Direct visualization of postoperative aortobronchial fistula on computed tomography

BACKGROUND Postoperative aortobronchial fistula(ABF)is a rare complication that can occur in 0.3%-5.0%of patients over an extended period of time after thoracic aortic surgery.Direct visualization of the fistula via imaging is rare.AIM To investigate the relationship between computed tomography(CT)findings and the clinical signs/symptoms of ABF after thoracic aortic surgery.METHODS Six patients(mean age 71 years,including 4 men and 2 women)with suspected ABF on CT(air around the graft)at our hospital were included in this retrospective study between January 2004 and September 2022.Chest CT findings included direct confirmation of ABF,peri-graft fluid,ring enhancement,dirty fat sign,atelectasis,pulmonary hemorrhage,and bronchodilation,and the clinical course were retrospectively reviewed.The proportion of each type of CT finding was calculated.RESULTS ABF detection after surgery was found to have a mean and median of 14 and 13 years,respectively.Initial signs and symptoms were asymptomatic in 4 patients,bloody sputum was found in 1 patient,and fever was present in 1 patient.The complications of ABF included graft infection in 2 patients and graft infection with hemoptysis in 2 patients.Of the 6 patients,3 survived,2 died,and 1 was lost to follow-up.The locations of the ABFs were as follows:1 in the ascending aorta;1 in the aortic arch;2 in the aortic arch leading to the descending aorta;and 2 in the descending aorta.ABFs were directly confirmed by CT in 4/6(67%)patients.Peri-graft dirty fat(4/6,67%)and peri-graft ring enhancement(3/6,50%)were associated with graft infection,endoleaks and pseudoaneurysms were associated with hemoptysis(2/6,33%).CONCLUSION Asymptomatic ABF after thoracic aortic surgery can be confirmed on chest CT.CT is useful for the diagnosis of ABF and its complications.

Radiation Dose Survey of Pediatric Chest Computed Tomography Examinations: A Local Diagnostic Reference Levels Approach to Patient Safety

Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .

Coronary artery calcium score on low-dose computed tomography for lung cancer screening

AIM: To evaluate the feasibility of coronary artery calcium score(CACS) on low-dose non-gated chest CT(ngCCT).METHODS: Sixty consecutive individuals(30 males; 73 ± 7 years) scheduled for risk stratification by means of unenhanced ECG-triggered cardiac computed to-mography(gCCT) underwent additional unenhanced ngCCT. All CT scans were performed on a 64-slice CT scanner(Somatom Sensation 64 Cardiac, Siemens, Germany). CACS was calculated using conventional methods/scores(Volume, Mass, Agatston) as previ-ously described in literature. The CACS value obtained were compared. The Mayo Clinic classification was used to stratify cardiovascular risk based on Agatston CACS. Differences and correlations between the two methods were compared. A P-value < 0.05 was considered sig-nificant.RESULTS: Mean CACS values were significantly higher for gCCT as compared to ngCCT(Volume: 418 ± 747 vs 332 ± 597; Mass: 89 ± 151 vs 78 ± 141; Agatston: 481 ± 854 vs 428 ± 776; P < 0.05). The correlation between the two values was always very high(Volume: r = 0.95; Mass: r = 0.97; Agatston: r = 0.98). Of the 6 patients with 0 Agatston score on gCCT, 2(33%) showed an Agatston score > 0 in the ngCCT. Of the 3 patients with 1-10 Agatston score on gCCT, 1(33%) showed an Agatston score of 0 in the ngCCT. Overall, 23(38%) patients were reclassified in a different car-diovascular risk category, mostly(18/23; 78%) shifting to a lower risk in the ngCCT. The estimated radiation dose was significantly higher for gCCT(DLP 115.8 ± 50.7 vs 83.8 ± 16.3; Effective dose 1.6 ± 0.7 mSv vs 1.2 ± 0.2 mSv; P < 0.01).CONCLUSION: CACS assessment is feasible on ngCCT; the variability of CACS values and the associated re-stratification of patients in cardiovascular risk groups should be taken into account.

