Anna Kociemba

Comparison of diffusion-weighted with T2-weighted imaging for detection of edema in acute myocardial infarction

BackgroundRecent studies, performed with the use of a commercially available diffusion weighted imaging (DWI) sequence, showed that they are sensitive to the increase of water content in the myocardium and may be used as an alternative to the standard T2-weighted sequences. The aim of this study was to compare two methods of myocardial edema imaging: DWI and T2-TIRM.MethodsThe study included 91 acute and post STEMI patients. We applied a qualitative and quantitative image analysis. The qualitative analysis consisted of evaluation of the quality of blood suppression, presence of artifacts and occurrence of high signal (edema) areas. On the basis of edema detection in AMI and control (post STEMI) group, the sensitivity and specificity of TIRM and DWI were determined. Two contrast to noise ratios (CNR) were calculated: CNR1 - the contrast between edema and healthy myocardium and CNR2 - the contrast between edema and intraventricular blood pool. The area of edema was measured for both TIRM and DWI sequences and compared with the infarct size in LGE images.ResultsEdema occurred more frequently in the DWI sequence. A major difference was observed in the inferior wall, where an edema-high signal was observed in 46% in T2-TIRM, whereas in the DWI sequence in 85%. An analysis of the image quality parameters showed that the use of DWI sequence allows complete blood signal suppression in the left ventricular cavity and reduces the occurrence of motion artifacts. However, it is connected with a higher incidence of magnetic susceptibility artifacts and image distortion. An analysis of the CNRs showed that CNR1 in T2-TIRM sequence depends on the infarct location and has the lowest value for the inferior wall. The area of edema measured on DWI images was significantly larger than in T2-TIRM.ConclusionsDWI is a new technique for edema detection in patients with acute myocardial infarction which may be recommended for the diagnosis of acute injuries, especially in patients with slow-flow artifacts in TIRM images.

Right coronary artery aneurysm with fistula into the coronary sinus in patient with systemic lupus erythematosus.

A 65-year-old woman was hospitalised in the Department of Hypertensiology, Angiology and Internal Diseases due to occasional chest pain and unsuccessfully treated hypertension. The patient had systemic lupus erythematosus (diagnosed in 2002 and treated with Metypred for 7 years). Physical examination: without deviation. ECG: sinus rhythm 67/min; q in III, aVF; negative T in III, incomplete RBBB. Laboratory tests: ESR 48 mm/h; antibodies ANA > 1:300; anti-Ro (anti-SSA) 8.3; anti-ds DNA < 1:10. Stress ECG: (interrupted in 9 min, 10.8 METs, due to fatigue): 1 mm ST depression in II, III, aVF. Angiography: LM very short, no atherosclerotic lesions; LAD and LCX no atherosclerotic lesions; RCA dilated (aneurysm). Cardiac magnetic resonance imaging (MRI) [cm]: LVIDd 5.1; LA 4.0; RVDd 3.0; LVPWd 0.8; IVSd 1.0; Ao 2.0/3.1/2.5; mild mitral and tricuspid regurgitations; EF 69%; no perfusion myocardial impairment; dilated RCA (6.5 mm) (Fig. 1). Coronary computed tomography angiography: LM and LCX without coronary stenosis, LAD in distal part of proximal segment — atherosclerotic plaque (20–30% narrowing), RCA dilated to 9 mm proximally and 5 mm distally (Fig. 2), winding, length about 40 cm (Fig. 3), in the distal part — the fistula to the coronary sinus (Fig. 4). In the literature data, coronary aneurysms are recognisable in nearly 5% of those undergoing angiography. When large, they may predispose to turbulent blood flow and thrombus formation. Of all the coronary arteries, the RCA is the most commonly dilated and predisposed to fistula formation. The most common aetiologies of an aneurysm are: atherosclerosis (50%), hereditary diseases (20–30%), vasculitis (10–20%) and damage (also iatrogenic). Fistulas between the coronary vessels are usually asymptomatic and discovered incidentally, but they can lead to steal syndromes causing myocardial ischaemia. In this case, due to the coexistence of systemic lupus erythematosus, the inflammatory aetiology of the RCA aneurysm should be recognised. Due to the relief of angina after blood pressure normalisation and the absence of myocardium perfusion impairment, conservative treatment was continued. The MRI failed to show the fistula of dilated RCA. This leads to the conclusion that coronary artery tomography is more accurate for the diagnosis and monitoring of this pathology. The patient remains in clinical observation with effective treatment comprising perindopril (5 mg), indapamide (2.5 mg), amlodipine (10 mg) and aspirin (150 mg).

