Hyper Enhancement Research Articles

CMR Imaging With Rapid Visual T1 Assessment Predicts Mortality in Patients Suspected of Cardiac Amyloidosis

This study tested the diagnostic and prognostic utility of a rapid, visual T1 assessment method for identification of cardiac amyloidosis (CA) in a "real-life" referral population undergoing cardiac magnetic resonance for suspected CA. In patients with confirmed CA, delayed-enhancement cardiac magnetic resonance (DE-CMR) frequently shows a diffuse, global hyperenhancement (HE) pattern. However, imaging is often technically challenging, and the prognostic significance of diffuse HE is unclear. Ninety consecutive patients referred for suspected CA and 64 hypertensive patients with left ventricular hypertrophy (LVH) were prospectively enrolled and underwent a modified DE-CMR protocol. After gadolinium administration a method for rapid, visual T1 assessment was used to identify the presence of diffuse HE during the scan, allowing immediate optimization of settings for the conventional DE-CMR that followed. The primary endpoint was all-cause mortality. Among patients with suspected CA, 66% (59 of 90) demonstrated HE, with 81% (48 of 59) of these meeting pre-specified visual T1 assessment criteria for diffuse HE. Among hypertensive LVH patients, 6% (4 of 64) had HE, with none having diffuse HE. During 29 months of follow-up (interquartile range: 12 to 44 months), there were 50 (56%) deaths in patients with suspected CA and 4 (6%) in patients with hypertensive LVH. Multivariable analysis demonstrated that the presence of diffuse HE was the most important predictor of death in the group with suspected CA (hazard ratio: 5.5, 95% confidence interval: 2.7 to 11.0; p < 0.0001) and in the population as a whole (hazard ratio: 6.0, 95% confidence interval 3.0 to 12.1; p < 0.0001). Among 25 patients with myocardial histology obtained during follow-up, the sensitivity, specificity, and accuracy of diffuse HE in the diagnosis of CA were 93%, 70%, and 84%, respectively. Among patients suspected of CA, the presence of diffuse HE by visual T1 assessment accurately identifies patients with histologically-proven CA and is a strong predictor of mortality.

Usefulness of contrast-enhanced cardiac magnetic resonance in identifying the ventricular arrhythmia substrate and the approach needed for ablation

The endocardial vs. epicardial origin of ventricular arrhythmia (VA) can be inferred from detailed electrocardiogram (ECG) analysis. However, despite its clinical usefulness, ECG has limitations. Alternatively, scarred tissue sustaining VAs can be identified by contrast-enhanced cardiac magnetic resonance (ce-CMR). The objective of this study was to determine the clinical value of analysing the presence and distribution pattern of scarred tissue in the ventricles to identify the VA site of origin and the ablation approach required. A ce-CMR study was carried out before the index ablation procedure in a cohort of 80 patients with non-idiopathic VA. Hyper-enhancement (HE) in each ventricular segment was coded as absent, subendocardial, transmural, mid-myocardial, or epicardial. The endocardial or epicardial VA site of origin was also assigned according to the approach needed for ablation. The clinical VA was successfully ablated in 77 (96.3%) patients, all of them showing HE on ce-CMR. In segments with successful ablation of the clinical ventricular tachycardia, HE was absent in 3 (3.9%) patients, subendocardial in 19 (24.7%), transmural in 36 (46.7%), mid-myocardial in 8 (10.4%), and subepicardial in 11 (14.3%) patients. Epicardial ablation of the index VA was necessary in 3 (6.1%) ischaemic and 12 (42.9%) non-ischaemic patients. The presence of subepicardial HE in the successful ablation segment had 84.6% sensitivity and 100% specificity in predicting an epicardial origin of the VA. Contrast-enhanced cardiac magnetic resonance is helpful to localize the target ablation substrate of non-idiopathic VA and also to plan the approach needed, especially in non-ischaemic patients.

