My Thesis in 3 Minutes

Cardiac

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Lectures

1
MyT3 16 - Screening potential of low-dose chest CT in assessing the degree of coronary arteries calcification

MyT3 16 - Screening potential of low-dose chest CT in assessing the degree of coronary arteries calcification

03:51O. Styazhkina, Moscow / RU

Purpose:

Coronary artery calcinosis is a specific biomarker of coronary atherosclerosis. It is often detected on chest CT scans. Today the popularity of lung cancer screening with low-dose CT is growing. The aim of the study is to compare the diagnostic value of low-dose chest CT for the assessment of calcium score in comparison with the standard gated calcium scoring.

Methods and materials:

Non-gated low-dose chest CT and gated calcium scoring were performed in 251 asymptomatic patients. The Agatston calcium score values obtained from low-dose CT and gated scans were analysed independently by two radiologists. Inter-observer and inter-technique agreement were evaluated (data with "zero" calcium scores was excluded). Inter-technique differences in a stratification of patients into five risk categories (scores 0, 1-100, 101-400, 401-1000 and> 1000) using the kappa coefficient (k) were analysed.

Results:

The sensitivity of non-gated calcium scoring compared to the standard technique was 95%, specificity - 99%. The proportion of "zero" calcium score values in our study was 31% (79 patients). The inter-technique concordance was quite high, both with the inclusion of "zero" values ​​(r=0.981, p<0.05) and without them (r=0.978, p<0.05). The inter-observer agreement was 0.998. The inter-technique agreement in the stratification of patients into the five risk groups according to the calcium score values was also high: k = 0.846. Effective radiation dose in low-dose chest CT was significantly lower than in the case of gated calcium scoring (0.96 ± 0.26 vs 1.51 ± 0.22 mSv, p<0.01).

Conclusion:

The study showed that non-gated low-dose chest CT can be effectively used both for lung cancer screening and coronary calcium scoring with lower radiation exposure to patients than in gated calcium score.

Limitations:

No limitations were identified.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

2
MyT3 16 - Diagnostic performance of myocardial CT perfusion imaging for the detection of obstructive coronary artery disease: intraindividual comparison of half scan and multisegment reconstruction

MyT3 16 - Diagnostic performance of myocardial CT perfusion imaging for the detection of obstructive coronary artery disease: intraindividual comparison of half scan and multisegment reconstruction

02:38D. Preuß, Berlin / DE

Purpose:

To compare the diagnostic performance of half scan reconstruction (HSR) and multisegment reconstruction (MSR) of myocardial CT perfusion (CTP) imaging for the detection of obstructive coronary artery disease (CAD).

Methods and materials:

A total of 134 consecutive patients (median age, 65.7 years; interquartile range, 55.9-70.2) prospectively underwent CTP. 93 patients had multisegment acquisition and were retrospectively interpreted for perfusion defects. In these patients, we performed both HSR and MSR and compared their diagnostic performance using ≥50% diameter stenosis in the supplying artery on quantitative coronary angiography as the reference standard. AUC and diagnostic performance were compared using DeLong et al.´s and McNemar´s approaches.

Results:

Per-patient analysis revealed an overall AUC of HSR and MSR of 0.79 [95% confidence interval: 0.69, 0.88] and 0.65 [0.53, 0.78] (P= .01), respectively. Diagnostic accuracy of HSR was superior to MSR in patients with known CAD (74% (50 of 68) vs 63% (43 of 68); P< .001) and low heart rate variability (70% (39 of 56) vs 59% (33 of 56); P= .001). Diagnostic performance of HSR and MSR was the same in patients with suspected CAD (72% (18 of 25) vs 76% (19 of 25); P= .99) and heart rates ≥75 beats per minute (67% (20 of 30) vs 70% (21 of 30); P= .24).

Conclusion:

HSR of myocardial CTP has a higher diagnostic performance than MSR in patients with known CAD and low heart rate variability. The two reconstruction methods have the same diagnostic performance in patients with suspected CAD and high heart rates.

Limitations:

The subgroups have only a small number of patients.

Ethics committee approval

IRB approval and written informed consent were obtained.

