then TOF MRA was scanned within 24 h after CTA on a 3T MRI system. Using 5-point scales (0 = poor to 4 = excellent), two radiologists rated the image quality and vessel integrity of bypass for three segments (extracranial, trepanation, intracranial). Results: Image quality was high in both CTA and TOF MRA (mean quality score 3.84 ± 0.37 and 3.8 ± 0.41), without statistical difference (p = 0.66). Mean scores of TOF MRA with respect to bypass visualization were higher than CTA in the intracranial segment (p = 0.026). No significant difference of bypass visualization regarding the extracranial and trepanation segments was found between TOF MRA and CTA (p = 0.66 and p = 0.34, respectively). For the trepanation segment, TOF MRA showed pseudo lesions in 2 of all 25 cases. Conclusions: 3T TOF MRA, a non-contrast technique not exposing the patients to radiation, proved to be at least equal to CTA for the assessment of EC-IC bypass, and even superior to CTA with respect to the intracranial segment. In addition, readers should be aware of a potential overestimation showing focal pseudo lesions of the bypass at the trepanation segment in TOF MRA.

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Absorbed dose and image quality in examinations of the colon with digital and analogue techniques

Acta Radiologica ◽

10.3109/02841859709172120 ◽

1997 ◽

Vol 38 (6) ◽

pp. 1010-1014

Author(s):

J. Persliden ◽

P. Larsson ◽

B. Noren ◽

S. Wirell

Keyword(s):

Image Quality ◽

Absorbed Dose

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Evaluation of image quality at the detector’s edge of dedicated breast positron emission tomography

EJNMMI Physics ◽

10.1186/s40658-020-00351-6 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Yoko Satoh ◽

Utaroh Motosugi ◽

Masamichi Imai ◽

Yoshie Omiya ◽

Hiroshi Onishi

Keyword(s):

Image Quality ◽

Chest Wall ◽

Clinical Studies ◽

Breast Imaging ◽

Phantom Study ◽

Breast Lesions ◽

Clinical Images ◽

Dedicated Breast Pet ◽

Pet Ct ◽

Significant Difference

Abstract Background Using phantoms and clinical studies in prone hanging breast imaging, we assessed the image quality of a commercially available dedicated breast PET (dbPET) at the detector’s edge, where mammary glands near the chest wall are located. These are compared to supine PET/CT breast images of the same clinical subjects. Methods A breast phantom with four spheres (16-, 10-, 7.5-, and 5-mm diameter) was filled with 18F-fluorodeoxyglucose solution (sphere-to-background activity concentration ratio, 8:1). The spheres occupied five different positions from the top edge to the centre of the detector and were scanned for 5 min in each position. Reconstructed images were visually evaluated, and the contrast-to-noise ratio (CNR), contrast recovery coefficient (CRC) for all spheres, and coefficient of variation of the background (CVB) were calculated. Subsequently, clinical images obtained with standard supine PET/CT and prone dbPET were retrospectively analysed. Tumour-to-background ratios (TBRs) between breast cancer near the chest wall (close to the detector’s edge; peripheral group) and at other locations (non-peripheral group) were compared. The TBR of each lesion was compared between dbPET and PET/CT. Results Closer to the detector’s edge, the CNR and CRC of all spheres decreased while the CVB increased in the phantom study. The disadvantages of this placement were visually confirmed. Regarding clinical images, TBR of dbPET was significantly higher than that of PET/CT in both the peripheral (12.38 ± 6.41 vs 6.73 ± 3.5, p = 0.0006) and non-peripheral (12.44 ± 5.94 vs 7.71 ± 7.1, p = 0.0183) groups. There was no significant difference in TBR of dbPET between the peripheral and non-peripheral groups. Conclusion The phantom study revealed poorer image quality at < 2-cm distance from the detector’s edge than at other more central parts. In clinical studies, however, the visibility of breast lesions with dbPET was the same regardless of the lesion position, and it was higher than that in PET/CT. dbPET has a great potential for detecting breast lesions near the chest wall if they are at least 2 cm from the edge of the FOV, even in young women with small breasts.

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

Applied Sciences ◽

10.3390/app11052047 ◽

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.

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