Low-dose computed tomography with 4th-generation iterative reconstruction algorithm in assessment of oncologic patients

AIM To compare radiation dose and image quality of lowdose computed tomography(CT) protocol combined with hybrid-iterative reconstruction algorithm with standarddose CT examinations for follow-up of oncologic patients. METHODS Fifty-one patients with known malignant diseases which underwent, during clinical follow-up, both standarddose and low-dose whole-body CT scans were enrolled. Low-dose CT was performed on 256-row scanner, with 120 kV and automated m A modulation, and iterative reconstruction algorithm. Standard-dose CT was performed on 16-rows scanner, with 120 kV, 200-400 m As(depending on patient weight). We evaluated density values and signal-to-noise ratio, along with image noise(SD), sharpness and diagnostic quality with 4-point scale.RESULTS Density values in liver, spleen and aorta were higher in lowdose images(liver 112.55 HU vs 103.90 HU, P < 0.001), as SD values in liver and spleen(liver 16.81 vs 14.41). Volumetric-Computed-Tomographic-Dose-Index(CTDIvol) and Dose-Length-Product(DLP) were significantly lower in low-dose CT as compared to standard-dose(DLP 1025.6 m Gy*cm vs 1429.2 m Gy*cm, P < 0.001) with overall dose reduction of 28.9%. Qualitative analysis did not reveal significant differences in image noise and diagnostic quality.CONCLUSION Automatic tube-current modulation combined with hybriditerative algorithm allows radiation dose reduction of 28.9% without loss of diagnostic quality, being useful in reducing dose exposure in oncologic patients.

Quantitative evaluation of deep convolutional neural network-based image denoising for low-dose computed tomography

To minimize radiation risk,dose reduction is important in the diagnostic and therapeutic applications of computed tomography(CT).However,image noise degrades image quality owing to the reduced X-ray dose and a possible unacceptably reduced diagnostic performance.Deep learning approaches with convolutional neural networks(CNNs)have been proposed for natural image denoising;however,these approaches might introduce image blurring or loss of original gradients.The aim of this study was to compare the dose-dependent properties of a CNN-based denoising method for low-dose CT with those of other noise-reduction methods on unique CT noise-simulation images.To simulate a low-dose CT image,a Poisson noise distribution was introduced to normal-dose images while convoluting the CT unit-specific modulation transfer function.An abdominal CT of 100 images obtained from a public database was adopted,and simulated dose-reduction images were created from the original dose at equal 10-step dose-reduction intervals with a final dose of 1/100.These images were denoised using the denoising network structure of CNN(DnCNN)as the general CNN model and for transfer learning.To evaluate the image quality,image similarities determined by the structural similarity index(SSIM)and peak signal-to-noise ratio(PSNR)were calculated for the denoised images.Significantly better denoising,in terms of SSIM and PSNR,was achieved by the DnCNN than by other image denoising methods,especially at the ultra-low-dose levels used to generate the 10%and 5%dose-equivalent images.Moreover,the developed CNN model can eliminate noise and maintain image sharpness at these dose levels and improve SSIM by approximately 10%from that of the original method.In contrast,under small dose-reduction conditions,this model also led to excessive smoothing of the images.In quantitative evaluations,the CNN denoising method improved the low-dose CT and prevented over-smoothing by tailoring the CNN model.

