Nuclear Medicine - image subtraction

Dual isotope digital image subtraction method for better image enhancement : 

Dual isotope digital image subtraction method for better image enhancement . Murali. Nucl Med Dept, Auckland city hospital

Patient History : 

Patient History A 55 years old patient referred for 111In- Octreotide study with multiple liver nodules and ectopic ACTH production causing Cushings syndrome. The objective is to check for primary and the possibility of more extensive disease

Intravenous injection of In-111 Octreotide 111 MBqWhole body Images was acquired at 4 hrs and 24 hrs post injection. Speed 6 cm/minPlanar images 256 Matrix. Acq time: 10 Mins. Collimator: MEGP, using 111-In window 171 Kev,245 Kev : 

Intravenous injection of In-111 Octreotide 111 MBqWhole body Images was acquired at 4 hrs and 24 hrs post injection. Speed 6 cm/minPlanar images 256 Matrix. Acq time: 10 Mins. Collimator: MEGP, using 111-In window 171 Kev,245 Kev Imaging Procedure

Slide 4: 

At 4hrs At 24hrs Whole body images

Planar picture of the abdomen at 24 hours : 

Planar picture of the abdomen at 24 hours

The 4 and the 24 hrs planar and whole body images show good tracer accumulation in the suspected sites of the liver. At 4hrs less intestinal activity was seen in comparison with the 24hrs images.No obvious focus is detected elsewhere. Normal uptake seen in the spleen, kidneys, and bladder accumulation. : 

The 4 and the 24 hrs planar and whole body images show good tracer accumulation in the suspected sites of the liver. At 4hrs less intestinal activity was seen in comparison with the 24hrs images.No obvious focus is detected elsewhere. Normal uptake seen in the spleen, kidneys, and bladder accumulation.

Planned to do digital subtraction study : 

Planned to do digital subtraction study 99mTechnetium tin colloid 150 MBq was injected intravenously Acquired a planar picture of the abdomen Imaging parameters - Same as 111-In study Matrix256.Acq time:10 Mins. Collimator: MEGP using 99mTc window 140Kev

99mTc Hepatate image : 

99mTc Hepatate image ANT POST

Image processing : 

Image processing Normalisation is a concept in nuclear medicine, which implies that a measurement has been brought to a standard. For instance, two images with different maximum counts may have their intensities normalised if the image with the lowest maximum count is multiplied so that the maximum counts match the second image.(NM Technology and Techniques.Normalisation Page-103)

Slide 10: 

87 K 148 K X 1.7 148K Normalisation of the 111In-octreotide image

Slide 11: 

ANT POST Pre & Post Normalisation

Slide 12: 

99mTc-Hepatate Normalised 111In-Octreotide Ant view Subtracted image

Slide 13: 

Post view Normalised 111In-Octreotide 99mTc-Hepatate Subtracted image

Slide 14: 

Subtraction images shows better contrast of the tumour. Surrounding tissue around the tumour is removed Subtracted images illustrates the role of Normalisation Improved the localisation of the tumour focus Conclusion

THANKYOU : 

THANKYOU