• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.8
• /
• pp.3572-3578
• /
• 2011

In Positron Emission Tomography Computed Tomography, Standardized Uptake Value(SUV)is most generally used to discern tumors. However, SUV may be influenced other factors. In this study, experiment was conducted distrotion in image and change in SUV according to substance with GEMINI TF PET/CT of Philips.. SUV for materials resulted in 1.8 for stainless, 1.4 for stent, 2.4 for iodine contrast medium, 2.6 for Barium Sulfate, 1.6 for Gypsum, and 1.4 for paraffin respectively. The distortion of image was remarkable for the iodine contrast medium and Barium Sulfate. For the barium sulfate, the higher the density, the larger the distrotion of the images. As a result of test, it appeared that the metallic substance whose atomic number is low and contrast medium whose concentration is low didn't affect the distortion in image and the change in SUV. However, it tis necessary to minimize distortion in image and change in SUV, by removing the metallic substance and checking if there are contrast mdeium or before examination.

• The monthly packaging world
• /
• s.174
• /
• pp.74-77
• /
• 2007

• Journal of the Korean Society of Radiology
• /
• v.12 no.5
• /
• pp.693-698
• /
• 2018

Currently, shields for shielding medical radiation during medical examinations in the medical environment are lead robe and lead glass. Lead, the main component of this shielding, has limitations in lead poisoning and light weight, and high price. Iodine, which is used as contrast medium instead of lead shield, is expected to be effective as a shield because it has radiation absorbing properties. The purpose of this study was to evaluate the effectiveness of shielding by using acrylic plate filled with CT contrast agent for clinical use instead of conventional lead glass. As a result, it was found that the acrylic plate filled with the CT contrast agent showed a shielding effect of 7 times or more when the scattering ray dose was not shielded. Therefore, CT contrast agent composed of iodine is expected to be used as a shield instead of conventional lead glass.

• Journal of the Korean Society of Radiology
• /
• v.15 no.1
• /
• pp.29-35
• /
• 2021

The purpose of this study was to investigate whether there is a difference in image quality before and after reducing the amount of contrast medium in cerebral hemorrhagic patients who periodically follow up CT, and after reducing the amount of contrast medium, the image before and after reduction was examined, and the image quality was assessed by setting ROI at each vessel location using MMWP program. First Rt. CCA, Lt.CCA. Rt.MCA, Lt.MCA and Basilar Artery each got an ROI. Second, the mean and standard deviation values for the ROI were obtained. Third, SNR and CNR were obtained through the average and standard deviation values obtained. T-test statistics show that the SNR and CNR values obtained show that the result values for SNR are Rt.CCA 0.765, Ltd.CCA 0.871, Rt.MCA 0.343 LT.MCA 0.235, Basilar alternative 0.916, result value for CNR Rt.CCA 0.088, Ltd.CCA 0.069, Rt.MCA 0.818, Let's...MCA 0.579 and Basilar Artery 0.878. The results obtained through the obtained SNR and CNR values showed no difference in the quality of the images before and after reducing contrast medium. Therefore, we hope that this study will be an indicator that reduces the burden on contrast agents on patients who do CT examinations periodically.

• Journal of the Korean Society of Radiology
• /
• v.14 no.5
• /
• pp.603-612
• /
• 2020

This study has a purpose to look into the effect of the relationship between the Tube current (mA) and SOD(Source to Object Distance), which is a parameter of lower limb angiography examination, and the dilution rate of the contrast medium concentration (300, 320, 350) on the image. To that end, using 3 mm vessel model water phantom, a vessel model custom made in the size of peripheral vessel diameter, this study measured relationships between change of parameters, such as tube current (mA), SOD and varying concentrations (300, 320, 350) of contrast medium dilution into SNR and CNR values while analyzing the coefficients of variance(cv<10). The software used to measure SNR and CNR values was Image J 1.50i from NIH (National Institutes of Health, USA). MPV (mean pixel value) and SD (standard deviation) were used after verifying numerically the image signal for region of interest (ROI) and background on phantom from the DICOM (digital imaging and communications in medicine) 3.0 file transmitted to PACS. As to contrast medium dilution by the change of tube current, when 146 mA and 102 mA were compared, For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 22.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 12.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As a result, set a low tube current value in other tests or procedures including peripheral angiography of the lower extremities in the intervention, and make the table as close as possible to the image receiver, and adjust the contrast agent concentration (300) to CM: N/S dilution (30%: 70%). ) Is suggested as the most efficient way to obtain images with an appropriate concentration while simultaneously reducing the burden on the kidney and the burden on exposure.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.5 no.1
• /
• pp.9-14
• /
• 2012

