• Journal of Chest Surgery
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• v.57 no.4
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• pp.360-368
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• 2024

Background: The left pulmonary artery (LPA) may be kinked and stenotic, especially in tetralogy of Fallot, because of ductal tissue and anterior deviation of the conal septum. If LPA stenosis is not effectively treated during total correction, surgical angioplasty is occasionally performed. However, whether pulmonary artery (PA) angioplasty in adolescents or adults improves perfusion in the ipsilateral lung remains unclear. Methods: This retrospective review enrolled patients who underwent PA angioplasty for LPA stenosis between 2004 and 2019. Among patients who underwent a lung perfusion scan (LPS) or cardiac magnetic resonance imaging (cMRI) pre- and post-pulmonary angioplasty, those aged >13 years with <40% left lung perfusion (p-left) in the pre-angioplasty study were included. Preoperative and postoperative computed tomography, LPS, and cMRI data were collected. The perfusion ratio was analyzed according to the LPA's anatomical characteristics. Results: Seventeen adolescents and 16 adults (≥18 years old) were finally included (median age, 17 years). The most common primary diagnosis was tetralogy of Fallot (87.9%). In all patients, LPA angioplasty was performed concomitantly with right ventricular outflow tract reconstruction. No patients died. Preoperative p-left was not significantly different between adolescents and adults; however, adolescents had significantly higher postoperative p-left than adults. P-left significantly increased in adolescents, but not in adults. Seven patients had significant stenosis (z-score <-2.0) confined only to the proximal LPA and demonstrated significantly increased p-left. Conclusion: PA angioplasty significantly increased ipsilateral lung perfusion in adolescents. If focal stenosis is confined to the proximal LPA, PA angioplasty may improve ipsilateral lung perfusion, regardless of age.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.33-40
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• 2013

Purpose : To evaluate late gadolinium enhancement (LGE) pattern of left ventricular (LV) myocardium and presence or absence of LGE in other regions of the heart on cardiac magnetic resonance (CMR) imaging in patients diagnosed with cardiac amyloidosis. Materials and Methods: From 2009 to 2011, 9 patients who were suspected cardiac amyloidosis underwent CMR. We retrospectively analyzed the presence or absence of LGE and enhancement pattern in LV myocardium, and the presence or absence of LGE in other chambers as well. Also we measured interatrial septal thickness (IST), relative signal intensities of atrial septum and epicardial fat over the left atrial (LA) cavity on delayed enhanced images. MRI parameters in these patients were compared to those of control group of patients with ischemic heart disease by Wilcoxon rank sum test. Results: Of nine patients, LGE were found in 8; subendocardial circumferential pattern in 4 and diffuse pattern in 4. LGE in right ventricle was observed in 7. IST was significantly increased in patients with cardiac amyloidosis (P = 0.02). Ratio of atrial septum to LA cavity and ratio of epicardial fat to LA cavity showed a significant difference (P = 0.0002 and P = 0.0006, respectively). Conclusion: In LGE CMR, subendocardial or diffuse enhancement pattern is a typical finding for patients with cardiac amyloidosis. Atrial septum and epicardial fat show relatively increased signal intensities over LA blood cavity.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.811-815
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• 1998

Primar99y cardiac tumors are rare and about 25% of primary cardiac tumors are malignant. A primary undifferentiated cardiac sarcoma, which very rare, is presented as follows: A 28-year old woman at the 32th week of pregnancy was admitted to the hospital because of dyspnea. A large intracardiac (left atrium) tumor was found with cardiac echocardiography and MRI. Emergency operation was performed under the diagnosis of left atrial myxoma. After Cesarean section, LA-tomy was done under the cardiopulmonary bypass. Tumor removal including endocardium of left atrium was done and final pathologic diagnosis was primary undifferentiated laft atrial sarcoma. After adjuvant radiotherapy, she has been followed up in out patient bases without problems up to now.

