• Journal of Digital Convergence
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• v.12 no.3
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• pp.353-358
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• 2014

This study was conducted to analyze the patient's exposed dose targeting the patients who had acute ischemic stroke symptoms and CT brain perfusion scan, by comparing fixed time technique and bolus tracking technique which was provided by the manufacturer and to identify the Time graph to implement the usability of contrast medium's tracking technique the best contrast enhancement intervals. $CTDI_{VOL}$ of PCT in patient appeared to be 431.72mGy in fixed scan delay protocol, whereas 323.61mGy in Bolus tracking technique. The value of DLP appeared to be $1243.47mGy{\cdot}cm$ in fixed scan delay protocol, whereas $932mGy{\cdot}cm$ in Bolus tracking technique. Time graph appeared to be various in fixed scan delay protocol, whereas the optimal time graph could be obtained in Bolus tracking. The exposure dose could be reduced by 25% applying Bolus tracking technique when taking brain perfusion CT scan.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.693-704
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• 2021

Objective : Endovascular mechanical thrombectomy (MT) has been regarded as one of the standard treatments for acute ischemic stroke caused by large vessel occlusion. Despite the wide use of stent retrievers for MT, arterial intimal damage caused when deployed stent is pulled has been a certain disadvantage. We hypothesized that statin could protect and stabilize vessel damage after endovascular MT using a stent retriever. In this animal study, we observed the protective effects of the statins towards MT-induced vessel wall injury. Methods : Twenty-eight carotid arteries of fourteen rabbits were used in the experiments with MT using stent retriever. We divided the rabbits into four groups as follows : group 1, negative control; group 2, positive control; group 3, statin before MT; and group 4, statin after MT. After MT procedures, we harvested the carotid arteries and performed histomorphological and immunohistochemical analyses. Results : In histomorphological analysis with hematoxylin and eosin and Masson's trichrome stain, significant intimal thickening (p<0.05) was observed in the positive control (group 2), compared to in the negative control (group 1). Intimal thickening was improved in the statin-administered groups (groups 3 and 4 vs. group 2, p<0.05). We also observed that statin administration after MT (group 4) resulted in a more effective decrease in intimal thickness than statin administration before MT (group 3) (p<0.05). We performed immunohistochemical analysis with the antibodies for tumor necrosis factor-alpha (TNF-α), cluster of differentiation (CD)11b, and CD163. In contrast to the negative control (group 1), the stained percentage areas of all immunological markers were markedly increased in the positive control (group 2) (p<0.05). Based on statin administration, the percentage area of TNF-α staining was significantly reduced (p<0.05) in group 3, compared to the positive control group (group 2). However, significant differences were not observed for CD11b and CD163 staining. In group 4, no significant differences were observed for TNF-α, CD11b, and CD163 staining (p≥0.05). The differences in the percentage areas of the different markers between the statin-administered groups (groups 3 and 4) were also not revealed. Conclusion : We presented that statin administration before and after MT exerted protective effects towards vessel wall injury. The efficacy of statins was greater post-administration than pre-administration. Thus, statin administration in routine prescriptions in the peri-procedural period is strongly advised.

• Journal of Korean Neurosurgical Society
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• v.65 no.6
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• pp.816-824
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• 2022

