| Objective: To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) semi-quantitative and quantitative in the diagnosis of pituitary microadenomas and differential diagnosis of different types of secreting microadenomas.Methods: collected clinical follow-up period, biochemical or pathological examination and other means of diagnosis of 76 cases of pituitary microadenoma in our hospital from June 2013 to February 2015,which including 38 cases of prolactinoma, 17 cases of ACTH adenoma, 21 cases of GH adenoma.and collected 20 cases of pituitary gland which related clinical symptoms, laboratory tests and imaging showed normal as a control group.these cases underwent routine and dynamic contrast-enhanced scan, then the images were analyzed, and the time- signal intensity curve is divided into three types. The semi-quantitative parameters which including time to peak(TTP), The maximum rise slope(Slope max) and the maximum enhancement ratio(CERmax) and quantitative parameters of volume transfer constant(Ktrans), exchange rate constant(Kep) and extravascular extracellular volume fraction(Ve) were measured in normal pituitary gland and microadenomas.independent samples t test was used to comparing normal pituitary and pituitary microadenomas,ANVOA and LSD method were used to comparing different types microadenomas.at the same time the ROC curve were drawn, the area under the curve were compared, analyzed the optimal diagnosis of pituitary adenoma detection threshold of the parameters and calculate sensitivity and specificity.Results:1, the number in three types T-SI curves of normal pituitary were 15,5,0, and in microadenomas were 2,48,26; most curve of normal pituitary was typeⅠ,and most of microadenomas was typeⅡand typeⅢ. 2, the TTP, Slope max and CER max of normal pituitary were 49.80 ± 16.98 s,3.49 ± 1.14,163.45 ± 31.88, and pituitary adenoma were 81.66 ± 21.86 s,2.04 ± 1.86,136.94 ± 38.37. TTP values in microadenomas was higher than in normal pituitary, and the difference was statistically significant(t values was 6.05,P<0.05). Slope max and CER max values in microadenomas was lower in normal pituitary respectively, and the difference was statistically significant(t values were 6.30、2.84,P<0.05). the area under the ROC were 0.877,0.850,0.695 during the three parameters. When the TTP = 58 s was the best diagnostic point, the sensitivity and specificity were 84%, 75%; when the Slope max = 2.65 was the best diagnostic point, the sensitivity and specificity were 85%, 89 %; when the CER max = 154.6% for the best diagnostic point, the sensitivity. 3, the Ktrans, Kep and Ve in normal pituitary were(0.902 ± 0.238) / min,(1.208 ± 0.599) / min,(0.928 ± 0.378); in microadenoma was(0.472 ± 0.292) / min,(0.765 ± 0.359) / min,(0.792 ± 0.345). Ktrans and Kep values in microadenomas were lower than normal pituitary, and the difference was statistically significant(t values were 6.07、3.16,P<0.05), Ve value was no significant difference between the two groups(t value was 1.55,P>0.05). comparison in different Secreting types of micro adenomas shows, Ktrans value was highest in GH adenomas, prolactinomas followed, ACTH adenomas was lowest. between GH adenoma and prolactinomas,between GH adenoma and ACTH adenomas were have statistically significant differences(P<0.05)Respectively. but between prolactinomas and ACTH adenomas was no significant difference. Kep values was highest in GH adenomas, ACTH adenomas followed, prolactinomas was lowest. between GH adenomas and prolactinomas, between GH adenomas and ACTH adenomas were statistically significant(P<0.05), but betweenACTH adenomas and prolactinomas showed no statistically significant(P>0.05). Ve value was no significant difference among the three groups(P>0.05). ROC analysis showed that, in the detection of adenoma, the area under the ROC in Ktrans and Kep were 0.884, 0.728 respectively.when Ktrans = 0.614 was the best diagnostic point, the sensitivity and specificity were 95%, 82% respectively; when the Kep = 0.985 was the best diagnostic point, sensitivity and specificity were 60% and 80%.Conclusion:1, According to the image and the different types of T-SI curve can diagnosis of pituitary microadenoma, typeⅡand typeⅢ curve can help to diagnose pituitary adenoma.2, Semi-quantitative parameters TTP and Slope max have higher value to diagnose pituitary microadenomas, and Slope max have higher Diagnostic efficacy. And relatively objective description of the physiological characteristics of pituitary microadenomas. 3, Quantitative parameters Ktrans and Kep can further diagnose pituitary microadenoma. compared to semi-quantitative parameters, Ktrans have highest diagnostic sensitivity. And importantly, Ktrans and Kep were able to identify different secreting types of pituitary microadenoma. |
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