Chapter 8

### INTERPRETATION

The review and interpretation of myocardial perfusion images is the key duty of a nuclear cardiologist. It is critical that image interpretation be performed in a systematic fashion so as to maximize the clinical value of the study and to ensure the highest quality result of the entire procedure. As discussed extensively in Chap. 4, the quality of the study must be reviewed and technical abnormalities be recognized. A comprehensive evaluation of all available imaging data must then be performed so as not to exclude potentially vital information.

A number of guidelines and tools have been recommended for the interpretation of myocardial perfusion studies.14 These policies and guidelines have been developed by experts in the field and should be used as a guide to the successful interpretation of myocardial perfusion imaging (MPI) interpretation. This chapter strives to be consistent with these recommendations. Of note, as single photon emission computed tomography (SPECT) imaging is performed in the vast majority of patients undergoing radionuclide imaging, this chapter focuses on the tomographic evaluation of perfusion and function with SPECT MPI.

The sequence of imaging should include (1) review of the raw planar images, (2) analysis of the tomographic slices, (3) interpretation of gated SPECT data, and (4) incorporation of clinical data (Table 8-1).

Table 8-1Sequence of SPECT Myocardial Image Interpretation

#### Image Display

It is highly recommended that myocardial perfusion images be reviewed on a computer monitor as opposed to x-ray film or paper. While other media may provide useful information, the resolution of a computer monitor screen and the flexibility in adjusting a variety of parameters, including contrast, thresholds, and colors, makes this the medium that is greatly preferred. The practice of interpreting only "hard copy" images is discouraged, especially in view of the dynamic data, which is available by use of a workstation.

The patient's body habitus should be considered when interpreting images, as this information may support the artifactual nature of apparent perfusion defects. Therefore, data regarding height, weight, and gender should be provided to the interpreting physician. Additional details, such as chest and bra size and the presence of a mastectomy or breast prostheses, may also be useful.

A linear color table is recommended for the interpretation of perfusion images. While linear gray scale is preferred and is recommended by many imaging guidelines, other continuous, linear color tables such as hot body/hot iron revised may also be used effectively (Fig. 8-1). A great variety of other color tables are available. It is critical that the interpreter understand the workings of these various color tables. It is usually recommended ...

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

## Subscription Options

### AccessCardiology Full Site: One-Year Subscription

Connect to the full suite of AccessCardiology content and resources including textbooks such as Hurst's the Heart and Cardiology Clinical Questions, a unique library of multimedia, including heart imaging, an integrated drug database, and more.