Objective : Emergency superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis in patients with large vessel occlusion who fails mechanical thrombectomy or does not become an indication due to over the time window can be done as an alternative for blood flow restoration. The authors planned this study to quantitatively measure the degree of improvement in cerebral perfusion flow using perfusion magnetic resonance imaging (MRI) after bypass surgery and to find out what factors are related to the outcome of the bypass surgery. Methods : For a total of 107 patients who underwent emergent STA-MCA bypass surgery with large vessel occlusion, the National Institute of Health stroke scale (NIHSS), modified Rankin score (mRS), infarction volume, and hypoperfusion area volume was calculated, the duration between symptom onset and reperfusion time, occlusion site and infarction type were analyzed. After emergency STA-MCA bypass, hypoperfusion area volume at post-operative 7 days was calculated and analyzed compared with pre-operative hypoperfusion area volume. The factors affecting the improvement of mRS were analyzed. The clinical status of patients who underwent emergency bypass was investigated by mRS and NIHSS before and after surgery, and changes in infarct volume, extent, degree of collateral circulation, and hypoperfusion area volume were measured using MRI and digital subtraction angiography (DSA). Results : The preoperative infarction volume was median 10 mL and the hypoperfusion area volume was median 101 mL. NIHSS was a median of 8 points, and the last normal to operation time was a median of 60.7 hours. STA patency was fair in 97.1% of patients at 6 months follow-up DSA and recanalization of the occluded vessel was confirmed at 26.5% of patients. Infarction volume significantly influenced the improvement of mRS (p=0.010) but preoperative hypoperfusion volume was not significantly influenced (p=0.192), and the infarction type showed marginal significance (p=0.0508). Preoperative NIHSS, initial mRS, occlusion vessel type, and last normal to operation time did not influence the improvement of mRS (p=0.272, 0.941, 0.354, and 0.391). Conclusion : In a patient who had an acute cerebral infarction due to large vessel occlusion with large ischemic penumbra but was unable to perform mechanical thrombectomy, STA-MCA bypass could be performed. By using time-to-peak images of perfusion MRI, it is possible to quickly and easily confirm that the brain tissue at risk is preserved and that the ischemic penumbra is recovered to a normal blood flow state.

• Korean Journal of Radiology
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• v.23 no.3
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• pp.333-342
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• 2022

Objective: Intracranial atherosclerotic stroke occurs through various mechanisms, mainly by artery-to-artery embolism (AA) or branch occlusive disease (BOD). This study evaluated the spatial relationship between middle cerebral artery (MCA) plaques and perforating arteries among different MCA territory infarction types using vessel wall magnetic resonance imaging (VW-MRI). Materials and Methods: We retrospectively enrolled patients with acute MCA infarction who underwent VW-MRI. Thirty-four patients were divided into three groups according to infarction pattern: 1) BOD, 2) both BOD and AA (BOD-AA), and 3) AA. To determine the factors related to BOD, the BOD and BOD-AA groups were combined into one group (with striatocapsular infarction [BOD+]) and compared with the AA group. To determine the factors related to AA, the BOD-AA and AA groups were combined into another group (with cortical infarction [AA+]) and compared with the BOD group. Plaque morphology and the spatial relationship between the perforating artery orifice and plaque were evaluated both quantitatively and qualitatively. Results: The plaque margin in the BOD+ group was closer to the perforating artery orifice than that in the AA group (p = 0.011), with less enhancing plaque (p = 0.030). In the BOD group, plaques were mainly located on the dorsal (41.2%) and superior (41.2%) sides where the perforating arteries mainly arose. No patient in the AA group had overlapping plaques with perforating arteries at the cross-section where the perforator arose. Perforating arteries associated with culprit plaques were most frequently located in the middle two-thirds of the M1 segment (41.4%). The AA+ group had more stenosis (%) than the BOD group (39.73 ± 24.52 vs. 14.42 ± 20.96; p = 0.003). Conclusion: The spatial relationship between the perforating artery orifice and plaque varied among different types of MCA territory infarctions. In patients with BOD, the plaque margin was closer and blocked the perforating artery orifice, and stenosis degree and enhancement were less than those in patients with AA.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.313-323
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• 2009

Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in $T_2^*$-DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1223-1235
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• 1998