Chest radiographic and computed tomographic manifestations in allergic bronchopulmonary aspergillosis

AIM: To investigate the chest radiographic and high resolution computed tomography (HRCT) chest manifestations in glucocorticoid-na?ve allergic bronchopulmonary aspergillosis (ABPA) patients. METHODS: This is a prospective observational study and includes 60 consecutive glucocorticoid-na?ve patients with ABPA who underwent chest radiography and HRCT of the chest (1.25 mm every 10 mm) in the routine diagnostic workup for ABPA. RESULTS: Chest radiographs were normal in 50% of cases. Of the remainder, most patients demonstrated permanent findings in the form of parallel line and ring shadows suggesting bronchiectasis. Consolidation was detected in 17 cases but in the majority, the corresponding HRCT chest scan showed mucus-filled bronchiectatic cavities. Chest HRCT was normal in 22 patients, while central bronchiectasis (CB) was demonstrated in the remaining 38 patients. Bronchiectasis extended to the periphery in 33%-43% depending on the criteria used for defining CB. The other findings observed on HRCT were mucoid impaction, centrilobular nodules and high-attenuation mucus in decreasing order of frequency. CONCLUSION: Patients with ABPA can present with normal HRCT chest scans. Central bronchiectasis cannot be considered a characteristic feature of ABPA as peripheral bronchiectasis is commonly observed. Consolidation is an uncommon finding in ABPA.

Management of computed tomography scan detected hemothorax in blunt chest trauma:What computed tomography scan measurements say?

AIM To investigate the hemothorax size for which tube thoracostomy is necessary.METHODS Over a 5-year period, we included all patients who were admitted with blunt chest trauma to our level 1 trauma center. Focus was placed on identifying the hemothorax size requiring tube thoracostomy.RESULTS A total number of 274 hemothoraces were studied. All patients with hemothoraces measuring above 3 cm received a chest tube. The 50% predicted probability of tube thoracostomy was 2 cm. Pneumothorax was associated with odds of receiving tube thoracostomy for hemothoraces below 2 cm(Odds Ratio:4.967, 95%CI: 2.225-11.097, P < 0.0001).CONCLUSION All patients with a hemothorax size greater than 3% underwent tube thoracostomy. Prospective studies are warranted to elucidate the clinical outcome of patients with smaller hemothoraces.

High-resolution computed tomography in patients with atypical 'cardiac' chest pain: a study investigating patients at 10-year cardiovascular risks defined by the Framingham and PROCAM scores

Background and objective Atypical 'cardiac' chest pain (ACCP) is not usually caused by myocardial ischaemia. Current noninvasive investigations for these symptoms are not yet as accurate as invasive coronary angiography. The latest 64-row multi-detector computed tomography (MDCT) technology is non-invasive, has high specificity and negative predictive values for the detection of significant coronary disease. Our aim was to investigate if this modality can provide more information in the assessment of outpatients with ACCP in addition to established cardiovascular risk scores. Methods Seventy consecutive patients presenting to the outpatient clinic with ACCP underwent 64-row MDCT scan of the coronary arteries. They were categorized into low, medium or high risk groups based upon the Framingham and PROCAM scores. We defined a clinically abnormal MDCT scan as coronary stenosis =50% or calcium score ＞400 Agatston. Results Fifty-three (75.7%) patients did not have clinically abnormal scans. Framingham score classified 43 patients as low-risk while PROCAM classified 59 patients as low-risk. MDCT scans were abnormal for 18.6% and 22.0% of the respective low-risk group of patients. For patients with medium-to-high risk, 33.3% and 36.4% of Framingham and PROCAM patient groups respectively had abnormal MDCT scans. Conclusion MDCT adds valuable information in the assessment of patients with ACCP by identifying a significant proportion of patients categorized as low-risk to have underlying significant coronary stenosis and coronary calcification by established cardiovascular risk scores.

Imaging Findings in Chest Computed Tomography: Initial Experience in a Developing Country

