• The Journal of Korean Society for Radiation Therapy
• /
• v.26 no.1
• /
• pp.107-114
• /
• 2014

Purpose : The purpose of this study is evaluation for the applicability of O-MAR(Metal artifact Reduction for Orthopedic Implants)(ver. 3.6.0, Philips, Netherlands) in head & neck radiation treatment planning CT with metal artifact created by dental implant. Materials and Methods : All of the in this study's CT images were scanned by Brilliance Big Bore CT(Philips, Netherlands) at 120kVp, 2mm sliced and Metal artifact reduced by O-MAR. To compare the original and reconstructed CT images worked on RTPS(Eclipse ver 10.0.42, Varian, USA). In order to test the basic performance of the O-MAR, The phantom was made to create metal artifact by dental implant and other phantoms used for without artifact images. To measure a difference of HU in with artifact images and without artifact images, homogeneous phantom and inhomogeneous phantoms were used with cerrobend rods. Each of images were compared a difference of HU in ROIs. And also, 1 case of patient's original CT image applied O-MAR and density corrected CT were evaluated for dose distributions with SNC Patient(Sun Nuclear Co., USA). Results : In cases of head&neck phantom, the difference of dose distibution is appeared 99.8% gamma passing rate(criteria 2 mm / 2%) between original and CT images applied O-MAR. And 98.5% appeared in patient case, among original CT, O-MAR and density corrected CT. The difference of total dose distribution is less than 2% that appeared both phantom and patient case study. Though the dose deviations are little, there are still matters to discuss that the dose deviations are concentrated so locally. In this study, The quality of all images applied O-MAR was improved. Unexpectedly, Increase of max. HU was founded in air cavity of the O-MAR images compare to cavity of the original images and wrong corrections were appeared, too. Conclusion : The result of study assuming restrained case of O-MAR adapted to near skin and low density area, it appeared image distortion and artifact correction simultaneously. In O-MAR CT, air cavity area even turned tissue HU by wrong correction was founded, too. Consequentially, It seems O-MAR algorithm is not perfect to distinguish air cavity and photon starvation artifact. Nevertheless, the differences of HU and dose distribution are not a huge that is not suitable for clinical use. And there are more advantages in clinic for improved quality of CT images and DRRs, precision of contouring OARs or tumors and correcting artifact area. So original and O-MAR CT must be used together in clinic for more accurate treatment plan.

• Journal of radiological science and technology
• /
• v.37 no.4
• /
• pp.239-246
• /
• 2014

Filter absorbs low-energy X-ray to increase the average energy and reduces patient exposure dose. This study investigates if the materials of Mo and W could be used for the digital imaging device CR by conducting image assessment and dose measurement of SNR, FOM and histogram. In addition, measurement of beam quality was conducted depending on the material of the filter, and at the same time, a proper combination of filters was examined depending on the change in tube voltage (kVp). In regard to entrance skin dose, Mo filter showed the dose reduction by 42~56%, compared to Cu filter. Moreover, Mo filter showed higher transmission dose by around 1.5 times than that of Cu filter. In image assessment, it was found that W was unsuitable to be used as a filter, whereas Mo could be used as a filter to reduce dose without decline in image quality at the tube voltage of 80 kVp or higher. As tube voltage increased, 2.0 mm Al+0.1 mm Mo almost had a similar histogram width to that of 2.0 mm Al+0.2 mm Cu. Therefore, Mo filter can be used at relatively high tube voltage of 80 kVp, 100 kVp and 120 kVp. The SNR of 2.0 mm Al+0.1 mm Mo did not show any significant difference from those of 2.0 mm Al+0.2 mm Cu and 2.0 mm Al+0.1 mm Cu. As a result, if Mo filter is used to replace Cu filter in general radiography, where 80 kVp or higher is used for digital radiation image, patient exposure dose can be reduced significantly without decline in image quality, compared to Cu filter. Therefore, it is believed that Mo filter can be applied to chest X-ray and high tube voltage X-ray in actual clinical practice.

