Halved contrast medium dose coronary dual-layer CT-angiography - phantom study of tube current and patient characteristics

Virtual mono-energetic images (VMI) using dual-layer computed tomography (DLCT) enable substantial contrast medium (CM) reductions. However, the combined impact of patient size, tube voltage, and heart rate (HR) on VMI of coronary CT angiography (CCTA) remains unknown. This phantom study aimed to assess VMI levels achieving comparable contrast-to-noise ratio (CNR) in CCTA at 50% CM dose across varying tube voltages, patient sizes, and HR, compared to the reference protocol (100% CM dose, conventional at 120 kVp). A 5 mm artificial coronary artery with 100% (400 HU) and 50% (200 HU) iodine CM-dose was positioned centrally in an anthropomorphic thorax phantom. Horizontal coronary movement was matched to HR (at 0, < 60, 60-75, > 75 bpm), with varying patient sizes simulated using phantom extension rings. Raw data was acquired using a clinical CCTA protocol at 120 and 140 kVp (five repetitions). VMI images (40-70 keV, 5 keV steps) were then reconstructed; non-overlapping 95% CNR confidence intervals indicated significant differences from the reference. Higher CM-dose, reduced VMI, slower HR, higher tube voltage, and smaller patient sizes demonstrated a trend of higher CNR. Regardless of HR, patient size, and tube voltage, no significant CNR differences were found compared to the reference, with 100% CM dose at 60 keV, or 50% CM dose at 40 keV. DLCT reconstructions at 40 keV from 120 to 140 kVp acquisitions facilitate 50% CM dose reduction for various patient sizes and HR with equivalent CNR to conventional CCTA at 100% CM dose, although clinical validation is needed.

Mitral Annular Disjunction in Idiopathic Ventricular Fibrillation Patients: Just a Bystander or a Potential Cause?

AIMS

Previously, we demonstrated that inferolateral mitral annular disjunction (MAD) is more prevalent in patients with idiopathic ventricular fibrillation (IVF) than in healthy controls. In the present study, we advanced the insights into the prevalence and ventricular arrhythmogenicity by inferolateral MAD in an even larger IVF cohort.

METHODS AND RESULTS

This retrospective multicentre study included 185 IVF patients (median age 39 [27, 52] years, 40% female). Cardiac magnetic resonance images were analysed for mitral valve and annular abnormalities and late gadolinium enhancement. Clinical characteristics were compared between patients with and without MAD. MAD in any of the 4 locations was present in 112 (61%) IVF patients and inferolateral MAD was identified in 24 (13%) IVF patients. Mitral valve prolapse (MVP) was found in 13 (7%) IVF patients. MVP was more prevalent in patients with inferolateral MAD compared with patients without inferolateral MAD(42% vs. 2%, p < 0.001). Proarrhythmic characteristics in terms of a high burden of premature ventricular complexes (PVC) and non-sustained ventricular tachycardia (VT) were more prevalent in patients with inferolateral MAD compared to patients without inferolateral MAD (67% vs. 23%, p < 0.001 and 63% vs 41%, p = 0.046, respectively). Appropriate implantable cardioverter defibrillator therapy during follow-up was comparable for IVF patients with or without inferolateral MAD (13% vs. 18%, p = 0.579).

CONCLUSION

A high prevalence of inferolateral MAD and MVP is a consistent finding in this large IVF cohort. The presence of inferolateral MAD is associated with a higher PVC burden and non-sustained VTs. Further research is needed to explain this potential interplay.

Anatomical differences of intracranial arteries according to sex: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Intracranial aneurysms are more common in women than in men. Some anatomical variants of the circle of Willis (CoW) are associated with a higher risk of developing intracranial aneurysms. We hypothesized that variations of the CoW are sex dependent which may partly explain why intracranial aneurysms are more common in women. We systematically reviewed and meta-analyzed the literature to compare the presence of anatomical variations of the CoW between women and men in the general population.

MATERIAL AND METHODS

A systematic search in Pubmed and EMBASE using predefined criteria, following the PRISMA guidelines was performed. The presence of different CoW anatomical variants and a complete CoW was compared between women and men using an inverse variance weighted random effects meta-analysis to calculate relative risks (RR) with 95% confidence intervals (95% CIs).

RESULTS

Fourteen studies were included reporting on 5478 healthy participants (2511 women, 2967 men). Bilateral fetal type posterior cerebral arteries (RR 2.79; 95%CI 1.65-4.72, I2=0%), and a complete CoW (RR 1.24, 95%CI 1.13-1.36; I2=0%) were more prevalent in women than in men. The variants absence or hypoplasia of one of the anterior cerebral arteries (RR 0.58, 95%CI 0.38-0.88, I2=57%) and hypoplasia or absence of both posterior communicating arteries (RR 0.79, 95%CI 0.71-0.87, I2=0%) were more prevalent in men.

CONCLUSIONS

Several anatomical variations of the CoW are sex dependent, with some variants being more common in women while others in men. Future research should assess how these sex-specific CoW variants relate to the sex-specific occurrence of intracranial aneurysms.

Redefining the upper limits of ventricular volumes in elite athletes

Background/Introduction

Specific athlete reference values for cardiac volumes and function using cardiac magnetic resonance (CMR) parameters have been reported and are used in clinical practice. Elite athletes are conventionally thought to demonstrate the highest levels of physiological adaptation to sports and therefore dictate the upper limit of normal for biventricular size and function in the athlete population.

Purpose

To compare volumetric parameters in a cohort of both male and female elite-level athletes to previously published reference values.

Methods

We used data from the prospective ELITE-cohort, which collects pre-participation data of elite athletes (national-, international-, Olympic-, Paralympic-level), including CMR imaging. Athletes suspected of pathology based on comprehensively investigated electrocardiograph, exercise test, echocardiogram and late gadolinium enhancement were excluded. Biventricular volumes were derived from short-axis cine images using Cvi42 (v5.1.2.) and indexed for body surface area (BSA). Volumetric parameters were compared to the previously reported gender- and Mitchell sports classification specific cardiac 95th percentile (95%tile) reference values, as reported by Luijkx et al.: left-ventricle (LV) end-diastolic volume (EDV) / BSA for high-static and high-dynamic sports (HS/HD; ♀ 142 ♂ 158); low-static and high-dynamic (LS/HD; ♀ 127 ♂ 149); high-static and low-dynamic (HS/LD; ♀ 114 ♂ 140); right ventricle (RV) EDV / BSA HS/HD (♀ 154 ♂ 184), LS/HD (♀ 136 ♂ 163), and HS/LD (♀ 120 ♂ 157).

Results

We analysed a total of 221 athletes (38% female), with a median age (IQR) of 26.0 (22.5–29.8) years, and mean ±SD BSA of 1.96±0.22 m2. Athletes were classified according to the Mitchell sports classification: HS/HD 116 (54%); LS/HD 61 (29%); moderate-static and high-dynamic (MS/HD) 20 (9.4%); HS/LD 16 (7.5%) (Table). We found smaller mean ±SD (95%tile) RV EDV/BSA in athletes participating in HS/HD sports (♀: 117±20 (148) and ♂: 133±20 (160)) and LS/HD sports (♀: 109±11 (129) and ♂: 119±15 (142)) and smaller LV EDV/BSA in male athletes in LS/HD sports (116±15 (138)) compared to reference values, (Figure). When using conventional cut-offs in our population we found 10 (4.5%) and 2 (0.9%) athletes above 95%tile for LVEDV/BSA and RVEDV/BSA, respectively (Figure).

