Publications by authors named "Myongjin Kang"

12 Publications

  • Page 1 of 1

Thrombolysis in Large Diffusion-Weighted Imaging Lesions: Lower Chance but Still a Chance.

J Stroke Cerebrovasc Dis 2018 Jun 3;27(6):1511-1516. Epub 2018 Feb 3.

Cerebrovascular center, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Republic of Korea. Electronic address:

Background: We sought to investigate whether early thrombolytic treatment can result in favorable functional outcome even in patients with large diffusion-weighted imaging (DWI) lesions.

Materials And Methods: We analyzed 566 patients who received intravenous alteplase within 4.5 hours from onset, initially underwent DWI and magnetic resonance angiography, and had acute infarction confined to anterior circulation. DWI lesion volumes were measured semiautomatically. The association between DWI lesion volume and 3-month outcome in patients who achieved early recanalization was assessed. The DWI lesion volume cutoff, which predicts unfavorable outcome despite recanalization, was determined. In patients with large DWI lesions, the distributions of modified Rankin Scale (mRS) score were compared according to the recanalization status.

Results: Four hundred thirty-six patients achieved early recanalization. Among these patients, 283 (65%) patients had a favorable functional outcome (mRS score 0-2). DWI lesion volume (odds ratio [OR], 1.38 per 10 mL; 95% confidence interval [CI], 1.22-1.56) was an independent variable associated with poor outcome, along with hypertension (OR, 1.87; 95% CI, 1.12-3.10), National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.13; 95% CI, 1.08-1.19), and onset-to-needle time (OR, 1.08 per 10 minutes; 95% CI, 1.03-1.13). The DWI lesion of 60 mL or higher highly predicted an unfavorable outcome with a positive predictive value of 95.3%. In patients with a DWI lesion of 60 mL or higher, recanalization had no benefit for an mRS score of 0-2 but was significantly associated with an mRS score of 0-3 (OR, 4.64; 95% CI, 1.08-19.97).

Conclusions: Despite early recanalization, the probability of favorable outcome is low in patients with a DWI lesion of 60 mL or higher. Nevertheless, the benefit of recanalization still persists in large DWI lesions.
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http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2017.12.037DOI Listing
June 2018

Spontaneous Regression of an Intracranial Aneurysm Following Remote Aneurysm Clipping: Evaluation with High-Resolution Vessel Wall MRI.

Cardiovasc Intervent Radiol 2018 Apr 19;41(4):660-663. Epub 2017 Dec 19.

Department of Radiology, Dong-A University Hospital, 3-1Ga, Dongdaeshin-Dong, Busan, 602-715, Republic of Korea.

Spontaneous regression of an unruptured aneurysm is very rare. We present a case of a 64-year-old woman with an unruptured cerebral aneurysm in which spontaneous regression occurred after contralateral clipping. High-resolution magnetic resonance imaging showed that the aneurysm had decreased in size and there was no evidence of thrombus. Level of Evidence Case, Level IV.
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http://dx.doi.org/10.1007/s00270-017-1864-1DOI Listing
April 2018

Safety of coil occlusion of the parent artery for endovascular treatment of anterior communicating artery aneurysm.

Neuroradiol J 2016 Jun 17;29(3):201-7. Epub 2016 Mar 17.

Department of Radiology, Dong-A University Hospital, Republic of Korea.

Many studies lay emphasis on the clinical importance of perforating branches of the anterior communicating artery (ACoA) and report that vascular damage of the perforators from ACoA aneurysm during surgery cause subsequent postoperative amnesia. The purpose of our study was to analyze the safety of parent artery occlusion for ACoA aneurysm coiling based on the anatomical features of the ACoA complex in 13 patients with 13 ACoA aneurysms. All patients underwent coiling of the aneurysm sac and ACoA. Aneurysm characteristics including size, dome-to-neck ratio, anterior/posterior orientation of the aneurysm dome with respect to the axis of the pericallosal artery, location of the aneurysm neck with respect to the A1-A2 segment of the anterior cerebral artery (ACA) or the ACoA, and the presence of hypoplasia/aplasia of A1 segment were assessed. The aneurysm neck was located directly on the ACoA in five aneurysms (38%), whereas eight (62%) had the neck located at the A1-A2 junction. Of the five patients whose aneurysm neck was located in the ACoA, four patients had infarcts in the basal forebrain. Three of the patients complained of amnesia. None of the aneurysms with the neck located at the A1-A2 junction were associated with infarction. There has been little evidence thus far that parent vessel occlusion of ACoA aneurysms is a safe method for the treatment of aneurysms. Patients with the aneurysm neck located at the A1-A2 junction and without A1 aplasia, who were treated with aneurysm sac and ACoA embolism, were potentially safe.
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http://dx.doi.org/10.1177/1971400916639604DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4977924PMC
June 2016

Thrombectomy using a stent retriever with artificially induced vertebral artery vasospasm in a patient with acute basilar artery occlusion: a case report.