Primary Small Bowel Adenocarcinoma in the Setting of Chronic Crohnʼs Disease

Purpose: 59 Y/O Female with a history of Crohn's disease with a recent flare, complicated by small bowel obstruction treated with IV corticosteroids, infliximab and nasogastric decompression. She presents now with diffuse cramping abdominal pain, anorexia, nausea, vomiting and abdominal distention. She denied fever, chills, diarrhea, or gastrointestinal bleeding. She quit tobacco 20 years ago and denies alcohol or illicit drug use. Her family history was negligible for cancer. Exam revealed a well nourished female. Her skin had no rashes, ulcers or jaundice. Abdominal exam demonstrated a mildly distended abdomen with hyperactive bowel sounds. She had no organomegaly. No rebound or guarding tenderness was elicited. Laboratory exams were normal. CT-enterography with contrast demonstrated diffuse small bowel dilatation. There was mucosal hyper enhancement, wall thickening and mural stratification. Findings were consistent with active Crohn's disease, stricture and small bowl obstruction. She underwent laparoscopic ileocolectomy with primary anastomosis. Pathological results of resected small bowl revealed a T3 N0 adenocarcinoma of the small bowel in a background of active and chronic Crohn's disease. She was discharged and is being followed by oncology. • Small bowel adenocarcinoma in the setting of longstanding Crohn's disease is usually diagnosed on post operative pathohistological analysis. • Signet ring cells are found in 30% of specimens received from patients with Crohn's disease. • The risk of small bowel adenocarcinoma 10-25 years after the diagnosis of ileal Crohn's disease is approximately 2.2%. • Males between the ages of 30-55 are at highest risk for small bowel malignancy. • Positron emission tomography, CT- Scan and double barium enema serve a role in early preoperative detection of small bowel adenocarcioma. • Delayed diagnosis in patients with small bowel adenocarcinoma leads to poor long term prognosis. Conclusion: The diagnosis of small bowel adenocarcinoma in the setting of chronic Crohn's disease should be entertained in patients presenting with small bowl obstruction secondary to stricture formation. Studies such as positron emission tomography, computer tomography and double barium enema may serve to increase the rate of early detection and initiation of treatment.Figure: [1584]

Relation of Replacement Fibrosis to Left Ventricular Diastolic Function in Patients with Dilated Cardiomyopathy

Previous studies have shown that delayed hyperenhancement (HE) by cardiac magnetic resonance (CMR) is related to left ventricular (LV) stiffness in a variety of cardiac diseases. However, it is not known whether this relation is also present in dilated cardiomyopathy (DCM), in which replacement fibrosis is less extensive. Consecutive patients with DCM (n= 50, age 56 ± 13 years, 20 females) were studied with CMR and two-dimensional and Doppler echocardiography. CMR images with breath-hold segmented inversion-recovery sequence were acquired 10 minutes after an intravenous bolus of gadolinium. The scar tissue distribution and extent were calculated in the 17 LV segments. LV diastolic function was assessed using mitral inflow and tissue Doppler velocities at the septal and lateral sides of the mitral annulus. The group had an ejection fraction of 30% ± 11% and left atrial volume of 103 ± 50 mL by CMR. HE was present in 31 patients with a mean scar burden of 4% ± 7.6%. Patients with DCM without HE had a significantly higher septal E/e' ratio than patients with scar (P= .05), and there was no significant correlation between deceleration time and extent of HE. Lateral late diastolic velocity (a') had a weak inverse relation with the number of segments with HE (r= -0.44, P= .005) and with scar burden (r= -0.31, P= .05). Patients with DCM without HE have higher LV filling pressures than patients with HE. Our findings suggest that other factors influence LV stiffness to a larger extent than replacement fibrosis in this population.