Conclusion

In a cohort consisting of healthy, elite athletes, volumetric adaptations were less outspoken as compared with current reference ranges, specifically in the RV. Only 1 percent of our athletes exceeded conventional 95%tile references for the RV. Potentially, current athlete reference values could overestimate healthy upper limits of cardiac volumes in elite athletes. Our study could indicate that a stricter definition of volumetric reference values, including 95%tile, might be of added value in the specific group of elite athletes to help differentiate between pathology and sports adaptation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Amsterdam Movement Sciences (P1A210AMC2018)

Detection of Early Ischemic Changes with Virtual Noncontrast Dual-Energy CT in Acute Ischemic Stroke: A Noninferiority Analysis

BACKGROUND AND PURPOSE

Dual-energy virtual NCCT has the potential to replace conventional NCCT to detect early ischemic changes in acute ischemic stroke. In this study, we evaluated whether virtual NCCT is noninferior compared with standard linearly blended NCCT, a surrogate of conventional NCCT, regarding the detection of early ischemic changes with ASPECTS.

MATERIALS AND METHODS

Adult patients who presented with suspected acute ischemic stroke and who underwent dual-energy NCCT and CTA and brain MR imaging within 48 hours were included. Standard linearly blended images were reconstructed to match a conventional NCCT. Virtual NCCT images were reconstructed from CTA. ASPECTS was evaluated on conventional NCCT, virtual NCCT, and DWI, which served as the reference standard. Agreement between CT assessments and the reference standard was evaluated with the Lin concordance correlation coefficient. Noninferiority was assessed with bootstrapped estimates of the differences in ASPECTS between conventional and virtual NCCT with 95% CIs.

RESULTS

Of the 193 included patients, 100 patients (52%) had ischemia on DWI. Compared with the reference standard, the ASPECTS concordance correlation coefficient for conventional and virtual NCCT was 0.23 (95% CI, 0.15-0.32) and 0.44 (95% CI, 0.33-0.53), respectively. The difference in the concordance correlation coefficient between virtual and conventional NCCT was 0.20 (95% CI, 0.01-0.39) and did not cross the prespecified noninferiority margin of -0.10.

CONCLUSIONS

Dual-energy virtual NCCT is noninferior compared with conventional NCCT for the detection of early ischemic changes with ASPECTS.

Exercise-induced cardiac troponin release in middle-aged and older athletes with different degrees of coronary atherosclerosis

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Radboud University Medical CenterAcademic Alliance Fund Maastricht - Nijmegen

Background

Current sports medical examinations do not appropriately detect occult coronary atherosclerosis in athletes, whereas coronary atherosclerosis is more prevalent in middle-aged and older athletes compared to physically active controls. Therefore, new diagnostic approaches need to be developed to identify individuals at risk. Cardiac troponin (cTn) is the standard biomarker to assess myocardial injury. Exercise is known to increase cTn concentrations and a delayed recovery of cTn concentrations after exercise cessation is suggested to be indicative of occult obstructive coronary artery disease. We hypothesized that the magnitude of exercise-induced cTn elevations may be associated with the degree of coronary atherosclerosis.

Purpose

To compare serial measures of exercise-induced cTnT elevations across middle-aged and older athletes with different degrees of coronary atherosclerosis.

Methods

A subgroup of 59 men from the Measuring Athlete’s Risk of Coronary events-2 study (MARC-2, n=291) were invited for this add-on study. All participants had undergone a cardiac computed tomography (CT) scan and coronary CT angiography to determine the prevalence and magnitude of coronary atherosclerosis. Athletes were stratified based on the degree of coronary atherosclerosis: I) n=20 with a coronary artery calcium score (CACS) of 0, II) n=20 with CACS ≥300 or ≥75th MESA-percentile, and III) n=19 with a &gt;50% stenosis in any coronary artery, but without ischemia on a stress imaging tests. Participants performed an individualized exercise test (&gt;1 hour, cycling) until volitional exhaustion. High-sensitivity cTnT concentrations were measured at baseline, after 30 minutes of exercise and at 0, 30, 60, 120, and 180 minutes post-exercise.

Results

Participants (age 60.8 [57.9-72.6] years, BMI 24.5 [23.9-27.3]) exercised for 76±14 minutes, up to 97.6 [94.4-101.8] % of their expected maximum heart rate. Exercise duration and workload did not differ across groups. Baseline hs-cTnT was detectable in everyone. Exercise induced a 1.98±1.63 fold increase in hs-cTnT concentrations. Peak hs-cTnT concentrations occurred at 180 minutes post-exercise (13.9 [9.4-17.0] ng/L versus 12.1 [10.0-21.5] ng/L versus 13.8 [9.1-19.9] ng/L, for group I, II and III, respectively) and the incidence of hs-cTnT concentrations above the URL (n=9 (45%) vs n=7 (35.0%) vs n=9 (47.4%)) was comparable across groups (p=0.92 and p=0.71, respectively). Patterns of time-dependent changes in hs-cTnT concentrations did not differ across groups (p=.49).

Conclusion

Exercise-induced elevations in hs-cTnT concentrations did not differ among middle-aged and older athletes with different degrees of coronary atherosclerosis. Our findings suggest that hs-cTnT sampled before, during or within 180 minutes following an exhaustive endurance cycling exercise test is not suitable to detect occult coronary atherosclerosis in athletes.

Prognostic value of strain by feature-tracking cardiac magnetic resonance in arrhythmogenic right ventricular cardiomyopathy

AIMS

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by ventricular dysfunction and ventricular arrhythmias (VA). Adequate arrhythmic risk assessment is important to prevent sudden cardiac death. We aimed to study the incremental value of strain by feature-tracking cardiac magnetic resonance imaging (FT-CMR) in predicting sustained VA in ARVC patients.

METHODS AND RESULTS

CMR images of 132 ARVC patients (43% male, 40.6 ± 16.0 years) without prior VA were analysed for global and regional right and left ventricular (RV, LV) strain. Primary outcome was sustained VA during follow-up. We performed multivariable regression assessing strain, in combination with (i) RV ejection fraction (EF); (ii) LVEF; and (iii) the ARVC risk calculator. False discovery rate adjusted P-values were given to correct for multiple comparisons and c-statistics were calculated for each model. During 4.3 (2.0-7.9) years of follow-up, 19% of patients experienced sustained VA. Compared to patients without VA, those with VA had significantly reduced RV longitudinal (P ≤ 0.03) and LV circumferential (P ≤ 0.04) strain. In addition, patients with VA had significantly reduced biventricular EF (P ≤ 0.02). After correcting for RVEF, LVEF, and the ARVC risk calculator separately in multivariable analysis, both RV and LV strain lost their significance [hazard ratio 1.03-1.18, P > 0.05]. Likewise, while strain improved the c-statistic in combination with RVEF, LVEF, and the ARVC risk calculator separately, this did not reach statistical significance (P ≥ 0.18).

CONCLUSION

Both RV longitudinal and LV circumferential strain are reduced in ARVC patients with sustained VA during follow-up. However, strain does not have incremental value over RVEF, LVEF, and the ARVC VA risk calculator.

Pulsatility Attenuation along the Carotid Siphon in Pseudoxanthoma Elasticum

We compared velocity pulsatility, distensibility, and pulsatility attenuation along the intracranial ICA and MCA between 50 patients with pseudoxanthoma elasticum and 40 controls. Patients with pseudoxanthoma elasticum had higher pulsatility and lower distensibility at all measured locations, except for a similar distensibility at C4. The pulsatility attenuation over the siphon was similar between patients with pseudoxanthoma elasticum and controls. This finding suggests that other disease mechanisms are the main contributors to increased intracranial pulsatility in pseudoxanthoma elasticum.

Reliability and Agreement of 2D and 3D Measurements on MRAs for Growth Assessment of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Reliable and reproducible measurement of unruptured intracranial aneurysm growth is important for unruptured intracranial aneurysm rupture risk assessment. This study aimed to compare the reliability and reproducibility of 2D and 3D growth measurements of unruptured intracranial aneurysms.

MATERIALS AND METHODS

2D height, width, and neck and 3D volume measurements of unruptured intracranial aneurysms on baseline and follow-up TOF-MRAs were performed by two observers. The reliability of individual 2D and 3D measurements and of change (growth) between paired scans was assessed (intraclass correlation coefficient) and stratified for aneurysm location. The smallest detectable change on 2D and 3D was determined. Proportions of growing aneurysms were compared, and Bland-Altman plots were created.

