CT Scan (Computed Tomography)
An imaging technique using X-rays to create detailed cross-sectional images of the body. CT scans are used to diagnose conditions treated by peptide drugs, including neuroendocrine tumours, pituitary adenomas, and assessment of visceral adipose tissue for metabolic studies.
Technical Context
CT acquires cross-sectional X-ray images reconstructed by computer into detailed 2D/3D images. Quantitative CT (QCT) can measure volumetric BMD (mg/cm³) at the spine — distinguishing cortical from trabecular bone (more sensitive to metabolic bone disease than DEXA areal BMD). CT is used diagnostically in peptide drug contexts for: pituitary imaging (detecting adenomas in acromegaly/Cushing's — though MRI is preferred for pituitary), abdominal visceral fat quantification (research standard for metabolic studies — measuring VAT area at L4-L5 in cm²), NET staging (detecting liver metastases, lymphadenopathy), and bone fracture assessment. CT-guided procedures: stereotactic pituitary biopsy, and CT-guided brachytherapy for certain cancers. Limitation: ionising radiation (effective dose 2-20 mSv depending on study) restricts use in serial monitoring, particularly in children and young adults.