scholarly journals Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction

2013 ◽  
Vol 12 (4) ◽  
pp. 406-410 ◽  
Author(s):  
Ryan P. Morton ◽  
Renee M. Reynolds ◽  
Rohan Ramakrishna ◽  
Michael R. Levitt ◽  
Richard A. Hopper ◽  
...  
Keyword(s):  
Image Quality ◽  
Ct Scan ◽  
Low Dose ◽  
Ct Scans ◽  
Head Ct ◽  
Full Dose ◽  
Low Dose Ct ◽  
Children's Hospital ◽  
Ct Protocol ◽  
Children’S Hospital

Object In this study, the authors describe their experience with a low-dose head CT protocol for a preselected neurosurgical population at a dedicated pediatric hospital (Seattle Children's Hospital), the largest number of patients with this protocol reported to date. Methods All low-dose head CT scans between October 2011 and November 2012 were reviewed. Two different low-dose radiation dosages were used, at one-half or one-quarter the dose of a standard head CT scan, based on patient characteristics agreed upon by the neurosurgery and radiology departments. Patient information was also recorded, including diagnosis and indication for CT scan. Results Six hundred twenty-four low-dose head CT procedures were performed within the 12-month study period. Although indications for the CT scans varied, the most common reason was to evaluate the ventricles and catheter placement in hydrocephalic patients with shunts (70%), followed by postoperative craniosynostosis imaging (12%). These scans provided adequate diagnostic imaging, and no patient required a follow-up full-dose CT scan as a result of poor image quality on a low-dose CT scan. Overall physician comfort and satisfaction with interpretation of the images was high. An additional 2150 full-dose head CT scans were performed during the same 12-month time period, making the total number of CT scans 2774. This value compares to 3730 full-dose head CT scans obtained during the year prior to the study when low-dose CT and rapid-sequence MRI was not a reliable option at Seattle Children's Hospital. Thus, over a 1-year period, 22% of the total CT scans were able to be converted to low-dose scans, and full-dose CT scans were able to be reduced by 42%. Conclusions The implementation of a low-dose head CT protocol substantially reduced the amount of ionizing radiation exposure in a preselected population of pediatric neurosurgical patients. Image quality and diagnostic utility were not significantly compromised.

scholarly journals Benefits of Low-Dose CT Scan of Head for Patients With Intracranial Hemorrhage

Dose-Response ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 155932582090977
Author(s):  
Dan Wu ◽  
Gang Wang ◽  
Bingyang Bian ◽  
Zhuohang Liu ◽  
Dan Li
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Ct Scan ◽  
Low Dose ◽  
Ct Scans ◽  
Current Time ◽  
Low Dose Ct ◽  
Tube Current ◽  
Conventional Ct ◽  
Tube Current Time Product

Objectives: For patients with intracranial hemorrhage (ICH), routine follow-up computed tomography (CT) scans are typically required to monitor the progression of intracranial pathology. Remarkable levels of radiation exposure are accumulated during repeated CT scan. However, the effects and associated risks have still remained elusive. This study presented an effective approach to quantify organ-specific radiation dose of repeated CT scans of head for patients with ICH. We also indicated whether a low-dose CT scan may reduce radiation exposure and keep the image quality highly acceptable for diagnosis. Methods: Herein, 72 patients with a history of ICH were recruited. The patients were divided into 4 groups and underwent CT scan of head with different tube current–time products (250, 200, 150, and 100 mAs). Two experienced radiologists visually rated scores of quality of images according to objective image noise, sharpness, diagnostic acceptability, and artifacts due to physiological noise on the same workstation. Organ-/tissue-specific radiation doses were analyzed using Radimetrics. Results: In conventional CT scan group, signal to noise ratio (SNR) and contrast to noise ratio (CNR) of ICH images were significantly higher than those in normal brain structures. Reducing the tube current–time product may decrease the image quality. However, the predilection sites for ICH could be clearly identified. The SNR and CNR in the predilection sites for ICH were notably higher than other areas. The brain, eye lenses, and salivary glands received the highest radiation dose. Reducing tube current–time product from 250 to 100 mA can significantly reduce the radiation dose. Discussion: We demonstrated that low-dose CT scan of head can still provide reasonable images for diagnosing ICH. The radiation dose can be reduced to ∼45% of the conventional CT scan group.

scholarly journals Agreement between low-dose and ultra-low-dose chest CT for the diagnosis of viral pneumonia imaging patterns during the COVID-19 pandemic

