Publications by authors named "Sunseob Choi"

14 Publications

  • Page 1 of 1

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/2156-7514.161853DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541165PMC
August 2015

Primary breast leiomyosarcoma located in the premammary zone: a case report.

Clin Imaging 2015 Nov-Dec;39(6):1105-7. Epub 2015 Jul 17.

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

We present the case of 51-year-old woman with a primary breast leiomyosarcoma. On the postoperative screening after breast cancer surgery, a 4-mm-sized mass assessed as BI-RADS category 3 was detected on her contralateral breast. We recommended follow-up and observation. However, the lesion increased in size and became palpable. It was excised and diagnosed as primary leiomyosarcoma. We review the literature on imaging findings and management of breast leiomyosarcoma, and discuss the differential diagnoses in breast imaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clinimag.2015.06.014DOI Listing
June 2016

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).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00431-015-2609-2DOI Listing
February 2016

CT-based assessment of renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones.

Abdom Imaging 2015 Oct;40(7):2446-52

Department of Radiology, Dong-A University College of Medicine, Dongdaesin-dong 3(sam)ga, Seo-gu, Busan, 602-715, South Korea.

Purpose: The purpose of our study was to evaluate computed tomography (CT) imaging factors related to renal function impairment in patients with acute unilateral ureteral obstruction by urinary stones.

Materials And Methods: The study included 94 patients who had acute unilateral ureteral obstruction due to a urinary stone and a normal contralateral kidney. We retrospectively investigated the serum creatinine (SCr) levels immediately prior to CT examination and at least 1 week after treatment. CT examinations were performed using a CT urography protocol, including pre- and post-contrast images. The 67 patients with a SCr change of less than 0.3 mg/dL constituted group A. The other 27 patients with a SCr decrease of more than 0.3 mg/dL constituted group B. To evaluate factors related to renal function impairment, differences in CT imaging factors between the two groups, including the cortical and medullary density, renal and pelvic anteroposterior diameter, and perinephric fluid, were statistically analyzed.

Results: The SCr immediately prior to CT examination significantly differed between the two groups. The follow-up SCr after resolution did not significantly differ between the two groups. The difference in the mean cortical and medullary HU on the nephrographic phase between the obstructed kidney and normal kidney was higher in group B than in group A (27.1 ± 23.1 and 69.4 ± 59.1 vs. 5.7 ± 8.8 and 31.8 ± 34.8; p < 0.001 and p = 0.004, respectively). The cut-off point for the difference in the mean cortical HU on the nephrographic phase between the obstructed kidney and normal kidney for renal function impairment was 15 HU, as determined by a receiver operating characteristic curve analysis.

Conclusions: Patients with significantly impaired renal function due to an acute unilateral ureteral obstruction may show a decreased nephrogram of the affected kidney and a significant difference in the HU on the nephrographic phase between the obstructed and normal kidney.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00261-015-0417-9DOI Listing
October 2015

Intra-articular fibroma of tendon sheath in a knee joint associated with iliotibial band friction syndrome.

Korean J Radiol 2015 Jan-Feb;16(1):169-74. Epub 2015 Jan 9.

Department of Orthopedics, Dong-A University Medical Center, Busan 602-715, Korea.

Iliotibial band (ITB) friction syndrome is a common overuse injury typically seen in the active athlete population. A nodular lesion on the inner side of the ITB as an etiology or an accompanying lesion from friction syndrome has been rarely reported. A 45-year-old male presented with recurrent pain and a movable nodule at the lateral joint area, diagnosed as ITB friction syndrome. The nodule was confirmed as a rare intra-articular fibroma of the tendon sheath (FTS) on the basis of histopathologic findings. We describe the MRI findings, arthroscopic and pathologic features, in this case of intra-articular FTS presenting with ITB friction syndrome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2015.16.1.169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4296266PMC
June 2015

Diffusion tensor imaging and T2 mapping in early denervated skeletal muscle in rats.

J Magn Reson Imaging 2015 Sep 11;42(3):617-23. Epub 2014 Dec 11.

