• Journal of the Korean Orthopaedic Association
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• v.55 no.3
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• pp.229-236
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• 2020

Purpose: This study examined the utility of preliminary magnetic resonance imaging (MRI) measurements in the ultrasound-guided L4 selective nerve root block. Materials and Methods: As a retrospective study, 71 patients, who met the criteria for outpatient visits from March 2016 to December 2017, were included. From March 2016 to February 2017, 31 patients who underwent an L4 nerve root block without MRI were classified as group A, and 40 patients who underwent an L4 nerve root block through MRI measurements from March 2017 to December 2017 were classified as group B. Group A was injected under ultrasound-guidance through the pararadicular approach without a pre-interventional MRI evaluation, and group B was injected under ultrasound-guidance according to the preliminary MRI measurements. The results were assessed using the numeric rating scale scores before, three hours, and two, six, and 12 weeks after the procedure. Results: At three hours after the procedure, the proportion of patients better than good results were 51.6% in group A and 67.5% in group B. At two weeks after the procedure, the proportion of patients with better than good results were 48.4% and 70.0% in groups A and B, respectively; 58.1% and 62.5% of patient of groups A and B, respectively, showed better than good results after six weeks. In 12 weeks after the procedure, the results of group A and B were 67.7% and 62.5%, respectively. At three hours and two weeks after the procedure, group B showed significant symptom improvement than group A (p<0.05). The procedures were repeated 2.8 and 1.7 times in groups A and B, respectively, between two and six weeks for satisfactory pain relief (p<0.05). Conclusion: A pre-interventional MRI evaluation might improve pain relief within the initial two weeks after ultrasound-guided L4 selective nerve root block by improving the success rate of the procedure.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.60-65
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• 1999

Purpose : The purpose of this study was to evaluate the image quality, contrast characteristics, and possible clinical utility of Medium Tau Inversion Recovery(MTIR) sequence with white matter suppression in patients with brain cortical lesion. Materials and methods : Two normal volunteers and twenty-one patients with cortical lesion were scanned with MTIR as well as other MR imaging sequences. Gray-white matter contrast was evaluated objectively using region-of-interest calculations, including percent contrast and contrast-to-noise ratio(CNR). MTIR sequence was visually compared with other sequences in 21 patients with cortical lesion including conspicuity and detection rate. Results : MTIR sequence had the highest present contrast and CNR between the gray matter and white matter. In twenty-one cases of cortical lesion including cortical dysplasia, MTIR sequence improved delineation and conspicuity of lesion, but MTIR sequence could not detect new lesions. Conclusion : The MTIR sequence well delineated the cortical lesions, particularly in including cortical dysplasia. It may be used as an adjunctive imaging sequence in case of poor gray and white matter differentiation with conventional T1-weighted sequences.

• Journal of Digital Contents Society
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• v.12 no.1
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• pp.49-55
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• 2011

Because of causing the geometrical transformation of the magnetic field, the patient implementing the fixation using the nonmagnetic metal screw causes the magnetic susceptibility artifact at an image. Thus, in this research, the distortion measure of the image according to the frequency oblique direction conversion tried to be compared in the magnetic susceptibility artifact occurence. First, the itself phantom inserting the nonmagnetic metal screw of the titanium component was made and the region of interest was set up and the frequency oblique direction the anterior - back side was converted to the right-to-left direction in the axial image and a right-to-left was converted to the upper side - bottom side in the coronal plane and the upper - bottom side was converted to the anterior - back side in the sagittal plane and the distortion measure of the region of interest was compared, it observed. In a result, when converting the frequency oblique direction, the distortion difference of the region of interest could be confirmed and it is considered to enhance the diagnostics efficiency changing the oblique direction appropriately.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.119-124
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• 1997

