RESUMEN
INTRODUCTION: We report on the use of CT in the study of bowed stringed instruments to assess structural defects and/or damage before proceeding to any repair. MATERIAL AND METHODS: Two antique masterpieces from the Castello Sforzesco Museum of Antique Musical Instruments were analyzed with CT. They were an exquisite wood and ivory guitar from Naples (Italy) and a very rare Giuseppe Guarneri "del Gesù" violin from Cremona (Italy), both crafted in the early years of the 18th century. We evaluated the wood thickness, the neck and its heel. In the wood structure we studied the course and thickness of hypo- and hyperdense lines. RESULTS: The examination showed three types of signs: normal wood structure: hypodense, thin, parallel lines; wormholes: hypodense lines with irregular course and variable thickness; previous repair signs: thin or thick more or less parallel hyperdense lines. CONCLUSIONS: The study confirmed that CT is a valuable tool to investigate normal structure, defects and damage, providing accurate information for the evaluation and repair of antique stringed instruments.