Influence of inflammatory response on infarct size and microvascular obstruction estimated by cardiac magnetic resonance in patients with ST-elevation myocardial infarction

Background The inflammatory response during ST-segment elevation myocardial infarction (STEMI) has been shown to influence the clinical outcome. Moreover, infarct size (IS) and microvascular obstruction (MVO) predict major adverse events in patients with STEMI. The aim of the study was to compare the inflammatory response measured by C-reactive protein (CRP) serum concentration and the number of white blood cells (WBC) with the infarct size and MVO estimated by CMR. Methods We examined 85 patients (mean age 59±11 years; 59 males and 26 females) with acute STEMI. CRP and white blood cells were measured at the admission to the hospital. CMR examinations were performed on a 1.5 T scanner (Siemens, Avanto) using an eight-channel phased-array coil combined with 4-6 elements of spinal coil within 3 days after STEMI. Cine imaging with steady-state free precession and late gadolinium enhancement (LGE) were performed in the long axis and the contiguous short axis slices to evaluate myocardial function, IS and MVO. Infarct size was defined as an area greater than 50% of the maximal signal intensity within LGE (FWMH - full-width half maximum). MVO was diagnosed as an area of contrast hypoenhancement within the infarct zone and was included in the assessment of IS. IS and MVO were determined by planimetry and a summation of discs method. Results

Detection of myocardial oedema with the use of diffusion-weighted imaging in acute myocardial infarction

MR diffusion-weighted imaging is an important application for oedema detection in various tissues. Evaluation of the area at risk in reperfused acute myocardial infarction (AMI) is currently performed with STIR T2-weighted and LGE sequences.

The Usefulness of Magnetic Resonance Imaging of the Cardiovascular System in the Diagnostic Work-Up of Patients With Turner Syndrome

Cardiovascular defects occur in 50% of patients with Turner syndrome (TS). The aim of the study was to estimate the usefulness of cardiac magnetic resonance imaging (CMR) and magnetic resonance angiography (angio-MR) as diagnostics in children and adolescents with TS. Forty-one females with TS, aged 13.9 ± 2.2 years, were studied. CMR was performed in 39 patients and angio-MR in 36. Echocardiography was performed in all patients. The most frequent anomalies diagnosed on CMR and angio-MR were as follows: elongation of the ascending aorta (AA) and aortic arch, present in 16 patients (45.7%), a bicuspid aortic valve (BAV), present in 16 patients (41.0%), and partial anomalous pulmonary venous return (PAPVR), present in six patients (17.1%). Aortic dilatation (Z-score > 2) was mostly seen at the sinotubular junction (STJ) (15 patients; 42.8%), the AA (15 patients; 42.8%), the thoracoabdominal aorta at the level of a diaphragm (15 patients; 42.8%), and the transverse segment (14 patients; 40.0%). An aortic size index (ASI) above 2.0 cm/m2 was present in six patients (17.1%) and above 2.5 cm/m2 in three patients (8.6%). The left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) were diminished (Z-score < −2) in 10 (25.6%), 9 (23.1%), and 8 patients (20.5%), respectively. A webbed neck was correlated with the presence of vascular anomalies (p = 0.006). The age and body mass index (BMI) were correlated with the diameter of the aorta. Patients with BAV had a greater aortic diameter at the ascending aorta (AA) segment (p = 0.026) than other patients. ASI was correlated with aortic diameter and descending aortic diameter (AD/DD) ratio (p = 0.002; r = 0.49). There was a significant correlation between the right ventricular (p = 0.002, r = 0.46) and aortic diameters at the STJ segment (p = 0.0047, r = 0.48), as measured by echocardiography and CMR. Magnetic resonance can identify cardiovascular anomalies, dilatation of the aorta, pericardial fluid, and functional impairment of the ventricles not detected by echocardiography. BMI, age, BAV, and elongation of the AA influence aortic dilatation. The ASI and AD/DD ratio are important markers of aortic dilatation. The performed diagnostics did not indicate a negative influence of GH treatment on the cardiovascular system.

Distinguishing high-flow from low-flow vascular malformations using maximum intensity projection images in dynamic magnetic resonance angiography – comparison to other MR-based techniques

Background In addition to ultrasound, magnetic resonance imaging (MRI) is considered a suitable, non-invasive technique to assess the type and extent of vascular malformations. The distinction between low- and high-flow lesions is crucial because it determines appropriate patient treatment. Purpose To distinguish high-flow from low-flow lesions on the basis of the enhancement pattern on MIP images acquired from dynamic time-resolved MR angiography (MRA) and compare it with previously described MR-based methods. Material and Methods We examined 25 consecutive patients with previously diagnosed vascular malformations. Next, each malformation was classified as “high-flow” or “low-flow” using the following criteria: (i) findings on T1-weighted (T1W) and T2-weighted (T2W) imaging (signal voids, signal intensity); (ii) the time interval between the start of arterial enhancement and the onset of lesion enhancement (artery–lesion time); (iii) the time of maximum lesion enhancement; and (iv) analysis of the slope of the enhancement curve. Results Of the 25 patients, seven had high-flow and 18 had low-flow malformations. Signal voids on spin-echo T1W images were observed only in four of seven high-flow malformations and in two of 18 low-flow malformations. Analysis of signal intensity on T2W images showed increased signal intensity in 17 of 18 low-flow malformations, and in two of seven high-flow lesions. Calculation of the artery–lesion time, maximum enhancement time, and slope revealed significant differences between the high- and low-flow groups. Conclusion In conclusion, the slope of the enhancement curve appears to be useful in distinguishing between high- and low-flow vascular malformations. Standardization of MR image evaluation criteria is essential.