RESULTS

Seventy-two patients with 84 unruptured intracranial aneurysms were included. The interobserver reliability was good-to-excellent for individual measurements (intraclass correlation coefficient  > 0.70), poor for 2D change (intraclass correlation coefficient < 0.5), and good for 3D change (intraclass correlation coefficient = 0.76). For both 2D and 3D, the reliability was location-dependent and worse for irregularly shaped aneurysms. The smallest detectable changes for 2D height, width, and neck and 3D volume measurements were 1.5 , 2.0, and 1.9 mm and 0.06 mL, respectively. The proportion of growing unruptured intracranial aneurysms decreased from 10% to 2%, depending on the definition of growth (1 mm or the smallest detectable changes for 2D and 3D).

CONCLUSIONS

The interobserver reliability of the size measurements of individual 2D and 3D unruptured intracranial aneurysms was good-to-excellent but lower for 2D and 3D growth measurements. For growth assessment, 3D measurements are more reliable than 2D measurements. The smallest detectable change for 2D measurements was larger than 1 mm, the current clinical definition of unruptured intracranial aneurysm growth.

Prevalence of mitral annulus disjunction and mitral valve prolapse in a multicenter cohort of idiopathic ventricular fibrillation patients

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation

Background

Idiopathic ventricular fibrillation (IVF) is diagnosed in patients with sudden onset of ventricular fibrillation of which the origin is not identified after extensive evaluations. Recent studies suggest an association between mitral annulus disjunction (MAD), mitral valve prolapse (MVP) and ventricular arrhythmias[1,2]. The prevalence of MAD and MVP in IVF patients in this regard, is not well established.

Purpose

To explore prevalence of MAD and MVP in IVF patients.

Methods

In this retrospective multicenter cohort study, Cardiac Magnetic Resonance images from IVF patients (i.e., negative for ischemia, cardiomyopathy and channelopathies) and matched control subjects were analyzed for MAD (≥2mm) and MVP (&gt;2mm).

Results

In total, 71 IVF patients (mean age 39, 59% male) and 71 controls (mean age 41, 58% male) were included. MAD in the inferolateral wall was more prevalent in IVF patients versus healthy controls (6 [10%] vs. 1 [1%], p = 0.035). MVP was only seen in IVF patients and not in controls (4 [7%] vs. 0 [0%], p = 0.037). MVP was observed both in IVF patients with (n = 3) and without (n = 1) MAD. Patients with MAD did not show papillary muscle fibrosis. Four (67%) patients with MAD showed frequent ventricular ectopy from the basal myocardial region.

Conclusion

Inferolateral MAD and MVP were significantly more prevalent in IVF patients compared to healthy controls (figure). This is in line with previous studies suggesting a correlation between mitral valve disease and IVF. Our findings support further exploration of the pathophysiological mechanisms underlying a subset of IVF that associates with MAD and MVP.

Exercise intensity is associated with progression of coronary artery calcification in middle-aged and older athletes: findings from the MARC-2 study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation

Background 

Recent studies have reported increased coronary artery calcification (CAC) in middle-aged male athletes, which is related to the amount and intensity of lifelong exercise. However, previous studies are limited by their cross-sectional study design. 

Purpose 

We prospectively assessed progression of CAC and its association to exercise volume and intensity in middle-aged and older athletes.

Methods 

318 asymptomatic middle-aged and older men were recruited in the Measuring Athlete’s Risk of Cardiovascular events (MARC) study between 2012-2014 and invited for follow-up (MARC-2) between 2019-2020. During both study visits, computed tomography imaging was performed to assess CAC. Exercise characteristics during follow-up were used to calculate exercise volumes (Metabolic equivalent of task [MET]-hours/week), whereas intensities were classified as moderate (3-6 MET), vigorous (6-9 MET) and very vigorous (&gt;9 MET). For linear regression analyses, CAC scores were transformed (Ln delta CAC score + 1) and analyses were adjusted for baseline confounders, CAC at baseline and time between CT scans. Exercise intensities were assessed as proportion of MET-hrs/week and separately included, while adjusting for exercise volume.

Results 

We included 289 men (54.9 ± 6.4 years) for MARC-2, with a follow-up of 6.3 ± 0.5 years. Participants exercised for 41 [25-57] MET-hrs/week, of which the median percentage was 0% [interquartile range 0-19] at moderate, 44% [0-84] at vigorous and 34% [0-80] at very vigorous intensity. At baseline, CAC was present in 151 (52%) men, and increased to 205 (71%) men at follow-up. CAC scores increased from 1 [0-32] to 31 [0-132]. Delta CAC score (26 [0-104]) was not associated with overall exercise volume. However, delta CAC score was negatively associated with vigorous intensity exercise and positively associated with very vigorous intensity exercise (Table).

Conclusion 

Progression of CAC was not associated with overall exercise volume during 6-year follow-up. However, the degree of vigorous intensity exercise was associated with attenuated CAC progression, whereas very vigorous intensity exercise was associated with accelerated CAC progression.

Linear regression analyses Progression of CAC (Ln Delta CAC score +1) B (95% CI) P-Value Exercise volume (MET-hours/week) .001 (-.005 - .008) .70 Exercise Intensity Moderate intensity (%) -.002 (-.009 - .005) .65 Vigorous intensity (%) -.005 (-.009 - .000) .03 Very vigorous intensity (%) .005 (.001 - .009) .02

Relationship between sporting discipline and aortic dimensions in middle-aged sportsmen

Funding Acknowledgements

Type of funding sources: None.

Background

A previous study reported a high prevalence (21%) of clinically relevant aortic dilatation (≥40 mm) in competitive veteran runners and rowers. It is uncertain whether this also applies to middle-aged sportsmen performing other sporting disciplines.

Purpose

To relate aortic dimensions to sporting disciplines in middle-aged sportsmen.

Methods

Middle-aged sportsmen, ≥45 years of age, underwent coronary CT angiography. Aortic size was measured at the sinus of Valsalva (cusp-cusp) and the ascending aorta (at the height of the pulmonary trunk). Dominant sporting discipline was categorized as running, cycling or other. Analysis of variance was used to compare baseline characteristics and aortic dimensions across sporting disciplines. Multivariable linear regression was used to adjust for baseline characteristics. 

Results

A total of 260 sportsmen (mean age 55.1 ± 6.4 years; 64 runners, 75 cyclists and 121 other sporting disciplines) were included (Table). Clinically relevant aortic dilatation was found in 5.0% (n = 13). Aortic size or presence of aortic dilatation did not differ across sporting disciplines. Ascending aorta and aortic root size were significantly related to age, body surface area, diastolic blood pressure and exercise tolerance, but not sporting disciplines.

Conclusions

We found clinically relevant aortic dilatation in 5% of middle-aged sportsmen. Aortic size was not different between sporting disciplines. Aortic size may be more related to level of exercise performance rather than sporting discipline.

Running (n = 64) Cycling (n = 75) Other (n = 121) p value Participant characteristics Age, yrs 54.6 ± 6.4 56.1 ± 6.8 54.8 ± 6.2 0.30 Systolic BP, mmHg 129 ± 12 128 ± 13 129 ± 12 0.95 Diastolic BP, mmHg 80 ± 8 79 ± 8 80 ± 9 0.32 Body surface area, m2 2.03 ± 0.14 2.02 ± 0.15 2.07 ± 0.15 0.08 Exercise tolerance, Watt 310 ± 42* 329 ± 47 307 ± 48 0.003 Aortic dimensions Ascending aorta maximum diameter, mm 32.5 ± 3.1 33.0 ± 3.8 32.5 ± 3.6 0.64 SoV mean diameter, mm 34.3 ± 2.8 34.1 ± 2.8 33.7 ± 3.2 0.46 SoV, NCC-RCC diameter, mm 34.2 ± 2.9 34.0 ± 2.9 33.7 ± 3.4 0.61 Any aortic diameter ≥40 mm, n (%) 3 (4.7) 2 (2.7) 8 (6.6) 0.46 Values are mean SD or n (%). *significantly different from cycling and other. BP = blood pressure; SoV = sinus of Valsalva; NCC = non-coronary cusp; RCC = right coronary cusp

Sex differences in intracranial and extracranial atherosclerosis in patients with acute ischemic stroke

Background and aim

To investigate sex differences with respect to presence and location of atherosclerosis in acute ischemic stroke patients.