Department of Microbiology, Medical Science Research Institute, College of Medicine, Dong-A University, Busan, Korea.

Background: To evaluate the temporal changes of diffusion tensor imaging (DTI) indices, T2 values, and visual signal intensity on various fat suppression techniques in the early state of denervated skeletal muscle in a rat model.

Methods: Institutional Animal Care and Use Committee approval was obtained. Sciatic nerves of eight rats were transected for irreversible neurotmesis model. We examined normal lower leg and denervated muscles at 3 days, 1 week, and 2 weeks on a 3 Tesla MR. fractional anisotropy (FA), mean apparent diffusion coefficient (mADC), and T2 values were measured by using DTI and T2 mapping scan. We subjectively classified the signal intensity change on various fat suppression images into the following three grades: negative, suspicious, and definite change. Wilcoxon-sign rank test and Kruskal-Wallis test were used for the comparison of FA, mADC, T2 values. McNemar's test was used for comparing signal intensity change among fat suppression techniques.

Results: FA values of denervated muscles at 3 days (0.35 ± 0.06), 1 week (0.29 ± 0.04), and 2 weeks (0.34 ± 0.05) were significantly (P < 0.05) lower than that in the control group (0.54 ± 0.17). mADC of denervated muscles decreased without statistically significant (P > 0.05) change. T2 values were significantly increased at 1 week (38.11 ± 6.42 ms, P = 0.017) and markedly increased at 2 weeks (46.53 ± 5.17 ms, P = 0.012). The grade of visual signal intensity change on chemical shift selective fat saturation, STIR and IDEAL images were identical in all cases (P = 1.000).

Conclusion: FA and T2 values can demonstrate the early temporal changes in denervated rat skeletal muscle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.24818DOI Listing
September 2015

Oculomotor nerve schwannoma: a case report.

Brain Tumor Res Treat 2014 Apr 29;2(1):43-7. Epub 2014 Apr 29.

Brain Tumor Institute Medical Science Research Center, College of Medicine, Dong-A University, Busan, Korea. ; Department of Neurosurgery, College of Medicine, Dong-A University, Busan, Korea.

Schwannomas account for about 8% of intracranial tumors and 90% are vestibular schwannomas. Oculomotor schwannoma without neurofibromatosis is extremely rare. A 41-year-old female presented with complaints of blurred vision, and the neurologic examination revealed afferent pupillary defect and decreased visual acuity of the left side. Brain magnetic resonance image showed an extra axial mass in the left superior orbital fissure. The patient underwent major surgery via the fronto-temporal approach. The tumor originated from the oculomotor nerve and was subtotally removed under microscopic surgery. The pathological findings confirmed the tumor as a schwannoma. After surgery, ptosis and medial gaze limitation of the left eye was detected, but the symptoms improved gradually.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14791/btrt.2014.2.1.43DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049556PMC
April 2014

Application of 31P MR spectroscopy to the brain tumors.

Korean J Radiol 2013 May-Jun;14(3):477-86. Epub 2013 May 2.

Department of Radiology, College of Medicine, Dong-A University, Busan 602-715, Korea.

Objective: To evaluate the clinical feasibility and obtain useful parameters of (31)P magnetic resonance spectroscopy (MRS) study for making the differential diagnosis of brain tumors.

Materials And Methods: Twenty-eight patients with brain tumorous lesions (22 cases of brain tumor and 6 cases of abscess) and 11 normal volunteers were included. The patients were classified into the astrocytoma group, lymphoma group, metastasis group and the abscess group. We obtained the intracellular pH and the metabolite ratios of phosphomonoesters/phosophodiesters (PME/PDE), PME/inorganic phosphate (Pi), PDE/Pi, PME/adenosine triphosphate (ATP), PDE/ATP, PME/phosphocreatine (PCr), PDE/PCr, PCr/ATP, PCr/Pi, and ATP/Pi, and evaluated the statistical significances.