A case of transient left ventricular apical ballooning syndrome in a child: clinical features and imaging findings

Transient left ventricular apical ballooning syndrome (TLVABS) is an acute cardiac disease that is characterized by transient left ventricular systolic dysfunction involving the apical region. The symptoms and electrocardiographic changes of TLVABS mimic those observed in acute myocardial infarction while obstructive coronary arterial lesions are not seen in patients with TLVABS. TLVABS usually occurs in elderly women after physical or emotional stress. However, it is very rare in children and so it not well known to pediatricians. Accordingly, TLVABS in children can be misdiagnosed as myocarditis or cardiomyopathy. We report here on a case of child who showed the typical findings of TLVABS in association with pericarditis. He presented with dyspnea and pericardial effusion, which required pericardiocentesis. After pericardiocentesis, he showed the typical echocardiographic and electrocardiographic findings of TLVABS. The MRI findings at 14days after the initial symptoms showed normal coronary arteries and normal left ventricular function without any wall motion abnormalities. In addition, no delayed hyper enhancement was found on delayed-enhanced (DE)-MRI. We also reviewed the other reported cases of TLVABS in patients who were under the age of 40.

Abstract 1100: A Novel Hybrid Of On-Pump Beating Heart Coronary Artery Bypass Grafting Results Produces Significant Myocardial Injury Compared to Conventional Cardioplegic Arrest

Beating heart coronary artery bypass grafting (CABG) improves early post-operative cardiac function in patients with at least moderate ventricular function but its effects in patients with significantly impaired ventricular function is uncertain. We compared a novel hybrid technique of on-pump beating heart (ONBEAT) to conventional cardioplegic arrest (ONSTOP) in CABG patients with impaired ventricular function using cardiac magnetic resonance (CMR) and biochemical markers. In a single centre randomized trial, 50 patients with impaired ventricular function undergoing CABG were randomly assigned to ONBEAT or ONSTOP. Patients underwent CMR assessment for function and delayed hyperenhancement (HE) for irreversible injury pre-operatively and early post operatively; in addition serum was taken for cTn I and CKMB (0,1,6,24,48 and 120 hours) after surgery. Forty-five patients completed surgery with follow up imaging. Pre-operative characteristics were well matched except for a higher incidence of renal impairment in ONBEAT patients (glomerular filtration rate 58 versus 68 ml.min−1, p=0.02). Mean ± SD cardiac index (CI): ONBEAT 2.85±0.53 and ONSTOP 2.62±0.59L.min−1.m−2. After surgery both groups sustained minor changes to CI (4% reduction ONBEAT, p = 0.43 versus 1% increase ONSTOP, p = 0.97) without significant inter-group difference. The incidence of new HE was significantly higher in the ONBEAT group (p = 0.04) with 6/17 patients (35%) sustaining 8.2 ± 5.2 g of new HE each compared with 2/23 patients (9%) in the ONSTOP group each with 9.8 ± 9.0 g of new HE, p = 0.86. Furthermore serum markers of myocardial injury were higher in ONBEAT patients; median AUC for Troponin I 461[226 – 1141]μg/L versus 160[98 – 357]μg/L, p=0.002 and CKMB 862[499 – 1768]ng/mL versus 549[447–704]ng/mL p=0.004. The incidence of new irreversible myocardial injury was significantly higher in ONBEAT patients, although there was no effect on global cardiac function. Inadequate coronary perfusion in patients with severe proximal coronary disease and low cardiac output may render distal coronary territories ischemic in the absence of formal myocardial protection.

Giant Focal Nodular Hyperplasia Presenting as Pseudo-Mirizzi Syndrome

Purpose: Focal nodular hyperplasia (FNH) is a relatively rare benign tumor of the liver typically seen in young to middle aged women. It is usually an incidental finding, with most patients being asymptomatic. We describe a previously unreported presentation of a FNH causing a Mirizzi like syndrome. Methods: An 18 year-old white female presented with two days of right upper quadrant and epigastric pain associated with nausea, vomiting and chills. She had no prior medical history other than eczema and asthma. She denied taking any prescription or over the counter medications including oral contraceptives. Liver biochemistries revealed elevated total bilirubin 2.9 gm/dL, alkaline phosphatase 270 U/L, AST 104 U/L, ALT 171 U/L and a normal alpha feto-protein. CT with contrast showed gallbladder thickening and a 9.0 × 7.4 cm mass in segment 4 of the liver demonstrating hyper enhancement on arterial phase with a central hypodense stellate focus (Fig. 1). An MRI revealed a 9.2 × 7.8 cm mass with a T2 hyperintense central scar with enlarged gallbladder with wall thickening. Finally, a hepatobiliary scan demonstrated radiotracer throughout the liver, prompt gallbladder visualization and a 0% gallbladder ejection fraction. Given the typical radiographic features of FNH seen with the above studies her mass was felt to be FNH presenting with a Mirizzi like syndrome.Figure 1: CT arterial phase showing giant FNH with central stellate scarResults: Due to the large size of FNH potentially leading to technical difficulty in performing a cholecystectomy, a cholecystostomy tube was placed to allow for gallbladder decompression. Subsequently, a right sided portal vein embolization was performed to allow left lobe hypertrophy of liver prior to successfully performing a right trisegmentectomy. The resected specimen revealed a 10.4 × 9.5 × 7.6 cm tan, heterogeneous, firm, diffusely nodular, well delineated mass with a central scar abutting the capsule and histology confirmed the presence of FNH. Gallbladder specimen did not reveal choleliths. Her post operative course was uncomplicated. Conclusion: This is the first case reported of a giant FNH presenting with Pseudo-Mirizzi syndrome.