Methods

Participants with acute ischemic stroke were included from the Dutch acute stroke trial, a large prospective multicenter cohort study performed between May 2009 and August 2013. All patients received computed tomography/computed tomography-angiography within 9 h of stroke onset. We assessed presence of atherosclerosis in the intra- and extracranial internal carotid and vertebrobasilar arteries. In addition, we determined the burden of intracranial atherosclerosis by quantifying internal carotid and vertebrobasilar artery calcifications, resulting in calcium volumes. Prevalence ratios between women and men were calculated with Poisson regression analysis and adjusted prevalence ratio for potential confounders (age, hypertension, hyperlipidemia, diabetes, smoking, and alcohol use).

Results

We included 1397 patients with a mean age of 67 years, of whom 600 (43%) were women. Presence of atherosclerosis in intracranial vessel segments was found as frequently in women as in men (71% versus 72%, adjusted prevalence ratio 0.95; 95% CI 0.89–1.01). In addition, intracranial calcification volume did not differ between women and men in both intracranial internal carotid (large burden 35% versus 33%, adjusted prevalence ratio 0.93; 95% CI 0.73–1.19) and vertebrobasilar arteries (large burden 26% versus 40%, adjusted prevalence ratio 0.69; 95% CI 0.41–1.12). Extracranial atherosclerosis was less common in women than in men (74% versus 81%, adjusted prevalence ratio 0.86; 95% CI 0.81–0.92).

Conclusions

In patients with acute ischemic stroke the prevalence of intracranial atherosclerosis does not differ between women and men, while extracranial atherosclerosis is less often present in women compared with men.

Correction to: Cardiovascular magnetic resonance native T2 and T2* quantitative values for cardiomyopathies and heart transplantations: a systematic review and meta-analysis

An amendment to this paper has been published and can be accessed via the original article.

Validation of thoracic aortic dimensions on ECG-triggered SSFP as alternative to contrast-enhanced MRA

Objectives

Assessment of thoracic aortic dimensions with non-ECG-triggered contrast-enhanced magnetic resonance angiography (CE-MRA) is accompanied with motion artefacts and requires gadolinium. To avoid both motion artefacts and gadolinium administration, we evaluated the similarity and reproducibility of dimensions measured on ECG-triggered, balanced steady-state free precession (SSFP) MRA as alternative to CE-MRA.

Methods

All patients, with varying medical conditions, referred for thoracic aortic examination between September 2016 and March 2018, who underwent non-ECG-triggered CE-MRA and SSFP-MRA (1.5 T) were retrospectively included (n = 30). Aortic dimensions were measured after double-oblique multiplanar reconstruction by two observers at nine landmarks predefined by literature guidelines. Image quality was scored at the sinus of Valsalva, mid-ascending aorta and mid-descending aorta by semi-automatically assessing the vessel sharpness.

Results

Aortic dimensions showed high agreement between non-ECG-triggered CE-MRA and SSFP-MRA (r = 0.99, p < 0.05) without overestimation or underestimation of aortic dimensions in SSFP-MRA (mean difference, 0.1 mm; limits of agreement, − 1.9 mm and 1.9 mm). Intra- and inter-observer variabilities were significantly smaller with SSFP-MRA for the sinus of Valsalva and sinotubular junction. Image quality of the sinus of Valsalva was significantly better with SSFP-MRA, as fewer images were of impaired quality (3/30) than in CE-MRA (21/30). Reproducibility of dimensions was significantly better in images scored as good quality compared to impaired quality in both sequences.

Conclusions

Thoracic aortic dimensions measured on SSFP-MRA and non-ECG-triggered CE-MRA were similar. As expected, SSFP-MRA showed better reproducibility close to the aortic root because of lesser motion artefacts, making it a feasible non-contrast imaging alternative.

Key Points

• SSFP-MRA provides similar dimensions as non-ECG-triggered CE-MRA.

• Intra- and inter-observer reproducibilities improve for the sinus of Valsalva and sinotubular junction with SSFP-MRA.

• ECG-triggered SSFP-MRA shows better image quality for landmarks close to the aortic root in the absence of cardiac motion.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-06963-x) contains supplementary material, which is available to authorized users.

Prediction of Outcome Using Quantified Blood Volume in Aneurysmal SAH

BACKGROUND AND PURPOSE

In patients with SAH, the amount of blood is strongly associated with clinical outcome. However, it is commonly estimated with a coarse grading scale, potentially limiting its predictive value. Therefore, we aimed to develop and externally validate prediction models for clinical outcome, including quantified blood volumes, as candidate predictors.

MATERIALS AND METHODS

Clinical and radiologic candidate predictors were included in a logistic regression model. Unfavorable outcome was defined as a modified Rankin Scale score of 4-6. An automatic hemorrhage-quantification algorithm calculated the total blood volume. Blood was manually classified as cisternal, intraventricular, or intraparenchymal. The model was selected with bootstrapped backward selection and validated with the R ², C-statistic, and calibration plots. If total blood volume remained in the final model, its performance was compared with models including location-specific blood volumes or the modified Fisher scale.

RESULTS

The total blood volume, neurologic condition, age, aneurysm size, and history of cardiovascular disease remained in the final models after selection. The externally validated predictive accuracy and discriminative power were high (R ² = 56% ± 1.8%; mean C-statistic = 0.89 ± 0.01). The location-specific volume models showed a similar performance (R ² = 56% ± 1%, P = .8; mean C-statistic = 0.89 ± 0.00, P = .4). The modified Fisher models were significantly less accurate (R ² = 45% ± 3%, P < .001; mean C-statistic = 0.85 ± 0.01, P = .03).

CONCLUSIONS

The total blood volume-based prediction model for clinical outcome in patients with SAH showed a high predictive accuracy, higher than a prediction model including the commonly used modified Fisher scale.

Cardiovascular magnetic resonance native T2 and T2* quantitative values for cardiomyopathies and heart transplantations: a systematic review and meta-analysis

BACKGROUND

The clinical application of cardiovascular magnetic resonance (CMR) T2 and T2* mapping is currently limited as ranges for healthy and cardiac diseases are poorly defined. In this meta-analysis we aimed to determine the weighted mean of T2 and T2* mapping values in patients with myocardial infarction (MI), heart transplantation, non-ischemic cardiomyopathies (NICM) and hypertension, and the standardized mean difference (SMD) of each population with healthy controls. Additionally, the variation of mapping outcomes between studies was investigated.

METHODS

The PRISMA guidelines were followed after literature searches on PubMed and Embase. Studies reporting CMR T2 or T2* values measured in patients were included. The SMD was calculated using a random effects model and a meta-regression analysis was performed for populations with sufficient published data.

RESULTS

One hundred fifty-four studies, including 13,804 patient and 4392 control measurements, were included. T2 values were higher in patients with MI, heart transplantation, sarcoidosis, systemic lupus erythematosus, amyloidosis, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and myocarditis (SMD of 2.17, 1.05, 0.87, 1.39, 1.62, 1.95, 1.90 and 1.33, respectively, P <  0.01) compared with controls. T2 values in iron overload patients (SMD = - 0.54, P = 0.30) and Anderson-Fabry disease patients (SMD = 0.52, P = 0.17) did both not differ from controls. T2* values were lower in patients with MI and iron overload (SMD of - 1.99 and - 2.39, respectively, P <  0.01) compared with controls. T2* values in HCM patients (SMD = - 0.61, P = 0.22), DCM patients (SMD = - 0.54, P = 0.06) and hypertension patients (SMD = - 1.46, P = 0.10) did not differ from controls. Multiple CMR acquisition and patient demographic factors were assessed as significant covariates, thereby influencing the mapping outcomes and causing variation between studies.

