PET CT (positron emission tomography-computed tomography scan)

A PET-CT (Positron Emission Tomography-Computed Tomography) scan is a powerful imaging tool that combines two technologies: PET, which detects metabolic activity in the body, and CT, which provides detailed anatomical images. This combination allows for more accurate diagnosis and staging of diseases, particularly in oncology, by highlighting areas of abnormal metabolic activity alongside precise anatomical structures. PET-CT is widely used in detecting cancers, assessing treatment response, and planning surgeries or radiation therapy.

1. RADIOLOGY IN THE NUTSHELL TOPIC – PET CT LECTURE BY – NABANITA DAS

2. PET CT stands for Positron Emission Tomography Computed Tomography It is a medical imaging technique using a device combines in a single gantry system both PET and CT It gives high accuracy than PET and CT alone PET CT is the combination of functional and anatomical imaging. Note: It will decrease radiation dose and cost effective. INTRODUCTION @radiology_in_thenutshell

3. PET CT DISCOVERY @radiology_in_thenutshell The first PET-CT system constructed by David Townsend(at the University of Geneva) and Ronald Nutt (at CPS Innovations in Knoxville, TN) with help from colleagues. The combinations of PET and CT scanners was first suggested by R. Raylman in his 1991 Ph.D. thesis.

4. PET stands for Positron Emission Tomography. A nuclear medical imaging technique which uses a small amount of radioactive compound (tracers) to help in the diagnosis of disease. CT stands for Computed Tomography. It gives cross sectional image and accurate diagnostic information about the distribution of structure inside the body. PeT vs CT

5. Pet CT

6. PET has incomparable abilities to determine metabolic activities of tissue but need the assistance of higher resolution, anatomical information that it can’t provide CT gives high quality anatomical imaging and highest resoultion tomographic modality to integrate into PET imaging. The combination of two offers the best of both works in an integrated data set thus improve diagnostic accuracy and localization of many lesion. Why using PET CT

7. The combination of anatomic and functional images is often called FUSION The term FUSION in this field often refers to the visualization of two distinct images on the same display and is probably better denoted as MERGED Fusion imaging

8. TRANSMISSION IMAGING EMISSION IMAGING FUSION IMAGING

9. Fusion imaging

10.  Consists of three main components CT SCANNER PET SCANNER A COAXIAL BED     Design of PET CT

11. The CT scan is in the first part of the scanner The function and capability of the scanner are similar to those of the stand-alone CT system The only difference is that the gantry of the CT scanner has no tilt capability. Main application was to supplement the functional information from PET with the intrinsically associated anatomy as imaged by CT Ct component of pet ct

12. The PET scan is in the second part of the scanner PET subsystems offer detector rings completely surrounding the patient. The individual detector elements are composed of scintillation crystals connected to photomultiplier tubes Pet component of pet ct

13. A single common table is for both the scanner 60-70 cm distance between the two machine PET/CT scanners feature a port diameter of 70 cm & axial length of 100 cm, the larger aperture also increases patient comfort A shared console for viewing the fused image  Coaxial table

14. Cross section of pet ct

15. Patient preparation

16. The typical dose of FDG is 10 mCi injected intravenously Imaging is initiated approximately 60 minutes following the injection The patient lie supine on the couch with arms above or side of the body A whole-body PET study (neck through pelvis) follows an enhanced whole-body CT study CT scan takes 60 – 70 sec PET scan takes 30 – 45 min depend on the study of FDG procedure

17. At first the  CT scanner takes a topogram The topogram used to outline the region of the body to be scanned The CT generates 100s of trans axial image through the body  The blue-purple rectangle represents CT coverage during the study, and each overlapping green rectangle represents PET coverage Now the table moves to the PET scanner part of the machine which began the detecting the radiation emitted from patients performing the emission part The patient is stepped through the scanner images a swath of about 14-15 cm through the patient, and generates about 30-40 contiguous trans axial image contd

18. The enormous data is generated from the scan 100s of trans axial PET & CT images are firstly reconstructed  The image is often reformatted into coronal and saggital images Finally a fusion image of PET and CT combines and image is generated Image generation

19. Flow chart of typical pet ct operation

20. THANK YOU @radiology_in_thenutshell @radiology_in_thenutshell