The Value of Low-dose Prospective Dual-energy Computed Tomography with Iodine Mapping in the Diagnosis of Gastric Cancer

Objectives: This study investigated the radiation dose and value of prospective dualenergy computed tomography (DECT) in the diagnosis of gastric cancer. Methods: Sixty patients scheduled for computed tomography (CT) for preoperative staging were divided into two groups. Thirty patients (Group A) underwent a single contrast-enhanced abdominal CT acquisition using a dual-source mode (100 kV/140 kV). Weighted average images of the two-kilovolt acquisitions and iodine maps were created. The remaining 30 patients underwent a standard CT scan (Group B). Two observers performed a blinded read of the images for gastric lesions, evaluating the image quality and recording effective dose. Results: During the blinded read, observers found 90% (27/30) of the cancers in both groups. The mean imaging quality scores were 2.1±0.9 for Group A, and 2.3±1.1 for Group B. The effective mean doses were 6.59±0.59 mSv and 25.86±0.44 mSv for Groups A and B, respectively. Compared with the control group (B), the imaging quality in the low-dose group decreased a little, but the radiation dose substantially decreased by 74.6%. Conclusion: The new DECT technique is valuable for examining gastric cancer patients. The dualkV scan mode can substantially reduce radiation dose while preserving good diagnostic image quality.

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First experiences of a low-dose protocol for CT-guided musculoskeletal biopsies combining different radiation dose reduction techniques

Acta Radiologica ◽

10.1177/0284185119847676 ◽

2019 ◽

Vol 61 (1) ◽

pp. 28-36

Author(s):

Zlatan Alagic ◽

Haris Alagic ◽

Robert Bujila ◽

Subhash Srivastava ◽

Saif Jasim ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Success Rate ◽

Low Dose ◽

Quality Parameters ◽

Ct Guided ◽

Protocol Group ◽

Group A ◽

The Mean ◽

Group B

Background The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% ( P<0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively ( P < 0.001). The success rate in group A was 91.2% and 87.9% in group B ( P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.

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Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department

Acta Radiologica ◽

10.1177/0284185121989958 ◽

2021 ◽

pp. 028418512198995

Author(s):

Erdal Tekin ◽

Kutsi Tuncer ◽

Ibrahim Ozlu ◽

Recep Sade ◽

Rustem Berhan Pirimoglu ◽

...

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Low Dose ◽

Standard Dose ◽

Control Group ◽

Study Group ◽

Effective Radiation Dose ◽

Wrist Trauma ◽

Effective Radiation

Background The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. Purpose To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). Material and Methods This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. Results The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group ( P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. Conclusion ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.

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Low-Dose Computed Tomography for the Optimization of Radiation Dose Exposure in Patients with Crohn’s Disease

Gastroenterology Research and Practice ◽

10.1155/2018/1768716 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Richard G. Kavanagh ◽

John O’Grady ◽

Brian W. Carey ◽

Patrick D. McLaughlin ◽

Siobhan B. O’Neill ◽

...

Keyword(s):

