Exercise related ventricular arrhythmias are related to cardiac fibrosis in hypertrophic cardiomyopathy mutation carriers.

AIMS: Hypertrophic cardiomyopathy (HCM) is a frequent cause of sudden cardiac death (SCD) due to exercise-related ventricular arrhythmias (ERVA); however the pathological substrate is uncertain. The aim was to determine the prevalence of ERVA and their relation with fibrosis as determined by cardiac magnetic resonance imaging (CMR) in carriers of an HCM causing mutation. METHODS: We studied the prevalence and origin of ERVA and related these with fibrosis on CMR in a population of 31 HCM mutation carriers. RESULTS: ERVA occurred in seven patients (23%) who all showed evidence of fibrosis (100% ERVA(+) vs. 58% ERVA(-), p = 0.04). No ventricular tachycardia or ventricular fibrillation occurred. In patients with ERVA, the extent of fibrosis was significantly larger (8 ± 4% vs. 3 ± 4%, p = 0.02). ERVA originated from areas with a high extent of fibrosis or regions directly adjacent to these areas. CONCLUSIONS: ERVA in HCM mutation carriers arose from the area of fibrosis detected by CMR; ERVA seems closely related to cardiac fibrosis. Fibrosis as detected by CMR should be evaluated as an additional risk factor to further delineate risk of SCD in carriers of an HCM causing mutation.

Magnetic resonance imaging of the coronary arteries.

Despite progress in prevention and early diagnosis, coronary artery disease (CAD) remains one of the leading causes of mortality in the world. For many years, invasive X-ray coronary angiography has been the method of choice for the diagnosis of significant CAD. However, up to 40% of patients referred for elective X-ray coronary angiography have no clinically significant stenoses. These patients still remain subjected to the potential risks of X-ray angiography. As an alternative, magnetic resonance imaging (MRI) is currently one of the most promising techniques for noninvasive imaging of the coronary arteries. Over the past two decades, many technical developments have been implemented that have led to major improvements in coronary MRI. Nowadays, both anatomical and functional information can be obtained with high temporal and spatial resolution and good image quality. In this review we will discuss the technical foundations and current status of clinical coronary MRI, and some potential future applications.

Comprehensive assessment of left ventricular pseudo-aneurysms with magnetic resonance imaging.

In a small number of patients, myocardial infarction, trauma, infection or cardiac surgery are complicated by incomplete wall rupture and pseudo-aneurysm formation. We describe the advances made in the non-invasive assessment of this condition with the introduction of magnetic resonance imaging (MRI) and discuss the value of specific MRI techniques for comprehensive structural and functional cardiac assessment.

Left ventricular viability in a patient with heart failure due to left main stem stenosis, predicted by SPECT and gadolinium-enhanced magnetic resonance but not by dobutamine stress echocardiography.

A 54-year-old woman with occlusive disease of the distal abdominal aorta was referred for pre-operative risk assessment, and was diagnosed with severe impairment of the left ventricular function due to left main stem coronary artery stenosis. Low-dose dobutamine stress echocardiography did not demonstrate contractile reserve, while gadoliniumenhanced cardiac magnetic resonance (CMR) suggested viability of the left ventricle. The patient underwent coronary bypass grafting, and had an uncomplicated post-operative course, with improvement of the left ventricular ejection fraction from the initial 20% to 44% after four months. The value of CMR in determining myocardial viability in left main stem stenosis has not previously been reported.

[Cardiac sarcoidosis: improved prognosis through new diagnostic tests and treatment]. / Cardiale sarcoïdose: betere prognose door nieuwe diagnostiek en behandeling.

Cardiac sarcoidosis was diagnosed in 3 patients: 2 men aged 52 and 51 years, respectively, and a woman aged 55 years. Both men had ventricular tachycardia. In the first man, a right-ventricle biopsy revealed a non-caseating granuloma. The second man had active granulomatous cardiac infiltration, according to a gallium scintigram. The first man recovered after receiving immunosuppression, heart-failure medication, and an implantable defibrillator; the second received the same plus radio-frequency catheter ablation, but experienced serious heart failure. The woman was being treated for pulmonary sarcoidosis but complained of progressive cardiac symptoms. She recovered after receiving heart-failure medication, immunosuppression, and a biventricular pacemaker. Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology with cardiac involvement in 20 to 30% of patients, resulting in severe morbidity and mortality. With the help ofgadolinium MRI and positron emission tomography (PET), these conditions can be detected at an earlier stage, which allows for improved evaluation of the efficacy of available therapies. The use of resynchronisation therapy and implantable defibrillators has improved the prognosis of patients with cardiac sarcoidosis.