Funding:

No funding was received for this work.

3
MyT3 16 - Myocardial CT perfusion imaging for the detection of obstructive coronary artery disease: should interpretation of perfusion defects be different depending on disease status?

MyT3 16 - Myocardial CT perfusion imaging for the detection of obstructive coronary artery disease: should interpretation of perfusion defects be different depending on disease status?

02:29D. Preuß, Berlin / DE

Purpose:

To investigate whether perfusion defect (PD) interpretation of myocardial CT perfusion (CTP) should be different in patients with suspected or known coronary artery disease (CAD) for the detection of obstructive CAD.

Methods and materials:

A total of 134 consecutive patients with known or suspected CAD prospectively underwent CTP. Rest and stress PDs were retrospectively interpreted in four reading categories (RC): RC 1 (stress volume positive), RC 2 (rest or stress volume positive), RC 3 (stress-induced PDs positive), RC 4 (stress-induced and partially reversible PDs positive). Detection of ≥50% diameter stenosis in the supplying artery on quantitative coronary angiography (reference 1) and intervention (reference 2) served as the reference standards.

Results:

When using reference 1, per-patient analysis revealed AUCs of RC 1-4 of 0.74, 0.65, 0.62, and 0.72, respectively, in patients with known CAD. In these patients, AUC of RC 1 was higher than RC 3 (P= .03) and, respectively, AUC of RC 4 was higher than RC 3 (P= .006). In patients with suspected CAD, AUCs of RC 1-4 were the same (0.83, 0.86, 0.85, 0.88; all P> .05). When using reference 2, AUCs of RC 1-4 in patients with known CAD (0.61, 0.60, 0.67, 0.69) and, respectively, in patients with suspected CAD (0.75, 0.80, 0.76, 0.80) were the same at per-patient level analysis (all P> .05).

Conclusion:

In patients with known or suspected CAD, every stress PD should be judged positive to detect obstructive CAD in myocardial CTP regardless of its presentation in rest.

Limitations:

Study design is retrospective.

Ethics committee approval

IRB approval and written informed consent were obtained.

Funding:

No funding was received for this work.

4
MyT3 16 - Clinical implications of measuring epicardial adipose tissue quantity

MyT3 16 - Clinical implications of measuring epicardial adipose tissue quantity

02:54A. Jermendy, Budapest / HU

Purpose:

Various adipose tissue compartments play an important role in the development of cardiometabolic diseases. The quantity of different fat compartments is influenced by genetic and environmental factors. In a classical twin study we sought to assess the heritability of epicardial adipose tissue (EAT) quantity in comparison to that of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) compartments. Furthermore, we aimed to evaluate the role of EAT in the pathomechanism of coronary artery disease (CAD).

Methods and materials:

We investigated 202 healthy adult twin subjects in whom CT based EAT, SAT and VAT quantity measurement, as well as coronary CT angiography, was performed. For the heritability assessment, intra-pair correlations were calculated and robust structural equation modelling was used. We performed logistic regression analysis to evaluate the association between CAD and clinical risk factors.

Results:

We demonstrated in our study that genetics have substantial, while environmental factors have only a modest influence on EAT, SAT and VAT volumes. Our findings show that common and specific genetic effects both play an important role in developing these phenotypes. None of the phenotypic appearances of EAT, SAT and VAT proved to be completely independent of the other two. According to our results, EAT quantity shows a significant association with the presence of CAD supporting the concept that EAT may have a role in the pathomechanism of developing CAD.

Conclusion:

As the presence of strong genetic predisposition does not automatically translate to the development of clinical disease phenotype, early and continuous preventive efforts should be implemented in order to prevent obesity. Our results also suggest that it seems reasonable to involve EAT quantity into cardiovascular risk assessment tools.