Purpose: To assess the utility of magnetic resonance(MR) cerebral blood volume (CBV) map in the evaluation of brain tumors. Materials and Methods: We performed perfusion MR imaing preoperatively in the consecutive IS patients with intracranial masses(3 meningiomas, 2 glioblastoma multiformes, 3 low grade gliomas, 1 lymphoma, 1 germinoma, 1 neurocytoma, 1 metastasis, 2 abscesses, 1 radionecrosis). The average age of the patients was 42 years (22yr -68yr), composed of 10 males and S females. All MR images were obtained at l.ST imager(Signa, CE Medical Systems, Milwaukee, Wisconsin). The regional CBV map was obtained on the theoretical basis of susceptibility difference induced by first pass circulation of contrast media. (contrast media: IScc of gadopentate dimeglumine, about 2ml/sec by hand, starting at 10 second after first baseline scan). For each patient, a total of 480 images (6 slices, 80 images/slice in 160 sec) were obtained by using gradient echo(CE) single shot echo-planar image(EPI) sequence (TR 2000ms, TE SOms, flip angle $90^{\circ}$, FOV $240{\times}240mm,{\;}matrix{\;}128{\times}128$, slice-thick/gap S/2.S). After data collection, the raw data were transferred to CE workstation and rCBV maps were generated from the numerical integration of ${\Delta}R2^{*} on a voxel by voxel basis, with home made software (${\Delta}R2^{*}=-ln (S/SO)/TE). For easy visual interpretation, relative RCB color coding with reference to the normal white matter was applied and color rCBV maps were obtained. The findings of perfusion MR image were retrospectively correlated with Cd-enhanced images with focus on the degree and extent of perfusion and contrast enhancement. Results: Two cases of glioblastoma multiforme with rim enhancement on Cd-enhanced Tl weighted image showed increased perfusion in the peripheral rim and decreased perfusion in the central necrosis portion. The low grade gliomas appeared as a low perfusion area with poorly defined margin. In 2 cases of brain abscess, the degree of perfusion was similar to that of the normal white matter in the peripheral enhancing rim and was low in the central portion. All meningiomas showed diffuse homogeneous increased perfusion of moderate or high degree. One each of lymphoma and germinoma showed homogenously decreased perfusion with well defined margin. The central neurocytoma showed multifocal increased perfusion areas of moderate or high degree. A few nodules of the multiple metastasis showed increased perfusion of moderate degree. One radionecrosis revealed multiple foci of increased perfusion within the area of decreased perfusion. Conclusion: The rCBV map appears to correlate well with the perfusion state of brain tumor, and may be helpful in discrimination between low grade and high grade gliomas. The further study is needed to clarify the role of perfusion MR image in the evaluation of brain tumor.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.115-125
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• 2009

Purpose: The purpose of the study is to evaluate the usefulness of CT arthrography (CTA) by conducting a comparative study of CTA and MR arthrography (MRA) with the arthroscopic findings in the same patients. Materials and methods: Forty nine patients who suffered from shoulder disease underwent MRA and CTA concurrently. The sensitivity and specificity of CTA was evaluated, as compared to MRA, in the case of four types of shoulder pathological lesions. The accuracy of CTA was evaluated by analyzing the arthroscopic findings of thirty four patients. Results: Compared to MRA, CTA showed a sensitivity of 90% and a specificity of 100% for diagnosing supraspinatus tendon (SST) full thickness tear, and CTA showed a sensitivity of 100% and a specificity of 97.5% for making the diagnosis of superior labrum anterior to posterior (SLAP) lesion. For diagnosing partial articular side supraspinatus avulsion (PASTA) lesion, some studies have shown the usefulness of CTA with a sensitivity of 71.4% and a specificity of 97.7%. However, for diagnosing SST bursal side partial tear, the sensitivity of CTA was as low as 10%. CTA has been shown to be relatively accurate when the diagnoses were verified with the arthroscopic findings; diagnosing SST full thickness tear and SLAP lesion with CTA has shown an accuracy of 100% and87.5% respectively, and CTA showed 71.4% diagnostic accuracy for PASTA lesion. Conclusion: CTA was a useful tool and it was equivalent to MRA for the assessment of SST full thickness tear, SLAP lesion and PASTA lesion, but not bursal side partial tear. Thus, it may be used preferably to diagnose shoulder pathology and for follow up as an inexpensive tool after operation.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.421-426
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• 2018

Unlike the traditional Radiological examinations, Magnetic Resonance Imaging (MRI) does not cause any harm and high levels of Radiation to the human body. Furthermore, MRI is widely used owing to its ability to adapt to different situations. However, the MRI equipment creates noises from its mechanical parts, and its magnetic bore structure can cause anxiety and claustrophobia in patients. To relieve claustrophobia, commercial refraction glasses were provided to the participants in this study, and the changes in anxiety and claustrophobia were measured. The participants were 30 volunteers with claustrophobia. To measure anxiety, the participants were asked to answer a Visual Analogue Scale (VAS) questionnaire. The physical markers of discomfort included perspiration on the forehead or hands (46.7%), mild frowning (30.3%), and leg shaking (40.1%). The subjective markers of discomfort included dizziness (2.85% in the men and 1.75% in the women). Although fear and anxiety levels were observed to be higher in the men, the difference was not significant. Hence, it was determined that both men and women felt discomfort (p >0.5). The fear coefficient was observed to decrease from 7.67 prior to wearing refraction glasses to 2.42 after wearing refraction glasses (p<0.000). In addition, use of refraction glass decreased MRI aversion from 1.97 to 1.03 (p<0.000). It can be inferred that refraction glasses are beneficial to patients undergoing MRI.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.577-582
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• 2016

This study is aimed to prove that a solid sialogogue can improve the defects of the liquid one and substitute it with no differences in the signal intensity. From January to August 2016, 60 patients with no salivary gland diseases were enrolled. The patients were divided into two groups as follows; a group with a liquid sialogogue and the other group with a solid sialogogue. MR images were acquired and signal intensities of the parotid glands were compared. As a result, the signal intensities of liquid and solid sialogogues showed no statistically significant differences($59.42{\pm}15.74$ and $61.80{\pm}13.99$, respectively) In conclusion, a solid sialogogue was verified to have no signal intensity differences from the liquid one while it could improve the defects of the liquid sialogogue.