Neuroradiol J 2016 Feb 17;29(1):90-2. Epub 2015 Dec 17.

Department of Neurosurgery, Busan-Ulsan Regional Cardio-Cerebrovascular Diseases Center, Republic of Korea.

An acute basilar artery occlusion is not an uncommon cause of stroke. It represents 6-10% of large vessel strokes and has been associated with poor clinical outcomes. Multimodal treatments have been introduced to recanalise a basilar artery occlusion successfully. However, all mechanical thrombectomy devices are not always usable in an emergent situation. We present a case of basilar artery occlusion treated with a stent retriever assisted by a vertebral artery vasospasm. We attempted thrombectomy with a stent retriever several times. However, the captured thrombus was not pulled out and migrated to the distal basilar artery and posterior cerebral artery due to anterograde flow of the vertebral artery. We carefully advanced the catheter into the distal vertebral artery and generated a vasospasm. The vertebral artery vasospasm reduced the forward flow significantly like a balloon-guided catheter. The thrombus was pulled out with the stent.
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http://dx.doi.org/10.1177/1971400915620438DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4978337PMC
February 2016

Liver Function Assessment Using Parenchyma-Specific Contrast-Enhanced Ultrasonography.

Ultrasound Med Biol 2016 Feb 21;42(2):430-7. Epub 2015 Nov 21.

Department of Internal Medicine, Dong-A University College of Medicine, Busan, Republic of Korea.

The aim of this study was to assess hepatic functional reserve by analyzing the hepatic parenchyma enhancement curve of parenchyma-specific contrast-enhanced ultrasonography (CEUS). Fifty-two patients with cirrhosis who underwent CEUS and indocyanine green tests (ICG) because of a focal liver lesion were enrolled. We evaluated the hemodynamic-related parameters of the time-intensity curve and compared these findings with the ICG retention rate at 15 min (ICG R15). The correlation between the time from peak to one half (s) and ICG R15 was statistically significant and was relatively proportional to the ICG R15. A cut-off value of 149 s was determined for the time from peak to one half for abnormal ICG R15 (>14). The sensitivity and specificity were 85.7% and 92.3%, respectively, for the detection of abnormal ICG R15. In conclusion, the time from peak to one half of the time-intensity curve of parenchyma-specific CEUS of the liver can be a useful parameter to predict the hepatic reserve in liver cirrhosis.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2015.08.020DOI Listing
February 2016

Mismatch of delayed perfusion volume between TTP and Tmax map of perfusion MRI.

Clin Imaging 2016 Jan-Feb;40(1):63-7. Epub 2015 Oct 21.

Department of Radiology, Dong-A University Medical Center, 1,3-ga, Dongdaeshin-dong, Seo-gu, Busan 602-715, Korea.

Objective: To look for another set of parameters to predict the change in infarct size in acute stroke patients with a perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch.

Materials And Methods: We reviewed 54 patients who had PWI-DWI mismatch and vascular occlusion on initial MRI and no recanalization of occluded vessel.

Results: Time-to-peak and time-to-max (TTP-Tmax) perfusion mismatch volume was independently significant as a correlate of infarct volume change (P=.004).

Conclusions: The finding of a large TTP-Tmax perfusion delay mismatch volume in patients with acute stroke who have a PWI-DWI mismatch on an initial MRI may predict that the infarct volume will not increase despite persistent vascular occlusion.
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http://dx.doi.org/10.1016/j.clinimag.2015.10.005DOI Listing
August 2016

Pilomyxoid Astrocytoma Occurring in the Third Ventricle.

J Clin Imaging Sci 2015 31;5:41. Epub 2015 Jul 31.

Department of Pathology, Dong-A University Medical Center, Seo-gu, Busan, Korea.

