Inclusion Criteria:

* Clinical diagnosis of interstitial lung disease
* Radiologic lung abnormalities on diagnostic CT chest
* Anatomic imaging (clinical diagnostic CT chest) obtained within ≤ 180 days prior to the planned FAPI 46 imaging exam or within 14 days after the imaging exam.
* Willingness and ability to provide informed consent

Exclusion Criteria:

* Pregnant as determined by a pregnancy test as per institutional guidelines for individuals of child-bearing potential
* Declining to use effective contraceptive methods during the study (for individuals of child-producing potential)
* Need for emergent surgery that would be delayed by participation
* Bacterial, viral, or fungal infections requiring systemic therapy
* Serious co-morbidities and serious nonmalignant disease (e.g., hydronephrosis, kidney failure, liver failure, or other conditions) that in the opinion of the investigator, physician of record and/or Sofie could compromise patient safety and/or protocol objectives.
* No available chest CT radiological data
* No clear diagnosis of ILD
* Intolerability to perform the exam due to exuberant dyspnea or severely low pulmonary capacity.
* Breastfeeding. Note: nursing parents are allowed if the potential participant commits to pumping breast milk and discarding it from injection to ≥ 24 hours from the time of the \[68Ga\]FAPI-46 injection.
* Known hypersensitivity to any excipients used in \[68Ga\]FAPI-46