• Investigative Magnetic Resonance Imaging
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• v.18 no.4
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• pp.332-340
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• 2014

Purpose : A relative increase in deoxyhemoglobin levels in hypoperfused tissue can cause prominent hypointense signals in the draining veins (PHSV) within areas of impaired perfusion in susceptibility-weighted imaging (SWI). The purpose of this study is to evaluate the usefulness of SWI in patients with acute cerebral infarction by evaluating PHSV within areas of impaired perfusion and to investigate the usefulness of PHSV in predicting prognosis of cerebral infarction. Materials and Methods: In 18 patients with acute cerebral infarction who underwent brain MRI with diffusion-weighted imaging and SWI and follow-up brain MRI or CT, we reviewed the presence and location of the PHSV within and adjacent to areas of cerebral infarction qualitatively and measured the signal intensity difference ratio of PHSVs to contralateral normal appearing cortical veins quantitatively on SWI. The relationship between the presence of the PHSV and the change in the extent of infarction in follow-up images was analyzed. Results: Of the 18 patients, 10 patients showed progression of the infarction, and 8 patients showed little change on follow- up imaging. On SWI, of the 10 patients with progression 9 patients showed peripheral PHSV and the newly developed infarctions corresponded well to area with peripheral PHSV on initial SWI. Only one patient without peripheral PHSV showed progression of the infarct. The patients with infarction progression revealed significantly higher presence of peripheral PHSV (p=0.0001) and higher mean signal intensity difference ratio (p=0.006) comparing to the patients with little change. Conclusion: SWI can demonstrate a peripheral PHSV as a marker of penumbra and with this finding we can predict the prognosis of acute infarction. The signal intensity difference of PHSV to brain tissue on SWI can be used in predicting prognosis of acute cerebral infarction.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.140-146
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• 2012

Purpose: The objective of this study was to assess the clinical outcome of arthroscopic release of the extensor carpi radialis brevis (ECRB) tendon in chronic recalcitrant lateral epicondylitis and tried to determine any prognostic factors. Materials and Methods: A retrospective review of 24 patients with lateral epicondylitis treated by arthroscopic ECRB release was performed. Outcome measures included a patient self rating and visual analog scale (VAS). Functional evaluation was made with Quick-disabilities of the arm, shoulder and hand (DASH) score system to identify preoperative factors that might be associated with the outcomes. Results: Twenty one (88%) elbows received benefit from the procedure. A mean preoperative VAS pain score and the mean Quick-DASH were significantly improved at final follow up. Age, sex, dominant arm and duration of symptom, presence of capsular tear or calcification did not correlate significantly with the clinical outcome. Three of four patients without T2-weighted high signal focus of the ECRB origin on preoperative magnetic resonance imaging (MRI) showed higher Quick-DASH score. Conclusion: Arthroscopic release of the ECRB is an effective option for chronic recalcitrant lateral epicondylitis. Lack of high signal focus on preoperative MRI is significantly associated with a poor surgical outcome and a considerable factor for the proper surgical indication.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1205-1210
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• 2008

Purpose : The development of the corpus callosum occupies the entire period of cerebral formation. The myelination pattern on magnetic resonance imaging (MRI) is very useful to evaluate neurologic development and to predict neurologic outcome in high risk infants. The thickness of the corpus callosum is believed to depend on the myelination process. It is possible to calculate the length and thickness of the corpus callosum on MRI. Thus, we can quantitatively evaluate the development of the corpus callosum. We investigated the clinical significance of measuring various portions of the corpus callosum in neonate with neurologic disorders such as hypoxic brain damage and seizure disorder. Methods : Forty-two neonates were evaluated by brain MRI. We measured the size of the genu, body, transitional zone, splenium, and length of the corpus callosum. Each measurement was divided by the total length of the corpus callosum to obtain its corrected size. The ratio of corpus callosal length and the anteroposterior diameter of the brain was also measured. Results : There was no statistical significance in the sample size of each part of the corpus callosum. However, the corrected size or the ratio of body of the corpus callosum correlated with periventricular leukomalacia and hypoxic ischemic encephalopathy. Conclusion : The abnormal size of the corpus callosum showed a good correlation with periventricular leukomalacia and hypoxic ischemic encephalopathy in neonates. We can predict clinical neurological problems by estimation of the corpus callosum in the neonatal period.