Limitations:

The limitations of this study lay in the fact that it is a single-centre, cross-sectional study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

5
MyT3 16 - The use of CTPA in the evaluation of heart failure in the acute setting

MyT3 16 - The use of CTPA in the evaluation of heart failure in the acute setting

02:55L. O'Halloran, Clare / IE

Purpose:

Heart failure is a clinical diagnosis characterised by non-specific symptoms such as dyspnoea, fatigue and oedema. The European Society of Cardiology recommends obtaining objective measures for heart failure in order to confirm a diagnosis. However, it can be challenging to obtain objective measures such as echocardiography in the acute setting. CTPA is conventionally used to outrule pulmonary embolus, however, CTPA provides great detail of the heart and lungs as a whole. The aim of this study was to investigate what role CTPA could play in diagnosing heart failure.

Methods and materials:

We reviewed 230 CTPA results, of these we confirmed which of these patients had heart failure by confirming a heart failure diagnosis with BNP and echocardiogram criteria. We divided the groups into those who had heart failure and those that did not. We then analysed which features found on CTPA were most specific for a diagnosis of heart failure.

Results:

In our study the most specific signs were shown to be left ventricular enlargement, left atrial enlargement and right ventricular enlargement. This was demonstrated using chi-square analysis; right ventricular enlargement (value = 5.426 P=0.02), left atrial enlargement (value = 4.9 P=0.027) and left ventricular enlargement (value = 5.692 P=0.017).

Conclusion:

Several findings on CTPA were demonstrated to be quite specific for a diagnosis of heart failure which includes left ventricular enlargement, left atrial enlargement and right ventricular enlargement. Acute physicians should utilise, if available, recent CTPA results while awaiting echocardiography in determining the presence of heart failure in patients.

Limitations:

Study based at a single centre. A prospective study would have highlighted CTPA's clinical utility.

Ethics committee approval

Obtained from University Hospital Limerick's ethics committee.

Funding:

No funding was received for this work.

6
MyT3 16 - Compared with the left atrium, left atrial appendage function and myocardial remodeling, play a greater role in relapse of AF after radiofrequency ablation

MyT3 16 - Compared with the left atrium, left atrial appendage function and myocardial remodeling, play a greater role in relapse of AF after radiofrequency ablation

02:56Xin Tian, Shijiazhuang / CN

Purpose:

To evaluate the role of the left atrium and left atrial appendage in the recurrence of atrial fibrillation (AF) after radiofrequency ablation.

Methods and materials:

63 patients with AF who underwent radiofrequency ablation for the first time were enrolled. According to the recurrence of AF after radiofrequency ablation, the patients were divided into the recurrence group (n = 20 cases) and non-recurrence group (n = 43 cases). All patients underwent a 256-slice spiral CT examination before the operation. The maximum volume of LAA (LAAVmax), minimum volume of LAA (LAAVmin), LAA emptying fraction (LAAEF), and LAA ejection volume (LAAEV), LAA volume strain (LAA-VS), maximum volume of LA (LAVmax), minimum volume of LA (LAVmin), LA emptying fraction (LAEF), LA ejection volume (LAEV), and LA volume strain (LAVS) were measured.

Results:

The LAAVmax, LAAVmin, LAVmax, and LAVmin in the recurrence group were higher than those in the non-recurrence group (P < 0.05), while LAAEF, LAEF and LAA-VS in the recurrence group were lower than those in the non-recurrence group (P < 0.05). There was no difference in LA-VS between the two groups. LAAEF was an independent predictor of recurrence after radiofrequency ablation of AF. LAAEF < 44.68% had the highest predictive value for recurrence after radiofrequency ablation.

Conclusion:

LAAEF is a predictor of recurrence after radiofrequency ablation of AF. Compared with LA volume strain, LAA volume strain which represented fibrosis of LAA myocardia is more useful in evaluating myocardial remodelling associated with recurrence of AF.

Limitations:

Our team paid attention to patients' ECG and ambulatory ECG results through a clinic or telephone follow-up, but asymptomatic atrial fibrillation attacks may be omitted, leading to underestimation of recurrence rate.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

7
MyT3 16 - A comparative study between cardiac computed tomography and magnetic resonance imaging in the assessment of cavopulmonary anastomosis

MyT3 16 - A comparative study between cardiac computed tomography and magnetic resonance imaging in the assessment of cavopulmonary anastomosis

02:58M. Gamal ElDen, Cairo / EG

Purpose:

Could MRI replace CT in the detection of veno-venous collaterals in cases of cavopulmonary anastomosis?