Computed Tomography ◽

Crohn’S Disease ◽

Image Quality ◽

Crohn's Disease ◽

Radiation Dose ◽

Ionizing Radiation ◽

Low Dose ◽

Radiation Doses ◽

Radiation Dose Exposure ◽

Ct Technology

Magnetic resonance imaging (MRI) is the mainstay method for the radiological imaging of the small bowel in patients with inflammatory bowel disease without the use of ionizing radiation. There are circumstances where imaging using ionizing radiation is required, particularly in the acute setting. This usually takes the form of computed tomography (CT). There has been a significant increase in the utilization of computed tomography (CT) for patients with Crohn’s disease as patients are frequently diagnosed at a relatively young age and require repeated imaging. Between seven and eleven percent of patients with IBD are exposed to high cumulative effective radiation doses (CEDs) (>35–75 mSv), mostly patients with Crohn’s disease (Newnham E 2007, Levi Z 2009, Hou JK 2014, Estay C 2015). This is primarily due to the more widespread and repeated use of CT, which accounts for 77% of radiation dose exposure amongst patients with Crohn’s disease (Desmond et al., 2008). Reports of the projected cancer risks from the increasing CT use (Berrington et al., 2007) have led to increased patient awareness regarding the potential health risks from ionizing radiation (Coakley et al., 2011). Our responsibilities as physicians caring for these patients include education regarding radiation risk and, when an investigation that utilizes ionizing radiation is required, to keep radiation doses as low as reasonably achievable: the “ALARA” principle. Recent advances in CT technology have facilitated substantial radiation dose reductions in many clinical settings, and several studies have demonstrated significantly decreased radiation doses in Crohn’s disease patients while maintaining diagnostic image quality. However, there is a balance to be struck between reducing radiation exposure and maintaining satisfactory image quality; if radiation dose is reduced excessively, the resulting CT images can be of poor quality and may be nondiagnostic. In this paper, we summarize the available evidence related to imaging of Crohn’s disease, radiation exposure, and risk, and we report recent advances in low-dose CT technology that have particular relevance.

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Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

Acta Veterinaria Scandinavica ◽

10.1186/s13028-019-0495-8 ◽

2019 ◽

Vol 61 (1) ◽

Author(s):

Christin Röttiger ◽

Maren Hellige ◽

Bernhard Ohnesorge ◽

Astrid Bienert-Zeit

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Post Mortem ◽

Mr Images ◽

Adjacent Structures ◽

Group A ◽

Group B ◽

The Impact ◽

Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

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Low Dose Computed Tomography in Diagnosis of Ureteric Calculus in Obese Patients

Journal of Nobel Medical College ◽

10.3126/jonmc.v9i1.29464 ◽

2020 ◽

Vol 9 (1) ◽

pp. 27-31

Author(s):

Mahesh Gautam ◽

Aziz Ullah ◽

Manish Raj Pathak

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Radiation Dose ◽

Iterative Reconstruction ◽

Low Dose ◽

Standard Dose ◽

Reconstruction Technique ◽

Obese Patients ◽

Low Dose Computed Tomography ◽

Effective Radiation

Background: Standard dose computed tomography is standard imaging modality in diagnosis of urolithiasis. The introduction of low dose techniques results in decrease radiation dose without significant change in image quality. However, the image quality of low dose computed tomography is affected by skin fold thickness and subcutaneous abdominal adipose tissue. The aim of this study to evaluate stone location, size, and density using low dose computed tomography compared with standard dose computed tomography in obese population. Material and Methods: This non-randomized non-inferiority trial includes 120 patient having BMI≥25kg/m2 with acute ureteric colic. The low dose and standard dose computed tomography were performed accordingly. Effective radiation doses were calculated from dose-length product obtained from scan report using conversion factor of 0.015. The images were reconstructed using iterative reconstruction algorithm. Effective dose, number and size of stone, Hounsfield Unit value of stone and image quality was assessed. Results: Stones were located in 69 (57.5%) in right and 51 (42.5%) in left ureter. There was no statistical difference in mean diameter, number and density of stones in low dose as compared with standard dose. The radiation dose was significantly lower with low dose. (3.68 mSv) The delineation of the ureter, outline of the stones and image quality in low dose was overall sufficient for diagnosis. No images of low dose scan were subjectively rated as non-diagnostics. Conclusion: Low dose computed tomography with iterative reconstruction technique is as effective as standard dose in diagnosis of ureteric stones in obese patients with lower effective radiation dose.