2022 ◽  
Vol 53 (1) ◽  
Author(s):  
Hooman Bahrami-Motlagh ◽  
Yashar Moharamzad ◽  
Golnaz Izadi Amoli ◽  
Sahar Abbasi ◽  
Alireza Abrishami ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ct Scan ◽  
Predictive Value ◽  
Low Dose ◽  
Ground Glass Opacity ◽  
Chest Ct ◽  
Viral Pneumonia ◽  
Ct Scans ◽  
Low Dose Ct ◽  
Chest Ct Scan

Abstract Background Chest CT scan has an important role in the diagnosis and management of COVID-19 infection. A major concern in radiologic assessment of the patients is the radiation dose. Research has been done to evaluate low-dose chest CT in the diagnosis of pulmonary lesions with promising findings. We decided to determine diagnostic performance of ultra-low-dose chest CT in comparison to low-dose CT for viral pneumonia during the COVID-19 pandemic. Results 167 patients underwent both low-dose and ultra-low-dose chest CT scans. Two radiologists blinded to the diagnosis independently examined ultra-low-dose chest CT scans for findings consistent with COVID-19 pneumonia. In case of any disagreement, a third senior radiologist made the final diagnosis. Agreement between two CT protocols regarding ground-glass opacity, consolidation, reticulation, and nodular infiltration were recorded. On low-dose chest CT, 44 patients had findings consistent with COVID-19 infection. Ultra-low-dose chest CT had sensitivity and specificity values of 100% and 98.4%, respectively for diagnosis of viral pneumonia. Two patients were falsely categorized to have pneumonia on ultra-low-dose CT scan. Positive predictive value and negative predictive value of ultra-low-dose CT scan were respectively 95.7% and 100%. There was good agreement between low-dose and ultra-low-dose methods (kappa = 0.97; P < 0.001). Perfect agreement between low-dose and ultra-low-dose scans was found regarding diagnosis of ground-glass opacity (kappa = 0.83, P < 0.001), consolidation (kappa = 0.88, P < 0.001), reticulation (kappa = 0.82, P < 0.001), and nodular infiltration (kappa = 0.87, P < 0.001). Conclusion Ultra-low-dose chest CT scan is comparable to low-dose chest CT for detection of lung infiltration during the COVID-19 outbreak while maintaining less radiation dose. It can also be used instead of low-dose chest CT scan for patient triage in circumstances where rapid-abundant PCR tests are not available.

Comparison of Sensitivity of Low-Dose CT Scan and Serum Galactomannan in Patients with Hematologic Malignancies and Positive Bronchoalveolar Lavage for Invasive Pulmonary Aspergillosis

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1490-1490 ◽  
Author(s):  
Sita Bhella ◽  
Narinder Paul ◽  
Shahid Husain ◽  
Joseph M. Brandwein
Keyword(s):  
Acute Leukemia ◽  
Ct Scan ◽  
Low Dose ◽  
Invasive Pulmonary Aspergillosis ◽  
Hematologic Malignancies ◽  
Ct Scans ◽  
Pulmonary Aspergillosis ◽  
Low Dose Ct ◽  
Radiologic Findings ◽  
Positive Serum