Methods and materials:

The study involves 11 patients (three adult and eight children) who have complex heart anomalies and underwent bidirectional Glenn. They should have a normal renal function with no general contraindication for MRI, like claustrophobia or non-compatible pacemaker or cochlear implant. They were assessed by using MDCT and short protocol MRI (TWIST, contrast-enhanced (CE) 3D whole-heart and flow studies). The study is descriptive.

Results:

The study includes four female and seven male patients. We arranged the results into minor and major collaterals detected by CT and CE 3D navigator as well as capability of the twist technique to show the contrast through both pulmonary arteries and if there are collaterals or not. CT and CE 3D navigator show minor and major venous collaterals with similar accuracy. Twist technique shows the contrast passing through both pulmonary arteries and collaterals yet it could not visualise the collaterals in four cases. MRI, the only method, to calculate flow in the venous collaterals.

Conclusion:

CE 3D navigator beside TWIST technique can replace cardiac CT in the assessment of Glenn and collaterals. Additionally, MRI can measure the flow.

Limitations:

The small number of cases.

Ethics committee approval

Written consent was taken from patients and/or their guardian to do CT and short protocol MRI.

Funding:

No funding was received for this work.

8
MyT3 16 - Very low volume of contrast material in pre-TAVI CT: how low can we get?

MyT3 16 - Very low volume of contrast material in pre-TAVI CT: how low can we get?

02:42P. Olga, Jerusalem / IL

Purpose:

To evaluate and compare the image quality of pre-TAVI (transaortic valve implantation) CT protocol of high pitch using weight adapted reduced contrast media (CM) injection vs standard pre-TAVI protocol.

Methods and materials:

Retrospective analysis of 117 (73 females) consecutive patients undergoing pre-TAVI CT on Siemens FORCE scanner. 95 patients (mean age 81±7; weight 70kg±13) using FLASH high pitch single combined heart-aorta acquisition. CM volume (Omnipaq) and injection rate administrated per weight. 23 patients (age 79±9;80kg±24) in the standard protocol control group underwent spiral cardiac scan followed by high pitch aortic acquisition. In both groups, scan was triggered by bolus-tracking. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the aortic root, abdominal aorta and femorals. Image quality considered sufficient at attenuation >200HU.

Results:

CM volume and injection rate were significantly lower in FLASH group compared to control group (39±9ml/ 3±0.5ml/sec vs 75±8ml/ 4.2±0.8 ml/sec; p<0.05). DLP in FLASH was 303±104 vs 1175±772 in control. Image quality was sufficient in FLASH and control groups respectively: root-89 (93%) vs 19 (82%) of patients, abdominal aorta-94 (99%) vs 20 (87%) and femorals-85 (89%) vs 20 (87%) (P=NS). Non-significant difference in attenuation and CNR found between two groups for root ( 350±100HU/16 vs 348±256HU/15.6) and abdominal aorta (372±98/HU30 vs 416±257HU/30.5). Significant decrease in femorals attenuation and CNR in FLASH group (301±109HU/23 vs 449±221HU/33; p<0.05). Patient weight and DLP were lower in FLASH group (p<0.05).

Conclusion:

Using single high pitch cardiac-aortic pre-TAVI CT scan with weight-adjusted injection allows significant CM volume and radiation dose reduction with preserved images quality.

Limitations:

Single institution study. The standard group was smaller than FLASH group.

Ethics committee approval

Approved by the IRB, informed consent waved.

Funding:

N/A

9
MyT3 16 - Heart rate-dependent degree of motion artefacts in coronary CT angiography acquired by a dedicated cardiac CT scanner

MyT3 16 - Heart rate-dependent degree of motion artefacts in coronary CT angiography acquired by a dedicated cardiac CT scanner

02:53M. Vecsey-Nagy, Budapest / HU

Purpose:

Currently used wide detector CT scanners enable precise assessment of coronary artery disease (CAD). However, no data is available regarding the degree of motion artefacts in images acquired by the recently introduced 560-slice CardioGraphe (CG) scanner. We aimed to assess the heart rate (HR) dependent presence and degree of motion artefacts in coronary CT angiography (CCTA) scans acquired by CG compared to a conventional 256-slice CT scanner.

