Ultrasound real-time imaging in the differential diagnosis of periapical lesions

To assess whether the use of real-time ultrasound imaging (echography), together with the application of 'Colour Power Doppler', can help the differential diagnosis of periapical lesions based on their contents.

Eleven patients diagnosed with periapical lesions using conventional clinical and radiographic findings and who had been scheduled for endodontic surgery were examined using ultrasound imaging and Colour Power Doppler at the site of the lesions. Lesions were described in each case by an expert echographist, together with an endodontist, according to a scheme described previously. Information on the size of each lesion, its content and its vascular supply was gained and recorded by means of the ultrasound images; then, a tentative differential diagnosis between a cyst and a granuloma was made. The lesions obtained during endodontic surgery were processed and examined with a light microscope. The results from the biopsies were compared with the descriptions made with the ultrasound images.

The differential diagnoses between periapical granulomas and cystic lesions, which were based on the echograpic findings, were confirmed by the results of the histopathologic examination in all the 11 cases: four being granulomas and seven being cystic lesions.

Ultrasound real-time imaging is a technique that may help make a differential diagnosis between cysts and granulomas by revealing the nature of the content of a bony lesion. This technique may have further applications in the study of other lesions of the jaws.