• Investigative Magnetic Resonance Imaging
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• v.17 no.2
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• pp.83-90
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• 2013

Purpose : To report our clinical experience with cardiac 3.0 T MRI in patients compared with 1.5 T using individually optimized imaging protocols. Materials and Methods: We retrospectively reviewed 30 consecutive patients and 20 consecutive patients who underwent 1.5 T and 3 T cardiac MRI within 10 months. A comparison study was performed by measuring the signal-to-noise ratio (SNR), the contrast-to-noise ratio (CNR) and the image quality (by grading each sequence on a 5-point scale, regarding the presence of artifacts). Results: In morphologic and viability studies, the use of 3.0 T provided increase of the baseline SNRs and CNRs, respectively (T1: SNR 29%, p < 0.001, CNR 37%, p < 0.001; T2-SPAIR: SNR 13%, p = 0.068, CNR 18%, p = 0.059; viability imaging: SNR 45%, p = 0.017, CNR 37%, p = 0.135) without significant impairment of the image quality (T1: $3.8{\pm}0.9$ vs. $3.9{\pm}0.7$, p = 0.438; T2-SPAIR: $3.8{\pm}0.9$ vs. $3.9{\pm}0.5$, p = 0.744; viability imaging: $4.5{\pm}0.8$ vs. $4.7{\pm}0.6$, p = 0.254). Although the image qualities of 3.0 T functional cine images were slightly lower than those of 1.5 T images ($3.6{\pm}0.7$ vs. $4.2{\pm}0.6$, p < 0.001), the mean SNR and CNR at 3.0 T were significantly improved (SNR 143% increase, CNR 108% increase, p < 0.001). With our imaging protocol for 3.0 T perfusion imaging, there was an insignificant decrease in the SNR (11% decrease, p = 0.172) and CNR (7% decrease, p = 0.638). However, the overall image quality was significantly improved ($4.6{\pm}0.5$ vs. $4.0{\pm}0.8$, p = 0.006). Conclusion: With our experience, 3.0 T MRI was shown to be feasible for the routine assessment of cardiac imaging.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.376-381
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• 2004

Primary cardiac lymphoma is an extranodal malignant lymphoma of any cell type involving only heart and pericardium without dissemination. Patients usually present symptoms of heart failure, arrhythmias, pericardial effusion and cardiac tamponade. Diagnosis of primary cardiac lymphoma can be performed by echocardiogram, CT and MRI and cytologic examination of pericardial effusion or transvenously biopsied cardiac tissue. Prognosis of primary cardiac lymphoma is poor. Because of poor prognosis, early diagnosis and complete surgical excision is essential and postoperative systemic chemotherapy or radiotherapy is useful. In this case extensive tumor infiltration on the right ventricle and atrioventricular groove preclude surgical excision. Tissue biopsy revealed primary cardiac lymphoma. After postoperative chemotherapy and radiotherapy, the size of intracardiac mass is decreased in follow up chest CT scan and echocardiogram and symptoms of patient are relieved. Therefore, we report a case of primary cardiac lymphoma with review of literatures.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.486-489
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• 2006

A 16 year-old boy was admitted to our department because of mild chest discomfort and mild dyspnea. A mass involving posterior wall of the left ventricle near posterior mitral annulus was found on echocardiography and cardiac MRI. Total excision of the mass was performed via posterior ventriculotomy under the cardiopulmonary bypass. The pathologic diagnosis revealed mature cardiac myocyte hamartoma. There was no evidence of arrhythmia and tumor recurrence during the 1 year of follow up after the surgery.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1321-1327
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• 2021

Neurofibromatosis type 1 (NF1) is a relatively common inherited disorder characterized by the formation of neurofibromas, pigmentary abnormalities of the skin, Lisch nodules of the iris, and skeletal abnormalities. Multiple cutaneous neurofibromas are benign nerve sheath tumors and the main manifestation of NF1. Cardiac neurofibroma associated with NF1 is very rare, and few cases have been reported in the literature. Herein, we present the CT and MRI findings of a surgically confirmed left ventricular neurofibroma in a 32-year-old female with NF1.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.462-470
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• 2020