Abstract 3095: Prognostic Significance Of Post-revascularisation Irreversible Myocardial Injury Detected By Cardiovascular Magnetic Resonance Imaging

Background The prognostic significance of revascularization procedure related myocardial injury is uncertain. Delayed enhancement CMR (DE-CMR) has been shown to reliably identify areas of irreversible myocardial injury. We evaluated the prognostic significance of procedure related myocardial injury in a consecutive series of patients undergoing high risk PCI or CABG. Methods/Results 152 patients underwent DE-CMR pre and 1– 6 days post elective PCI or CABG. Primary endpoint was defined as total mortality, non-fatal MI, ventricular arrhythmia terminated by ICD (VA), and unstable angina or heart failure requiring hospitalization. Secondary endpoint was the composite of total mortality, non-fatal MI and VA. During a median follow-up of 2.9 years, 27 patients (18%) reached the primary endpoint and 12 patients (8%) the secondary endpoint. 49 patients (32%) had evidence of new myocardial hyperenhancement (HE) with a median mass of 5.0g (IQR 4.8 –7.1). In a univariate analysis, age, LV EF post intervention, and presence of new HE were predictive of the primary outcome. Elevated troponin (at 24 h) showed a trend towards poorer outcome. In a multivariate Cox regression analysis only age and presence of new HE (HR 2.7, 95% CI 1.1, 5.8) remained independently correlated with occurrence of the primary endpoint. New myocardial HE was the single independent predictor of the composite secondary endpoint (HR 4.2 95% CI 1.2, 16.1). Conclusion Even small amounts of procedure-related myocardial injury are associated with poorer medium term clinical outcomes. CMR identified myocardial injury may be a stronger prognostic marker than cardiac troponin in the setting of coronary revascularisation.

Abstract 3012: Impact of Thromboaspiration during Primary PCI on Microvascular Damage and Infarct Size: Acute and Long term ce-MRI Evaluation.