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Ultra-low-dose CT-guided lung biopsy in clinic: radiation dose, accuracy, image quality, and complication rate

Acta Radiologica ◽

10.1177/0284185120917622 ◽

2020 ◽

pp. 028418512091762

Author(s):

Ting Liang ◽

Yonghao Du ◽

Chenguang Guo ◽

Yuan Wang ◽

Jin Shang ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Complication Rate ◽

Lung Biopsy ◽

Ct Guided ◽

Significant Difference ◽

Group A ◽

Mode Group ◽

Dose Accuracy ◽

Group B

Background Computed tomography (CT)-guided percutaneous lung biopsy is usually performed by helical scanning. However, there are no studies on radiation dose, diagnostic accuracy, image quality, and complications based on axial scan mode. Purpose To determine radiation dose, accuracy, image quality, and complication rate following an ultra-low-dose (ULD) protocol for CT-guided lung biopsy in clinic. Material and Methods A total of 105 patients were enrolled to receive CT-guided lung biopsy. The use of an ULD protocol (axial scan) for CT-guided biopsy was initiated. Patients were randomly assigned to axial mode (Group A) and conventional helical mode (Group B) CT groups. 64-slice CT was performed for CT-guided pulmonary biopsy with an 18-G coaxial cutting biopsy needle. The radiation dose, accuracy, image quality, and complication rate were measured. Results Ninety-seven patients were selected for the final phase of the study. There was no significant difference between the two groups for pulmonary nodule characteristics ( P > 0.05). The mean effective dose in group A (0.077 ± 0.010 mSv) was significantly reduced relative to group B (0.653 ± 0.177 mSv, P < 0.001). There was no significant difference in accuracy, image quality, and complication rate ( P > 0.050) between the two modes. Conclusion An ULD protocol for CT-guided lung nodule biopsy yields a reduction in the radiation dose without significant change in the accuracy, image quality, and complication rate relative to the conventional helical mode scan.

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Readjustment of abdominal computed tomography protocols in a university hospital: impact on radiation dose

Radiologia Brasileira ◽

10.1590/0100-3984.2014.0054 ◽

2015 ◽

Vol 48 (5) ◽

pp. 292-297 ◽

Cited By ~ 4

Author(s):

Ricardo Francisco Tavares Romano ◽

Priscila Silveira Salvadori ◽

Lucas Rios Torres ◽

Elisa Almeida Sathler Bretas ◽

Daniel Bekhor ◽

...

Keyword(s):

Computed Tomography ◽

Radiation Dose ◽

Clinical Suspicion ◽

University Hospital ◽

Abdominal Ct ◽

Abdominal Computed Tomography ◽

Computed Tomography Scans ◽

Group A ◽

Group B ◽

Tomography Scan

AbstractObjective:To assess the reduction of estimated radiation dose in abdominal computed tomography following the implementation of new scan protocols on the basis of clinical suspicion and of adjusted images acquisition parameters.Materials and Methods:Retrospective and prospective review of reports on radiation dose from abdominal CT scans performed three months before (group A – 551 studies) and three months after (group B – 788 studies) implementation of new scan protocols proposed as a function of clinical indications. Also, the images acquisition parameters were adjusted to reduce the radiation dose at each scan phase. The groups were compared for mean number of acquisition phases, mean CTDIvol per phase, mean DLP per phase, and mean DLP per scan.Results:A significant reduction was observed for group B as regards all the analyzed aspects, as follows: 33.9%, 25.0%, 27.0% and 52.5%, respectively for number of acquisition phases, CTDIvol per phase, DLP per phase and DLP per scan (p < 0.001).Conclusion:The rational use of abdominal computed tomography scan phases based on the clinical suspicion in conjunction with the adjusted images acquisition parameters allows for a 50% reduction in the radiation dose from abdominal computed tomography scans.

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Image quality and radiation dose of CT venography with double dose reduction using model based iterative reconstruction: comparison with conventional CT venography using filtered back projection

Acta Radiologica ◽

10.1177/0284185117725780 ◽

2017 ◽

Vol 59 (5) ◽

pp. 546-552 ◽

Cited By ~ 2

Author(s):

Yeo-Jin Jeong ◽

Ki Seok Choo ◽

Kyung Jin Nam ◽

Ji Won Lee ◽

Jin You Kim ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Iterative Reconstruction ◽

Radiation Doses ◽

Back Projection ◽

Filtered Back Projection ◽

Ct Venography ◽

Group A ◽

Vascular Enhancement ◽

Group B

Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B ( P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups ( P > 0.05). In addition, radiation dose in group A was significantly lower than in group B ( P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP.

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