Objective: To demonstrate that human visual illusion can contribute to sub-endocardial dark rim artifact in contrast-enhanced myocardial perfusion magnetic resonance images. Materials and Methods: Numerical phantoms were generated to simulate the first-passage of contrast agent in the heart, and rendered in conventional gray scale as well as in color scale with reduced luminance variation. Cardiac perfusion images were acquired from two healthy volunteers, and were displayed by the same gray and color scales used in the numerical study. Before and after k-space windowing, the left ventricle (LV)-myocardium boarders were analyzed visually and quantitatively through intensity profiles perpendicular the boarders. Results: k-space windowing yielded monotonically decreasing signal intensity near the LV-myocardium boarder in the phantom images, as confirmed by negative finite difference values near the board ranging -1.07 to -0.14. However, the dark band still appears, which is perceived by visual illusion. Dark rim is perceived in the in-vivo images after k-space windowing that removed the quantitative signal dip, suggesting that the perceived dark rim is a visual illusion. The perceived dark rim is stronger at peak LV enhancement than the peak myocardial enhancement, due to the larger intensity difference between LV and myocardium. In both numerical phantom and in-vivo images, the illusory dark band is not visible in the color map due to reduced luminance variation. Conclusion: Visual illusion is another potential cause of dark rim artifact in contrast-enhanced myocardial perfusion MRI as demonstrated by illusory rim perceived in the absence of quantitative intensity undershoot.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.718-723
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• 2008

Background: The advances in surgical techniques, anesthesia management, perfusion methodology and postoperative intensive care have markedly decreased the mortality and cardiac morbidity of patients who undergo heart surgery over the past 2 decades. Nevertheless, it is well recognized that cardiac surgery carries a substantial risk for central nervous system complications. This study was conducted to evaluate the prevalence of subclinical cerebrovascular lesions in the head and neck by performing magnetic resonance angiography (MRA), and we investigated the clinical course of patients who had abnormal lesion seen on head and neck MRA. Material and Method: The subjects were 107 patients (71 men and 36 women ranging in age from 21 to 83 years) who were scheduled for cardiac surgery under nonemergency conditions between October 2005 and June 2008. Informed consent was obtained before the MRA. The carotid arteries, intracranial arteries and brain parenchyme were examined for subclinical cerebrovascular lesions by performing MRA. We reviewed the patients' medical records and MR findings to evaluate the prevalence of neurologically high risk patients and their clinical course. Result: The overall prevalence of neurologically high risk patients was 15.7% (17 patients). Among these patients, 11 patients had ischemic heart disease and 6 patients had valvular heart disease. Only 2 patients had a history of cerebrovascular disease. The clinical courses of 14 patients (13.1%) were changed according to their MRI findings. Conclusion: The prevalence of subclinical cerebrovascular disease in patients who were scheduled for cardiac surgery was higher than was expected. MR angiography was of value to identify these patients.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.341-349
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• 2003

A real time interactive controller (spectrometer) for magnetic resonance imaging (MRI) system has been developed using high speed digital signal processors (DSP). The controller generates radio frequency (rf) waveforms and audio frequency gradient waveforms and controls multiple receivers for data acquisition. By employing DSPs having high computational power (e.g., TMS320C670l) real time generation of complicated gradient waveforms and interactive control of selection planes are possible, which are important features in real-time imaging of moving organs, e.g., cardiac imaging. The spectrometer was successfully implemented at a 1.5 Tesla whole body MRI system for clinical application. Performance of the spectrometer is verified by various experiments including high- speed imaging such as fast spin echo (FSE) and echo planar imaging (EPI). These high-speed imaging techniques reduce measurement time, however, usually intensify artifact if there is any systematic phase error or jitter in the synchronization between the transmitter, receiver, and gradients.