Background: In patients with ST-elevatrion myocardial infarction (STEMI), impairment of microcirculatory function is a negative independent predictor of myocardial function recovery. Compared with conventional stenting, thrombectomy during primary percutaneous coronary intervention (PCI) seems to improve the parameters of myocardial tissue perfusion. We sought to evaluate the impact of thromboaspiration on procedural outcomes and microascualr damage and infarct size by contrast enhanced-MRI (ce-MRI) as compared to conventional primary PCI. Methods:We randomized 75 patients (mean age 64.3±10.2, 55 male) referred to our Hospital with a STEMI (&lt;9 hours from symptoms onset) and an occlusive thrombus at basal angiography, to thromboaspiration with a manual device (Export ®-Medtronic (n=38) (group 1)) and standard PCI (n=37) (group 2). 3 days after procedure and 3 months later a ce-MRI was performed to assess the microvascular damage (as hypoenhancement (HO)) and infarct size (as hyperenhancement(HR)) in the 2 groups. The primary end points were the angiographic result in terms of the TIMI ≥ II flow , MBG ≥ 2 and ST-segment resolution (STr)≥ 70% post-stenting and the microvascular damage (grams/g) and infarct size (grams/g) evaluated by ce-MRI. Results: No differences on baseline, clinical and angiographic preprocedural findings were observed between the two groups. After trombectomy, a TIMI II flow was present in in 38.6 vs 19.6% (p=0.054) and TIMI III was 30.7 vs 72.5% (for group 1 and 2, respectively, p&lt;0.001). Postprocedural MBG ≥2 was 70,3% vs 28,7% (p&lt;0.001) and 90′ ST-segment resolution was 80% vs 37.5% (for group 1 and 2, respectively, p&lt;0.001). Ce-MRI showed an HO of 4.04±5.87g at 3 days vs 0.12±0.4g at 3 months (p= 0.04) in group 1, and 3.7±5.04 vs 2.7±2.3 (3 d and 3 m. respectively)(p=ns) in group 2. At 3 days HR was 17.39±15.6g vs 11.01±8.07g at 3 months in group 1 (p=0.04) and 14.02±7.5g vs 13.6±12.7g ( 3 d. and 3 m. respectively) (p=ns) in group 2. Conclusion:Compared with conventional stenting, a pretreatment with thrombectomy during primary PCI, improves epicardial flow and procedural outcomes. The long term ce-MRI evaluation suggests a reduction in microvascular damage and infarct size compared with the acute evaluation in the thrombectomy group.

Irreversible Myocardial Injury: Assessment with Cardiovascular Delayed-Enhancement MR Imaging and Comparison of 1.5 and 3.0 T—Initial Experience

To prospectively compare visualization and quantification of irreversible myocardial injury in patients with chronic myocardial infarction at 1.5- and 3.0-T magnetic resonance (MR) imaging. The institutional research ethics committee approved the study. Participants gave written informed consent. Sixteen male patients (mean age, 66 years +/- 13 [standard deviation]) with myocardial infarction were imaged with the same sequence by the same operator at 1.5 and 3.0 T. After cine imaging, a bolus of gadodiamide was administered. Short-axis images of entire left ventricle (LV) were acquired with a breath-hold T1-weighted segmented inversion-recovery turbo fast low-angle shot (FLASH) sequence. Agreement for myocardial hyperenhancement (HE) mass between field strengths was assessed with Bland-Altman method; agreement for detection and transmural extent of HE was assessed with kappa statistics. Intra- and interobserver reproducibility of mass and transmural extent of HE were assessed at 1.5 and 3.0 T. Bland-Altman analysis revealed no systematic bias (mean difference, 0.2 g; 95% confidence interval: -0.7 g, 1.2 g) and acceptable limits of agreement (-3.3 to 3.8 g) between field strengths for HE mass. HE mass measurements were strongly correlated (R(2) = 0.99); there was no significant difference in measurements at 1.5 and 3.0 T (28.1 g +/- 15.7 [22.6% +/- 10.9 of LV mass] vs 27.8 g +/- 15.7 [22.3% +/- 10.7 of LV mass], respectively; P = .599). For all segments, there was a high degree of agreement for HE detection (kappa = 0.90) and transmural grade (kappa = 0.79) between field strengths. Intra- and interobserver variability were low between both field strengths. Initial inversion time selected to null the signal of normal myocardium at 3.0 T was 57 msec +/- 20 longer than at 1.5 T (P < .01). By using the same turbo FLASH MR pulse sequence, there was strong agreement in mass and transmural extent of myocardial HE between 1.5 and 3.0 T.

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Delayed Contrast-Enhanced Magnetic Resonance Imaging For the Detection of Autoimmune Myocarditis and Long-term Follow-Up

MRI proved to be a valuable tool for the evaluation and monitoring of myocarditis. We report the case of a 36 year old caucasian male with an undifferentiated collagenosis who presented first four years ago with unspecific symptoms and impaired exercise capacity. On echocardiography left ventricular function was impaired as well as on MRI. In addition, after administration of Gd-DTPA an intramyocardial pathological signal enhancement was observed on TSE T1 weighted and contrast enhanced FLASH 3D IR sequences. Based on several diagnostic tests including myocardial biopsy an autoimmune myocarditis due to an undifferentiated collagenosis was diagnosed. On long time follow up over almost 3 years with repeated MRI examinations, the delayed hyper enhancement (dHE) decreased or disappeared with successful treatment, respectively. However, in the area of recurrent inflammation, a persisting area of dHE developed with a subsequent perfusion defect. This area represents myocardial fibrosis due to recurrent inflammation.