Background:?High resolution chest computed tomography (HRCT) is an established imaging modality that accurately assesses disease processes that are non-specific on conventional chest radiography. Chest Computed Tomography (CT) has proven invaluable in the evaluation of various diseases of the chest providing precise diagnosis that have great impact on the course of management. In this study, our aim is to evaluate the spectrum of radiological findings in all patients that had chest CTs at a tertiary health Institution in a developing Country. Method: This is a 6-year retrospective study of all patients that had Chest CT from 2009 till 2015. All patient data were retrieved and their Chest CT images reviewed and radiological findings and diagnosis documented. Results: Age range of patients was 1 - 84 years with a mean of 52.36 ± 22.9 years. Ten patients were children (12%). There were more males 53 (63.1%) than females 31 (36.9%) in the study. Referral for imaging was predominantly from internal medicine 33 (47.1%) and Surgery 27 (38.6%) departments. Most of the patients, 53 (63.1%) did not have previous chest radiographs. Consolidative changes were the most common parenchymal finding (77.4%). Few mediastinal masses were found in the study population. CT angiography constituted only 10.7% of all chest CTs done in adults. Conclusion: Few chest CT evaluations are performed compared to CTs of other parts of the body done in the same period. Chest CT is generally under-utilized even in a tertiary institution. There is a need to educate chest physicians on the role and advantages of CT use for the management of their patients.

Cardiovascular Risk Factors and Epicardial Adipose Tissue Measured by Chest Computed Tomography in Healthy Adults

Background: Epicardial adipose tissue (EAT) may produce several cytokines contributed to coronary atherosclerosis. EAT was measured by transthoracic echocardiography or 3 dimensional cardiac computed tomography (CT) on previous studies. We aimed to evaluate the correlation between EAT thickness and cardiovascular risk factors in healthy adults. Method: We collected clinical, biochemical information from 469 subjects (371 men and 98 women) who visited our health promotion center. EAT thickness was measured by chest CT on the free wall of the right ventricle. Result: The mean EAT thickness was 2.47 ± 1.64 mm in total of 469 subjects. EAT thickness was significantly correlated to age, weight, body mass index (BMI), total body fat, systolic and diastolic blood pressure, total cholesterol, low density lipoprotein (LDL)-cholesterol, and fasting glucose in men and to age, height, weight, BMI, total body fat, systolic and diastolic blood pressure, triglycerides, C-reactive protein (CRP), and fasting glucose in women. Multivariate analysis showed that age, BMI, systolic blood pressure, fasting glucose were the variables that independently correlated to EAT thickness in men. But there was no significant independent variable in women. Conclusion: In our study, EAT thickness measured with chest CT in healthy individuals correlates with cardiovascular risk factors in men.

Lung cancer screening: Computed tomography or chest radiographs?

Worldwide, lung cancer is the leading cause of mortalitydue to malignancy. The vast majority of cases of lung cancer are smoking related and the most effective way of reducing lung cancer incidence and mortality is by smoking cessation. In the Western world, smoking cessation policies have met with limited success. The other major means of reducing lung cancer deaths is to diagnose cases at an earlier more treatable stage employing screening programmes using chest radiographs or low dose computed tomography. In many countries smoking is still on the increase, and the sheer scale of the problem limits the affordability of such screening programmes. This short review article will evaluate the current evidence and potential areas of research which may benefit policy making across the world.

Usefulness of Chest Computed Tomography for Diagnosis of Idiopathic Pneumomediastinum with Negative Findings on Plain X-Ray

Idiopathic pneumomediastinum is rare in children. Few cases of patients with pneumomediastinum show negative findings on X-ray examination. Chest computed tomography (CT) was very useful for the diagnosis and evaluation of the extent of pneumomediastinum. We report here a case of idiopathic pneumomediastinum in a 15-year-old boy who exhibited no significant chest X-ray finding. The patient was referred to our institute for the further evaluation of pre-cordial pain and breathing difficulty. Precordial pain suddenly developed, when he was carrying a portable shrine on his shoulder (day of onset). He was admitted to another institute 3 days after onset because of worsening precordial pain. On admission, he presented with 98% saturation of hemoglobin in the peripheral blood under room air. Plain chest X-ray also revealed no abnormal findings. A half-dissolved gastrographin swallow showed no leakage of gastrographin from the pharynx and esophagus to the mediastinum, and no diverticulum within the esophagus. Plain chest CT revealed extensive emphysema around the trachea from the neck to the portion inferior to the carina of trachea. The patient was diagnosed with idiopathic pneumomediastinum because the cause was unclear. We decided to admit him to our institute under fasting conditions and rest. His symptoms improved 3 days after onset. The lesion had disap-peared 8 days after onset on chest CT. When young people experience precordial pain which increases on inspiration, we must consider pneumomediastinum in a differential diagnosis, and it is important to perform chest CT.