• Journal of Korean Traditional Oncology
• /
• v.16 no.1
• /
• pp.55-61
• /
• 2011

Objectives : Epidermal growth factor receptor-inhibitors have demonstrated improved overall survival in patients with non-small cell lung cancer, but their use is associated with dermatologic adverse reactions that often require symptomatic treatment. Methods : A 44-year-old woman, who started the chemotherapy of Iressa$^{(R)}$ on August 2010, developed cutaneous symptoms such as papulopustular rash, dry skin, and pruritus on her face and scalp after taking Iressa$^{(R)}$ for four weeks. The patient visited our clinic with such symptoms on March 2011 and underwent herebal remedy targeted to alleviate the skin reactions. The severity of dermatologic symptoms was evaluated with the numeric rating scale and the Common Terminology Criteria for Adverse Events version 4.0. Results : Noticeable changes on the skin lesion were observed after the two months of treatment, without any dose modification of the Iressa$^{(R)}$. The cutaneous symptoms as papulopustular rash, dry skin and pruritus were improved and there was no adverse event induced by the treatment with herbal medicine. Conclusions : This case report suggests that the treatment with a herbal medicine, Samultang-gagambang be considered as a useful treatment to relieve EGFR-inhibitor induced dermatologic adverse reactions.

• Archives of Plastic Surgery
• /
• v.38 no.2
• /
• pp.207-211
• /
• 2011

Purpose: Surgery for thyroid gland requires skin incisions that can result in postsurgical neck scar. To overcome this, many surgeons performed a endoscopic thyroidectomy. But, this approach had a some problems. One of postoperative problems, iatrogenic cervical dystonia (CD) may occur. At common, CD is defined as a syndrome characterized by prolonged muscle contraction causing twisting, repetitive movements or abnormal posture. Botulinum toxin A (BTA, Botox$^{(R)}$, Allergan, Irvine, CA, USA) is well known treatment agent in the treatment of CD. So, the authors applied BTA injection in rare case with iatrogenic CD resulting in endoscopic thyroidectomy. Methods: A 43-year-old female had endoscopic subtotal thyroidectomy operation 3 years ago. She had symptoms such as progressive cervical pain, abnormal neck posture, depression, and sleep difficulty. About 1 year later, the patient who had previous myomectomy of the clavicular head of sternocleidomastoid muscle, however, symptoms were not improved. And then the patient received BTA therapy in our department. The 2 units per 0.1 mL solution was administered in a 1 mL tuberculin syringe. Results: The dose of BTA used in the patient was 36 units for vertical platysmal bands, superficially, and 10 units for ipsilateral sternocleidomastoid muscle, intramuscularly. After 2 weeks, additional the dose of BTA used in the patient was 5 points for remained scar bands, superficially. Complications related to injection such as significant swallowing difficulties, neck muscle weakness, or sensory change were not observed. In 9 months follow-up, the patient maintained a good result from the method of BTA injection alone. Conclusion: The basic concept is selective denervation for the hyperactive individual muscles and scar bands. We conclude that BTA is an effective and safe treatment for CD despite the iatrogenic and complex presentation of this complication.

• Journal of radiological science and technology
• /
• v.15 no.1
• /
• pp.65-78
• /
• 1992