Methods and materials:

In this retrospective study, we have compared the images of 75 patients who underwent CCTA with CG (240 ms rotation time) to 75 scans acquired by a 256-slice CT scanner (270 ms rotation time). The mean age of the groups was 57.3 years, 49.3% males. Motion artefacts were assessed using a Likert-type scale, ranging from 1 to 4 (1: non-diagnostic, 2: severe motion artefacts, 3: mild motion artefacts, 4: no motion artefacts). The patients were divided into 3 equal groups (50-50-50 patients) according to HR ranges during image acquisition (51-60/min, 61-70/min, above 71/min). The image quality of each of the three groups in both scanners was compared using Wilcoxon rank-sum test.

Results:

The CG scanner had a better image quality, with reduced motion artefacts as compared to the 256-slice scanner (mean Likert-score 2.7 ± 0.9 vs 2.3 ± 0.7, respectively, p<0.003). The CG images had higher Likert-scores in all 3 heart rate ranges (51-60/min, 61-70/min, 71+/min), which was statistically significant in the lower 2 ranges (p=0.025, p=0.043, p=.156, respectively).

Conclusion:

The new 560-slice CG scanner allows for CCTA image acquisition with reduced motion artefacts as compared to a 256-slice scanner. The beneficial effect of fast gantry rotation was especially present at HR below 70/min.

Limitations:

Not applicable.

Ethics committee approval

Not applicable.

Funding:

Not applicable.

10
MyT3 16 - Radiological visualisation in the diagnosis of potentially life-threatening conditions of an athlete's pathological heart

MyT3 16 - Radiological visualisation in the diagnosis of potentially life-threatening conditions of an athlete's pathological heart

02:29B. Sergey, Moscow / RU

Purpose:

Frequency of fatal cardiac abnormalities development in athletes resulted in an increase in mortality, which reaches 75%. With the evidence of such dangerous changes development, it becomes extremely important to make an early diagnosis of these.

Methods and materials:

We examined 11 male athletes 18-23 yo without significant family history regarding the pathology of cardiovascular system, involved for 14±2 yrs in playing sports with anamnestic presence of chronic physical fatigue and heart pains that underwent clinical examination, biochemical blood tests, ECG, stress-echocardiography, 12-leads Holter-monitoring, myocardial scintigraphy with 123I-MIBG, 99mTc-tetrofosmin rest/stress SPECT and, gadolinium-enhanced MRI.

Results:

Biochemical markers of cardiomyocytes’ acute damage were concordant to the clinical significance of these disorders matching to complaints severity of cardiac arrhythmias. Along with these data no violations of morphology, size and function of myocardium were revealed. Results of myocardial SPECT, stress ECG-test, stress echocardiography, daily Holter monitoring had no signs of myocardial ischemia. We didn’t have laboratory and other data for inflammatory myocardial damage. Early phase 123I-MIBG scintigraphy (15’ p.i.) showed impaired tracer accumulation in apex, anterolateral and inferior walls down to 61-67%. In the delayed phase (240’ p.i.) less significant decrease of radiopharmaceutical uptake was noted. Diffuse-focal decrease of tracer uptake by myocardial perfusion SPECT with 99mTc-tetrofosmin not exceeding 8% of LV was noted in the anteroseptal region with improvement after the physical exercise test.

Conclusion:

The combined use of diagnostic methods, such as SPECT, CE-MRI, stress echocardiography, make it possible to carry out differential diagnosis, to exclude acute coronary insufficiency, acute inflammatory damage of heart, regarding changes as a variant of takotsubo syndrome.

Limitations:

This study is limited by its sample.

Ethics committee approval

All patients provided informed consent for examination, treatment, data processing and use of data in scientific work.

Funding:

No funding was received for this work.

