• Korean Journal of Radiology
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• 제20권1호
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• pp.102-113
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• 2019

Objective: To assess the accuracy and potential bias of computed tomography (CT) ventricular volumetry using semiautomatic three-dimensional (3D) threshold-based segmentation in repaired tetralogy of Fallot, and to compare them to those of two-dimensional (2D) magnetic resonance imaging (MRI). Materials and Methods: This retrospective study evaluated 32 patients with repaired tetralogy of Fallot who had undergone both cardiac CT and MRI within 3 years. For ventricular volumetry, semiautomatic 3D threshold-based segmentation was used in CT, while a manual simplified contouring 2D method was used in MRI. The indexed ventricular volumes were compared between CT and MRI. The indexed ventricular stroke volumes were compared with the indexed arterial stroke volumes measured using phase-contrast MRI. The mean differences and degrees of agreement in the indexed ventricular and stroke volumes were evaluated using Bland-Altman analysis. Results: The indexed end-systolic (ES) volumes showed no significant difference between CT and MRI (p > 0.05), while the indexed end-diastolic (ED) volumes were significantly larger on CT than on MRI (93.6 ± 17.5 mL/m² vs. 87.3 ± 15.5 mL/m² for the left ventricle [p < 0.001] and 177.2 ± 39.5 mL/m² vs. 161.7 ± 33.1 mL/m² for the right ventricle [p < 0.001], respectively). The mean differences between CT and MRI were smaller for the indexed ES volumes (2.0-2.5 mL/m²) than for the indexed ED volumes (6.3-15.5 mL/m²). CT overestimated the stroke volumes by 14-16%. With phase-contrast MRI as a reference, CT (7.2-14.3 mL/m²) showed greater mean differences in the indexed stroke volumes than did MRI (0.8-3.3 mL/m²; p < 0.005). Conclusion: Compared to 2D MRI, CT ventricular volumetry using semiautomatic 3D threshold-based segmentation provides comparable ES volumes, but overestimates the ED and stroke volumes in patients with repaired tetralogy of Fallot.

• Korean Journal of Radiology
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• 제22권9호
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• pp.1441-1450
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• 2021

Anomalous origin of the coronary artery from the pulmonary artery is a rare and potentially fatal congenital heart defect. Up to 90% of infants with an anomaly involving the left coronary artery die within the first year of life if left untreated. Patients who survive beyond infancy are at risk of sudden cardiac death. Cardiac CT and MRI are increasingly being used for the accurate diagnosis of this anomaly for prompt surgical restoration of the dual coronary artery system. Moreover, life-long imaging surveillance after surgery is necessary for these patients. In this pictorial review, multimodal cardiac imaging findings of this rare and potentially fatal coronary artery anomaly are comprehensively discussed, and representative images are provided to facilitate the understanding of this anomaly.

• Journal of Chest Surgery
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• 제41권6호
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• pp.718-723
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• 2008

배경: 최근 20년간 수술적인 기법, 마취 기술, 심폐기 운용, 중환자실 관리의 발전으로 심장수술의 사망률과 합병증은 상당히 감소하였지만 심장수술이 중추신경계에 상당한 위험 요소가 되는 것은 널리 알려진 바이다. 이 연구는 두경부 MRA를 통해 심장 수술 대상자에서 불현성 뇌혈관계 질환의 유병률과 두경부 MRA 상에서 비정상적인 소견을 보인 환자의 치료 방침의 변화를 알아보고자 하였다. 대상 및 방법: 2005년 10월부터 2008년 6월까지 두경부 MRA 촬영에 동의한 107명의 심장수술 예정자(21세에서 83세까지의 연령분포를 보인 남자 71명과 여자 36명)를 대상으로 하였다. 이 환자들 중에서 신경학적인 고위험군의 비율과 그 환자들의 치료 방침의 변화를 관찰하였다. 결과: 신경학적으로 고위험군 환자의 비율은 15.7% (17예)였으며, 이중 11예는 허혈성 심질환, 6예는 판막 질환이였으며, 이 중 2예의 환자만이 이전에 신경학적인 병력이 있었다. 14명(13.1%)의 환자에서 치료 방침에 변화가 있었다. 결론: 심장수술 대상자에 있어 불현성 뇌혈관계 질환은 비교적 높은 것으로 생각되며, 이를 밝히는 데 있어 두경부 MRA가 의미 있는 것으로 생각된다.