Chest Computed Tomography of Elderly Subjects at University Hospital Campus Lomé

Background: Radiology in elderly as pediatric radiology poses a number of problems. The normal radiological appearance of the elderly patient’s chest is very varied and the changes are ubiquitous. Purpose: To describe the computed tomography profile of the elderly subject’s chest. Materials and Methods: Descriptive prospective study from January 1st to June 30th, 2018 carried out at the University Campus Hospital of Lomé. Results: We recorded 64 chest CT scans. The average age of the patients was 71.3. Internists (n = 21, 32.8%) and general practitioner (n = 16, 25%) were the major applicants for these tests. In most cases, thoracic CT examinations were requested as part of an extension assessment (n = 21, 32.8%), dyspnea and pneumonitis in 18.8% of cases each. All thoracic CT examinations were performed with contrast injection. CT with the TAP protocol was the most observed, accounted for more than half of the exams (56%). The main pathological lesions observed were diffuse parenchymal lesions (39.5%), pleurisy (11.1%) and PAH (11.1%). Conclusion: Computed tomography occupies an important place in the care of the elderly but the actors involved in their care must be trained to take optimal care.

“Pulmonary target sign” as a diagnostic feature in chest computed tomography of COVID-19

BACKGROUND In chest computed tomography(CT)scan,bilateral peripheral multifocal groundglass opacities,linear opacities,reversed halo sign,and crazy-paving pattern are suggestive for coronavirus disease 2019(COVID-19)in clinically suspicious cases,but they are not specific for the diagnosis,as other viral pneumonias,like influenza and some viral pneumonia may show similar imaging findings.AIM To find a specific imaging feature of the disease would be a welcome guide in diagnosis and management of challenging cases.METHODS Chest CT imaging findings of 650 patients admitted to a university Hospital in Tehran,Iran between January 2020 and July 2020 with confirmed COVID-19 infection by RT-PCR were reviewed by two expert radiologists.In addition to common non-specific imaging findings of COVID-19 pneumonia,radiologic characteristics of“pulmonary target sign”(PTS)were assessed.PTS is defined as a circular appearance of non-involved pulmonary parenchyma,which encompass a central hyperdense dot surrounded by ground-glass or alveolar opacities.RESULTS PTS were presented in 32 cases(frequency 4.9%).The location of the lesions in 31 of the 32 cases(96.8%)was peripheral,while 4 of the 31 cases had lesions both peripherally and centrally.In 25 cases,the lesions were located near the pleural surface and considered pleural based and half of the lesions(at least one lesion)were in the lower segments and lobes of the lungs.22 cases had multiple lesions with a>68%frequency.More than 87%of cases had an adjacent bronchovascular bundle.Ground-glass opacities were detectable adjacent or close to the lesions in 30 cases(93%)and only in 7 cases(21%)was consolidation adjacent to the lesions.CONCLUSION Although it is not frequent in COVID-19,familiarity with this feature may help radiologists and physicians distinguish the disease from other viral and noninfectious pneumonias in challenging cases.