Detection of myocardial edema with diffusion weighted imaging in patients with acute myocarditis

Methods We have analyzed 26 consecutive patients: 22 male, average age: 27 years (range 13-43) with clinical diagnosis of acute myocarditis. The CMR examinations were performed on a 1,5 T scanner using an eight-channel phasedarray coil combined with 4-6 elements of spinal coil. All patients underwent assessment of myocardial oedema: T2weighted triple inversion recovery (STIR), T1-weighted turbo spin echo pre and post contrast, function (cine Steady State Free Precession) and scar (Late Gadolinium Enhancement). Additionally DWI EPI sequence with b = 50 sec/mm was acquired before contrast administration. The sequence parameters were as follows: slice thickness 10 mm, repetition time (depending on patient breath cycle) 3-4 s, echo time 78 ms, bandwidth 1,736 Hz/Px. The DWI sequence was ECG-gated and synchronized to the respiratory cycle using PACE technique. For all patients T1 and T2 ratio were calculated and presence of LGE areas were reported. For STIR and DWI contrast between healthy myocardium and edema was calculated as a difference between edematous and normal myocardial muscle divided by standard deviation of image noise. Results We managed to acquired good quality DWI images in all 26 patients, average acquisition time was 120s per slice, distortion artifacts occurred in 5 patients but did not impaired diagnostic value of analyzed images. Increased signal intensity in DWI images occurred in all patients in the area of LGE enhancement and were consistent with areas of increased signal in STIR. All patients met at least two out of three criteria for inflammatory activity and injury. T2 ratio was increased (≥ 2) in 24 patients, T1 ratio (≥ 4) in 23 cases, all patients had focal non ischemic enhancement in LGE. CNR was higher in DWI than in STIR: 23,8 vs. 17,6 respectively.

Extent of infarct size and microvascular obstruction following unsuccessful reperfusion in patients with ST-segment elevation myocardial infarction.

Background Impaired microvascular reperfusion (no-reflow) and unsuccessful infarct-related artery (IRA) revascularization are associated with a worse clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Reperfusion can be identified by epicardial or microvascular flow determined by angiography as Thrombolysis in Myocardial Infarction (TIMI) flow grade and a myocardial blush grade (MBG), respectively. Moreover, microvascular obstruction (MVO) determined by CMR is also a well-known predictor of an unfavorable clinical outcome after STEMI. The aim of the study was to determine the effect of impaired reperfusion estimated by angiography on microvascular obstruction and infarct size (IS) measured by CMR.

Cardiovascular Magnetic Resonance Imaging in Asymptomatic Acute Heart Rejection: A Case Report

BACKGROUND Diagnosis of rejection is a major objective in the management of heart transplant recipients. It has been reported that one-third of protocol biopsies in asymptomatic, biochemically stable organ transplant recipients in the first 6 months show unsuspected subclinical graft rejection. CASE REPORT We present the case of a 43-year-old man suffering from dilated cardiomyopathy who underwent orthotropic heart transplantation. The patient was admitted for a protocol endomyocardial biopsy and magnetic resonance imaging (MRI) on the 4th postoperative month as a protocol procedure. The examination revealed clinical status NYHA I with no signs of fatigue, diminution of exercise tolerance, or shortness of breath. His body temperature was not raised. He was referred for endomyocardial biopsy and cardiovascular magnetic resonance (CMR) imaging. CMR imaging showed good left and right ventricle function and contractility. T2 imaging revealed increased signal in the area of the right ventricular free wall, seen both in 4-chamber and short axis views. The patient underwent an endomyocardial biopsy, which demonstrated diffuse infiltrate with multifocal miocyte damage and cellular edema recognized as acute rejection (3a ISHLT grade). Consequently, he was treated with parenteral methylprednisolone administration. The CMR study performed after 1 week of therapy showed that the signal intensity of the edematous areas was significantly decreased. Repetitive endomyocardial biopsy revealed no signs of rejection. CONCLUSIONS CMR can be helpful in graft monitoring following heart transplantation. It gives a whole-heart perspective that can be competitive with and/or complementary to endomyocardial biopsy. As a noninvasive study it can be applied more often and facilitates diagnosis of asymptomatic rejection episodes.

A comparision of oedema detection with diffusion-weighted imaging and T2-STIR imaging in patients with acute myocardial infarction

Background The diffusion weighted imaging (DWI) is a well known technique in neuroradiology, due to its ability to detect ischemic regions in brain tissue. A recent, rapid development of the magnetic resonance technology and echo planar imaging enabled the application of diffusion imaging in cardiac examinations. The aim of this study was to compare the diffusion weighted imaging with widely used STIR sequences in the evaluation of edema in patients with acute myocardial infarction (AMI).