CONCLUSIONS

The clinical utility of T2 and T2* mapping to distinguish affected myocardium in patients with cardiomyopathies or heart transplantation from healthy myocardium seemed to be confirmed based on this meta-analysis. Nevertheless, variation of mapping values between studies complicates comparison with external values and therefore require local healthy reference values to clinically interpret quantitative values. Furthermore, disease differentiation seems limited, since changes in T2 and T2* values of most cardiomyopathies are similar.

P4451Screening for Coronary Artery Disease USing Primary Evaluation with Cardiac CT (SUSPECT) in Aviation Medicine in the Royal Netherlands Air Force

Background

Military aircrew are subjected to both stress and excessive G-forces, which may be associated with an increased risk of coronary artery disease (CAD) and sudden cardiac death. Annual cardiac screening has therefore been implicated using exercise testing, which suffers from both false-positive and false-negative results. In this study, we have evaluated the prevalence of CAD in military aircrew using cardiac computed tomography (CT), and assessed whether cardiac CT would be a useful screening tool within this population.

Methods

Prospective, single-center, cohort study in 250 asymptomatic aircrew >40 years old in the Royal Netherlands Air Force. Included subjects underwent cardiac CT, in addition to the routine annual check-up that included an electrocardiogram, exercise test and laboratory analysis. Primary endpoint was obstructive CAD, defined as a coronary stenosis ≥50%. Secondary endpoints were non-obstructive CAD (<50% stenosis) and coronary artery calcium score (CACS) >100.

Results

Of the first 108 inclusions, mean age was 49 years (range 40–57), 99% were male and mean body mass index was 25.8 (SD 2.6). The prevalence of hypertension was 8%, hypercholesterolemia 9% and familial heart disease was noted in 22%. 16% were active smokers and none had diabetes. Obstructive CAD was observed in 2% of patients, non-obstructive CAD in 40% and CACS >100 in 11%. All subjects with obstructive CAD on cardiac CT underwent coronary artery angiography, which confirmed a stenosis >70% that required revascularization.

Conclusion

In asymptomatic military aviation aircrew >40 years old currently active in the Royal Netherlands Air Force, the prevalence of obstructive and non-obstructive CAD was 2% and 40%, respectively

Acknowledgement/Funding

Royal Netherlands Air Force

Imaging Findings Associated with Space-Occupying Edema in Patients with Large Middle Cerebral Artery Infarcts

BACKGROUND AND PURPOSE

Prominent space-occupying cerebral edema is a devastating complication occurring in some but not all patients with large MCA infarcts. It is unclear why differences in the extent of edema exist. Better knowledge of factors related to prominent edema formation could aid treatment strategies. This study aimed to identify variables associated with the development of prominent edema in patients with large MCA infarcts.

MATERIALS AND METHODS

From the Dutch Acute Stroke Study (DUST), 137 patients were selected with large MCA infarcts on follow-up NCCT (3 ± 2 days after stroke onset), defined as ASPECTS ≤4. Prominent edema was defined as a midline shift of ≥5 mm on follow-up. Admission patient and treatment characteristics were collected. Admission CT parameters used were ASPECTS on NCCT and CBV and MTT maps, and occlusion site, clot burden, and collaterals on CTA. Permeability on admission CTP, and day 3 recanalization and reperfusion statuses were obtained if available. Unadjusted and adjusted (age and NIHSS) odds ratios were calculated for all variables in relation to prominent edema.

RESULTS

Prominent edema developed in 51 patients (37%). Adjusted odds ratios for prominent edema were higher with lower ASPECTS on NCCT (adjusted odds ratio, 1.32; 95% CI, 1.13-1.55) and CBV (adjusted odds ratio, 1.26; 95% CI, 1.07-1.49), higher permeability (adjusted odds ratio, 2.35; 95% CI, 1.30-4.24), more proximal thrombus location (adjusted odds ratio, 3.40; 95% CI, 1.57-7.37), higher clot burden (adjusted odds ratio, 2.88; 95% CI, 1.11-7.45), and poor collaterals (adjusted odds ratio, 3.93; 95% CI, 1.78-8.69).

CONCLUSIONS

Extensive proximal occlusion, poor collaterals, and larger ischemic deficits with higher permeability play a role in the development of prominent edema in large MCA infarcts.

Association of Automatically Quantified Total Blood Volume after Aneurysmal Subarachnoid Hemorrhage with Delayed Cerebral Ischemia

BACKGROUND AND PURPOSE

The total amount of extravasated blood after aneurysmal subarachnoid hemorrhage, assessed with semiquantitative methods such as the modified Fisher and Hijdra scales, is known to be a predictor of delayed cerebral ischemia. However, prediction rates of delayed cerebral ischemia are moderate, which may be caused by the rough and observer-dependent blood volume estimation used in the prediction models. We therefore assessed the association between automatically quantified total blood volume on NCCT and delayed cerebral ischemia.

MATERIALS AND METHODS

We retrospectively studied clinical and radiologic data of consecutive patients with aneurysmal SAH admitted to 2 academic hospitals between January 2009 and December 2011. Adjusted ORs with associated 95% confidence intervals were calculated for the association between automatically quantified total blood volume on NCCT and delayed cerebral ischemia (clinical, radiologic, and both). The calculations were also performed for the presence of an intraparenchymal hematoma and/or an intraventricular hematoma and clinical delayed cerebral ischemia.

RESULTS

We included 333 patients. The adjusted OR of total blood volume for delayed cerebral ischemia (clinical, radiologic, and both) was 1.02 (95% CI, 1.01-1.03) per milliliter of blood. The adjusted OR for the presence of an intraparenchymal hematoma for clinical delayed cerebral ischemia was 0.47 (95% CI, 0.24-0.95) and of the presence of an intraventricular hematoma, 2.66 (95% CI, 1.37-5.17).

CONCLUSIONS

A higher total blood volume measured with our automated quantification method is significantly associated with delayed cerebral ischemia. The results of this study encourage the use of rater-independent quantification methods in future multicenter studies on delayed cerebral ischemia prevention and prediction.

Assessment of Collateral Status by Dynamic CT Angiography in Acute MCA Stroke: Timing of Acquisition and Relationship with Final Infarct Volume

BACKGROUND AND PURPOSE

Dynamic CTA is a promising technique for visualization of collateral filling in patients with acute ischemic stroke. Our aim was to describe collateral filling with dynamic CTA and assess the relationship with infarct volume at follow-up.

MATERIALS AND METHODS

We selected patients with acute ischemic stroke due to proximal MCA occlusion. Patients underwent NCCT, single-phase CTA, and whole-brain CT perfusion/dynamic CTA within 9 hours after stroke onset. For each patient, a detailed assessment of the extent and velocity of arterial filling was obtained. Poor radiologic outcome was defined as an infarct volume of ≥70 mL. The association between collateral score and follow-up infarct volume was analyzed with Poisson regression.

RESULTS

Sixty-one patients with a mean age of 67 years were included. For all patients combined, the interval that contained the peak of arterial filling in both hemispheres was between 11 and 21 seconds after ICA contrast entry. Poor collateral status as assessed with dynamic CTA was more strongly associated with infarct volume of ≥70 mL (risk ratio, 1.9; 95% CI, 1.3-2.9) than with single-phase CTA (risk ratio, 1.4; 95% CI, 0.8-2.5). Four subgroups (good-versus-poor and fast-versus-slow collaterals) were analyzed separately; the results showed that compared with good and fast collaterals, a similar risk ratio was found for patients with good-but-slow collaterals (risk ratio, 1.3; 95% CI, 0.7-2.4).