Purpose: The purpose of the study was to evaluate the accuracy and clinical outcome of ultrasound-guided glenohumeral joint steroid injection on adhesive capsulitis. Materials and Methods: Patients who were diagnosed as adhesive capsulitis by MRI and physical examination and did not improve their symptom with physical therapy and NSAIDS treatment more than 6 months were included in the study. Patients who showed any other shoulder pathology or history if trauma were excluded from the study. 33 patients including 15 males and 18 females were enrolled in the study, the average age being 55.1 (age 42~72). Cocktail of steroid, lidocaine, saline and contrast medium injected inside shoulder glenohumeral joint using novel approach (which we called acromioclavicular approach) under ultrasound guidance. Clinical outcome was measured through passive range of motion and VAS scoring system. Results: Based on radiographic findings, cases were classified according to the leakage of contrast medium; perfect confinement of contrast-medium inside the capsule, partial leakage of the medium and contrast-medium found at outside the joint. Total 25 cases (76%) out of 33 cases showed perfect confinement of contrast-medium inside the glenohumeral joint. Partial leakage was observed in 6 cases (18%), and contrast medium was observed outside of the glenohumeral joint in 2 cases (6%). Perfect-confinement group showed $111^{\circ}$($80{\sim}140^{\circ}$) of forward flexion and $48^{\circ}$($0{\sim}90^{\circ}$) of external rotation before injection, and improved to $134^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($30{\sim}90^{\circ}$) of external rotation after injection (p<0.01). Partial leakage showed $120^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($10{\sim}90^{\circ}$) of external rotation before injection, and improved to $139^{\circ}$($135{\sim}140^{\circ}$) of forward flexion and $78^{\circ}$($50{\sim}90^{\circ}$) of external rotation after injection (p<0.01). VAS score improved from 7.1 (score 3~9) to 2.6 (score 0~5) (p<0.01) in perfect confinement group, from 7.5 (score 7~9) to 3.3 (score 2~4) (p<0.01) in partial leakage group. Two group showed no significant difference. Conclusion: Accuracy of Acromioclavicular approach was 94% which is better than any other methods published so far. Partial leakage of the injection material did not show inferior result compared to perfect injection.

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

• The Korean Journal of Pain
• /
• v.34 no.3
• /
• pp.339-345
• /
• 2021

Background: Ultrasound-guided caudal epidural injection (CEI) is limited in that it cannot confirm drug distribution at the target site without fluoroscopy. We hypothesized that visualization of solution flow through the inter-laminar space of the lumbosacral spine using color Doppler ultrasound alone would allow for confirmation of drug distribution. Therefore, we aimed to prospectively evaluate the usefulness of this method by comparing the color Doppler image in the paramedian sagittal oblique view of the lumbosacral spine (LS-PSOV) with the distribution of the contrast medium observed during fluoroscopy. Methods: Sixty-five patients received a 10-mL CEI of solution containing contrast medium under ultrasound guidance. During injection, flow was observed in the LSPSOV using color Doppler ultrasonography, following which it was confirmed using fluoroscopy. The presence of contrast image at L5-S1 on fluoroscopy was defined as "successful CEI." We then calculated prediction accuracy for successful CEI using color Doppler ultrasonography in the LS-PSOV. We also investigated the correlation between the distribution levels measured via color Doppler and fluoroscopy. Results: Prediction accuracy with color Doppler ultrasonography was 96.9%. The sensitivity, specificity, positive predictive value, and negative predictive value were 96.7%, 100%, 100%, and 60.0%, respectively. In 52 of 65 patients (80%), the highest level at which contrast image was observed was the same for both color Doppler ultrasonography and fluoroscopy. Conclusions: Our findings demonstrate that color Doppler ultrasonography in the LS-PSOV is a new method for determining whether a drug solution reaches the lumbosacral region (i.e., the main target level) without the need for fluoroscopy.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.3
• /
• pp.639-644
• /
• 2010

Amphiphilic porphyrin derivatives have been synthesized and characterized by $^1H$ NMR and MALDI-TOF-MS. All porphyrin derivatives showed very high solubility to aqueous medium as well as hydrophobic organic solvent. The UV-vis absorption of the porphyrin derivatives showed significant broadness and decrease of maximum intensity of absorption in aqueous solution. SEM experiment showed the formation of spherical micellar structure. The $T_1$ relaxation time of aqueous medium was drastically decreased in the presence of Mn(III)-porphyrin derivative, indicating that the supramolecular micelle has strong possibility to use as a $T_1$ contrast agent.

• Journal of Veterinary Clinics
• /
• v.35 no.6
• /
• pp.299-301
• /
• 2018

A 7-year-old intact female Shih-Tzu with chylothorax was presented. Percutaneous popliteal computed tomographic lymphangiography was performed to evaluate the thoracic duct and seek any potential cause of chylothorax. Despite two attempts, visualization of the thoracic duct failed and perianal subcutaneous computed tomographic lymphangiography with injection of iodinated, nonionic water-soluble contrast medium (0.6 ml/kg) was performed. A single branch of intact thoracic duct and dilated and tortuous lymphatics were detected. It was diagnosed as idiopathic chylothorax. Perianal subcutaneous lymphangiography is considered a less-invasive, easy and reliable method to visualize lymphatics in patients with chylothorax.