Artificial intelligence computed tomography helps evaluate the severity of COVID-19 patients:A retrospective study

BACKGROUND:Computed tomography(CT)is a noninvasive imaging approach to assist the early diagnosis of pneumonia.However,coronavirus disease 2019(COVID-19)shares similar imaging features with other types of pneumonia,which makes differential diagnosis problematic.Artificial intelligence(AI)has been proven successful in the medical imaging field,which has helped disease identification.However,whether AI can be used to identify the severity of COVID-19 is still underdetermined.METHODS:Data were extracted from 140 patients with confirmed COVID-19.The severity of COVID-19 patients(severe vs.non-severe)was defined at admission,according to American Thoracic Society(ATS)guidelines for community-acquired pneumonia(CAP).The AI-CT rating system constructed by Hangzhou YITU Healthcare Technology Co.,Ltd.was used as the analysis tool to analyze chest CT images.RESULTS:A total of 117 diagnosed cases were enrolled,with 40 severe cases and 77 non-severe cases.Severe patients had more dyspnea symptoms on admission(12 vs.3),higher acute physiology and chronic health evaluation(APACHE)II(9 vs.4)and sequential organ failure assessment(SOFA)(3 vs.1)scores,as well as higher CT semiquantitative rating scores(4 vs.1)and AI-CT rating scores than non-severe patients(P<0.001).The AI-CT score was more predictive of the severity of COVID-19(AUC=0.929),and ground-glass opacity(GGO)was more predictive of further intubation and mechanical ventilation(AUC=0.836).Furthermore,the CT semiquantitative score was linearly associated with the AI-CT rating system(Adj R2=75.5%,P<0.001).CONCLUSIONS:AI technology could be used to evaluate disease severity in COVID-19 patients.Although it could not be considered an independent factor,there was no doubt that GGOs displayed more predictive value for further mechanical ventilation.

Typical and atypical COVID-19 computed tomography findings

In December 2019 a novel coronavirus,named severe acute respiratory syndrome coronavirus 2 was identified and the disease associated was named coronavirus disease 2019(COVID-19).Fever,cough,myalgia,fatigue associated to dyspnea represent most common clinical symptoms of the disease.The reference standard for diagnosis of severe acute respiratory syndrome coronavirus 2 infection is real time reverse-transcription polymerase chain reaction test applied on respiratory tract specimens.Despite of lower specificity,chest computed tomography(CT),as reported in manifold scientific studies,showed high sensitivity,therefore it may help in the early detection,management and follow-up of COVID-19 pneumonia.Patients affected by COVID-19 pneumonia usually showed on chest CT some typical features,such as:Bilateral ground glass opacities characterized by multilobe involvement with posterior and peripheral distribution;parenchymal consolidations with or without air bronchogram;interlobular septal thickening;crazy paving pattern,represented by interlobular and intralobular septal thickening surrounded by ground-glass opacities;subsegmental pulmonary vessels enlargement(>3 mm).Halo sign,reversed halo sign,cavitation and pleural or pericardial effusion represent some of atypical findings of COVID-19 pneumonia.On the other hand lymphadenopathy’s and bronchiectasis’frequency is unclear,indeed conflicting data emerged in literature.Radiologists play a key role in recognition of high suspicious findings of COVID-19 on chest CT,both typical and atypical ones.Thus,the aim of this review is to illustrate typical and atypical CT findings of COVID-19.

Accuracy of baseline low-dose computed tomography lung cancer screening: a systematic review and meta-analysis

Background:Screening using low-dose computed tomography(LDCT)is a more effective approach and has the potential to detect lung cancer more accurately.We aimed to conduct a meta-analysis to estimate the accuracy of population-based screening studies primarily assessing baseline LDCT screening for lung cancer.Methods:MEDLINE,Excerpta Medica Database,and Web of Science were searched for articles published up to April 10,2022.According to the inclusion and exclusion criteria,the data of true positives,false-positives,false negatives,and true negatives in the screening test were extracted.Quality Assessment of Diagnostic Accuracy Studies-2 was used to evaluate the quality of the literature.A bivariate random effects model was used to estimate pooled sensitivity and specificity.The area under the curve(AUC)was calculated by using hierarchical summary receiver-operating characteristics analysis.Heterogeneity between studies was measured using the Higgins I 2 statistic,and publication bias was evaluated using a Deeks’funnel plot and linear regression test.Results:A total of 49 studies with 157,762 individuals were identified for the final qualitative synthesis;most of them were from Europe and America(38 studies),ten were from Asia,and one was from Oceania.The recruitment period was 1992 to 2018,and most of the subjects were 40 to 75 years old.The analysis showed that the AUC of lung cancer screening by LDCT was 0.98(95%CI:0.96-0.99),and the overall sensitivity and specificity were 0.97(95%CI:0.94-0.98)and 0.87(95%CI:0.82-0.91),respectively.The funnel plot and test results showed that there was no significant publication bias among the included studies.Conclusions:Baseline LDCT has high sensitivity and specificity as a screening technique for lung cancer.However,long-term follow-up of the whole study population(including those with a negative baseline screening result)should be performed to enhance the accuracy of LDCT screening.