CONCLUSIONS

Dynamic CTA provides a more detailed assessment of collaterals than single-phase CTA and has a stronger relationship with infarct volume at follow-up. The extent of collateral flow is more important in determining tissue fate than the velocity of collateral filling. The timing of dynamic CTA acquisition in relation to intravenous contrast administration is critical for the optimal assessment of the extent of collaterals.

Hemodynamic Differences in Intracranial Aneurysms before and after Rupture

BACKGROUND AND PURPOSE

Rupture risk of intracranial aneurysms may depend on hemodynamic characteristics. This has been assessed by comparing hemodynamic data of ruptured and unruptured aneurysms. However, aneurysm geometry may change before, during, or just after rupture; this difference causes potential changes in hemodynamics. We assessed changes in hemodynamics in a series of intracranial aneurysms, by using 3D imaging before and after rupture.

MATERIALS AND METHODS

For 9 aneurysms in 9 patients, we used MRA, CTA, and 3D rotational angiography before and after rupture to generate geometric models of the aneurysm and perianeurysmal vasculature. Intra-aneurysmal hemodynamics were simulated by using computational fluid dynamics. Two neuroradiologists qualitatively assessed flow complexity, flow stability, inflow concentration, and flow impingement in consensus, by using flow-velocity streamlines and wall shear stress distributions.

RESULTS

Hemodynamics changed in 6 of the 9 aneurysms. The median time between imaging before and after rupture was 678 days (range, 14-1461 days) in these 6 cases, compared with 151 days (range, 34-183 days) in the 3 cases with unaltered hemodynamics. Changes were observed for flow complexity (n = 3), flow stability (n = 3), inflow concentration (n = 2), and region of flow impingement (n = 3). These changes were in all instances associated with aneurysm displacement due to rupture-related hematomas, growth, or newly formed lobulations.

CONCLUSIONS

Hemodynamic characteristics of intracranial aneurysms can be altered by geometric changes before, during, or just after rupture. Associations of hemodynamic characteristics with aneurysm rupture obtained from case-control studies comparing ruptured with unruptured aneurysms should therefore be interpreted with caution.

Predictors of reperfusion in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Ischemic stroke studies emphasize a difference between reperfusion and recanalization, but predictors of reperfusion have not been elucidated. The aim of this study was to evaluate the relationship between reperfusion and recanalization and identify predictors of reperfusion.

MATERIALS AND METHODS

From the Dutch Acute Stroke Study, 178 patients were selected with an MCA territory deficit on admission CTP and day 3 follow-up CTP and CTA. Reperfusion was evaluated on CTP, and recanalization on CTA, follow-up imaging. Reperfusion percentages were calculated in patients with and without recanalization. Patient admission and treatment characteristics and admission CT imaging parameters were collected. Their association with complete reperfusion was analyzed by using univariate and multivariate logistic regression.

RESULTS

Sixty percent of patients with complete recanalization showed complete reperfusion (relative risk, 2.60; 95% CI, 1.63-4.13). Approximately one-third of patients showed some discrepancy between recanalization and reperfusion status. Lower NIHSS score (OR, 1.06; 95% CI, 1.01-1.11), smaller infarct core size (OR, 3.11; 95% CI, 1.46-6.66; and OR, 2.40; 95% CI, 1.14-5.02), smaller total ischemic area (OR, 4.20; 95% CI, 1.91-9.22; and OR, 2.35; 95% CI, 1.12-4.91), lower clot burden (OR, 1.35; 95% CI, 1.14-1.58), distal thrombus location (OR, 3.02; 95% CI, 1.76-5.20), and good collateral score (OR, 2.84; 95% CI, 1.34-6.02) significantly increased the odds of complete reperfusion. In multivariate analysis, only total ischemic area (OR, 6.12; 95% CI, 2.69-13.93; and OR, 1.91; 95% CI, 0.91-4.02) was an independent predictor of complete reperfusion.

CONCLUSIONS

Recanalization and reperfusion are strongly associated but not always equivalent in ischemic stroke. A smaller total ischemic area is the only independent predictor of complete reperfusion.

Rationale and design of the Measuring Athlete's Risk of Cardiovascular events (MARC) study : The role of coronary CT in the cardiovascular evaluation of middle-aged sportsmen

Background

More than 90 % of exercise-related cardiac arrests occur in men, predominantly those aged 45 years and older with coronary artery disease (CAD) as the main cause. The current sports medical evaluation (SME) of middle-aged recreational athletes consists of a medical history, physical examination, and resting and exercise electrocardiography. Coronary CT (CCT) provides a minimally invasive low radiation dose opportunity to image the coronary arteries. We present the study protocol of the Measuring Athlete’s Risk of Cardiovascular events (MARC) study. MARC aims to assess the additional value of CCT to a routine SME in asymptomatic sportsmen ≥45 years without known CAD.

Design

MARC is a prospective study of 300 asymptomatic sportsmen ≥45 years who will undergo CCT if the SME does not reveal any cardiac abnormalities. The prevalence and determinants of CAD (coronary artery calcium score ≥100 Agatston Units (AU) or ≥50 % luminal stenosis) will be reported. The number needed to screen to prevent the occurrence of one cardiovascular event in the next 5 years, conditional to adequate treatment, will be estimated.

Discussion

We aim to determine the prevalence and severity of CAD and the additional value of CCT in asymptomatic middle-aged (≥45 years) sportsmen whose routine SME revealed no cardiac abnormalities.

Electronic supplementary material

The online version of this article (doi:10.1007/s12471-014-0630-0) contains supplementary material, which is available to authorized users.

Predictive value of thrombus attenuation on thin-slice non-contrast CT for persistent occlusion after intravenous thrombolysis

BACKGROUND

In stroke erythrocyte-rich thrombi are more sensitive to intravenous thrombolysis with recombinant tissue plasminogen activator (IV-rtPA) and have higher density on non-contrast CT (NCCT). We investigated the relationship between thrombus density and recanalization and whether persistent occlusions can be predicted by Hounsfield unit (HU) measurements.

METHODS

In 88 IV-rtPA-treated patients with intracranial ICA or MCA occluding thrombus and follow-up imaging, thrombus and contralateral vessel attenuation measurements were performed on thin-slice NCCT. Mean absolute and relative HU were compared between patients with persistent occlusion (modified Thrombolysis in Cerebral Infarction system, grade 0/1/2a) and recanalization (grade 2b/3). Univariate and multivariate (adjusted for stroke subtype, clot burden score, occlusion site and time to thrombolysis) odds ratios for persistent occlusion were calculated. Additional prognostic value for persistent occlusion was estimated by adding HU measurements to the area under the curve (AUC) of known determinants and calculating optimal cut-off values.

RESULTS

Patients with persistent occlusion (n = 19) had significant lower mean HU (absolute 52.2 ± 9.5, relative 1.29 ± 0.20) compared to recanalization (absolute 63.1 ± 10.7, relative 1.54 ± 0.23, both p < 0.0001). Odds ratios for persistent occlusion were 3.1 (95% confidence interval, CI 1.6-6.0) univariate and 3.1 (95% CI 1.7-5.7) multivariate per 10 absolute HU decrease and 3.2 (95% CI 1.6-6.5) univariate and 4.1 (95% CI 1.8-9.1) multivariate per 0.20 relative HU decrease. Attenuation measurements significantly increased the AUC (0.67) of the known determinants to 0.84 (absolute HU) and 0.86 (relative HU). Cut-off values of <56.5 absolute HU and <1.38 relative HU showed optimal predictive values for persistent occlusion.

CONCLUSIONS

Thrombus density is related to recanalization rate. Lower absolute and relative HU are independently related to persistent occlusion and HU measurements significantly increase discriminative performances of known recanalization determinants.