• Journal of Chest Surgery
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• 제54권1호
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• pp.45-52
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• 2021

Background: Atrial septal defect (ASD) is the most common congenital heart disease. However, the details of cardiac chamber remodeling after surgery are not well known, although this is an important issue that should be analyzed to understand long-term outcomes. Methods: Between November 2017 and January 2019, cardiac magnetic resonance imaging was performed preoperatively, at a 1-month postoperative follow-up, and at a 1-year postoperative follow-up. Cardiac chamber volume, valve regurgitation volume, and ejection fraction were measured as functions of time. Results: Thirteen patients (10 men and 3 women) were included. The median age at surgery was 51.4 years. The preoperative median ratio of flow in the pulmonary and systemic circulation was 2.3. The preoperative mean right ventricular (RV) end-diastolic volume index (EDVi) and RV end-systolic volume index (ESVi) had significantly decreased at the 1-month postoperative follow-up (p<0.001, p=0.001, respectively). The decrease in the RVEDVi (p=0.085) and RVESVi (p=0.023) continued until the postoperative 1-year follow-up, although the rate of decrease was slower. Tricuspid valve regurgitation had also decreased at the 1-month postoperative follow-up (p=0.022), and continued to decrease at a reduced rate (p=0.129). Although the RVEDVi and RVESVi improved after ASD closure, the RV volume parameters were still larger than the left ventricular (LV) volume parameters at the 1-year follow-up (RVEDVi vs. LVEDVi: p=0.016; RVESVi vs. LVESVi: p=0.001). Conclusion: Cardiac remodeling after ASD closure is common and mainly occurs in the early postoperative period. However, complete normalization does not occur.

• Korean Journal of Radiology
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• 제21권4호
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• pp.450-461
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• 2020

Objective: We performed a meta-analysis to evaluate the agreement of cardiac computed tomography (CT) with cardiac magnetic resonance imaging (CMRI) in the assessment of right ventricle (RV) volume and functional parameters. Materials and Methods: PubMed, EMBASE, and Cochrane library were systematically searched for studies that compared CT with CMRI as the reference standard for measurement of the following RV parameters: end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), or ejection fraction (EF). Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and correlation coefficient (r) between CT and CMRI. Heterogeneity was also assessed. Subgroup analyses were performed based on the probable factors affecting measurement of RV volume: CT contrast protocol, number of CT slices, CT reconstruction interval, CT volumetry, and segmentation methods. Results: A total of 766 patients from 20 studies were included. Pooled bias and LOA were 3.1 mL (-5.7 to 11.8 mL), 3.6 mL (-4.0 to 11.2 mL), -0.4 mL (5.7 to 5.0 mL), and -1.8% (-5.7 to 2.2%) for EDV, ESV, SV, and EF, respectively. Pooled correlation coefficients were very strong for the RV parameters (r = 0.87-0.93). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, an RV-dedicated contrast protocol, ≥ 64 CT slices, CT volumetry with the Simpson's method, and inclusion of the papillary muscle and trabeculation had a lower pooled bias and narrower LOA. Conclusion: Cardiac CT accurately measures RV volume and function, with an acceptable range of bias and LOA and strong correlation with CMRI findings. The RV-dedicated CT contrast protocol, ≥ 64 CT slices, and use of the same CT volumetry method as CMRI can improve agreement with CMRI.

