• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1104-1108
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• 2022

Myocardial calcification can develop owing to several conditions. It is a rare complication following sepsis and renal failure. We report a case of rapid development of left ventricular mid-wall calcification observed using CT and cardiac MRI in a patient after recovery from sepsis and acute renal failure.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.219-228
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• 2003

Purpose: The amount of salvaged myocardium is an important prognostic factor in patients with acute myocardial infarction (MI). We investigated if early Tl-201 SPECT imaging could be used to predict the salvaged myocardium and functional recovery in acute MI after primary PTCA. Materials and Methods: In 36 patients with first acute MI treated with primary PTCA, serial echocardiography and Tl-201 SPECT imaging ($5.8{\pm}2.1$ days after PTDA) were performed. Regional wall motion and perfusion were quantified with on 16-segment myocardial model with 5-point and 4-point scaling system, respectively. Results: Wall motion was improved in 78 of the 212 dyssynergic segments on 1 month follow-up echocardiography and 97 on 7 months follow-up echocardiography, which were proved to be salvaged myocardium. The areas under receiver operating characteristic curves of Tl-201 perfusion score for detecting salvaged myocardial segments were 0.79 for 1 month follow-up and 0.83 for 7 months follow-up. The sensitivity and specificity of Tl-201 redistribution images with optimum cutoff of 40% of peak thallium activity for detecting salvaged myocardium were 84.6% and 55.2% for 1 month follow-up, and 87.6% and 64.3% for 7 months follow-up, respectively. There was a linear relationship between the percentage of peak thallium activity on early redistribution imaging and the likelihood of segmental functional improvement 7 months after reperfusion. Conclusion: Tl-201 myocardial perfusion SPECT imaging performed early within 10 days after reperfusion can be used to predict the salvaged myocardium and functional recovery with high sensitivity during the 7 months following primary PTCA in patients with acute MI.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.846-856
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• 2005

Purpose : To measure the peak myocardial tissue velocities and patterns of longitudinal motion of atrioventricular(AV) annuli and assess body weight and heart rates-related changes in normal children. Methods : Using pulsed wave Tissue Doppler Imaging(TDI), we measured peak systolic, early and late diastolic myocardial velocities in 72 normal children at six different sites in apical-4 chamber (A4C) view and at four different sites in apical-2 chamber(A2C) view and compared those values with each other, also observing effects with body weights and heart rates. Longitudinal motions of the AV annuli were measured at three different sites in A4C. Results : There were no significant differences of the TDI parameters between gender, ECHO-machines and among the three Doctors performing TDI. Peak myocardial velocities were significantly higher at the base of the heart than in the mid-ventricular region and in the right lateral ventricular wall than in the left lateral ventricular wall or IVS. The TDI parameters showed no significant correlation with fractional shortening(%). Peak systolic and early diastolic myocardial velocities had no correlation with heart rates, but peak late diastolic velocities and A/E ratio correlated positively with heart rates. Correlations between the TDI parameters and body weight were inconsistent. Absolute longitudinal displacement and % displacement were not differ between gender and not correlated with the TDI parameters. Conclusion : We measured the peak myocardial velocities with TDI and the longitudinal motion of the AV annuli using M-mode echocardiography in normal children. With more large scale evaluation, we may establish reference values in normal children and broaden clinical applicabilities in congenital and acquired heart diseases.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.386-394
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• 2009

Purpose: We aimed to assess the myocardial velocity on gated myocardial perfusion SPECT (gated MPS), to compare myocardial velocity between patients without coronary artery disease (CAD) and CAD patients and to assess the correlation of myocardial velocity and perfusion and wall thickening on CAD group. Materials and Methods: Seventeen patients without CAD (M:F=9:8, mean age $61.8{\pm}11.1$ yrs: group A) and thirty-nine patients with CAD (M:F=18:21, mean age $66.9{\pm}8.1$ yrs : group B) had undergone one-day adenosine stress gated MPS. In twenty segment model, 12 segments (except apical and basal segments) of each patient were included. We obtained systolic and diastolic gate ratio in left ventricular volume curve by eight frames per cardiac cycle on gated MPS. Using the systolic and diastolic gate ratio and R-R time of each patient, we obtained systolic and diastolic time ratio. The myocardial velocity was defined as wall thickening over systolic or diastolic time. Results: We presented normal range of myocardial velocities according segments and territories of coronary artery. The myocardial velocity of group B was significantly lower than group A (p=0.00). There was no significant difference between the myocardial velocity of group B with preserved EF and group A. The stress systolic velocity significantly correlated with regional myocardial perfusion in group B with preserved EF (p=0.00) as well as decreased EF (p=0.01). In group B, stress perfusion of segments which had decreased wall thickening and decreased myocardial velocity was significantly lower than segments which had decreased wall thickening and preserved myocardial velocity (p=0.01). Conclusion: The new functional index of velocity will be used as an useful of gated MPS.

• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.361-369
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• 2017

Hemodynamic information in the carotid artery bifurcation is very important for understanding the development and progression mechanisms of cerebrovascular disease and for its early diagnosis and prediction of the progress. In this paper, we constructed a mock pulsatile blood circulation system using an anthropomorphic elastic vessel of the carotid artery bifurcation and ex vivo pig blood to acquire ultrasound images from blood and vessels synchronized with internal pressure while controlling the blood flow. Echogenicity, blood flow velocity, and blood vessel wall motion from the ultrasound images, and internal blood pressure were extracted over a cycle averaged from five cycles when the pulsatile pump rates are 20 r/min, 40 r/min, and 60 r/min. As a result, respectively, the peak systolic blood flow velocities were 20 cm/s, 25 cm/s, and 40 cm/s, the blood pressure differences were 30 mmHg, 70 mmHg, and 85 mmHg, the arterial walls were expanded to 0.05 mm, 0.15 mm, and 0.25 mm. Time-delayed cyclic variation of echogenicity compared to blood flow and pressure was observed, but the variation was minimal at 20 r/min. Time-synchronized cyclic variations of these parameters are important information for accurate input parameters and validation of the computational hemodynamic experiments which will provide useful information for the development and progress mechanisms of carotid artery stenosis.

• Investigative Magnetic Resonance Imaging
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• v.5 no.1
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• pp.18-23
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• 2001

Purpose : To describe the MRI findings in the bronchial anthracofibrosis mimicking lung cancer on CT examination. Materials and methods : Ten patients, who showed CT findings mimicking lung cancer, were selected among fifty patients of bronchial anthracofibrosis proven by bronchoscopic biopsy, consisting of two men and eight women, ranging in age from 58 to 79 years old faverage age, 68 years old). CT scan and MRI were performed in all patients (n=10). Percutaneous lung biopsy on mass was performed in one patient. MRI findings were analyzed with the emphasis on the signal intensity of the mass (n=4), collapsed lung (n=4) and Iymph node (n=10) on axial T1 and T2-weighted images by two radiologists in consensus. No contrast enhancement was used in all cases. Results : CT scan revealed mass (n=4), atelectasis with obstructive pneumonia(n=4) and bronchial wall thickening(n=2). All patients showed enlarged medistinal Iymph nodes(n=10). The mass showed low signal intensity on T1WI and T2WI (n =4). The collapsed lung in patients with atelectasis indicated intermediate signal intensity on T1WI and low signal intensity on T2WI (n= 4). Nine patients showed low sisnal intensity of Iymph node on T1WI and T2WI, except one patient who showed central high signal intensity with peripheral rim of low signal intensity in right lower paratracheal llmph node on T2WI. Conclusion : Low signal intensity of a mass, collapsed lung, and lymph nodes on T2WI in anthracofibrosis patients may be helpful in differentiation of the lesion from lung cancer.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.699-706
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• 2016

This study aimed to propose the necessity and system establishment of noise reduction facility via evaluating noise level exposed by the radiographer due to MRI scan. Noise measurements were carried out using at S general hospital in Daejeon using 1.5 Tesla MRI (7 exams) and 3.0 Tesla MRI (16 exams), while using SC-804 noise meter. The measurement distance was from the soundproof door of the MRI room to the radiographer which measured 100cm, and the measurement height, the height to the radiographer's ears when working, 100cm. The noise measured for each exam was an average of three measures per exam which observed the noise occurring in each sequence recorded every 20 seconds. As the results, the maximum of noise exposed by the radiographer is 73.3 dB(A), which is MRCP by the 3.0 Tesla device, and also the maximum of average noise is 66.9(3.1) dB(A), which is Myelogram by the 3.0 Tesla device. Average noise by each device is 61.9(4.1) dB(A) by the 3.0 Tesla device and 52.0(3.1) dB(A) by the 1.5 Tesla device, which comes to the result that the 3.0 Tesla MRI device is about 10 dB(A) degree higher(p <0.001). The noise level exposed by the radiographer does not affect auditory acuity, but the level is able to incur a non auditory effect. The reflect sound can be removed by installing curtains in the rear wall of MRI control room in order to reduce the noises, but, first of all, An institutional system is needed in order to prevent noise.

