What is attenuation correction?
Attenuation correction is a mechanism that removes soft tissue artifacts from SPECT images. Attenuation artifacts vary among patients, but the most common corrections are to artifacts associated with breast attenuation in women and diaphragmatic attenuation in men.
What is attenuation correction in PET MRI?
MR-based attenuation correction (AC) approaches consist of distinguishing the regions with different attenuation properties, assigning the correct linear attenuation coefficients to them and utilising the resultant attenuation map to correct the PET emission data during reconstruction.
What is attenuation correction in PET CT?
CT-based attenuation correction PET image data scanned with PET-CT scanners is attenuation corrected using data from CT (computed tomography). Although CT-based attenuation correction is generally reliable, patient movement and remains of CT contrast media may cause quantitative errors and image artefacts.
How does attenuation correction influence SPECT?
Attenuation correction increases the diagnostic accuracy of myocardial perfusion SPECT and is thus recommended for clinical use (1). It has, however, also added methodologic complexity and new aspects of quality control. SPECT/CT systems are increasingly successful and more widely applied.
Why are attenuation corrections important in clinical SPECT scans?
Attenuation-corrected SPECT images have demonstrated the ability to better detect areas of viable myocardium, correlate better with positron emission tomography imaging, and provide improved prediction of functional recovery after revascularization.
Why is attenuation important?
The importance of attenuation Attenuation is important in telecommunications and ultrasound applications because it’s critical to determining signal strength as a function of distance.
What are the methods of attenuation in PET imaging?
Atlas and direct imaging based methods are two major categories of MR based PET/MR attenuation correction (AC). Atlas based methods are accurate and robustness in brain PET AC.; however, atlas based approach cannot account for inter-subject variations and is time consuming.
Which of following is used for attenuation correction on PET CT scanners?
In stand alone PET systems, the most widely used attenuation correction technique is radionuclide transmission scanning before (pre-injection), during (simultaneous) or after (post-injection) emission scan .
Which of the following rotating transmission sources can be used to perform the attenuation correction in PET scanning?
Until the advent of PET/CT scanners, attenuation correction was performed most often with a source of coincident 511-keV γ-rays (e.g., 68Ge) that rotated around the patient.
What is the most common method for producing attenuation corrected images in nuclear medicine?
The primary mechanism for attenuation in tissue throughout the diagnostic energy range in conventional nuclear medicine is Compton scattering, which results in changes in photon directions of travel with loss of energy.
What is research attenuation?
Attenuation is a statistical concept that refers to underestimating the correlation between two different measures because of measurement error. Because no test or other measurement of any construct has perfect reliability, the validity of the scores between predictor and criterion will decrease.