Cardiac involvement of Churg Strauss syndrome demonstrated by magnetic resonance imaging.

Churg Strauss syndrome (CSS) may lead to cardiac involvement in up to 60% of patients. The myocardium, coronary vasculature, valves and pericardium may be affected. This results in significant morbidity and mortality, accounting for 48% of deaths due to CSS. Cardiac magnetic resonance imaging (CMR) is used to evaluate cardiac structure and function, and is able to evaluate myocardial perfusion and delineate scar tissue. We are the first to demonstrate these features in a 53-year-old CSS patient who presented with palpitations and atypical chest pains, and was found to have myocardial perfusion defects and scar tissue, most likely secondary to vasculitis of the small myocardial vasculature and myocardial infiltration.

Transmural gradients of cardiac myofiber shortening in aortic valve stenosis patients using MRI tagging.

Aortic valve stenosis impairs subendocardial perfusion with a risk of irreversible subendocardial tissue damage. A likely precursor of damage is subendocardial contractile dysfunction, expressed by the parameter TransDif, which is defined as epicardial minus endocardial myofiber shortening, normalized to the mean value. With the use of magnetic resonance tagging in two short-axis slices of the left ventricle (LV), TransDif was derived from LV torsion and contraction during ejection. TransDif was determined in healthy volunteers (control, n = 9) and in patients with aortic valve stenosis before (AVSten, n = 9) and 3 mo after valve replacement (AVRepl, n = 7). In the control group, TransDif was 0.00 +/- 0.14 (mean +/- SD). In the AVSten group, TransDif increased to 0.96 +/- 0.62, suggesting impairment of subendocardial myofiber shortening. In the AVRepl group, TransDif decreased to 0.37 +/- 0.20 but was still elevated. In eight of nine AVSten patients, the TransDif value was elevated individually (P < 0.001), suggesting that the noninvasively determined parameter TransDif may provide important information in planning of treatment of aortic valve stenosis.

Time course of structural adaptations in chronic AV block dogs: evidence for differential ventricular remodeling.

To determine the nature and time course of biventricular hypertrophy and concomitant electrical and mechanical changes after creation of complete atrioventricular block (CAVB), six adult dogs (22-30 kg) were subjected to serial magnetic resonance imaging (MRI) and electrocardiography. After 6 days of CAVB, left ventricular (LV) mass, ejection fraction (EF), and Q-T time at a paced rhythm of 60 beats/min were already significantly increased. Maximal values were reached within 14-21 days of CAVB: LV mass, from 116 +/- 11 to 143 +/- 12 g; right ventricular (RV) mass, from 40 +/- 3 to 55 +/- 6 g; EF, from 68 +/- 6% to 86 +/- 5%; and Q-T time, from 285 +/- 25 to 330 +/- 35 ms, all P < 0.05. Cardiac output returned to baseline at day 14. End-diastolic wall thickness increased only in the RV, in which angiotensin type 1 (AT1) receptor mRNA expression was significantly greater. The autopsy correlated well with the MRI results (r = 0.98, P< or = 0.01). In conclusion, electrophysiological, mechanical, and structural adaptation processes after bradycardia-induced volume overload develop rapidly and are completed within 3 wk. The degree of hypertrophy was greater in the RV, which was associated with an increase in AT1 receptor mRNA.

Improving contrast and tracking of tags in cardiac magnetic resonance images.

Cardiac tagging permits non-invasive study of myocardial motion with high accuracy. Unfortunately, tagging contrast is impaired at later heart phases due to longitudinal relaxation. Histogram modification is presented as a method for improving contrast in later, faded images of a tagging series by altering these images such that their intensity histograms approximate the shape of the first, unfaded image of the series. This technique greatly improves the contrast and facilitates automatic detection of tags. Furthermore, a method is described for automatically tracking tag positions in short-axis images of the left ventricle modulated with a tagging grid. The method differs from previously reported methods in that, in one single filtering process in the Fourier domain, both the grid crossings as well as the grid centers are detected, and thus increased sampling resolution is obtained. The method was validated by applying a mathematical model of left ventricular motion to tagged images of the thigh muscle. The average discrepancy between theoretically predicted and automatically detected tag positions was 0.04 +/- 0.17 mm (mean +/- SD).

Preoperative imaging of a choledochal cyst in children: non-breath-holding magnetic resonance cholangiopancreatography.

Magnetic resonance cholangiopancreaticography (MRCP) was used to visualize the biliary tract in two children, aged 7 weeks and 10 years, with a choledochal cyst. MRCP was successful in both cases and the findings were confirmed by intraoperative cholangiography.