Results: The brain tumors had a tendency of alkalization (pH = 7.28 ± 0.27, p = 0.090), especially the pH of the lymphoma was significantly increased (pH = 7.45 ± 0.32, p = 0.013). The brain tumor group showed increased PME/PDE ratio compared with that in the normal control group (p = 0.012). The ratios of PME/PDE, PDE/Pi, PME/PCr and PDE/PCr showed statistically significant differences between each brain lesion groups (p < 0.05). The astrocytoma showed an increased PME/PDE and PME/PCr ratio. The ratios of PDE/Pi, PME/PCr, and PDE/PCr in lymphoma group were lower than those in the control group and astrocytoma group. The metastasis group showed an increased PME/PDE ratio, compared with that in the normal control group.

Conclusion: We have obtained the clinically applicable (31)P MRS, and the pH, PME/PDE, PDE/Pi, PME/PCr, and PDE/PCr ratios are helpful for differentiating among the different types of brain tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2013.14.3.477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3655304PMC
April 2014

Triple rule-out acute chest pain evaluation using a 320-row-detector volume CT: a comparison of the wide-volume and helical modes.

Int J Cardiovasc Imaging 2012 Jun 23;28 Suppl 1:7-13. Epub 2012 May 23.

Department of Radiology, Dong-A University College of Medicine, 1, 3-ga Dongdaesin-dong, Seo-gu, Busan 602-715, Republic of Korea.

The purpose of this study was to investigate the image quality and radiation dose of triple rule-out computed tomography (TROCT) using a 320-row-detector volume CT system to compare the wide-volume and helical modes of this CT system. Sixty-four patients with noncritical chest pain were allocated to one of 2 groups according to the type of CT examination mode used. Group 1 patients were examined using the wide-volume (non-spiral) mode and group 2 patients were examined using the 160-detector row helical mode, with the same contrast injection protocol in both methods [biphasic injection protocol; injection rate of 4 ml/s, median volume, 70 ml (range 65-100 ml)]. Attenuations of the pulmonary trunk, ascending aorta, and coronary arteries were measured in Hounsfield units; a subjective overall patient-based image quality score of 1-3 was awarded to each study. Effective doses, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Average effective dose was significantly lower in group 1 than group 2 (9.7 ± 5.1 vs. 16 ± 5.9 mSv, P < 0.001). The mean attenuation of the main pulmonary trunk was significantly higher in group 1 than group 2 (P = 0.04) and mean attenuations in other vessels were not significant different. SNR and CNR were not significantly different between the groups. The proportion of diagnostic image qualities for chest CT angiography (CTA) was similar between the groups (93.5 vs. 93.9 %). In coronary CTA, group 1 showed a higher proportion of diagnostic image qualities than group 2 (100 vs. 87.9 %). The use of wide-volume mode of 320-detector CT reduces the overall effective radiation dose and results in similar attenuation and image quality for TROCT as compared with the helical mode.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10554-012-0072-yDOI Listing
June 2012

Aneurysmal bone cyst of the orbit : a case report with literature review.

J Korean Neurosurg Soc 2012 Feb 29;51(2):113-6. Epub 2012 Feb 29.

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

Aneurysmal bone cyst (ABC) is benign vascular lesion destructing the cortical bone by the expansion of the vascular channel in the diploic space that usually involve long bone and spine. Orbital ABC is rare and the clinical symptoms deteriorate rapidly after initial slow-progression period for a few months. A 12-year-old female patient visited ophthalmologist due to proptosis and upward gaze limitation of the right eye, and orbital mass was noted in the upper part of right eye on orbital MRI. Five months later, exophthalmos was worsened rapidly with other features of ophthalmoplegia. Orbital mass was enlarged on MRI with intracranial extension. Surgery was done through frontal craniotomy and intracranial portion of the tumor was removed. Destructed orbital roof and mass in the orbit was also removed, and surrounding bone which was suspected to have lesion was resected as much as possible. Histopathological diagnosis was aneurysmal bone cyst. Postoperative course was satisfactory and the patient's eye symptoms improved. Authors report a rare case of orbital ABC with review of the literature. Exact diagnosis by imaging studies is important and it is recommended to perform surgical resection before rapid-progressing period and to resect the mass completely to prevent recurrence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3340/jkns.2012.51.2.113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3322208PMC
February 2012

Radiofrequency ablation treatment for renal cell carcinoma: early clinical experience.

