Color-Mapping of 4D-CTA for the Detection of Cranial Arteriovenous Shunts.

BACKGROUND AND PURPOSE: 4D CT angiography is increasingly used in clinical practice for the assessment of different neurovascular disorders. Optimized processing of 4D-CTA is crucial for diagnostic interpretation because of the large amount of data that is generated. A color-mapping method for 4D-CTA is presented for improved and enhanced visualization of the cerebral vasculature hemodynamics. This method was applied to detect cranial AVFs. MATERIALS AND METHODS: All patients who underwent both 4D-CTA and DSA in our hospital from 2011 to 2018 for the clinical suspicion of a cranial AVF or carotid cavernous fistula were retrospectively collected. Temporal information in the cerebral vasculature was visualized using a patient-specific color scale. All color-maps were evaluated by 3 observers for the presence or absence of an AVF or carotid cavernous fistula. The presence or absence of cortical venous reflux was evaluated as a secondary outcome measure. RESULTS: In total, 31 patients were included, 21 patients with and 10 without an AVF. Arterialization of venous structures in AVFs was accurately visualized using color-mapping. There was high sensitivity (86%-100%) and moderate-to-high specificity (70%-100%) for the detection of AVFs on color-mapping 4D-CTA, even without the availability of dynamic subtraction rendering. The diagnostic performance of the 3 observers in the detection of cortical venous reflux was variable (sensitivity, 43%-88%; specificity, 60%-80%). CONCLUSIONS: Arterialization of venous structures can be visualized using color-mapping of 4D-CTA and proves to be accurate for the detection of cranial AVFs. This finding makes color-mapping a promising visualization technique for assessing temporal hemodynamics in 4D-CTA.

Standardized evaluation framework for evaluating coronary artery stenosis detection, stenosis quantification and lumen segmentation algorithms in computed tomography angiography.

Though conventional coronary angiography (CCA) has been the standard of reference for diagnosing coronary artery disease in the past decades, computed tomography angiography (CTA) has rapidly emerged, and is nowadays widely used in clinical practice. Here, we introduce a standardized evaluation framework to reliably evaluate and compare the performance of the algorithms devised to detect and quantify the coronary artery stenoses, and to segment the coronary artery lumen in CTA data. The objective of this evaluation framework is to demonstrate the feasibility of dedicated algorithms to: (1) (semi-)automatically detect and quantify stenosis on CTA, in comparison with quantitative coronary angiography (QCA) and CTA consensus reading, and (2) (semi-)automatically segment the coronary lumen on CTA, in comparison with expert's manual annotation. A database consisting of 48 multicenter multivendor cardiac CTA datasets with corresponding reference standards are described and made available. The algorithms from 11 research groups were quantitatively evaluated and compared. The results show that (1) some of the current stenosis detection/quantification algorithms may be used for triage or as a second-reader in clinical practice, and that (2) automatic lumen segmentation is possible with a precision similar to that obtained by experts. The framework is open for new submissions through the website, at http://coronary.bigr.nl/stenoses/.

CT fractional flow reserve: the next level in non-invasive cardiac imaging.

The haemodynamic effect of a coronary artery stenosis is a better predictor of prognosis than anatomical lumen obstruction. Until recently, no individual non-invasive test could provide both accurate coronary anatomy and lesion-specific myocardial ischaemia. However, computer tomography (CT) fractional flow reserve, which can be calculated from a standard CT coronary angiogram, was recently demonstrated to accurately detect and rule out the haemodynamic significance of individual coronary artery stenoses.

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.

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.).

Left ventricular hypertrophy: a shift in paradigm.

Observational studies have identified left ventricular hypertrophy (LVH) as a strong, independent risk factor for the development of heart failure (HF), coronary heart disease and stroke. LVH develops in response to hemodynamic overload. Classical conceptualization has it that LVH would start as an adaptive, beneficial response in order to normalize wall stress. With progression of the disease, deterioration to maladaptive hypertrophy, and further on to HF could occur. Recent experiments in animal models of pressure-overload and myocardial infarction now challenge this concept by demonstrating that blunting the hypertrophic response is actually associated with preserved cardiac function, and with improved survival. These findings may have profound therapeutical implications.

Treatment of poikiloderma of Civatte with the pulsed dye laser: a series of patients with severe depigmentation.