Background and Objective : Although prone positioning has been reported to improve gas exchange, prone positioning alone does not seem to be sufficient to increase systemic oxygen transport in an acute lung injury. The objective of this study was to investigate whether the combined therapy of low dose nitric oxide (NO) inhalation and prone positioning has an additive effect on the oxygenation and hemodynamics in patients with severe ARDS. Patients and Methods : Twelve patients with ARDS were included. Prone positioning alone, later combined with nitric oxide inhalation (5~10 ppm) from the supine position (baseline) were performed with serial measurement of gas exchange, respiratory mechanics and hemodynamic at sequential time points. The patient was regarded as a responder to prone positioning if an increase in $PaO_2/FiO_2$ of more than 20 mm Hg at 30 min or 120 min intervals after prone positioning was observed compared to that of the baseline. The same criterion was applied during nitric oxide inhalation. Results : Eight patients (66.5%) responded to prone positioning and ten patients (83.3%) including the eight just mentioned responded to the addition of NO inhalation. The $AaDO_2$ level also decreased promptly with the combination of prone positioning and NO inhalation compared to that of prone positioning alone ($191{\pm}109$ mm Hg vs. $256{\pm}137$ mm Hg, P<0.05). Hemodynamic parameters and lung compliance did not change significantly during prone positioning only. Following the addition of NO inhalation to prone positioning, the mean pulmonary artery pressure and pulmonary artery occlusion pressure decreased and cardiac output, stroke volume and oxygen delivery increased (P < 0.05) compared to those of prone 120 min. Conclusion : These findings indicate that NO inhalation would provide additional improvement in oxygenation and oxygen transport to mechanically ventilated patients with ARDS who are in a prone position.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.140-152
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• 1998

Background: Prone position improves oxygenation in patients with ARDS probably by reducing shunt Reduction of shunt in prone position is thought to be effected by lowering of the critical opening pressure (COP) of the dorsal lung because the pleural pressure becomes less positive in prone position compared to supine position. It can then be assumed that prone position would bring about greater improvement in oxygenation when PEEP applied in supine position is just beneath COP than when PEEP is above COP. Hemodynamically, prone position is expected to attenuate the lifting of cardiac fossa induced by PEEP. Based on these backgrounds, we investigated whether the effect of prone position on oxygenation differs in magnitude according to the level of PEEP applied in supine position, and whether impaired cardiac output in supine position by PEEP can be restored in prone position. Methods: In seven mongrel dogs, $PaO_2/F_1O_2$(P/F) was measured in supine position and at prone position 30 min. Cardiac output (CO), stroke volume (SV), pulse rate (PR), and pulmonary artery occlusion pressure (PAOP) were measured in supine position, at prone position 5 min, and at prone position 30 min. After ARDS was established with warmed saline lavage(P/F ratio $134{\pm}72$ mm Hg), inflection point was measured by constant flow method($6.6{\pm}1.4cm$ $H_2O$), and the above variables were measured in supine and prone positions under the application of Low PEEP($5.0{\pm}1.2cm$ $H_2O$), and Optimal PEEP($9.0{\pm}1.2cm$ $H_2O$)(2 cm $H_2O$ below and above the inflection point, respectively) consecutively. Results : P/F ratio in supine position was $195{\pm}112$ mm Hg at Low PEEP and $466{\pm}63$ mm Hg at Optimal PEEP(p=0.003). Net increase of P/F ratio at prone position 30 min, however, was far greater at Low PEEP($205{\pm}90$ mm Hg) than at Optimal PEEP($33{\pm}33$ mm Hg)(p=0.009). Compared to CO in supine position at Optimal PEEP($2.4{\pm}0.5$ L/min), CO in prone improved to $3.4{\pm}0.6$ L/min at prone position 5 min (p=0.0180) and $3.6{\pm}0.7$ L/min at prone position 30 min (p=0.0180). Improvement in CO was attributable to the increase in SV: $14{\pm}2$ ml in supine position, $20{\pm}2$ ml at prone position 5 min (p=0.0180), and $21{\pm}2$ ml at prone position 30 min (p=0.0180), but not to change in PR or PAOP. When the dogs were turned to supine position again, MAP ($92{\pm}23$ mm Hg, p=0.009), CO ($2.4{\pm}0.5$ L/min, p=0.0277) and SV ($14{\pm}1$ ml, p=0.0277) were all decreased compared to prone position 30 min. Conclusion: Prone position in a dog with saline-lavaged acute lung injury appeared to augment the effect of relatively low PEEP on oxygenation, and also attenuate the adverse hemodynamic effect of relatively high PEEP. These findings suggest that a PEEP lower than Optimal PEEP can be adopted in prone position to achieve the goal of alveolar recruitment in ARDS avoiding the hemodynamic complications of a higher PEEP at the same time.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.322-327
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• 2004

