H A Hassan1, M A Bessar2, I R Herzallah3, A M Laury4, M M Arnaout5, M A A Basha2. 1. Department of Radiodiagnosis, Faculty of Medicine, Zagazig University, Egypt. Electronic address: hananabdelhameed.ml@gmail.com. 2. Department of Radiodiagnosis, Faculty of Medicine, Zagazig University, Egypt. 3. Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Zagazig University, Egypt. 4. Department of Otolaryngology-Head and Neck Surgery, San Antonio Uniformed Services Health Education Consortium, Houston, TX, USA. 5. Department of Neurosurgery, Faculty of Medicine, Zagazig University, Egypt.
Abstract
AIM: To establish the value of early contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in differentiating residual pituitary adenoma from postoperative surgical changes. MATERIALS AND METHODS: Thirty patients with non-functioning pituitary macroadenomas, who were undergoing trans-sphenoidal adenomectomy, were prospectively studied. Patients were imaged with both MRI and DWI in the early postoperative period, as well as 6-months post-surgery. Patterns of postoperative contrast enhancement were described (non-enhancement, peripheral enhancement, and nodular enhancement). Apparent diffusion coefficient (ADC) maps were utilised to select the region of interest (ROI) for ADC calculations. RESULTS: Seventeen patients had postoperative surgical granulation tissue and 13 had residual adenoma based on the 6 months follow-up imaging. Mean ADC values of postoperative granulation tissue and residual adenoma were 1.476±0.476×10-3 mm2/s and 0.855±0.190×10-3 mm2/s, respectively, in the early postoperative period, and 1.357±0.416×10-3 mm2/s and 0.829±0.201×10-3 mm2/s, respectively, at the 6-month follow-up. ADC values of granulation tissue were significantly different from that of residual adenoma at both time points (p<0.001). Sensitivity, specificity, positive and negative predictive values of early MRI were 84.6%, 94.1%, 91.7%, and 88.9% respectively, and of early DWI were 91%, 97%, 94.3%, and 93%, respectively. CONCLUSION: Early postoperative DWI after trans-sphenoidal resection of pituitary macroadenomas may be more helpful than early MRI in differentiating residual adenoma from post-surgical changes.
AIM: To establish the value of early contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in differentiating residual pituitary adenoma from postoperative surgical changes. MATERIALS AND METHODS: Thirty patients with non-functioning pituitary macroadenomas, who were undergoing trans-sphenoidal adenomectomy, were prospectively studied. Patients were imaged with both MRI and DWI in the early postoperative period, as well as 6-months post-surgery. Patterns of postoperative contrast enhancement were described (non-enhancement, peripheral enhancement, and nodular enhancement). Apparent diffusion coefficient (ADC) maps were utilised to select the region of interest (ROI) for ADC calculations. RESULTS: Seventeen patients had postoperative surgical granulation tissue and 13 had residual adenoma based on the 6 months follow-up imaging. Mean ADC values of postoperative granulation tissue and residual adenoma were 1.476±0.476×10-3 mm2/s and 0.855±0.190×10-3 mm2/s, respectively, in the early postoperative period, and 1.357±0.416×10-3 mm2/s and 0.829±0.201×10-3 mm2/s, respectively, at the 6-month follow-up. ADC values of granulation tissue were significantly different from that of residual adenoma at both time points (p<0.001). Sensitivity, specificity, positive and negative predictive values of early MRI were 84.6%, 94.1%, 91.7%, and 88.9% respectively, and of early DWI were 91%, 97%, 94.3%, and 93%, respectively. CONCLUSION: Early postoperative DWI after trans-sphenoidal resection of pituitary macroadenomas may be more helpful than early MRI in differentiating residual adenoma from post-surgical changes.