• Investigative Magnetic Resonance Imaging
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• 제22권1호
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• pp.26-36
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• 2018

Purpose: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. Materials and Methods: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, $k_f$ of the creatine-kinase reaction in the heart using magnetization transfer $^{31}P$ magnetic resonance spectroscopy, home built $^1H/^{31}P$ transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. Results: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both $k_f$ and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. Conclusion: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

• Journal of Veterinary Science
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• 제22권1호
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• pp.2.1-2.10
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• 2021

Background: Diseases related to cerebrospinal fluid flow, such as hydrocephalus, syringomyelia, and Chiari malformation, are often found in small dogs. Although studies in human medicine have revealed a correlation with cerebrospinal fluid flow in these diseases by magnetic resonance imaging, there is little information and no standard data for normal dogs. Objectives: The purpose of this study was to obtain cerebrospinal fluid flow velocity data from the cerebral aqueduct and subarachnoid space at the foramen magnum in healthy beagle dogs. Methods: Six healthy beagle dogs were used in this experimental study. The dogs underwent phase-contrast and time-spatial labeling inversion pulse magnetic resonance imaging. Flow rate variations in the cerebrospinal fluid were observed using sagittal time-spatial labeling inversion pulse images. The pattern and velocity of cerebrospinal fluid flow were assessed using phase-contrast magnetic resonance imaging within the subarachnoid space at the foramen magnum level and the cerebral aqueduct. Results: In the ventral aspect of the subarachnoid space and cerebral aqueduct, the cerebrospinal fluid was characterized by a bidirectional flow throughout the cardiac cycle. The mean ± SD peak velocities through the ventral and dorsal aspects of the subarachnoid space and the cerebral aqueduct were 1.39 ± 0.13, 0.32 ± 0.12, and 0.76 ± 0.43 cm/s, respectively. Conclusions: Noninvasive visualization of cerebrospinal fluid flow movement with magnetic resonance imaging was feasible, and a reference dataset of cerebrospinal fluid flow peak velocities was obtained through the cervical subarachnoid space and cerebral aqueduct in healthy dogs.

• Korean Journal of Radiology
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• 제24권9호
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• pp.838-848
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• 2023

Objective: To quantitatively analyze the cardiac magnetic resonance imaging (CMR) characteristics of chemotherapy-related cardiac dysfunction (CTRCD) and explore their prognostic value for major adverse cardiovascular events (MACE). Materials and Methods: A total of 145 patients (male:female = 76:69, mean age = 63.0 years) with cancer and heart failure who underwent CMR between January 2015 and January 2021 were included. CMR was performed using a 3T scanner (Siemens). Biventricular functions, native T1 T2, extracellular volume fraction (ECV) values, and late gadolinium enhancement (LGE) of the left ventricle (LV) were compared between those with and without CTRCD. These were compared between patients with mild-to-moderate CTRCD and those with severe CTRCD. Cox proportional hazard regression analysis was used to evaluate the association between the CMR parameters and MACE occurrence during follow-up in the CTRCD patients. Results: Among 145 patients, 61 had CTRCD and 84 did not have CTRCD. Native T1, ECV, and T2 were significantly higher in the CTRCD group (1336.9 ms, 32.5%, and 44.7 ms, respectively) than those in the non-CTRCD group (1303.4 ms, 30.5%, and 42.0 ms, respectively; P = 0.013, 0.010, and < 0.001, respectively). They were not significantly different between patients with mild-to-moderate and severe CTRCD. Indexed LV mass was significantly smaller in the CTRCD group (65.0 g/m² vs. 78.9 g/mm²; P < 0.001). According to the multivariable Cox regression analysis, T2 (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.01-1.27; P = 0.028) and quantified LGE (HR: 1.07, 95% CI: 1.01-1.13; P = 0.021) were independently associated with MACE in the CTRCD patients. Conclusion: Quantitative parameters from CMR have the potential to evaluate myocardial changes in CTRCD. Increased T2 with reduced LV mass was demonstrated in CTRCD patients even before the development of severe cardiac dysfunction. T2 and quantified LGE may be independent prognostic factors for MACE in patients with CTRCD.