Coronary artery bypass grafting on the beating heart is no longer a new methods for any cardiac surgeon. We evaluated the application of the off-pump coronary artery bypass procedure relative to safety and efficiency as measured by postoperative complication and operative mortality. Material and Method: We used our retrospective database to compare the patients having off-pump coronary surgery (n=100) with those having on-pump coronary surgery (n=100) between June, 1999 and August, 2002. Patients whom underwent associated valvular or aortic aneurysmal operation were excluded. Result: Neither groups showed any differences in the patient's risk factors and extent of coronary disease. Off-pump CABG group did not have significantly less mean operation time (295$\pm$73 min vs 323$\pm$83 min, p=ns) and mean hospital day (15.34$\pm$6.02 day vs 13.80$\pm$4.95 day, p=ns). However, off-pump CABG group had significantly shorter mean ventilation time (17.3$\pm$11.27 hour vs 24.98$\pm$16.1 hour, p＜0.05). No patients were converted to on-pump CABG in off-pump CABG. Intraoperative hemodynamic instability in off-pump CABG were 6 cases, of whom 2 cases were in lateral wall approach and 4 cases in right coronary anastomosis. Postoperative mortality was 1 case in off-pump CABG and 2 cases in on-pump CABG. Intra-aortic ballon pump (IABP) was applied in 1 case with off-pump CABG and in 2 cases with on-pump CABG. No patients presented postoperative cerebral infarction ＆ stroke in off-pump CABG but 2 patients in on-pump CABG. Postoperative arrhythmia presented in 4 cases with off-pump CABG and in 6 cases with on-pump CABG. Acute renal failure (ARF) was complicated in 3 cases with off-pump CABG and in 2 cases with on-pump CABG. Conclusion: This study documented the immediate safety and efficiency of the off-pump CABG procedure.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.3
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• pp.53-66
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• 1996

Home Health Care is one part of the total health care system. It includes health care services that link the hospital to the community. While it is important for early discharge patients, home care is also important for people with chronic illnesses or handicapping conditions. In 1989 the Korean government passed a law that opened the way for formal development of home health care services beginning with education programs to certify nurses for home care, and then demonstration home care services. Part of the mandate of the demonstration projects was evaluation of home care services. This study was done in order to provide basic data that would contribute to the development of records that could be used for evaluation through a retrospective audit and to examine the care that had been given in Home Care at Wonju Christian Hospital over a twenty year period from 1974 to 1994. The purposes of the study were : to identify to characteristics of the clients who had received home care, to identify the reasons for client referrals, to identify the nursing problems of these clients, to identify the nursing care provided to these clients, and to identify differences in these areas over the twenty year period. The study was a descriptive study involving a retrospective audit of the client records. Demographic data on all clients were included : 4,171 clients from 2,564 families. Data on referrals, nursing diagnosis and nursing interventions were from even numbered records which had a patient problem list included in the record, 2,801 clients, Frequencies and ANOVA were used in the analysis. The results of the study showed that the majority of the clients were from Wonju city /county. There were more women than men related to the high number of postpartum clients(1,300). The high number of postparttum clients and newborns was also evident in the age distribution. An the number of maternal-child clients decreased over the 20 years, the mean age of the clients increased significantly. Other factors also contributed to this change ; as increasing number of clients with brain injuries or with cancer, and fewer children with burns, osteomyelitis and tuberculosis. There was a decrease in the mean number of visits and mean length of coverage, reflecting a movement towards a short term acute care model. The number of new clents dropped sharply after 1985. The reasons for this are : the development of other treatment alternatives for clients, the establishment of an active wellbaby clinic, many more options plus a decreasing number of new cases of Hansen's Disase, and insurance that allows people with burns to be kept in hospital until skin grafts are healed. Socioeconomic changes have resulted in an increase in the number of cases of cancer, stroke, head injuries following car accidents, and of diabetes. Of the 2,801 client records, 2,541(60.9%) contained a written referral but for 1,802 it contained only the medical diagnosis. The number of records with a referral requesting specific nursing care was 739(29.1%). Many family members who were identified as in need of nursing care had no written referral. Analysis of the patient problem list showed that 41.9% of the enteries were nursing diagnoses. Others incuded medical diagnosis, symptoms, and plans. The most frequently used diagnoses were alteration in nutrition, less than body requirements(115 entries), alteration in skin integrity(114), knowledge deficit(111), pain(78), self-care deficit(66), and alteration in pattern of urinary elimination(50). These are reflected in the NANDA categories for which the highest number of diagnosis was in the Exchanging pattern(446), followed by Moving(178), Feeling(136) and Knowing (115). Analysis of the frequency of interventions showed that exercise and teaching about exercise was the most frequent intervention, followed by teaching concering the need for follow-up care, checking vital signs, managing nutritional problems, managing catheters, giving emotional support, changing dressings, teaching about medication, teaching (subject not specified), teaching about diet, IM and IV medications or fluid, and skin care, in that order. Recommendations included: development of a record that would allow for efficient recording of frequently used nursing diagnoses and nursing interventions: expansion of the catchment area for Home Care at Wonju Christian Hospital ; expansion of the service to provide complication prevention, rehabilitation services, and support to increase the health maintenance /health promotion of the people being served as well as providing client dentered care ; and development of a clinical record that will allow efficient data collection from records, even though the recording is done by a variety of health care providers.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.47-52
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• 2018