Ethnic differences in ventricular hypertrabeculation on cardiac MRI in elite football players

PURPOSE

Left ventricular (LV) trabeculation may be more pronounced in ethnic African than in Caucasian (European) athletes, leading to possible incorrect diagnosis of left ventricular non-compaction cardiomyopathy (LVNC). This study investigates ethnic differences in LV hypertrabeculation amongst elite athletes with cardiac magnetic resonance (CMR) and electrocardiography (ECG).

METHODS

38 elite male football (soccer) players (mean age 23.0, range 19-34 years, 28/38 European, 10/38 African) underwent CMR and ECG. Hypertrabeculation was assessed using the ratio of non-compacted to compacted myocardium (NC/C ratio) on long-axis and short-axis segments. ECGs were systematically rated.

RESULTS

No significant differences were seen in ventricular volumes, wall mass or E/A ratio, whereas biventricular ejection fraction (EF) was significantly lower in African athletes (European/African athletes LVEF 55/50 %, p = 0.02; RVEF 51/48 %, p = 0.05). Average NC/C ratio was greater in African athletes but only significantly at mid-ventricular level (European/African athletes: apical 0.91/1.00, p = 0.65; mid-ventricular 0.89/1.45, p < 0.05; basal 0.40/0.46, p = 0.67). ECG readings demonstrated no significant group differences, and no correlation between ECG anomalies and hypertrabeculation.

CONCLUSIONS

A greater degree of LV hypertrabeculation is seen in healthy African athletes, combined with biventricular EF reduction at rest. Recognition of this phenomenon is necessary to avoid misdiagnosis of LVNC.

CT brain perfusion protocol to eliminate the need for selecting a venous output function

BACKGROUND AND PURPOSE

In CTP, an arterial input function is used for cerebral blood volume measurement. AIFs are often influenced by partial volume effects resulting in overestimated CBV. A venous output function is manually selected to correct for partial volume. This can introduce variability. Our goal was to develop a CTP protocol that enables AIF selection unaffected by partial volume.

MATERIALS AND METHODS

First, the effects of partial volume on artery sizes/types including the MCA were estimated by using a CTP phantom with 9 protocols (section thicknesses of 1, 1.8, and 5 mm and image resolutions of 0.5, 1, and 1.5 mm). Next, these protocols were applied to clinical CTP studies from 6 patients. The influence of the partial volume effect was measured by comparison of the time-attenuation curves from different artery locations with reference veins.

RESULTS

AIFs from MCAs were unaffected by partial volume effects when using high image resolution (1 mm) and medium section thickness (1.8 mm). For the clinical data, a total of 104 arteries and 60 veins was selected. The data confirmed that high image resolution and thin section thickness enable selection of MCAs for AIFs free of partial volume influences. In addition, we found that large veins were not insusceptible to partial volume effects relative to large arteries, questioning the use of veins for partial volume correction.

CONCLUSIONS

A CTP protocol with 1.8-mm section thickness and 1-mm image resolution allows AIF selection unaffected by partial volume effects in MCAs.

Differences in CT perfusion summary maps for patients with acute ischemic stroke generated by 2 software packages

BACKGROUND AND PURPOSE

Although CT perfusion is a promising tool to support treatment decisions for patients with acute ischemic stroke, it still lacks a standardized method for CTP analysis. The purpose of this study was to assess the variability of the area of infarct core and penumbra as presented in summary maps produced by 2 different software packages.

MATERIALS AND METHODS

Forty-one CTP image datasets of 26 consecutive patients who presented with acute ischemic stroke were retrospectively evaluated. Identical image datasets were analyzed by using 2 different commercially available CTP analysis software packages, each representing a mainstream of widely used algorithms: delay-sensitive and delay-insensitive. Bland-Altman analyses were performed to evaluate the level of agreement between the 2 methods in determining the area of infarct core and penumbra area in the summary maps.

RESULTS

There was a statistically significant difference in infarct core area (-23.6 ± 25.6 cm(2)) and penumbra area (15.8 ± 25.3 cm(2)) between the 2 software packages. For all the areas presented in the summary maps, the Bland-Altman interval limit of agreement was larger than 100 cm(2).

CONCLUSIONS

The infarct core and penumbra area of CTP summary maps generated by 2 commonly used software packages were significantly different, emphasizing the need for standardization and validation of CTP analysis before it can be applied to patient management in clinical practice.

Rationale and design of the SMART Heart study: A prediction model for left ventricular hypertrophy in hypertension

Left ventricular hypertrophy (LVH) is an independent risk factor for the development of heart failure, coronary heart disease and stroke. LVH develops in response to haemodynamic overload, e.g. hypertension. LVH was originally thought to start as an adaptive and beneficial response required to normalise wall stress. However, this concept has been challenged by recent animal experiments suggesting that any degree of LVH is detrimental for the preservation of cardiac function and survival. If confirmed in humans, these findings imply that an increase in LV mass should be prevented, e.g. by lifestyle or pharmacological interventions. To facilitate and optimise interventions, the SMART Heart study was recently set up to develop a prediction model, also involving single nucleotide polymorphism data, for the identification of subjects at high risk of developing LVH in hypertension. For this purpose 1000 subjects with chronic hypertension will undergo cardiac MR imaging. In addition, this study allows the extrapolation of animal experimental genetic research into the human situation. (Neth Heart J 2007;15:295-8.).

Image quality assessment of the right ventricle with three different delayed enhancement sequences in patients suspected of ARVC/D

Histopathologic findings in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) are replacement of the normal myocardium with fatty and fibrous elements with preferential involvement of the right ventricle. The right ventricular fibrosis can be visualised by post-gadolinium delayed enhancement inversion recovery imaging (DE imaging). We compared the image quality of three different gradient echo MRI sequences for short axis DE imaging of the right ventricle (RV). We retrospectively analysed MRI scans performed between February 2005 and December 2008 in 97 patients (mean age: 41.2 years, 67% men) suspected of ARVC/D. For DE imaging either a 2D Phase Sensitive (PSIR), a 2D (2D) or a 3D (3D) inversion recovery sequence was used in respectively 38, 32 and 27 MRI-examinations. The RV, divided in 10 segments, was assessed for image quality by two radiologists in random sequence. A consensus reading was performed if results differed between the two readings. Image quality was good in 24% of all segments in the 3D group, 66% in the 2D group and 79% in the PSIR group. Poor image quality was observed in 51% (3D), 10% (2D), and 2% (PSIR) of all segments. Exams were considered suitable for clinical use in 7% of exams in the 3D group, 75% of exams in the 2D group and 90% of exams of the PSIR group. Breathing-artifacts occurred in 22% (3D), 59% (2D) and 53% (PSIR). Motion-artifacts occurred in 56% (3D), 28% (2D) and 29% (PSIR). Post-gadolinium imaging using the PSIR sequence results in better and more consistent image quality of the RV compared to the 2D and 3D sequences.

Advances in cardiac imaging: the role of magnetic resonance imaging and computed tomography in identifying athletes at risk

Advanced cardiac imaging, using cardiac magnetic resonance imaging (MRI) and multidetector computed tomography (CT), is increasingly used in the work-up of athletes with suspected abnormalities on screening. Both imaging modalities produce highly accurate and reproducible structural and functional cardiac information. Cardiac MRI has the advantage of imaging without radiation exposure or the use of iodine-containing contrast agents, but is sometimes not possible due to claustrophobia or other contraindications. Although cardiac MRI can rule out coronary artery anomalies, multidetector CT is superior to cardiac MRI for visualising the full extent of the coronary arteries and atherosclerotic coronary artery disease. For patients less than 35 years of age, cardiac MRI is the first option after initial echocardiography for further assessment of cardiomyopathies, myocarditis and coronary anomalies, which are major causes of sudden cardiac death in young athletes. For athletes over 35 years of age the most common cause of sudden cardiac death is coronary artery disease, whereby cardiovascular screening requires further diagnostic modalities and may include multidetector CT.

