The study of new reconstruction method for Brain SPECT on dual detector system 사진 속도 느리게,, Hyung Jin Lee

Brain spect procedure(1day protocol) First source acetazolamide Basal acquisition Second source 애니메이션 클릭하면서 설명 TST : 40~45min Diamox acquisition

Brain SPECT Dual detector Short exam time Parallel collimator OSEM 2D Triple detector Short exam time Fan-beam collimator Spatial resolution FBP-Metz filter Optical contrast FLASH 3D Resolution De-noise Contrast 1day protocol Metz filter: resolution recovery=contrast 2번째 사각형 컬러 변화,화살표 색깔 변환,.그물 빼고 Brain SPECT

Equivalent total exam time 1 Equivalent total exam time 2 Setting acquisition parameter 3 Parallel collimator 4 New reconstruction method 5 Reasonable image quality

Hoffman 3D Brain Phantom Specifications - Cylinder inside diameter and height : 20.8 and 17.5 cm 100% bubble을 제거할 필요가 없는것은 머리안에 defect라고 가정하고 동일하게 acquire하였다. - Fillable volume: ~ 1.2 liter Source activity - Basal/Diamox brain SPECT : 99mTc-HMPAO 15 mCi (15/30 mCi) - 99mTc : 0.625 mCi/L (=15mCi*0.05/1.2L, 투여량의 5% 뇌조직에 분포를 가정함)

Experiment for Volunteer 99mTc-HMPAO : 15 mCi Total count 1) Normal scan : 50 Kcounts/view (120 views : 6x106, 128 views : 6.4x106) 2) Short scan : 35 Kcounts/view (60% of Normal scan) (120 views : 4.2x106, 128 views : 4.5x106) Experiment summary *TST : total scan time Date Scanner Collimator cps Scan Time Total Count 08/08 (pm 7:10) ECAM 3 (Normal) LEHR 1.5 32sec TST : 34 min 5,931,948 08/12 (pm 8:00) PRISM Fan-beam (FB) 2.7 20sec TST : 13.3 min 6,079,541 (pm 8:20) (Short) LEAP 2.3 15sec TST : 16 min 4,116,391 08/22 (am 9:30) 1.8 TST : 21.3 min 4,699,939 *Unit : Kcount/sec (cps), sec/view (scan time)

*LEHR : low energy high resolution Add Your Title 256% TST Similar TC PRISM-FB (Normal) 63% TST 79% TC Add Your Title ECAM3-LEHR (Normal) 32 sec/frame (TST=34 min) TC : 5.9×106 (5,931,948) 20 sec/frame (TST=13.3 min) TC : 6.1×106 (6,079,541) Add Your Title ECAM3-LEHR (Short) 20sec/frame (TST=21.3 min) TC : 4.7×106 (4,699,939) 75% TST Similar TC Add Your Title ECAM3-LEAP (Short) 15sec/frame (TST=16 min) TC : 4.1×106 (4,116,391) 변화조건을 더 강조 *TST : total scan time *FB : fan-beam collimator *LEAP : low energy all purpose *TC : total count *LEHR : low energy high resolution

What is FLASH3D? Flash 3D is an iterative reconstruction method for SPECT imaging with three dimensional resolution recovery and scatter correction Benefits: They can be used to shorten SPECT and planar acquisition times, or to improve image quality.

Result Drawing ROI on 6 cold spheres and 4 background regions Contrast To do… Drawing ROI on 6 cold spheres and 4 background regions Contrast 결과 그래프 애니메이션 효과로 삽입

Result Drawing ROI on 4 hot spheres and 3 background regions To do… Drawing ROI on 4 hot spheres and 3 background regions SNR=lesion average divided by background standard deviation Sphere S/R

Result

PRISM3000 vs ECAM (Hoffman 3D Phantom)

Hoffman-3D 비교 PRISM-FB-30sec *FBP-METZ ECAM-LEHR-15sec *FLASH3D-S8I8 **GAUSS-7mm 토탈 검사스캔타임 쓰고 이미지 강조, ECAM-LEHR-25sec *FLASH3D-S8I8 **GAUSS-7mm

Subset8에 iteration 변화 이미지(FLASH3D) Non-filter OSEM2D 이미지 삽입(노말로) Post-filtering Gaussian 5mm

PRISM3000 vs ECAM (Volunteer image)

Why it has to be 20sec! Diamox 1day protocol Tc-99m dosage 15~20sec/frame Tc-99m dosage 기준카운터 즉 50,000카운터 의 65~70% 65~70% raw data

Result e.Cam fbp/osem/flash

Result E.cam/LEAP/15sec/FLASH3D E.cam/LEHR/20sec/FLASH3D 이미지 배경화면 다시,,,택스트 상자 편집 및 글자 색깔 강조 콜리메이터 E.Cam/LEUHR/20sec FLASH3D

Result PRISM/Fan/20SEC/METZ E.cam/LEAP/15sec/FLASH3D E.cam/LEHR/32sec/FLASH3D 8/8/5…마지막 20SEC 영상을 강조하게 테두리 효과 E.camLEHR/20sec/FLASH3D

Conclusion

Thank You !