Pilomyxoid astrocytoma (PMA) is a rare central nervous system tumor that has been included in the 2007 World Health Organization Classification of Tumors of the Central Nervous System. Due to its more aggressive behavior, PMA is classified as Grade II neoplasm by the World Health Organization. PMA predominantly affects the hypothalamic/chiasmatic region and occurs in children (mean age of occurrence = 10 months). We report a case of a 24-year-old man who presented with headache, nausea, and vomiting. Brain CT and MRI revealed a mass occupying only the third ventricle. We performed partial resection. Histological findings, including monophasic growth with a myxoid background, and absence of Rosenthal fibers or eosinophilic granular bodies, as well as the strong positivity for glial fibrillary acidic protein were consistent with PMA.
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http://dx.doi.org/10.4103/2156-7514.161853DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541165PMC
August 2015

A case report of sporadic hemiplegic migraine associated cerebral hypoperfusion: comparison of arterial spin labeling and dynamic susceptibility contrast perfusion MR imaging.

Eur J Pediatr 2016 Feb 7;175(2):295-8. Epub 2015 Aug 7.

Department of Radiology, Dong-A University Medical Center, 1,3-ga, Dongdaeshin-dong, Seo-gu, Busan, 602-715, South Korea.

Unlabelled: The pathogenesis of sporadic hemiplegic migraine remains unclear, and perfusion-weighted magnetic resonance imaging (PWI) has been used for characterization of hemodynamic changes in migraine aura. We report a case of sporadic hemiplegic migraine in which magnetic resonance perfusion imaging showed left cerebral hypoperfusion. Dynamic susceptibility contrast (DSC) perfusion maps showed hypoperfusion with posterior predominance in the left cerebral hemisphere. Findings with arterial spin labeling (ASL) perfusion correlated well with DSC perfusion findings.

Conclusion: With unique advantages compared with DSC PWI, ASL has significant potential in the evaluation of the patients with sporadic hemiplegic migraine.

What Is Known: Sporadic hemiplegic migraine is a rare variety of migraine defined by migraine attacks, which include the presence of motor weakness/hemiparesis during the aura phase and where no first- or second-degree relative (parent, sibling, or child) has identical attacks.

What Is New: Reports on imaging abnormalities described in sporadic hemiplegic migraine are sparse. To our knowledge, this is the first report to describe arterial spin labeling (ASL) perfusion abnormalities in patients with sporadic hemiplegic migraine, as compared with dynamic susceptibility contrast perfusion-weighted magnetic resonance imaging (PWI).
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http://dx.doi.org/10.1007/s00431-015-2609-2DOI Listing
February 2016

Comparative Analysis of Endovascular Stroke Therapy Using Urokinase, Penumbra System and Retrievable (Solitare) Stent.

J Korean Neurosurg Soc 2015 May 31;57(5):342-9. Epub 2015 May 31.

Department of Diagnostic Radiology, Busan-Ulsan Regional Cardiocerebrovascular Center, Medical Science Research Center, College of Medicine, Dong-A University, Busan, Korea.

Background: Higher reperfusion rates have been established with endovascular treatment for acute ischemic stroke patients. There are limited data on the comparative performance of mechanical thrombectomy devices. This study aimed to analyse the efficacy and safety of the stent retriever device (Solitaire stent) by comparing procedure time, angiographic outcome, complication rate and long term clinical outcome with previous chemical thrombolysis and mechanical thrombectomy using penumbra system.

Methods: A retrospective single-center analysis was undertaken of all consecutive patients who underwent chemical thrombolysis and mechanical thrombectomy using Penumbra or Solitaire stent retriever from March 2009 to March 2014. Baseline characteristics, rate of successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3), symptomatic intracerebral hemorrhage, procedure time, mortality and independent functional outcomes (mRS ≤2) at 3 month were compared across the three method.

Results: Our cohort included 164 patients, mechanical thrombectomy using stent retriever device had a significant impact on recanalization rate and functional independence at 3 months. In unadjusted analysis mechanical thrombectomy using Solitaire stent retriever showed higher recanalization rate than Penumbra system and chemical thrombolysis (75% vs. 64.2% vs. 49.4%, p=0.03) and higher rate of functional independence at 3 month (53.1% vs. 37.7% vs. 35.4%, p=0.213). In view of the interrelationships between all predictors of variables associated with a good clinical outcome, when the chemical thrombolysis was used as a reference, in multiple logistic regression analysis, the use of Solitaire stent retriever showed higher odds of independent functional outcome [odds ratio (OR) 2.62, 95% confidence interval (CI) 0.96-7.17; p=0.061] in comparison with penumbra system (OR 1.57, 95% CI 0.63-3.90; p=0.331).