Brain perfusion CT scanning is often employed usefully in clinical conditions as it accurately and promptly provides information about the perfusion state of patients having acute ischemic stroke with a lot of time constraints and allows them to receive proper treatment. Despite those strengths of it, it also has a serious weakness that Lens may be exposed to a lot of dose of radiation in it. In this study, as a way to reduce the dose of radiation to Lens in brain perfusion CT scanning, this researcher conducted an experiment with Bismuth shielding and change of patients' position. TLD (TLD-100) was placed on both lens using the phantom (PBU-50), and then, in total 4 positions, parallel to IOML, parallel to IOML (Bismuth shielding), parallel to SOML, and parallel to SOML (Bismuth shielding), brain perfusion scanning was done 5 times for each position, and dose to Lens were measured. Also, to examine how the picture quality changed in different positions, 4 areas of interest were designated in 4 spots, and then, CT number and noise changes were measured and compared. According to the results of conducting one-way ANOVA on the doses measured, as the significance probability was found to be 0.000, so there was difference found in the doses of radiation to crystalline lenses. According to the results of Duncan's post-hoc test, with the scanning of being parallel to IOML as the reference, the reduction of 89.16% and 89.66% was observed in the scanning of being parallel to SOML and that of being parallel to SOML (Bismuth shielding) respectively, so the doses to Lens reduced significantly. Next, in the scanning of being parallel to IOML (Bismuth shielding), the reduction of 37.12% was found. According to the results, reduction in the doses of radiation was found the most significantly both in the scanning of being parallel to SOML and that of being parallel to SOML (Bismuth shielding). With the limit of the equivalent dose to Lens as the reference, this researcher conducted comparison with the dose to occupational exposure and dose to Public exposure in the scanning of being parallel to IOML and found 39.47% and 394.73% respectively; however in the scanning of being parallel to SOML (Bismuth shielding), considerable reduction was found as 4.08% and 40.8% respectively. According to the results of evaluation on picture quality, every image was found to meet the evaluative standards of phantom scanning in terms of the measurement of CT numbers and noise. In conclusion, it would be the most useful way to reduce the dose of radiation to Lens to use shields in brain perfusion CT scanning and adjust patients' position so that their lens will not be in the field of radiation.