Relationship of ventricular and atrial dilatation to valvular function in endurance athletes

OBJECTIVE

To establish cardiac magnetic resonance imaging (MRI) reference values for atrial adaptation to training in endurance athletes in comparison with matched non-athletes. In addition, to study the relationship of atrial size to ventricular and annular size and valvular function.

DESIGN

Cross-sectional study.

PARTICIPANTS

180 healthy individuals aged 18-39 years (41% women): 60 elite endurance athletes (exercising > 18 h/week), 60 regular endurance athletes (9-18 h/ week), and 60 age and gender matched non-athletes (exercising ≤3 h/week) underwent cardiac MRI. Quantitative atrial dimensions and volumes, indexed for body surface area (BSA), were compared with ventricular and annular dimensions. Regurgitant fractions of all four valves and peak velocities of mitral and tricuspid valves were also assessed.

RESULTS

BSA-corrected right and left atrial volumes and diameters were significantly larger for athletes compared with non-athletes (p<0.05-p<0.0005). Ventricular, annular and atrial ratios remained constant for all groups, suggesting balanced adaptation to exercise training. E/A ratios remained statistically unchanged in all groups. Regurgitant fractions of the four cardiac valves were all mild (≤15%) and not significantly different in athletes compared with non-athletes.

CONCLUSIONS

Atrial remodelling in endurance athletes may be regarded as a balanced physiological adaptation to exercise training with preservation of valvular function.

Unrecognised myocardial infarction in subjects at high vascular risk: prevalence and determinants

OBJECTIVE

To investigate the prevalence and determinants of unrecognised myocardial infarction (UMI).

DESIGN, SETTING, PATIENTS

In this cross-sectional study in a tertiary centre, a delayed enhancement cardiac MRI (DE-CMR), which identifies both Q-wave and non-Q wave MIs, was performed in 502 subjects with manifest extracardiac atherosclerotic disease or marked risk factors for atherosclerosis without symptomatic coronary artery disease.

MAIN OUTCOME MEASURES

UMI was defined as the presence of delayed enhancement without corresponding clinical history.

RESULTS

DE-CMR was of sufficient image quality in 480 (95.6%) subjects. A UMI was present in 45 (9.4%) of all subjects; in 13.1% of men and in 3.7% of women. The risk of UMI increased from 6.0% (95% CI 2.2 to 9.8%) in those with two vascular risk factors up to 26.2% (95% CI 15.2 to 37.3%) in those with four or five risk factors. In a multivariable analysis, the risk of UMI was related to male gender (OR 2.3 (95% CI 1.0 to 5.6)), age (OR 1.04 (95% CI 1.00 to 1.07) per year), ever smoking (OR 3.1 (95% CI 1.0 to 9.1), history of stroke (OR 1.9 (95% CI 0.8 to 4.3)) and history of aneurysm of the abdominal aorta (OR 2.6 (95% CI 1.0 to 6.9)).

CONCLUSIONS

In cardiac asymptomatic subjects at high vascular risk, UMI is common. The risk of UMI increases with increasing presence of risk factors.

MR angiography follow-up 5 years after coiling: frequency of new aneurysms and enlargement of untreated aneurysms

BACKGROUND AND PURPOSE

Patients with intracranial aneurysms are at risk for future development of new aneurysms and growth of additional untreated aneurysms. Because in previous long-term studies duration of follow-up varied widely, the time interval after which screening could be effective remains largely unknown. The purpose of this study was to assess the incidence of de novo aneurysm formation and the growth of additional untreated aneurysms in patients with coiled aneurysms followed up with MR angiography (MRA) after a fixed period of 5 years.

MATERIALS AND METHODS

In 65 patients with coiled intracranial aneurysms, high-resolution 3T MRA was performed 5.1 +/- 0.2 years after coiling. MRA follow-up imaging was compared with MRA or CT angiography at the time of coiling. Additional aneurysms detected at MRA follow-up were classified as unchanged, grown, de novo, or incomparable with previous imaging.

RESULTS

In 13 of 65 patients (20%), 24 additional aneurysms were found. Four aneurysms were incomparable with previous imaging and 2 of these were clipped. Of the remaining 20 additional aneurysms, 1 was de novo, 1 had grown slightly, and 18 were unchanged. The incidence of de novo aneurysm formation after 5 years was 1.54% (95% confidence interval, 0.01-9.0%). For additional aneurysms known at the time of initial coiling and for the 1 de novo aneurysm, no treatment was indicated.

CONCLUSIONS

MRA screening 5 years after coiling for detection of de novo aneurysms and growth of additional untreated aneurysms has a low yield in terms of finding aneurysms that need to be treated.

Stability of intracranial aneurysms adequately occluded 6 months after coiling: a 3T MR angiography multicenter long-term follow-up study

BACKGROUND AND PURPOSE

The long-term fate of coiled intracranial aneurysms is largely unknown, and prolonged imaging follow-up has been advocated. The yield of follow-up imaging in coiled aneurysms adequately occluded at 6 months is unknown. In such patients, we performed time-of-flight MR angiography (MRA) to assess the incidence and therapeutic consequences of reopening 5-11 years after coiling.

MATERIALS AND METHODS

Between 1995 and 2002, 661 aneurysms in 607 patients were coiled in 3 participating centers. Six-month follow-up angiograms were obtained in 497 (75%) aneurysms, of which 316 (64%) in 297 patients were adequately occluded. Of 297 patients, 84 were excluded for various reasons and 73 could not be traced. Of 140 eligible patients, 104 (74%) with 111 aneurysms were studied with 3T MR imaging and high-resolution MRA at a mean of 6.0 years after coiling (median, 5.6 years; range, 5.0-10.6 years).

RESULTS

The proportion of aneurysms with reopening was 3.6% (4/111; 95% confidence interval [CI], 1.1%-9.2%). One reopened aneurysm, which initially contained intraluminal thrombus, was additionally coiled (0.9%; 95% CI, 0.0%-5.4%).

CONCLUSION

In intracranial aneurysms with adequate occlusion at 6 months after coiling, the proportion of reopening needing retreatment after >5 years is low. The number of reopened aneurysms with therapeutic consequences was too small to assess risk factors, but probably the presence of intraluminal thrombus is one such risk factor. Most patients with coiled intracranial aneurysms that are adequately occluded at 6 months might not need prolonged imaging follow-up.

Reproducibility of quantitative CT brain perfusion measurements in patients with symptomatic unilateral carotid artery stenosis

BACKGROUND AND PURPOSE

To establish intraobserver and interobserver variability for regional measurement of CT brain perfusion (CTP) and to determine whether reproducibility can be improved by calculating perfusion ratios.

MATERIALS AND METHODS

CTP images were acquired in 20 patients with unilateral symptomatic carotid artery stenosis (CAS). We manually drew regions of interest (ROIs) in the cortical flow territories of the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries and the basal ganglia in each hemisphere; recorded cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT); and calculated ratios of perfusion values between symptomatic and asymptomatic hemisphere. We assessed intraobserver and interobserver variability by performing a Bland-Altman analysis of the relative differences between 2 observations and calculated SDs of relative differences (SDD(rel)) as a measure of reproducibility. We used an F test to assess significance of differences between SDD(rel) of absolute CTP values and CTP ratios, and the Levine test to compare the 4 perfusion territories.

RESULTS

MTT was the most reproducible parameter (SDD(rel) <or= 10%). Intraobserver and interobserver variability were higher for absolute CTP values compared with CTP ratios for CBV (16%-17% versus 11%-16%) and CBF (18% versus 10%-13%) but not for MTT (5%-9%). Reproducibility was best in the MCA territory: SDD(rel) was <or=11% for perfusion ratios of all 3 parameters.

CONCLUSION

MTT is the most reproducible CTP parameter in patients with unilateral symptomatic CAS. Measurement variability in CBV and CBF can be improved if CTP ratios instead of CTP values are used. The MCA territory shows the least measurement variability.