Abstract Abstract 1490 Background: Invasive pulmonary aspergillosis (IPA) is associated with considerable morbidity and mortality in patients with acute leukemia and those undergoing hematopoietic stem cell transplantation (HSCT). Timely diagnosis of IPA is crucial, but difficult. Strategies for early detection of IPA include serum galactomannan (GM), bronchoalveolar lavage (BAL) GM and characteristic radiologic abnormalities on CT scan; however, the relative sensitivity of these diagnostic tests is unclear. We sought to determine the utility of serum GM and characteristic CT radiologic abnormalities in diagnosing IPA in patients with hematologic malignancies who had a positive BAL for Aspergillus. Methods: We performed a single center retrospective cohort study from 2010 to 2012 to determine the sensitivity serum GM (OD > 0.5) and low dose CT scan in patients with hematologic malignancies. All positive BAL GM samples and Aspergillus isolates from BAL fluid cultures from patients with acute leukemia and those undergoing HSCT were reviewed; all patients had abnormal chest CT scans consistent with pulmonary infection. IPA was classified as proven, probable or possible according to EORTC/MSG criteria. Recent low dose CT scans correlating to the date of the positive BAL GM or Aspergillus isolation were reviewed and graded: halo signs, cavities, crescents and nodules were deemed to be consistent with IPA, while other changes (e.g. ground-glass changes, consolidation) were considered non-specific. Results: A total of 49 BAL samples were included; of these, 31 were considered probable IPA and 18 possible IPA (on the basis of non-specific radiologic findings). Most patients had either no prior or 1–2 days of mold-active antifungal agents. There were 43 cases with positive BAL GM and 11 cases of positive Aspergillus BAL isolates; 5 patients had both. Of the positive BAL GM cases, 27 (63%) were associated with radiologic findings consistent with IPA. The remaining cases were associated with non-specific radiologic findings. Of the patients with Aspergillus isolates on BAL, 55% (6/11) had radiologic features consistent with IPA, while the remaining cases had non-specific radiologic findings. We next evaluated the sensitivity of serum GM. Of 34 patients with BAL GM positivity who had concomitant serum GM testing, 4 (12%) had positive serum GM. Of 8 patients with Aspergillus species isolated on BAL who had serum GM performed, only 1 (12.5%) had positive serum GM. In contrast, 5/8 patients (63%) with Aspergillus isolates on BAL had a positive BAL GM. The combined sensitivity of serum GM was 12% (5/42). Conclusions: Although the majority of patients with positive BAL for Aspergillus (+GM and/or isolates) had characteristic radiologic findings on CT scan, the absence of such findings did not exclude this diagnosis, as over one third had only non-specific radiologic findings. Serum GM had very low sensitivity in this population and should not be used in isolation to diagnose IPA. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Extracting Information From Previous Full-Dose CT Scan for Knowledge-Based Bayesian Reconstruction of Current Low-Dose CT Images

2016 ◽  
Vol 35 (3) ◽  
pp. 860-870 ◽  
Author(s):  
Hao Zhang ◽  
Hao Han ◽  
Zhengrong Liang ◽  
Yifan Hu ◽  
Yan Liu ◽  
...  
Keyword(s):  
Ct Scan ◽  
Low Dose ◽  
Ct Images ◽  
Bayesian Reconstruction ◽  
Full Dose ◽  
Low Dose Ct ◽  
Knowledge Based

scholarly journals Use of Low-dose Chest CT Scan in the Evaluation of Breast Composition According to the Recommendations of BI-RADS Atlas-Fifth Edition

2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Feng Ao ◽  
Xueguo Liu ◽  
Mingzhu Liang ◽  
Jiebing Gao
Keyword(s):  
Lung Cancer ◽  
Ct Scan ◽  
Low Dose ◽  
Chest Ct ◽  
Dense Breast ◽  
Ct Scans ◽  
Low Dose Ct ◽  
Dense Breasts ◽  
Breast Tissues ◽  
Chest Ct Scan

Background: Breast cancer and lung cancer are the leading causes of cancer-related mortality in women. Computed tomography (CT) plays an important role in lung cancer examination but an unidentified role in breast examination. Objectives: To investigate the feasibility of breast composition categorization according to the fifth edition of Breast Imaging-Reporting and Data System (BI-RADS) atlas in low-dose CT screening. Patients and Methods: This was a cross-sectional study completed in The 5th Affiliated Hospital of Sun Yat-sen University, Zhuhai, China. We collected the imaging data of 57 women, who underwent low-dose chest CT scan and mammography within one week from 1st October 2013 to 31st March 2015. Two radiologists independently interpreted the mammograms and chest CT scans and classified the breast composition into categories a, b, c, and d. We also summarized the distribution of breast composition categories by collecting, observing, and classifying the chest CT scans from 1916 female examinees from 1st October 2013 to 31st March 2016. Results: Excellent agreement was observed between the two radiologists, using both low-dose CT scan (κ = 0.91) and mammography (κ = 0.86). Agreement between low-dose chest CT scan and mammography was moderate for radiologist A (κ = 0.50) and radiologist B (κ = 0.43). More breasts were classified in categories a and b on the chest CT scan compared to mammography according to both radiologist A (P < 0.01) and radiologist B (P < 0.01). The proportion of non-dense breast tissues (categories a & b) increased with advancing age, while the proportion of dense breast tissues (categories c & d) decreased (P < 0.05). With advancing age, the probability of non-dense breasts increased, while the probability of dense breasts decreased. Conclusions: Based on the findings, it is feasible to categorize breast composition using low-dose chest CT. In the older age group, the probability of non-dense breasts increased.