11
MyT3 16 - Relationships between coronary atherosclerotic morphology of computed tomography coronary angiography and myocardial perfusion abnormalities

MyT3 16 - Relationships between coronary atherosclerotic morphology of computed tomography coronary angiography and myocardial perfusion abnormalities

03:09A. Maltseva, Tomsk / RU

Purpose:

The purpose was to assess the relationships between morphological CT-characteristics of coronary atherosclerosis and myocardial perfusion downstream in patients with an intermediate pretest probability of stable coronary artery disease (SCAD).

Methods and materials:

The study group comprised 68 patients (42 men, age 63 (56;68) years) who underwent coronary computed tomography angiography (CCTA) as well as stress-rest MPI (with CT attenuation correction) on the hybrid system GE Discovery NM/CT 570С. The patients were divided into two groups: 1) moderate and large stress perfusion defect extent (SSS≥9); 2) small perfusion defect extent (SSS<9).

Results:

According to the univariate logistic regression, maximum stenosis (OR 1,04; CI 1,02-1,06; p=0,0001), the sum of stenoses (OR 1,01; CI 1,00-1,01; p=0,02), Segment Stenosis Score (OR 1,14; CI 1,04-1,25; p=0,04) and CT_SS (OR 1,32; CI 1,12-1,56; p=0,01), the presence of stenosis >50% (OR 5,4; CI 1,69-17,16; p=0,004), noncalcified (OR 1,79; CI 1,11-2,87; p=0,017) and circular features (OR 2,99; CI 1,48-6,04; p=0,002) of the atherosclerotic plaques were the independent determinants of moderate and large perfusion defect. By the results to multivariable logistic analysis the combination of several CT-characteristics of coronary atherosclerosis did not improve the prognostic model.

Conclusion:

Segment Stenosis Score, CT_SS as well as the noncalcified structure and circular geometry of the atherosclerotic plaques are the most significant independent predictors of moderate and large stress perfusion defects. These CT morphological characteristics could be used for risk stratification in patients with an intermediate pretest probability of SCAD.

Limitations:

This is the relatively small size of the study population.

Ethics committee approval

The local research ethics committee approved this study.

Funding:

No funding was received for this work.

12
MyT3 16 - Aortic valve calcification scoring with computed tomography: the impact of advanced modelled iterative image reconstruction

MyT3 16 - Aortic valve calcification scoring with computed tomography: the impact of advanced modelled iterative image reconstruction

02:54R. Hinzpeter, Zurich / CH

Purpose:

To investigate whether advanced modelled iterative reconstruction (ADMIRE) of CT scans affects aortic valve calcification (AVC) scoring and likelihood categorisation of severe aortic stenosis.

Methods and materials:

In this IRB-approved retrospective study, we included 100 consecutive patients with symptomatic aortic stenosis (median age: 77 years; 39 females) undergoing CT prior to transcatheter aortic valve replacement between 03/2019 and 10/2019. CT scans dedicated to calcium scoring were performed according to current guidelines and reconstructed with filtered back projection (FBP) and ADMIRE at strength levels 1-5. AVC Agatston scores were evaluated using a commercially available software platform. Gender-specific AVC Agatston score cut-off values were applied according to the current European Society of Cardiology recommendations to assign patients to different likelihood categories of aortic stenosis (unlikely to very likely). AVC scores are shown as median and interquartile-range (IQR). Friedman test was applied to analyse interval- and ordinal-scaled data.

Results:

Each reconstruction algorithm produced statistically significant numerical AVC Agatston scores (p<0.001). Median AVC Agatston score for image reconstruction with FBP was 2527 (IQR: 1602-3673) and decreased with increasing ADMIRE strength levels. Image reconstruction with ADMIRE at strength level 5 showed the lowest median AVC Agatston score (2281, IQR: 1357-3362). Likelihood categorisation of severe aortic stenosis was significantly different between image reconstruction algorithms (p<0.001). For image reconstruction with FBP, 55 cases were assigned to the “very likely” category, compared to 44 cases performing image reconstruction with ADMIRE at strength level 5.

Conclusion:

Image reconstruction of CT scans dedicated to AVC scoring with ADMIRE causes a significant decrease of AVC scores with increasing ADMIRE strength levels and therefore affects likelihood categorisation of severe aortic stenosis.

Limitations:

This study is performed in a single-site, one vendor.