BACKGROUND: Pulsed dye laser (PDL) treatment is widely used for poikiloderma of Civatte. Some adverse events in small numbers of patients have been reported. Guidelines for treatment of poikiloderma of Civatte do not exist. OBJECTIVE: To report the occurrence of persistent depigmentation as a late adverse event in a series of patients with poikiloderma of Civatte after treatment with PDL. METHODS: Eight patients (seven women and one man, mean age 48 years) with poikiloderma of Civatte were treated with PDL using a 585-nm wavelength and a fixed pulse duration of 450 micros. In all patients one or two test PDL patches were performed and reviewed after 3 months. All of the patients tolerated the testing without complications. Subsequent treatments were undertaken at intervals of 3 months. RESULTS: All patients were treated with fluences between 3.5 and 7 J/cm2, using a 7- or 10-mm spot size. All patients had a good result with respect to clearing of the vascular component. Nevertheless, six of them, treated with 5-7 J/cm2, reported severe depigmentation 4-11 months after treatment. Two patients treated with lower fluences (3.5-5.5 J/cm2) did not report this depigmentation. CONCLUSIONS: Great care is needed when PDL treatment is used for poikiloderma of Civatte. Pigment changes have been incidentally mentioned as late complications but have not been well documented as the late depigmentation has been in this series. It is advisable to use fluences as low as possible, and not exceeding an upper limit of 5 J/cm2, on a 10-mm spot size. More research is needed to define an optimal pulse duration.

Progress in noninvasive coronary artery imaging using multislice CT.

Conventional coronary angiography (CAG) has been the reference standard for the assessment of coronary artery disease since its introduction in 1958. However, several studies have shown that diagnostic CAG has an average morbidity of 2% and a mortality of approximately 0.1%. In the last decade, progress in medical imaging has opened the way to noninvasive assessment of the coronary arteries at lower cost and risk. Of the different modalities, multislice CT (MSCT) has made the biggest step forward. At the 2005 European Congress of Radiology (ECR), experiences with the latest developments in noninvasive coronary artery imaging were reported. This report summarises the advances in the use of MSCT in coronary stenosis detection, emergency decision-making, plaque imaging, and the analysis of cardiac function and late enhancement. Also, attention is paid to new strategies to reduce MSCT-related radiation exposure.

Acquired arteriovenous malformation induced by pressure: a case report.

Arteriovenous malformations may be congenital or acquired. In the latter case, usually a traumatic injury to the arteries precedes the arteriovenous anastomoses. Two elderly patients presented with large, purple-colored verrucous tumors on the buttocks. Both patients were obese and immobile, and reported repeated bleeding from the lesions after minor trauma. The tumors were soft and could be emptied by applying pressure. Doppler examination revealed arterial pulsations over the lesions. Both cases were diagnosed as pressure-induced arteriovenous malformations. The lesions are assumed to have been caused by tissue damage in the deep subcutis induced by decubitus.

[Boerhaave's syndrome: also in the emergency room]. / Het Boerhaave-syndroom: ook op de eersteharthulp.

Two men, aged 52 and 57 years, had vomited and then developed chest pain, dyspnoea and tachypnoea. After a myocardial infarction had been excluded in the cardiac emergency room, further examination revealed a rupture of the oesophagus. This was treated surgically with the ultimate creation of a tubular stomach. Both patients then recovered well. The Boerhaave's syndrome, a 'spontaneous' perforation of the oesophagus, is a rare and potentially lethal condition which should be diagnosed at an early stage. Pain in the chest, dyspnoea and vomiting are frequent symptoms. A cardiac cause is sometimes erroneously suspected. Subcutaneous emphysema is a major indication for a perforation of the oesophagus. The chest X-ray shows also mediastinal emphysema and infiltrative abnormalities; in case of doubt a second X-ray should be made some hours later.

Effect of exercise-induced ischemia on QT interval dispersion.

An increased spatial dispersion of ventricular repolarization duration (QT dispersion) is associated with an increased vulnerability to arrhythmias. This study was designed to examine the effect of exercise on QT dispersion in ischemic heart disease (IHD). QT dispersion, corrected QT dispersion, and percentage change in uncorrected and corrected QT dispersion between rest and peak exercise were examined in 14 members of a control group, 17 patients with IHD, and 14 patients with IHD who were receiving beta-blockers (IHD-B). All subjects had undergone a standard Bruce protocol exercise test, and QT intervals were measured at rest and peak exercise with a digitizing tablet interfaced to a personal computer. QT dispersion at rest was markedly increased in the IHD group compared with that in the control and IHD-B groups, respectively (corrected QT dispersion in milliseconds), 74 +/- 7, 40 +/- 4, 49 +/- 5, p < 0.03). The corrected QT dispersion at peak exercise was greater in the IHD group compared with that in the control group (57 +/- 5 vs 26 +/- 3 msec, p < 0.03). The percentage change in QT dispersion with exercise was significantly higher in the IHD group (52% +/- 5%) compared with that in both the control group (28% +/- 4%, p < 0.002) and the IHD-B group (30% +/- 3%, p < 0.01). A larger mean QT dispersion at peak exercise and an increased percentage change in QT dispersion with exercise may help explain the increased susceptibility of the IHD group for arrhythmias. The cardioprotective action of beta-blockers may be explained by their blunting effect on exercise-related changes in QT dispersion.