Multi-slice helical CT perfusion imaging in evaluating intracranial neoplasms and tumor-like lesions / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the clinical value of CT perfusion in diagnosing and assessing intracranial neoplasms and tumor-like lesions.</p><p><b>METHODS</b>16-slice helical CT perfusion imaging was performed in 56 patients who were clinically suspected to have intracranial neoplasm or tumor-like lesion. With a GE-Light Speed 16-slice helical CT scanner, routine plain-CT scanning was performed to localize the central slice of the lesion. Perfusion imaging was then carried out using cine scan technique to maintain a slice thickness of 5-10 mm, a total dose of 50-70 ml of contrast-medium at an injection flow rate of 3-5 ml/s, a delay time of 7 s and a total scan time of 50 s. The images were processed using perfusion software in an ADW 4.0 workstation, meanwhile, time-density curves (TDC) of different kinds of lesions were also produced and analyzed.</p><p><b>RESULTS</b>The pathological types in this series included: 29 gliomas (12 low-grade and 17 high-grade), 2 ependemomas, 2 hemangioblastomas, 1 medulloblastoma, 2 metastatic tumors, 1 lymphoma, 5 meningiomas, 2 schwannomas, 1 germinoma, 1 teratoma in the pineal region, 6 cavernous hemangiomas, 2 inflammatory granulomas, 1 tuberculoma, and 1 hyperplasia of the choroid plexus. TDC of high-grade glioma, low-grade glioma and meningioma was different from each other. The cerebral blood flow (CBF), cerebral blood volume (CBV), particularly, the permeability surface (PS) value of glioma was found to increase significantly with the escalation of tumor differentiation grade. In PS map, margin of the tumor could be clearly showed, which was very useful when hemorrhaging within the tumor occurred. CBF in meningioma was lower than that in high-grade glioma, but there was no statistical difference in CBV, MTT and PS between these two types of tumor. The features of intracranial cavernous hemangioma such as significant prolongation of MTT, different TDCs, and zero perfused areas were diverse on CTP image, which was helpful in differentiating it from the other lesions. The germinoma and teratoma had rather low CBF and CBV value, but a remarkably high PS value, furthermore, they showed a rapid escalated TDC with a slowly and continuously elevated platform. The perfusion features of schwannoma was concordant with its pathological findings. However, no visible specific feature of inflammatory lesion was found on CTP image in this series.</p><p><b>CONCLUSION</b>Multi-slice helical CT perfusion imaging may be helpful in revealing histopathological features and hemodynamic changes as well as differential diagnosis of intracranial neoplasms and tumor-like lesions. When combined with other image and clinical information, CTP can play an important role in pre-operative diagnosis and treatment planning for intracranial neoplasms and tumor-like lesions.</p>

Imaging characteristics of intraparenchymal schwannoma and the related pathology / 中华放射学杂志

Objective To Analyze the imaging characteristics of intraparenchymal schwannoma and the related pathology,in order to improve the accuracy of diagnosis and be in favor of the clinics and the prognosis.Methods Four cases were confirmed to be intraparenchymal schwannoma by pathological and immunohistochemistry examination.One case was examined with precontrast and enhanced CT scanning,one with unenhanced MRI scanning,two with unenhanced and enhanced CT and MRI scanning.Their images were retrospectively analyzed.Results Of the four cases,three patients were less than 30 years old,with tumors located supratentorially.Cysts were found in all cases,with nodules on the wall in 3 cases.The nodules were enhanced markedly in two cases and moderately in one ease.In addition,calcification was detected in one case and prominent peritumoral edema existed in 1 case.The picture of the pathology demonstrated Antoni type A and Antoni type B.Immunostaining showed intense immunoreactivity for S-100 protein and Vim and negative immunoreactivity for GFAP and EMA.Conclusions Intraparenchymal schwannoma mostly occurred in juvenile,which located supratentorially in most cases.The presence of a cyst and peritumoral edema together with the tumor appears to be characteristic of intraparenchymal schwannoma.Calcification or the enhanced nodule is the helpful sign for the diagnosis.Combining the imaging findings with the pathology and immunohistochemistry results can gain the accurate diagnosis.