Martin Masek

Submilisievert ultralow-dose CT colonography using iterative reconstruction technique: a feasibility study

Background Computed tomography (CT) colonography is a well established modality for the examination of symptomatic patients as well as in screening. Recent technical advances in improving image quality by iterative reconstruction contribute to the reduction of the radiation dose which is a major concern in CT imaging. Purpose To evaluate image quality of ultralow-dose submilisievert CT colonography using hybrid iterative reconstruction technique. Material and Methods Sixteen patients underwent contrast-enhanced CT colonography with standard protocol in supine position and ultralow-dose protocol in prone position. Ultralow-dose datasets were reconstructed with filtered back projection and an advanced hybrid iterative reconstruction technique. Two radiologists independently evaluated 96 colonic segments for image quality in the endoluminal view and axial thin sections. Colonic distension, smoothness of colonic wall and distortion of folds in the endoluminal view, sharpness of colonic wall delineation, perceived image noise, and presence of photon starvation artifact were rated on a five-point scale. Intraluminal noise expressed as standard deviation of Hounsfield density was measured in all segments. Results The mean radiation dose was 0.42 mSv and 5.48 mSv in prone and supine scans, respectively. All distended segments were rated evaluable in standard dose and ultralow-dose series reconstructed with the iterative reconstruction technique, whereas in 61% segments image quality was rated poor or unacceptable in ultralow-dose series where filtered back projection was used with worst ratings in the rectum and the sigmoid colon. Conclusion This pilot study shows that iterative reconstruction technique is a feasible method to decrease the radiation dose from CT colonography for both positions below 1mSv. Further investigations of larger scale need to be done to clarify, whether such a low radiation dose would influence the detection of polyps.

Computed Tomographic Angiography in Proximal Femoral Focal Deficiency

BACKGROUND Because there is limited information concerning the vascular pattern and the role of vessels in patients with proximal femoral focal deficiency, the vascular supply of the lower extremities was studied systematically with use of computed tomographic angiography in order to identify vascular changes, relate any vascular changes to the classification of the deficiency, and establish that there are no major changes in the topographical anatomy of the vessels. METHODS Standardized computed tomographic techniques were used in twenty-one patients (thirteen boys and eight girls who ranged from one to nineteen years old) with proximal femoral focal deficiency types I through IV and VII, VIII, and IX, according to the Pappas classification. RESULTS A common anatomical vascular pattern, in which the hypoplastic extremity was supplied through the femoral artery, was detected in nineteen patients. In patients with Pappas type-I through IV disease, the external iliac, femoral, and deep femoral arteries were substantially reduced in length and diameter and the deep femoral artery arose more proximally in comparison with that in the contralateral extremity; however, in the patients with Pappas type-VII, VIII, or IX disease, the diameters of the arteries and the origin of the deep femoral artery were similar to those of the contralateral extremity. In two patients with Pappas type-III disease, atypical anatomy of the vessels was found. The anterior part of the thigh and the pseudarthrosis were supplied through the femoral artery (the external iliac artery) as a terminal branch, while the remainder of the extremity was supplied from the internal iliac artery, which entered the thigh posterior to the hip as the inferior gluteal artery and continued as the artery to the sciatic nerve to the popliteal artery. No substantial anastomoses were found between the femoral and the posterior arteries in these vascular patterns. CONCLUSIONS Computed tomographic-angiographic reconstruction can be used to depict the spatial configuration of the pseudarthrosis and the vascular pattern of the extremity in patients with proximal femoral focal deficiency. We found distinct vascular changes in the majority of the involved thighs, but there were no typical changes related to the Pappas classification. Because we found atypical vascular patterns in two patients, evaluation of the vessels with use of various diagnostic methods is recommended in patients with severe types of proximal femoral focal deficiency.

Current Diagnostic and Therapeutic Aspects of Eosinophilic Myocarditis.

Eosinophilic myocarditis (EM) represents a rare form of myocardial inflammation with very heterogeneous aetiology. In developed countries, the most prevalent causes of EM are hypersensitivity or allergic reactions, as well as hematological diseases leading to eosinophilia. The disease may have a variable clinical presentation, ranging from asymptomatic forms to life-threatening conditions. Most patients with EM have marked eosinophilia in peripheral blood. Endomyocardial biopsy needs to be performed in most cases in order to establish a definitive diagnosis of EM. The therapy depends on the underlying aetiology. Immunosuppressive therapy represents the treatment mainstay in the majority of EM forms.