Korean J Radiol 2008 Jul-Aug;9(4):340-7

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

Objective: To evaluate the early clinical experience associated with radiofrequency (RF) ablation in patients with renal cell carcinoma (RCC).

Materials And Methods: The RF ablation treatment was performed on 17 tumors from 16 patients (mean age, 60.5 years; range, 43-73 years) with RCC. The treatment indications were localized, solid renal mass, comorbidities, high operation risk, and refusal to perform surgery. All tumors were treated by a percutaneous CT (n = 10), followed by an US-guided (n = 2), laparoscopy-assisted US (n = 2), and an open (n = 2) RF ablation. Furthermore, patients underwent a follow-up CT at one day, one week, one month, three and six months, and then every six months from the onset of treatment. We evaluated the technical success, technical effectiveness, ablation zone, benign periablation enhancement, irregular peripheral enhancement, and complications.

Results: All 17 exophytic tumors (mean size, 2.2 cm; range, 1.1-5.0 cm) were completely ablated. Technical success and effectiveness was achieved in all cases and the mean follow-up period was 23.8 months (range, 17-33 months). A local recurrence was not detected in any of the cases; however, five patients developed complications as a result of treatment, including hematuria (n = 2), mild thermal injury of the psoas muscle (n = 1), mild hydronephrosis (n = 1), and fistula formation (n = 1).

Conclusion: The RF ablation is an alternative treatment for exophytic RCCs and represents a promising treatment for some patients with small RCCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2008.9.4.340DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627268PMC
January 2009

Metaplastic breast carcinoma with extensive osseous differentiation: a case report.

Breast 2008 Jun 26;17(3):314-6. Epub 2007 Nov 26.

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

We present a case of a 77-year-old female who had a metaplastic breast carcinoma with extensive osseous differentiation. Her mammogram showed a largely calcified mass, but the pathology revealed that the calcification was ossification. The radiologic differentiation between an osteoid matrix and a dense calcification is discussed. Radiologic and pathologic correlation is also provided.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.breast.2007.09.006DOI Listing
June 2008

Perfusion imaging of the brain using Z-score and dynamic images obtained by subtracting images from before and after contrast injection.

Korean J Radiol 2004 Jul-Sep;5(3):143-8

Department of Diagnostic Radiology, Dong-A University College of Medicine, Seo-gu, Busan, Korea.

Objective: The aim of this study was to examine the feasibility of perfusion imaging of the brain using the Z-score and subtraction dynamic images obtained from susceptibility contrast MR images.

Materials And Methods: Five patients, each with a normal MRI, Moya-moya, a middle cerebral artery occlusion, post-trauma syndrome, and a metastatic brain tumor, were selected for a presentation. A susceptibility-contrast echo-planar image after a routine MRI was taken as the source image with a rapid manual injection of 0.1 mmol/kg of Gd-DTPA. The inflow and washout patterns were observed from the time-signal intensity curve of the serial scans using the standard program of an MRI machine. The repeated Z-score images of the peak and late phases were made using the threshold Z-score values between 1.4 and 2.0 in four to five studies of the pre-contrast, peak, and late phases. Dynamic subtraction images were produced by subtracting sequential post-contrast images from a pre-contrast image and coloring these images using a pseudocolor mapping method.

Results: In the diseases with perfusion abnormalities, the Z-score images revealed information about the degree of perfusion during the peak and late phases. However, the quality varied with the Z-score threshold and the studies selected in a group. The dynamic subtraction images were of sufficient quality with no background noise and more clearly illustrated the temporal changes in perfusion and delayed perfusion.

Conclusion: The Z-scores and dynamic subtraction images illustrated the degree of perfusion and sequential changes in the pattern of perfusion, respectively. These images can be used as a new complimentary method for observing the perfusion patterns in brain diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2698155PMC
http://dx.doi.org/10.3348/kjr.2004.5.3.143DOI Listing
February 2005