• Journal of Gastric Cancer
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• v.3 no.3
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• pp.151-157
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• 2003

Purpose: In this study, we attempted to ascertain the proton magnetic resonance spectroscopy (${1}^H$ MRS) peak characteristics of human gastric tissue layers and finally to use the metabolic peaks of MRS to distinguish between normal and abnormal gastric specimens. Materials and Methods: Ex-vivo ${1}^H$ MRS examinations of thirty-five gastric specimens were performed to distinguish abnormal gastric tissues invaded by carcinoma cells from normal stomach-wall tissues. High-resolution 400-MHz (9.4-T) ${1}^H$ nuclear magnetic resonance (NMR) spectra of two gastric layers, a proper muscle layer, and a composite mucosasubmucosa layer were compared with those of clinical 64- MHz (1.5-T) MR spectra. Three-dimensional spoiled gradient recalled (SPGR) images were used to determine the size and the position of a voxel for MRS data collection. Results: For normal gastric tissue layers, the metabolite peaks of 400-MHz ${1}^H$ MRS were primarily found to be as follows: lipids at 0.9 ppm and 1.3 ppm; alanine at 1.58 ppm; N-acetyl neuraminic acid (sialic acid) at 2.03 ppm; and glutathione at 2.25 ppm in common. The broad and featureless featureless spectral peaks of the 64-MHz MRS were bunched near 0.9, 1.3, and 2.0, and 2.2 ppm in human specimens without respect to layers. In a specimen (Borrmmann type III) with a tubular adenocarcinoma, the resonance peaks were measured at 1.26, 1.36 and 3.22 ppm. All the peak intensities of the spectrum of the normal gastric tissue were reduced, but for gastric tumor tissue layers, the lactate peak split into 1.26 and 1.39 ppm, and the peak intensity of choline at 3.21 ppm was increased. Conclusion: We found that decreasing lipids, an increasing lactate peak that split into two peaks, 1.26 ppm and 1.36 ppm, and an increasing choline peak at 3.22 ppm were markers of tumor invasion into the gastric tissue layers. This study implies that MR spectroscopy can be a useful diagnostic tool for gastric cancer.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.439-445
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• 2020

The purpose of this study was to investigate the feasibility of stent placement and the evaluation of tissue hyperplasia caused by bare metallic stent placement in a mouse colon model. In a pilot study, C57BL/6 mouse were used to verify diameter of colon. Mean diameter size was 4.05 mm. Twenty C57BL/6 mice were divided into two groups to assess differing stent diameters (Group A, 5 mm diameter; Group B. Group B, 4 mm diameter). Follow-up, 1-week fluoroscopic imaging, 4-week endoscopic imaging were obtained. Mice were sacrificed 4-week after stent placement. Microscopic findings were evaluated. Stent placement was technically successful except one mouse in Group A. Data from the mouse was omitted. During follow-up, five mice in Group A died within 7 days after stent placement, and one stent in Group B was migrated into the rectum. The incidence of stent-related complication was 60% and 10% between group A and Group B, respectively. Gross and Endoscopic findings showed tissue hyperplasia through the mesh, and all the stents had become incorporated into the wall of the colon. Microscopic findings were no statistically significant difference. colonic stent placement was technically feasible, and stent-induced tissue hyperplasia was evident in a mouse model. With stent large size, there was the highest incidence of colon perforation.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.46-52
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• 1991

Radioaerosol inhalation imaging (RII) has been used in radionuclide pulmonary studies for the past 20 years. The method is well accepted for assessing regional ventilation because of its usefulness, easy fabrication and simple application system. To evaluate its clinical utility in the study of impaired regional ventilation in bronchial asthma, we obtained and analysed RIIs in 31 patients (16 women and 15 men; age ranging 21-76 years) with typical bronchial asthma at the Department of Radiology, Kangnam St. Mary's Hospital, Catholic University Medical college, from January, 1988 to August, 1989. Scintiscans were obtained with radioaerosol produced by a BARC(Bhabha Atomic Reserch Center, India) nebulizer with 15 mCi of $^{99m}Tc-phytate$. The scanning was peformed in anterior, posterior and lateral projections following 5-minute inhalation of radioaerosol on sitting position. The scans were analyzed and correlated with the results of pulmonary function study and the findings of chest radiography. Fifteen patients had concomitant lung perfusion image with $^{99m}Tc-MAA$. Follow-up scans were obtained in 5 patients after bronchodilator therapy. The patients were divided into (1) attack type (4 patients), (2) resistant type (5 patients), (3) remittent type (10 patients) and (4) bronchitic type (12 patients). Chest radiography showed hyperinflation, altered pulmonary vascularity, thickening of the bronchial wall and accentuation of basal interstitial markings in 26 of the 31 patients. Chest radiographs were norma! in the remaining 5 patients. Regardless of type, the findings of RII were basically the same, and characterized by the deposition of radioaerosol in the central parts or in the main respiratory air ways along with mottled nonsegmental ventilation defects in the periphery. Peripheral parenchymal defects were more extensive than that of expected findings from clinical symptoms, pulmonary function test and chest radiograph. Broomstick sign was present in 17 patients. The abnormality of RII was poorly correlated with perfusion scans. In all 5 patients treated with bronchodilators, follow-up study demonstrated a decrease in the degree of radioaerosol deposition in the central air way with improved ventilation defects. This study indicates that RII is a useful technique for the evaluation of regional ventilation abnormality and the effect of treatment with bronchodilators in patients with bronchial asthma.