Quantification of peri-operative myocardial infarction after coronary artery bypass surgery

Dear Editor, In a recent study in the Journal , Steuer and colleagues1 report that elevated biochemical markers after on-pump CABG correspond to the amount of peri-operatively infarcted myocardium as measured by delayed-enhancement cardiac MRI (DE-MRI). They found that 18 out of 23 (78%) patients studied demonstrated delayed hyper-enhancement (HE) on MRI, with a median mass of 4.4 g. While we applaud the use of state of the art imaging techniques to address fundamental questions regarding the pathophysiology of peri-operative myocardial injury, this study suffers from a number of …

Resolution of Ventricular Thrombus Identified by Contrast Enhanced Cardiac MRI

A 53 year old man was referred for a contrast enhanced cardiovascular magnetic resonance (CMR) scan for assessment of anterior myocardial wall viability. An earlier coronary angiogram had shown a mid left anterior descending artery (LAD) occlusion, and echocardiography had shown mildly reduced global left ventricular function without any other abnormalities. Cine CMR images (steady state free precession sequence) showed a dilated left ventricle (LV) with reduced global systolic function [End-diastolic volume 224 mls (NR 77-195 mls); end-systolic volume 124 mis (NR 19-72 mls); ejection fraction 45%]. There was wall thinning and akinesis of the anteroapical wall and severe hypokinesis of the mid anteroseptal wall. Postgadolinium images (segmented inversion recovery turboFLASH sequence) revealed a prominent LV apical thrombus which measured 1.4 cm at greatest diameter (Figure 1). Using the late gadolinium technique there was extensive (mainly transmural) hyperenhancement (HE) involving the mid and apical septum and the apex. The patient was commenced on warfarin. A second CMR scan repeated after 4 months of warfarin therapy showed complete resolution of the thrombus in the early and late post-gadolinium images (Figures 2 and 3). CMR imaging post-contrast administration is a sensitive tool in the detection of left ventricular thrombi, and overcomes some of the near-field limitations of 2D echocardiography.

Infarct Involution and Improved Function During Healing of Acute Myocardial Infarction: The Role of Microvascular Obstruction #,?

Delayed contrast-enhanced cardiac magnetic resonance imaging (ceCMR) delineates infarct size. The presence of hypoenhancement consistent with microvascular obstruction (MO) signifies larger infarcts with a worse prognosis. We hypothesized that the size of the contrast defect (CD) on ceCMR in acutely infarcted myocardium may change during infarct healing and depend upon the presence of MO. Twenty-five patients underwent CMR on weeks 1 and 8 after reperfused myocardial infarction. After short-axis cine CMR was performed, gadolinium was infused and ceCMR images and matched tagged cine MR images were obtained in the three most dysfunctional short-axis slices on cine CMR. The area and transmural extent of hyperenhancement (HE) with or without MO representing total CD size were planimetered. Between week 1 and week 8, the CD area fell from 1729+/-970 mm2 at week 1 to 1270+/-706 mm2 (p<0.001), as did the transmural extent of infarction (71+/-22% to 63+/-24%, p<0.001). The decline in CD trended to be higher in patients with MO (840+/-807 mm2) than in HE (312+/-485 mm2, p<0.07). In the patient group as a whole, ejection fraction (EF) improved (56+/-9% to 60+/-10%, p=0.002) between weeks 1 and 8, but patients with MO showed no increase in EF. Segments with some HE demonstrated partial functional improvement whereas no improvement was seen in HE+MO segments. In patients 8 weeks after reperfused myocardial infarction (MI), the size of infarction by ceCMR decreases compared to week 1 post-MI, especially in those with microvascular obstruction in whom there is little improvement in regional or global function.