Impending paradoxical embolus: clinical imaging and successful surgical treatment.

In a patient with pulmonary emboli, transesophageal echocardiography showed a thrombus straddling the foramen ovale (impending paradoxical embolism). Proximal pulmonary emboli were visualized by spiral computed tomography and subsequent surgical treatment, consisting of removal of intracardiac clot, closure of the open foramen ovale and pulmonary embolectomy, was successful.

Detection of bone marrow metastases in small cell lung cancer. Comparison of magnetic resonance imaging with standard methods.

In small cell lung cancer (SCLC), bone marrow metastases are frequently detected by bone scintigraphy (BS) and/or unilateral bone marrow biopsy and aspiration (BMBA). In this study, the value of magnetic resonance imaging (MRI) of thoracic spine and pelvis was compared with BS and BMBA and its clinical implication was evaluated in 42 patients with SCLC. Patients were staged (including BS, BMBA, CT thorax, Liver ECHO) as limited (LD) or extensive disease (ED) before and after MRI. MRI was positive in 12 BS negative (P = 0.003) and in 14 BMBA negative patients (P < 0.001), while in 8 patients, MRI was the only sign of ED, which resulted in a decrease of patients categorised with LD from 52 to 33%. However, in this small group of LD patients, there was no significant survival difference between LD (MRI pos) and LD (MRI neg) patients. It is concluded that MRI can be of value in the staging of LD patients, but it has no influence on survival.

The value of computed tomography in the diagnosis of grating scapula.

Snapping or grating scapula is a condition of the shoulder girdle in which the patient complains of pain and an audible snapping sound which may be associated with pain. We evaluated the diagnostic value of the computed tomography (CT) scans using the clinical diagnosis of a grating scapula as the gold standard. This retrospective study reports the sensitivity, specificity, likelihood ratio and receiver operator characteristic curve for the CT scans and the kappa value as a measure of the interobserver agreement. None of the parameters validated the examination. We therefore concluded that CT scans are inappropriate for differentiation between a grating scapula and a normally functioning shoulder except in cases where bony abnormalities are present.

Traumatic trabecular lesions observed on MR imaging of the knee.

Examinations carried out on 302 consecutive patients with MR of the knee between January 1988 and March 1989 were reviewed for detection of trabecular lesion. Twenty-seven patients found presenting trabecular lesion were further reviewed with specific reference to their activity level and need for specific therapy to determine the clinical significance of the trabecular lesion. Twenty-one of the trabecular lesions were in the femur, 5 were in the tibia, and one was in the fibula. Three of them were associated with a direct trauma, 12 with a valgus type injury, 3 with pure rotation mechanism, and 5 with a combination of valgus and rotation. In 17 cases trabecular lesion was a single finding, in 10 cases it was associated with some ligamentous tear. At the follow-up visit, 26 of the 27 patients with trabecular lesion had no symptoms, and the patient with moderate knee symptoms had had similar knee symptoms prior to the accident due to an osteochondral defect. We conclude that a trabecular lesion in an MR image is a benign bone change associated with knee trauma which heals without sequelae.

A swollen cheek, an unusual course of acute mastoiditis.

An acute mastoiditis can occasionally present as a swelling in front of the ear. An inflammation of the air cells of the mastoid cavity can spread, via the cells in the root of the zygomatic arch, to the soft tissues of the cheek. Unfamiliarity with this underlying cause of a swollen cheek can lead to delay of proper treatment with potential harm to the patient. This case presents such an uncommon form of mastoiditis in a 3-year-old boy; the failure to recognize the disease initially led to extensive osteomyelitis of the temporal bone. CT scanning was important in establishing the cause of the persistently severe condition of the boy, in spite of bilateral myringotomies and mastoidectomy on the right side. Destruction of bone from the zygomatic arch to the suture between temporal and occipital bone was shown. Extensive removal of diseased bone was achieved neurosurgically, thus leading to uneventful recovery.

Magnetic resonance imaging of the normal female pelvis.

9 healthy volunteers were examined by magnetic resonance imaging in order to describe the anatomy of the normal female genital tract as seen by this technique. The visualization of the bony and pelvic skeleton and the muscles surrounding these structures is excellent. Due to high contrast resolution relatively small structures like the femoral blood vessels can be positively identified. Imaging of the small bowel is disappointing. Visualization of the rectum and sigmoid colon is relatively good. In the uterine wall three distinct layers can be identified. An interpretation of the origin of these layers based on comparison with macroscopic and microscopic examination of sections of uterine tissue is given. Further research is needed to demonstrate possible cyclic changes in the appearance of the uterus. The ovaries could not be identified with certainty.