Patients’ Stratification and Correlation of Brain Magnetic Resonance Imaging Parameters with Disability Progression in Multiple Sclerosis

Aims: The objective was to correlate the change in the lesion load (LL) and brain atrophy in patients with multiple sclerosis (MS) with progression of clinical disability, represented by the Expanded Disability Status Scale (EDSS), and to test if stratification of patients according to magnetic resonance imaging (MRI) criteria can increase the predictive ability of MRI for MS clinical development. Methods: 181 patients with clinically definite relapsing-remitting MS underwent MRI for a period of up to 5 years. Grouping of patients according to the LL value at the study entry revealed a substantial increase in the Spearman rank correlation coefficient R. Results: For the low LL cohort of patients, we found a statistically significant correlation (R up to –0.71 with p < 0.01) of a later increase in the EDSS score (years 4 and 5) with increased brain atrophy in the first 2 years. For the high LL group, we found a statistically significant correlation (R up to 0.72 with p < 0.01) of a later increase in the EDSS score (years 4 and 5) with an increase in the LL value in the first year. Conclusions: We conclude that stratification of patients according to the MRI criterion (LL) can increase the predictive ability of MRI.

The Role of Magnetic Resonance Imaging and Cardiac Computed Tomography in the Assessment of Left Atrial Anatomy, Size, and Function

In the last decade, there has been increasing evidence that comprehensive evaluation of the left atrium is of utmost importance. Numerous studies have clearly demonstrated the prognostic value of left atrial volume for long-term outcome. Furthermore, advances in catheter ablation procedures used for the treatment of drug-refractory atrial fibrillation require the need for detailed knowledge of left atrial and pulmonary venous morphology as well of atrial wall characteristics. This review article discusses the role of cardiac magnetic resonance and computed tomography in assessment of left atrial size, its normal and abnormal morphology, and function. Special interest is paid to the utility of these rapidly involving noninvasive imaging methods before and after atrial fibrillation ablation.

A congenital diverticulum of the left ventricular apex manifested by stroke and recurrent ventricular tachycardia

Ventricular outpouchings include acquired abnormalities (aneurysms and pseudoaneurysms) and congenital ventricular diverticula (CVD). CVD represent rare cardiac pathologies. Although CVD is often associated with other cardiac and extracardiac congenital anomalies, it can also be incidentally observed in otherwise healthy subjects. CVD may lead to significant morbidity and even have lethal consequences. We describe a case of arrhythmogenic left ventricle (LV) apical CVD revealed by cardiac magnetic resonance imaging (CMRI) after being initially overlooked by echocardiography. The paper includes the review of the literature also. This clinical case highlights the possible association of this pathology with recurrent ventricular tachycardia and stroke, and illustrates the importance of multimodal imaging approach in differential diagnosis.

Cardiac involvement in lymphoma mimicking hypertrophic cardiomyopathy

12nd Department of Medicine – Department of Cardiovascular Medicine, 1st Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic 2Department of Radiology, 1st Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic 3Institute of Nuclear Medicine, 1st Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic

A rare case of regressively changed lipomatous hypertrophy of the interatrial septum presenting with anemia and recurrent fever

Lipomatous hypertrophy of the interatrial septum (LHIS) is characterized by excessive accumulation of adipose tissue within some segments of the interatrial septum. Only one published case so far describes fever as a presenting feature of LHIS. On the other hand, systemic symptoms including anemia and fever are well-known clinical presentations of cardiac myxomas. We report an unusual case of a 79-year-old woman who was thoroughly but unsuccessfully investigated for recurrent fever and anemia in several specialized departments over the course of 4 years. Computed tomography scan showed a pathological mass localized in the interatrial septum and spreading to ascending aorta. Histological analysis of the biopsy samples from surgery revealed the unexpected diagnosis of regressively changed LHIS. We discuss the clinical and pathologic features of this lesion suggesting that its regressive changes may be associated with inflammation and can cause systemic symptoms such as fever and anemia.