1.Development of an Automatic 3D Coregistration Technique of Brain PET and MR Images.
Myung Chul LEE ; June Key CHUNG ; Dong Soo LEE ; Cheol Eun KWARK ; Jae Sung LEE ; Kwang Suk PARK
Korean Journal of Nuclear Medicine 1998;32(5):414-424
PURPOSE: Cross-modality coregistration of positron emission tomography (PET) and magnetic resonance imaging (MR) could enhance the clinical information. In this study we propose a refined technique to improve the robustness of registration, and to implement more realistic visualization of the coregistered images. MATERIALS AND METHODS: Using the sinogram of PET emission scan, we extracted the robust head boundary and used boundary-enhanced PET to coregister PET with MR. The pixels having 10% of maximum pixel value were considered as the boundary of sinogram. Boundary pixel values were exchanged with maximum value of sinogram. One hundred eighty boundary points were extracted at intervals of about 2 degree using simple threshold method from each slice of MR images. Best affined transformation between the two point sets was performed using least square fitting which should minimize the sum of Euclidean distance between the point sets. We reduced calculation time using pre-defined distance map. Finally we developed an automatic coregistration program using this boundary detection and surface matching technique. We designed a new weighted normalization technique to display the coregistered PET and MR images simultaneously. RESULTS: Using our newly developed method, robust extraction of head boundary was possible and spatial regishation was successfully performed. Mean displacement error was less than 2.0mm. In visualization of coregistered images using weighted normalization method, structures shown in MR image could be realistically represented. CONCLUSION: Our refined technique could practically enhance the performance of automated three dimensional coregistration.
Brain*
;
Head
;
Magnetic Resonance Imaging
;
Positron-Emission Tomography
2.Quantitative assessment of obstructive uropathy with diuretic renography in children.
Jong Ho KIM ; Dong Soo LEE ; Cheol Eun KWARK ; Kyung Han LEE ; Chang Woon CHOI ; June Key CHUNG ; Myung Chul LEE ; Chang Soon KOH ; Yong CHOI ; Hwang CHOI
Korean Journal of Nuclear Medicine 1993;27(2):239-247
No abstract available.
Child*
;
Humans
;
Radioisotope Renography*
3.A preliminary quantification of Tc-HMPAO brain SPECT images for assessment of volumetric regional cerebral blood flow.
Cheol Eun KWARK ; Seok Gun PARK ; Hyung In YANG ; Chang Woon CHOI ; Kyung Han LEE ; Dong Soo LEE ; Jung Key CHUNG ; Myung Chul LEE ; Chang Soon KOH
Korean Journal of Nuclear Medicine 1993;27(2):170-174
No abstract available.
Brain*
;
Tomography, Emission-Computed, Single-Photon*
4.The Usefulness of F-18 FDG Whole Body PET in the Evaluation of Postoperative Recurrence of Cancer.
Chang Soon KOH ; Myung Chul LEE ; June Key CHUNG ; Dong Soo LEE ; Won Jun KANG ; Jae Min JEONG ; Young SO ; Cheol Eun KWARK ; Soon Beum KANG ; Hee Won JUNG ; Kwang Hyun KIM ; Jae Gahb PARK
Korean Journal of Nuclear Medicine 1997;31(3):372-380
he purpose of this study was to evaluate the usefulness of whole body F-18 FDG PET scan for deceting postoperative recurrence of cancer. One hundred four cancer patients after operation were enrolled(l4 brain tumor, 15 head and neck cancer, 23 gynecologic cancer). Besides conventional images(CI) including CT and MRI, F-18 FDG PET scan was obtained on ECAT EXACT 47 scanner(Siemens-CTI), beginning 60 minutes after injection of 370MBq(10mCi) of F-18 FDG. Regional scan was also obtained with emission image. Transmission images using Ge-68 were carried out for attenuation correction in both whole body and regional images. Findings of PET and CI were confirmed by pathology or clinical follow up. The sensitivity and specificity of PET for detecting recurrence were 94% and 92%, respectively. Contrarily, the sensitivity and specific it of CI were 78% and 68% CI results were negative and PET results were positive in 11 cases. The biopsy or clinical follow-up of those cases confirmed recurrence of tumor. False negative cases of CI were frequent in patients with gynecologic cancers. Also we measured the Serum concentration of tumor markers in patients with gynecologic cancer(CA125), thyroid cancer(thyroglobulin), and colorectal cancer(CEA). The sensitivity and specificity of tumor markers were 71% and 84%, respectively. We conclude that F-18 FDG PET can be used valuably in detecting recurrent foci of a wide variety of malignancy compared to conventional diagnositic methods.
Biopsy
;
Brain Neoplasms
;
Follow-Up Studies
;
Head and Neck Neoplasms
;
Humans
;
Magnetic Resonance Imaging
;
Pathology
;
Positron-Emission Tomography
;
Recurrence*
;
Sensitivity and Specificity
;
Thyroid Gland
;
Biomarkers, Tumor