Contrast-Enhanced Perfusion MR Imaging to Differentiate Between Recurrent/Residual Brain Neoplasms and Radiation Necrosis

Purpose: To determine the value of dynamic susceptibility contrast enhanced (DSC) MRI (magnetic resonance imaging) perfusion in the characterization of newly developed/enlarging lesions within irradiated regions after treatment of brain tumors. Methods: This prospective cross-sectional study covered 23 patients, 12 females and 11 males. All cases initially presented with histologically proven malignant brain tumors and underwent surgical intervention followed by radiotherapy (+/- chemotherapy). On follow up imaging, they presented with newly developed/progressively enhancing mass lesions at the sites of the primary tumors. All patients then underwent conventional MRI, DSC MRI perfusion and MR spectroscopy. Results: In our study, we found DSC MR perfusion to be a useful non-invasive method for differentiating recurrent brain tumors from radiation necrosis. This approach allows hemodynamic measurements to be obtained within the brain as the relative cerebral blood volume (rCBV) to complement the anatomic information obtained with conventional contrast enhanced MR imaging. The sensitivity and specificity of DSC MR perfusion for differentiation were found to be 77.8% and 80.0%, respectively. Conclusion: DSC MR perfusion is a promising technique in differentiating recurrent brain tumors from radiation necrosis as it has acceptable spatial resolution and can be routinely performed in the same settings after conventional MRI.

Evaluation of an integrated orbital tissue expander in congenital anophthalmos: report of preliminary clinical experience.

PURPOSE: To evaluate the effectiveness of an orbital tissue expander designed to stimulate orbital bone growth in an anophthalmic socket. DESIGN: Retrospective, noncomparative, interventional case series. SETTINGS: Institutional. STUDY POPULATION: Nine consecutive patients with unilateral congenital anophthalmos. INTERVENTION: The orbital tissue expander is made of an inflatable silicone globe sliding on a titanium T-plate secured to the lateral orbital rim with screws. The globe is inflated by a transconjunctival injection of normal saline through a 30-gauge needle to a final volume of approximately 5 cm(3). Computed tomography scans were used to determine the orbital volume. The data studied were: demographics, prior orbital expansion procedures, secondary interventions, orbital symmetry, and implant-related complications. MAIN OUTCOME MEASURES: The primary outcome measure was the orbital volume change, and the secondary outcome measures were changes in forehead, brow, and zygomatic eminence contour and adverse events. RESULTS: The average patient age at implantation was 41.89 ± 39.42 months (range, 9 to 108 months). The initial average volume of inflation was 3.00 ± 0.87 cm(3) (range, 2.0 to 4.0 cm(3)), and the average final volume of 4.33 ± 0.50 cm(3) (range, 4.0 to 5.0 cm(3)) was achieved. The duration of expansion was 18.89 ± 8.80 months (range, 4 to 26 months). All patients demonstrated an average increase in the orbital tissue expander implanted orbital volume of 5.112 ± 2.173 cm(3) (range, 2.81 to 10.38 cm(3)). The average difference between the volume of the implanted and the initial contralateral orbit was 5.68 ± 2.34 cm(3), which decreased to 2.53 ± 1.80 cm(3) at the final measurement (P < .001, paired t test). All implants remained inflated except for 2 iatrogenic punctures at the second inflation and 1 that was the result of implant failure. All were replaced. CONCLUSIONS: The integrated orbital tissue expander is safe and effective in stimulating anophthalmic socket bone growth.