Ronan P. Killeen

Cardiac Tumors: Optimal Cardiac MR Sequences and Spectrum of Imaging Appearances

OBJECTIVE This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors. CONCLUSION Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.

Cardiac MR imaging of nonischemic cardiomyopathies: imaging protocols and spectra of appearances.

Cardiac MR is an excellent noninvasive imaging technique for the detection and assessment of the morphology, function, and myocardial contrast-enhancement characteristics of the nonischemic cardiomyopathies.

Congenital cystic adenomatoid malformation of the lung: Hazards of delayed diagnosis

Congenital cystic adenomatoid malformation is a rare pulmonary developmental anomaly, which typically manifests in neonates and infants. Presentation in adulthood is uncommon, with <60 cases reported in the literature. The majority of cases involve one lobe only. We report a case of type 1 congenital cystic adenomatoid malformation in an adult presenting with a respiratory tract infection and haemoptysis. At thoracotomy, complex cystic masses were noted in the right upper and lower lobes. Lung‐sparing surgery, in the form of two segmentectomies and a non‐anatomical resection, was performed in order to avoid pneumonectomy. Such presentations may be problematic as potentially incomplete resections may increase the risk of complications and malignant transformation. This suggests the importance of appropriate clinical and radiological follow up.

Noncardiac findings on cardiac CT part I: Pros and cons.

Cardiac computed tomography (CT) has evolved into an effective imaging technique for the evaluation of coronary artery disease in selected patients. Two distinct advantages over other noninvasive imaging modalities include its ability to evaluate directly the coronary arteries and to provide an opportunity to evaluate extracardiac structures, such as the lungs and mediastinum. Some centers reconstruct a small field of view (FOV) cropped around the heart, but a full FOV (from skin to skin in the irradiated area) is obtainable in the raw data of every scan so that clinically relevant noncardiac findings are identifiable. Debate in the scientific community has centered on the necessity for this large FOV evaluation. A review of noncardiac structures provides the opportunity to make alternative diagnoses that may account for the patients presentation or to detect important but clinically silent problems such as lung cancer. Critics argue that the yield of biopsy-proven cancers is low and that the follow-up of incidental noncardiac findings is expensive, resulting in increased radiation exposure and possibly unnecessary further testing. In this two-part review we outline the issues surrounding the concept of the noncardiac read looking for noncardiac findings on cardiac CT. Part I focuses on the pros and cons of the practice of identifying noncardiac findings on cardiac CT.

Ectopic Focus in an Accessory Left Atrial Appendage Radiofrequency Ablation of Refractory Atrial Fibrillation

A 65-year-old man with symptomatic atrial fibrillation refractory to medical therapy was referred for repeat pulmonary vein (PV) isolation. Clinical symptoms included paroxysmal palpitations once to twice per week with associated light-headedness and chest pain. Initial PV isolation had been performed 6 months earlier without cessation of atrial fibrillation despite combined medical therapy with oral flecainide and bisoprolol. His past medical history was significant for hypertension, and in his family history, 1 brother had experienced a stroke at the age of 57 years. Physical examination, ECG, chest radiography, and coronary angiography were normal. Holter 24-hour ECG recordings revealed occasional atrial premature beats and paroxysmal atrial tachycardia. A magnetic resonance imaging study of the patient’s PVs and left atrium (LA) was performed before the repeat radiofrequency ablation. Images were acquired with a 1.5-T whole-body magnetic resonance system (Siemens Avanti, Siemens Medical Solutions, Forcheim, Germany) with an 8-element cardiac synergy coil for radiofrequency signal reception. First-pass breath-hold 3-dimensional contrast-enhanced magnetic resonance angiography of the PV was obtained after pump injection (3 mL/s) of 15 mmol of …

Imaging spectrum of sudden athlete cardiac death.

Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

Noncardiac findings on cardiac CT. Part II: Spectrum of imaging findings

Cardiac computed tomography (CT) has evolved into an effective imaging technique for the evaluation of coronary artery disease in selected patients. Two distinct advantages over other noninvasive cardiac imaging methods include its ability to directly evaluate the coronary arteries and to provide a unique opportunity to evaluate for alternative diagnoses by assessing the extracardiac structures, such as the lungs and mediastinum, particularly in patients presenting with the chief symptom of acute chest pain. Some centers reconstruct a small field of view (FOV) cropped around the heart but a full FOV (from skin to skin in the area irradiated) is obtainable in the raw data of every scan so that clinically relevant noncardiac findings are identifiable. Debate in the scientific community has centered on the necessity for this large FOV. A review of noncardiac structures provides the opportunity to make alternative diagnoses that may account for the patients presentation or to detect important but clinically silent problems such as lung cancer. Critics argue that the yield of biopsy-proven cancers is low and that the follow-up of incidental noncardiac findings is expensive, resulting in increased radiation exposure and possibly unnecessary further testing. In this 2-part review we outline the issues surrounding the concept of the noncardiac read, looking for noncardiac findings on cardiac CT. Part I focused on the pros and cons for and against the practice of identifying noncardiac findings on cardiac CT. Part II illustrates the imaging spectrum of cardiac CT appearances of benign and malignant noncardiac pathology.

Giant right atrial myxoma: characterization with cardiac magnetic resonance imaging☆

A 53-year-old woman presented to the emergency department with a 2-week history of dyspnoea and chest pain. Computed tomography pulmonary angiography was performed to exclude acute pulmonary embolism (PE). This demonstrated a large right atrial mass and no evidence of PE. Transthoracic echocardiography followed by cardiac magnetic resonance imaging confirmed a mobile right atrial mass. Surgical resection was then performed confirming a giant right atrial myxoma. We describe the typical clinical, radiologic, and pathologic features of right atrial myxoma.

Quantification of mitral regurgitation on cardiac computed tomography: comparison with qualitative and quantitative echocardiographic parameters.

Purpose: To assess whether cardiac computed tomographic angiography (CCTA) can quantify the severity of chronic mitral regurgitation (MR) compared to qualitative and quantitative echocardiographic parameters. Materials and Methods: Cardiac computed tomographic angiography was performed in 23 patients (mean ± SD age, 63 ± 16 years; range, 24-86 years) with MR and 20 patients without MR (controls) as determined by transthoracic echocardiography. Multiphasic reconstructions (20 data sets reconstructed at 5% increments of the electrocardiographic gated R-R interval) were used to analyze the mitral valve. Using CCTA planimetry, 2 readers measured the regurgitant mitral orifice area (CCTA ROA) during systole. A qualitative echocardiographic assessment of severity of MR was made by visual assessment of the length of the regurgitant jet. Quantitative echocardiographic measurements included the vena contracta, proximal isovelocity surface area, regurgitant volume, and estimated regurgitant orifice (ERO). Comparisons were performed using the independent t test, and correlations were assessed using the Spearman rank test. Results: All controls and the patients with MR were correctly identified by CCTA. For patients with mild, moderate, or severe MR, mean ± SD EROs were 0.16 ± 0.03, 0.31 ± 0.08, and 0.52 ± 0.03 cm2 (P < 0.0001) compared with mean ± SD CCTA ROAs 0.09 ± 0.05, 0.30 ± 0.04, and 0.97 ± 0.26 cm2 (P < 0.0001), respectively. When echocardiographic measurements were graded qualitatively as mild, moderate, or severe, strong correlations were seen with CCTA ROA (R = 0.89; P < 0.001). When echocardiographic measurements were graded quantitatively, the vena contracta and the ERO showed modest correlations with CCTA ROA (0.48 and 0.50; P < 0.05 for both). Neither the proximal isovelocity surface area nor the regurgitant volume demonstrated significant correlations with CCTA ROA. Conclusions: Single-source 64-slice CCTA provides a strong agreement with qualitative echocardiographic parameters but only a moderate correlation with quantitative echocardiographic parameters of chronic MR. Cardiac computed tomographic angiography slightly overestimates mild MR while slightly underestimating severe MR.

Posterior cortical and white matter changes on MRI in anti-AMPA receptor antibody encephalitis.

A 73-year-old woman presented with a 4-day history of progressive confusion. Her family reported that she was behaving erratically and had developed paranoia and hallucinations.