Low-Dose High-Pitch Cardiac CT to Evaluate Abnormal Pacemaker Lead Position

Displacement of a cardiac pacemaker lead or myocardial perforation by a lead is an infrequent complication of pacemaker implantation. While standard cardiac CT is useful for diagnosing such complications when routine examinations can not, the potential risks associated with exposure to the high doses of radiation used in CT are of concern. Here, we report three cases in which pacemaker lead displacement or myocardial perforation was definitively diagnosed by low-dose cardiac CT used in the high-pitch spiral mode, when other more routine examinations failed to suggest their occurrence. The mean dose of radiation used for definitively diagnosing the three patients was relatively low (2.19 mSv).

胸部CT图像质量评价与辐射剂量的临床应用研究

目的:归纳和分析影响胸部CT图像质量的因素,进一步对照分析常规剂量组和低剂量组两组图像质量有无差异,以论证胸部CT低剂量检查的可行性。方法:选取150例胸部CT查体的患者,A组为常规剂量组,管电压120kV,管电流自动调节;B组为低剂量组,管电压100kV,管电流自动调节。参照胸部CT的图像质量评价标准对常规剂量组和低剂量组图像质量进一步作出主观评价。对辐射剂量、信噪比等客观数据进行统计学处理,以P<0.05为差异有统计学意义。并与主观评价相比较。结果:主、客观评价两组图像质量均无统计学意义,A组辐射剂量与B组辐射剂量有统计学意义。结论:影响图像质量的因素包括患者的因素、设备的因素以及操作者的因素,胸部CT采用100kV低剂量检查可以作为常规扫描方案,获得的图像可以满足影像诊断的要求,具有可行性。

腹主动脉联合常规一站式胸痛三联CTA检查在急性胸痛患者诊疗中的价值

目的 探讨腹主动脉联合常规胸痛三联CT血管成像(triple rule-out computed tomography angiography, TRO-CTA)检查在急性胸痛患者检查中的价值。方法 回顾性纳入1 482例急性非创伤性胸痛患者,414例患者接受传统的TRO-CTA扫描,1 068例患者在临床医师的要求下接受包括腹主动脉的TRO-CTA扫描(TRO-CTAwAA)。两组患者主动脉期的扫描范围不同:常规TRO-CTA只扫描胸主动脉,TRO-CTAwAA扫描整个主动脉,其余所有的扫描参数均相同。采用卡方检验对两组主动脉主要血管异常(主动脉夹层、动脉瘤、穿透性溃疡、壁内血肿、血管闭塞和血栓形成)的检出率进行比较。采用方差分析(ANOVA)对两组辐射剂量(CTDIvol和DLP)和扫描时间进行比较。结果 TRO-CTAwAA组的主动脉异常检出率明显高于TRO-CTA组(35.1%vs. 4.8%,P<0.001)。在TRO-CTAwAA组中,有26.5%的血管异常在胸主动脉和腹主动脉上均可检出,另外8.6%只发生在腹主动脉上。两组间辐射剂量相比,TRO-CTAwAA组的总DLP明显高于常规TRO-CTA(P<0.001)。两组扫描时间对比差别无统计学意义(P=0.410)。结论 腹主动脉联合常规TRO-CTA检查,可显著提高急性胸痛患者主动脉血管异常的检出率,不增加检查流程。