During SPECT MPI, there are a myriad of reasons for “hot” and “cold” artifactual and potentially misleading imaging findings related to the chest wall (Table 7.1). Troubleshooting of “hot” and “cold” findings should be undertaken in conjunction with the performing technologist. “Hot” artifacts may be related to contamination on the patient (Fig. 7.1). If the patient’s arms are positioned along the chest wall and within the field-of-view, extravasation at the injection site will produce a characteristic focal “hot” region that might create scatter artifact (Fig. 7.2) (Hendel et al. 1999). Nearby radioactive sources emitting photons from another patient or a prepared syringe may be registered on the gamma camera detector during MPI (Fig. 7.3). On review of the raw projection data, blood, injectate, or urine contamination should be superficial, not deep (Hendel et al. 1999). If skin or clothing contamination is suspected, the technologist should ask the patient to wash and change clothing, and the patient should be re-imaged (Gentili et al. 1994; Williams et al. 2003). Analogously, the gamma camera detectors should be routinely checked for contamination and cleaned as necessary before use (Burrell and MacDonald 2006; Chamarthy and Travin 2010; Gedik et al. 2007). Mal-administration of the radiopharmaceutical inadvertently using an arterial instead of a venous access can produce an unusual muscular biodistribution (Afzelius and Henriksen 2008). Radiopharmaceutical-avid brown adipose tissue (BAT) may be present in the supraclavicular regions of the anterior chest wall or in a posterior paraspinal location (Goetze et al. 2008).