Thank you so much for your explanation, it really helped my understanding of the issue.
QUOTE: "There is a large area of mildly decreased activity in the inferior wall that is fixed, when compared with rest images and has normal wall motion. This is most likely due to soft tissues attenuation"
Soft tissue attenuation is one of the more common causes of an imaging artifact. The heart is surrounded by tissues of varying densities (eg, bone, lungs, and breast). Unpredictable artifacts may arise when the body build , physique, differs significantly from expected gender-specific patterns. Nonuniform photon are due to intervening structures attenuation and the resultant artifacts are affected by several factors, including:
Body size, depth of the heart in the body, and gender.
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Your husband did very well with the stress test and no chest pain (angina) is evidence there is no ischemia. The EF is in the normal range (normal is 50 to 75%) and reflects the amount of blood pumped into circulation with each heartbeat. I see no cause for concern regarding your husband's heart functionality based on the report.