Routine chest radiography is generally imaged by high voltage technique but some radiological technologists use low voltage for imaging. High voltage is usually said between $120\;kV{\sim}140\;kV$. Some RTs like using heavy filtration but others seldom like using it. However which is better for use calcium tungustate film screen system or ortho system and high contrast film or wide latitude c-type film for the exculusive use of chest radiography. We could not make a decision which is ideal method for use. In my opinion any method is not always exellent for chest radiography. In my experiments that I had at Kaken hospital in Japan last year I expect to keep the balance between image quality and diagnostic range and to reduce radiation dose for patients. My experiments are as follows. 1. We have looked into system characteristics(speed and contrast) in accordance with kVp($80{\sim}140$) and added filter($no{\sim}1/16\;VL$) in three screen film systems(BX3+CRONEX4, SRO750+MGH, SRO750+MGL). 2. We have looked into skin dose and film dose with same D=1.8 lung field density in accordance with kVp($80{\sim}140$) and added filter($no{\sim}1/16\;VL$) in three screen film systems. 3. We have compared with the evaluation between correlation of physical image quality(MTF) and optical diagnostic capability. Result are follows. 1. Speed of BX3+CRONEX4 became higher in accodance with kVp and thickness of filter but speed of ortho system was not as like regular system. Thicker filter diminished the speed over 100 kV range in SRO750+MGL. In case of SRO750+MGH speed of 1/16VL filter was looked into lower than speed of 1/4VL filter. Sensitivity of ortho system depends on tube voltage and added filter. 2. Skin dose has been detected $225\;{\mu}Gy{\sim}66\;{\mu}Gy$ in BX3+CRONEX4 from 80 kV, no filter to 140 kV, 1/16VL filter. SRO750+MGH could reduce the patient dose $1/2{\sim}1/3$ level in comparison to that of BX3+CRONEX4. 3. The higher kV was the worse MTF became the thicker filter was the worse MTF became too. MTF of BX3+CRONEX4 was detected better than MTF of SRO750+MGH but SRO750+MGH's optical detectability of small lesion in lung field came out better than that of BX3+CRONEX4. Conclusion Recently routine chest radiography is generally imaged by high voltage but it seems to be there are some questions in using of film screen combination. In high voltage chest radiography the subject contrast will come down that means latitude become wider. In this case if we select the low contrast film screen system(C or L type) the film contrast will fall down extremly and detectability of small lesion will be deteriorated. Wide latitude C, L type film has a merit of high detectability on mediastinum. Furthermore high contrast film screen system has the advantage to keep the high contrast in low density region as like mediastinum and heart shadow. Therefore in low subject contrast high voltage chest radiography we would rather choose the high contrast film screen system(H type) I think. From a view point of patient dose detectability of mediastinum and lung field. The optimum technical facter was found out 120 kV, 1/16VL filter : BX3+CRONEX4, 140 kV, 1/4VL filter : SRO750+MGH, 100 kV, 1/4VL filter : SRO750+MGL.

• Journal of Chest Surgery
• /
• v.32 no.3
• /
• pp.307-309
• /
• 1999

Warfarin-induced skin necrosis is a rare complication caused by transient hypercoagulable state. This state is a result of rapid decline of the protein C activity relative to that of coagulation factor II, IX, and X during initiation of oral anticoagulant therapy. We experienced a case of warfarin-induced skin necrosis involving both breasts in a patient who underwent double valve replacement 1 month before. Warfarin was replaced to a low- molecular weight heparin and the necrotic breast lesion was healed spontaneously. Low-dose warfarin was restarted and gradually increased, after which a low molecular weight heparin discontinued..

• Journal of the Korean Society of Radiology
• /
• v.13 no.5
• /
• pp.757-763
• /
• 2019

Recently, Following the recent development of flat panel detector with wide dynamic ranges, increasing numbers of healthcare providers have begun to use digital radiography. As a result, filter thickness standards should be reestablished, as current clinical practice requires the use of thicknesses recommended by the National Council on Radiation Protection and Measurements, which are based on information, acquired using conventional analog systems. Here we investigated the possibility of minimizing dose creep and optimizing patient dose using Al filters in digital radiography. The use of thicker Al filters resulted in a maximum 19.3% reduction in the entrance skin exposure dose when medical images with similar sharpness values were compared. However, resolution, which is a critical factor in imaging, had a significant change of 1.01 lp/mm. This change in resolution is thought to be due to the increased amount of scattered rays generated from the object due to the X-ray beam hardening effect. The increase in the number of scattered rays was verified using the scattering degradation factor. However, the FPD, which has recently been developed and is widely used in various areas, has greater response to radiation than analog devices and has a wide dynamic range. Therefore, the FPD is expected to maintain an appropriate level of resolution corresponding to the increase in the scattered-ray content ratio, which depends on filter thickness. Use of the FPD is also expected to minimize dose creep by reducing the exposure dose.

