Comparison between Gd-DTPA-enhanced MRI and USPIO-enhanced MRI in diagnosing benign and metastatic cervical lymph nodes in rabbit models / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the diagnostic value of gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA)-enhanced MRI with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI in differentiating reactive hyperplastic lymph nodes from metastatic lymph nodes in rabbit models.</p><p><b>METHODS</b>Reactive hyperplastic cervical lymph node model was established in 18 rabbits as hyperplasia group, and tumor-bearing lymph node model was established in another 18 rabbits as tumor group. For Gd-DTPA-enhanced MRI, T1WI and T2WI were performed on 9 animals of each model, and T1WI was acquired 80 seconds after administration of Gd-DTPA. For USPIO-enhanced MRI, T1WI, T2WI and T2*WI were performed on another 9 animals of each model before and 24 hours after administration of USPIO. MRI images were analyzed and correlated with surgical specimens and pathological results.</p><p><b>RESULTS</b>In the tumor group, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Gd-DTPA-enhanced MRI were 62.5%, 91.3%, 88.2%, 70.0% and 76.6%, respectively. The corresponding values of USPIO-enhanced MRI were 95.0%, 90.9%, 90.5%, 95.2% and 92.9%, respectively. The sensitivity and accuracy of USPIO-enhanced MRI differ significantly from those of Gd-DTPA-enhanced MRI. In the hyperplasia group, the accuracy of Gd-DTPA-enhanced MRI was 74.2%, while 87.1% for USPIO-enhanced MRI.</p><p><b>CONCLUSION</b>USPIO-enhanced MRI has higher accuracy in diagnosing metastatic lymph nodes than Gd-DTPA-enhanced MRI.</p>

Technique of radiologic measurements for the inner ear structures using computed tomography / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>The aim of this study was to find an accurate and feasible measurement technique for the inner ear structures using computed tomography and to check the inter-observer agreement</p><p><b>METHODS</b>Sixty patients without abnormal structure of temporal bones confirmed by means of high-resolution computed tomography were included in this study. The multi-planar reformations (MPR) were performed to show the maximum profile of cochlear, and to measure the height and width of cochlear. Areas of bony island encircled by three semicircular canals were measured on the MPR images that could show the whole canal. The data measured by two readers independently was compared to check the inter-observer agreement.</p><p><b>RESULTS</b>The application of MPR yielded satisfactory anatomic presentation of inner ear for radiologic measurements. There was good inter-observer agreement revealed by the paired t-test and correlation analysis (P>0.05, r>0.9). The height of cochlear (x+/-s) was (4.26+/-0.28) mm while the width of cochlear was (7.03+/-0.39) mm. The areas of bony islands encircled by the anterior, posterior and lateral semicircular canals were (25.49+/-3.84) mm2, (20.07+/-2.93) mm2 and (11.50+/-1.94) mm2, respectively.</p><p><b>CONCLUSIONS</b>MPR can display structures of cochlear and semicircular canals on planes along their central axis. Normative measurements on these MPR images derive excellent repeatability and provide reliable morphologic parameters of inner ear structures.</p>