Conclusion: Our initial data suggest that mechanical thrombectomy using stent retriever is superior to the mechanical thrombectomy using penumbra system and conventional chemical thrombolysis in achieving higher rates of reperfusion and better outcomes. Randomized clinical trials are needed to establish the actual benefit to specific patient populations.
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http://dx.doi.org/10.3340/jkns.2015.57.5.342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4479715PMC
May 2015

Direct Relationship between Angiographic Characteristics of Carotid Atherosclerotic Plaque and Filling Defect in the Cerebral Protection Filters : Based on the Conventional Angiography.

J Korean Neurosurg Soc 2013 Aug 31;54(2):93-9. Epub 2013 Aug 31.

Department of Neurosurgery, Busan-Ulsan Regional Cardiocerebrovascular Center, Medical Science Research Center, College of Medicine, Dong-A University, Busan, Korea.

Objective: Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS.

Methods: A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS.

Results: Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014).

Conclusion: Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.
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http://dx.doi.org/10.3340/jkns.2013.54.2.93DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3809450PMC
August 2013

Management of aneurysms of the proximal (A1) segment of the anterior cerebral artery.

J Cerebrovasc Endovasc Neurosurg 2013 Mar 31;15(1):13-9. Epub 2013 Mar 31.

Department of Neurosurgery, Busan-Ulsan Regional Cardiocerebrovascular Center, Medical Science Research Center, College of Medicine, Dong-A University, Busan, Korea.

Objective: Aneurysms originating from the proximal segment (A1) of the anterior cerebral artery are rare; however, because of their small size, the risk of injury of perforating arteries, and the location of the aneurysm in the surgical field, they are challenging to treat. We report on 15 patients with A1 aneurysms and review surgical views according to the direction of aneurysms.

Methods: Fifteen patients were diagnosed with A1 aneurysms and underwent surgical clipping or endovascular coiling at our institution between January 2006 and March 2012. We conducted a retrospective review of clinical and radiological features of all patients with A1 aneurysms.

Results: Nine patients underwent surgical clipping, and six patients received endovascular coiling. Six patients (40%) had multiple aneurysms. A1 aneurysms ranged in size from 1.5 to 8.2 mm, with an average size of 3.26 mm. Most A1 aneurysms (73%) had a posterior direction. In the surgical view, A1 aneurysms projecting posteriorly were located behind the A1 trunk. The A1 aneurysm projecting posteroinferiorly was completely eclipsed by the parent artery. In A1 aneurysms with a posterosuperior or superior direction, finding and clipping the aneurysm neck was relatively easy. Thirteen patients (87%) had an excellent outcome, one had moderate disability, and one died.

Conclusion: A1 aneurysms have certain characteristics; small size, multiple aneurysms, and, usually, a posterior direction. A1 aneurysms with a posterosuperior or superior direction are relatively easy to assess, however, clipping of A1 aneurysms with a posterior or posteroinferior direction is more difficult. Endovascular coiling is an alternative therapeutic option when surgical clipping is expected to be difficult.
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http://dx.doi.org/10.7461/jcen.2013.15.1.13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3625815PMC
March 2013

Comparative study of shear wave velocities using acoustic radiation force impulse technology in hepatocellular carcinoma: the extent of radiofrequency ablation.

Gut Liver 2012 Jul 2;6(3):362-7. Epub 2012 May 2.

Department of Radiology, Dong-A Medical Center, Dong-A University College of Medicine, Busan, Korea.

Background/aims: The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for predicting the extent of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) by correlating the elasticity of HCC and peritumoral parenchyma (as measured by ARFI) with the extent of ablation determined by computed tomography (CT).

Methods: From September 2009 to June 2011, 158 patients underwent RFA ablation for HCC (single, ≤3 cm). We evaluated the data of a total of 38 prospectively enrolled patients who underwent both ARFI imaging and contrast-enhanced CT after one session of 12 minutes of RFA without a change in needle position. The ARFI imaging indices, including the mean shear wave velocity (SWV) of HCC, mean SWV of the peritumoral parenchyma and tumor size, were evaluated to determine the statistical correlation with RFA extent after one session of 12 minutes of RFA.

Results: A stiffer liver parenchyma in patients with cirrhosis results in a smaller ablation zone.

Conclusions: SWV of ARFI in liver parenchyma was well correlated with RFA extent. After evaluating the correlation between ARFI and RFA extent, we suggest that the SWV in liver parenchyma might be a non-invasive supplementary tool for predicting the extent of RFA.
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http://dx.doi.org/10.5009/gnl.2012.6.3.362DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404175PMC
July 2012