• Journal of Cardiovascular Imaging
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• 제30권4호
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• pp.263-275
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• 2022

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a complication beyond the first-year post-heart transplantation (HTx). We aimed to test the utility of cardiac magnetic resonance (CMR) to detect functional/structural changes in HTx recipients with CAV. METHODS: Seventy-seven prospectively recruited HTx recipients beyond the first-year post-HTx and 18 healthy controls underwent CMR, including cine imaging of ventricular function and T1- and T2-mapping to assess myocardial tissue changes. Data analysis included quantification of global cardiac function and regional T2, T1 and extracellular volume based on the 16-segment model. International Society for Heart and Lung Transplantation criteria was used to adjudicate CAV grade (0-3) based on coronary angiography. RESULTS: The majority of HTx recipients (73%) presented with CAV (1: n = 42, 2/3: n = 14, 0: n = 21). Global and segmental T2 (49.5 ± 3.4 ms vs 50.6 ± 3.4 ms, p < 0.001;16/16 segments) were significantly elevated in CAV-0 compared to controls. When comparing CAV-2/3 to CAV-1, global and segmental T2 were significantly increased (53.6 ± 3.2 ms vs. 50.6 ± 2.9 ms, p < 0.001; 16/16 segments) and left ventricular ejection fraction was significantly decreased (54 ± 9% vs. 59 ± 9%, p < 0.05). No global, structural, or functional differences were seen between CAV-0 and CAV-1. CONCLUSIONS: Transplanted hearts display functional and structural alteration compared to native hearts, even in those without evidence of macrovasculopathy (CAV-0). In addition, CMR tissue parameters were sensitive to changes in CAV-1 vs. 2/3 (mild vs. moderate/severe). Further studies are warranted to evaluate the diagnostic value of CMR for the detection and classification of CAV.

• Investigative Magnetic Resonance Imaging
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• 제7권2호
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• pp.100-107
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• 2003

목적 : 급성심근경색을 진단하는데 있어 심장자기공명영상의 유용성을 알아보고, 생존심근을 평가하는데 있어 Tl-201 심근관류 SPECT와 비교하고자 하였다. 대상 및 방법 : 흉통 및 호흡곤란이 있는 환자 중 심장자기공명영상과 Tl-201 SPECT를 시행한 17명을 후향적으로 조사하였다. 심장자기공명영상에서는 T2강조영상에서 심벽의 고신호 강도 유무, 영화영상에서 심벽 운동, Gd-DTPA 조영 증강 후 좌심실 벽의 관류 결손 및 주입 15분 후의 지연조영증강 유무를 평가하였다. T1-201 SPECT에서는 아데노신 부하 영상과 휴식기 영상을 얻어 관류 결손 유무와 관류 결손시 가역성 여부를 평가하였다. 결과 심장자기공명영상과 T1-201 SPECT 모두 급성심근경색을 진단하는데 통계적으로 의미가 있었고, T2강조영상, T1-201 SPECT, 지연조영증강 및 심벽운동 순으로 연관성이 있는 것으로 나타났고, 관류 결손은 통계적 유의성이 없었다. 생존심근 평가에 있어서는 두 검사간 유의한 차이가 없었으며, T2강조영상과 관류영상에서 T1-201 SPECT와 높은 일치율, 지연조영증강 및 심벽운동은 낮은 일치율을 보였다. 결론 : 심장자기공명영상은 급성심근경색을 진단하는데 매우 유의한 진단율을 보였고, 생존 심근여부의 판단에 있어 SPECT와 높은 일치율을 보였다. 그러나 각 검사별 판독 기준과 방법에서 많은 연구가 필요할 것으로 생각된다.