• Journal of the Korean Society of Radiology
• /
• v.17 no.4
• /
• pp.497-506
• /
• 2023

In the case of radiation workers in medical institutions, radiation exposure is made for patient protection and accurate procedures, so they have a problem of low dose exposure. Low-dose radiation exposure occurs mainly in parts of the body other than the Apron area, and the most frequent place is the skin of the back of the hand. In particular, since the medical personnel's hands require senses and fine movements during the procedure, they are defenseless in the radiation exposure area and are at risk of exposure. It can solve the problem of shielding such as lead gloves, and it is difficult to use by suggesting the activity of the hand during the procedure. To solve this problem, a shielding cream capable of obtaining a functional radiation protection effect was developed and its shielding performance was compared with lead equivalent of 0.1 mmPb. In the process of manufacturing shielding cream, the shielding performance was improved by adding a defoaming process to reduce air holes to increase the density of the cream. Therefore, the shielding cream using barium sulfate as the main material has a lower shielding rate than the lead plate, and in the realm of effective energy, it is 59%, At high effective energy, a difference of about 37% was shown, indicating that there is a functional radiation protection effect. The advantage is that it can be used directly on the skin, and it is considered that it can be used before wearing surgical gloves and has a permanent protective effect.

• Clinical and Experimental Pediatrics
• /
• v.52 no.1
• /
• pp.119-123
• /
• 2009

Renal cell carcinoma (RCC) arising from epithelial cells of the renal tubules is a highly aggressive and malignant tumor in all ages; however, it rarely occurs in children. the standard treatment for RCC is radical nephrectomy with lymph node dissection when the tumor is localized and can be completely resected. Adjuvant chemotherapy, radiotherapy, and immunotherapy are used for pediatric patients with advanced RCC involving lymph nodes or metastatic lesions. Sorafenib is an oral, multikinase inhibitor that has recently been approved for use in metastatic RCC. Common toxicities that have been reported include dermatologic changes such as rash or desquamation and hand-foot skin reaction, diarrhea, fatigue, alopecia, and hypertension. In particular, hand-foot syndrome (HFS) an erythematous skin lesion of the palms and solesis most often caused by cytostatic chemotherapeutic agents. In this report, we have studied a 14-year-old female patient with hand-foot syndrome that occurred in association with sorafenib for the treatment of metastatic RCC. Furthermore, this case demonstrates that reversal of complications can be achieved by discontinuing the drug and intervention with topical steroids, vitamin E, and high-dose pyridoxine.

• Journal of radiological science and technology
• /
• v.33 no.4
• /
• pp.327-334
• /
• 2010

Exposure during childhood results in higher risk for certain detrimental cancers than exposure during adulthood. We measured entrance skin dose (ESD) under 7-year children undergoing chest imaging and compared the relationship between ESD and age, height, weight, chest thickness. Though it is important to measure chest thickness for setting up the exposure condition of chest examination, it is difficult to measure chest thickness of children. We set up exposure parameters according to age because chest thickness of children has correlation with age. In the exposure parameters, for chest A-P examination under 2 year-children, tube voltage (kVp) in hospital A was higher than that in hospital B while tube current (mAs) was higher in hospital B, thus the ESD values were about 1.7 times higher in hospital B. However, for chest P-A examination over 4 year-children, the tube voltage was 7 kVp higher in hospital B, the tube current were same in all two systems, and focus to image receptor distance (FID) in hospital B (180 cm) was longer than that in hospital A (130 cm), thus the ESD values were 1.4 times higher in hospital A. For same ages, the ESD values for chest A-P examinations were higher than those for chest P-A examinations. Comparing ESD according to age, ESD values were $154{\mu}Gy$, $194{\mu}Gy$ and $138{\mu}Gy$ for children under 1 year, 1 to under 4 years and 4 to under 7 years of age, respectively. These values were lower than reference level ($200{\mu}Gy$) recommended in JART (japan association of radiological technologists), however these were higher than reference values recommended by EC (european commission), NRPB (national radiological protection board) and NIFDS (national institute of food & drug safety evaluation). In conclusion, the values of ESD were affected by exposure parameters from radiographer's past experience more than x-ray system. ESD values for older children were not always higher than those for younger children. Therefore we need to establish our own DRLs (diagnostic reference levels) according to age of the children in order to optimize pediatric patient protection.