scholarly journals A Preliminary Study of Personalized Head CT Scan in Pediatric Patients

Dose-Response ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 155932582098566
Author(s):  
Bian Bingyang ◽  
Wang Gang ◽  
Shao Zhiqing ◽  
Nan Li ◽  
BoXu Zhou ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Ct Scan ◽  
Low Dose ◽  
Pediatric Patients ◽  
Radiation Doses ◽  
Current Time ◽  
Head Ct ◽  
Tube Current ◽  
Organ Specific

Objectives: In the present study, we introduced a practical approach to quantify organ-specific radiation doses and investigated whether low-dose head circumference (HC)-based protocols for non-enhanced head computed tomography (CT) could reduce organs-specific radiation dose in pediatric patients while maintaining high image quality. Methods: A total of 83 pediatric patients were prospectively recruited. Without limits to the HC, 15 patients were selected as a convention group (CON group) and underwent non-enhanced head CT scan with standard-dose protocols (tube current-time products of 250mAs). Low-dose group (LD group), including remaining 68 pediatrics were divided into 3 subgroups based on the HC: 54.1-57.0 cm for LD200mAs group (HC-based protocols of 200mAs), 51.1-54.0 cm for LD150mAs group (HC-based protocols of 150mAs), 48.1-51.0 cm for LD100mAs group (HC-based protocols of 100mAs). Subjective and objective image quality was evaluated and measured by 2 experienced radiologists. Radimetrics was used to calculate organs-specific radiation dose, including the brain, eye lenses, and salivary glands. Results: In CON250mAs group, radiation doses in the brain and salivary glands were conversely correlated with HC, and pediatric patients with smaller HC received higher organs-specific radiation dose. Reducing tube current-time product from 250 to 100mAs could significantly reduce the organ-specific radiation dose. The subjective image quality score ≥ 3.0 is acceptable for diagnosis purposes. The signal to noise ratio (SNR) and the contrast to noise ratio (CNR) of bilateral thalamus and centrum semiovale in 3 LD subgroups were not statistically different compared with the CON group. Conclusion: Our research indicated that low-dose HC-based protocols of non-enhanced head CT scan can evidently reduce the organ-specific radiation doses, while maintaining high image quality. HC can serve as a vital tool to guide personalized low-dose head CT scan for pediatric patients.

scholarly journals Clinical Features of Pregnant Women and Neonates with COVID-19 in Wuhan: a paired comparison study

2020 ◽  
Author(s):  
Qin Xie ◽  
Quan Gan ◽  
Jing Hu ◽  
Dong Zhou ◽  
Shuhan Cai ◽  
...  
Keyword(s):  
Ct Scan ◽  
Pregnant Women ◽  
Hubei Province ◽  
Chest Ct ◽  
Ct Scans ◽  
Premature Delivery ◽  
Children's Hospital ◽  
Children’S Hospital ◽  
The Impact ◽  
In Pregnancy

Abstract Background Our study aimed to find symptoms unique in pregnancy and to help the early diagnosis in pregnant women and to evaluate the impact of COVID-19 in postpartum women and their newborns. Methods Clinical data were reviewed and collected for 11 pregnant women with laboratory-confirmed COVID-19 who were consecutively admitted to Zhongnan Hospital of Wuhan University and Women and Children’s Hospital of Hubei Province, from Jan 26 to Feb 26, 2020. Results All the confirmed women didn’t have any exposure history and their early symptoms were mildly elevated temperate and fatigue. The chest CT scans of confirmed women can be atypical manifestations, such as bilateral pleural effusions and slightly increased densities. Eight of eleven confirmed women did not feel anything unusual until abnormalities were found on chest CT scans on admission screening test. All three groups had elevated white blood cell count, neutrophil count and lactate dehydrogenase, and reduced total protein.The infection did not increase the risk for premature delivery, premature rupture of membrane, or comorbidities in pregnancy. Conclusions Pregnant women were often asymptomatic and accidentally detected abnormalities on chest CT scan on admission which emphasize the importance of CT scan in prevalent areas of the COVID-19. Even after the laboratory confirmation, the manifestation of the CT scan could be atypical, which alerted the necessity of protection for healthcare workers. The COVID-19 did not increase the risk of complications in pregnant women and their neonates. Trial registration: This case series was approved by the institutional ethics board of Zhongnan Hospital of Wuhan University (No. 2020020) and Women and Children’s Hospital of Hubei Province(NO. LW035).

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