Ethics committee approval

The IRB approved, written informed consent obtained.

Funding:

No funding was received for this work.

13
MyT3 16 - Histological validation of cardiac magnetic resonance T1 mapping for evaluation the variation in myocardial infarction on day 1, day 7 and 3 months in a swine model

MyT3 16 - Histological validation of cardiac magnetic resonance T1 mapping for evaluation the variation in myocardial infarction on day 1, day 7 and 3 months in a swine model

04:03Lu Zhang, Chengdu / CN

Purpose:

Our aims were to explore 1) how native T1 and extracellular volume (ECV) measured on CMR changed with time in infarcted myocardium; 2) the correlation between ECV and native T1 against histology-evaluated ECV.

Methods and materials:

A total of 22 pigs were subjected to occlude anterior descending artery and underwent serial CMR examinations at acute(within 24h, n = 22), subacute (7 days, n = 13) and chronic (3 months. n = 6) after myocardial infarction (MI). The CMR protocol included cine, Modified Look-Lock Inversion (MOLLI) recovery and late gadolinium enhancement (LGE). Hematoxylin-eosin and Masson trichrome staining were conducted following scanning. The CMR exams and histopathological staining were performed in the same day.

Results:

Infarcted native T1 changed with peaking at 7 days while a progressively increasing was observed in ECV during 3 months. The histology-evaluated ECV demonstrated a well correlation in the comparison with native T1 (acute, r = 0.89, p < 0.001; subacute, r = 0.94, p < 0.001; chronic, r = 0.83, p < 0.001); Also, a high correlation was found when compared with CMR-measured ECV (acute, r = 0.89, p < 0.001; subacute, r=0.96, p < 0.001; chronic, r = 0.82, p < 0.001).

Conclusion:

Both native T1 and ECV in infarcted myocardium demonstrated dynamical changed with time. This may be explained by the severe interstitial oedema and the progressive collagenous deposition. These results have implication for the timing of CMR imaging early after MI.

Limitations:

The experimental setup did not allow for baseline examination and early imaging after MI.

Ethics committee approval

This study was approved by the institutional ethics review board.

Funding:

No funding was received for this work.

14
MyT3 16 - Evaluation of image quality and radiation dose with prospective ECG-gated 80-slice CT angiography, in 182 consecutive children examinations with congenital heart disease

MyT3 16 - Evaluation of image quality and radiation dose with prospective ECG-gated 80-slice CT angiography, in 182 consecutive children examinations with congenital heart disease

03:38K. Warin Fresse, Nantes / FR

Purpose:

Computed tomography angiography (CTA) is a reliable imaging tool to evaluate children congenital heart disease (CHD) but requires radiation exposure. This study aims to investigate image quality and radiation dose with a prospective electrocardiogram (ECG)-gated 80-slice CTA, in 182 consecutive children examinations with CHD.

Methods and materials:

182 consecutive examinations performed with a prospective ECG-gated 80-slice CTA from March 2016 to December 2017 in Nantes university hospital were retrospectively analysed. Radiation dose was assessed by dose length product (DLP) and effective dose (E). The objective quality image was assessed by contrast to noise ratio (CNR) and subjective quality image by two radiologists with a 10-point scale evaluating visualisation of coronary arteries. Correlation between quality image, radiation dose, age, weight, heart rate was analysed.

Results:

DLPand E were 29.3±15.5mGy.cm and 0.6±0.2mSv respectively. Agreement between radiologists for subjective image quality was 0.79. Subjective image quality score was significantly better (p<0.01) with higher age, weight, DLP and lower heart rate in univariate analysis. CNR was significantly lower with increasing weight and DLP (p<0.05) but there was no correlation between CNR and age and heart rate.

Conclusion:

Prospective ECG-gated 80-slice CTA is performing for the evaluation of children CHD with good image quality and low radiation dose. Visualisation of small structures is better when age and weight increase, heart rate decreases and when the radiation dose is more important. CNR evolves in the opposite side to subjective image quality score. It seems less appropriate to assess image quality from the clinical view of the radiologist.

Limitations:

The study is retrospective.

Ethics committee approval

n/a

Funding:

No funding was received for this work.