ObjectiveTo assess the value of simulation craniotomy (SC) technique in evaluation of superficial cerebral veins(SCVs)and its relationship with convexity,parasagittal and falcine meningiomas.MethodsForty-nineconsecutivepatientswithconvexity,parasagittal,andfalcine meningiomas performed SC technique and three-dimensional contrast enhanced MR venography (3D CE MRV) in a prospective study.The number of SCVs ( diameter ＞ 1 mm) within 2 cm around the margin of tumors detected by two techniques were compared with the paired t test.Furthermore,49 cases were divided into groups according to the tumor largest diameter,position,and dural enhancement.The image quality of SC technique in different groups were analyzed by Wilcoxon test in order to find influence factors.Results The number of SCVs within 2 cm around the margin of tumor in SC was 4.4 ± 1.9,which was significantly less than that on 3D CE MRV (5.1 ± 2.7) ( t =3.131,P ＜ 0.05 ).The relationship between meningiomas and the SCVs was demonstrated well on SC in majority of cases with the score of image quality was 2.5 ±0.7.The score of image quality of 12 patients with obvious dural enhancement was 1.5 ± 0.5,which was significantly lower than that of 37 patients without dural enhancement ( 2.8 ± 0.3 )( Z =- 3.093,P ＜ 0.05 ).The score of image quality of 18 patients with tumor larger than 4 cm in diameter ( 2.2 ± 0.9 )was significantly lowed than that of 31 patients with small tumors (2.7 ± 0.5 ) ( Z =- 2.057,P ＜ 0.05 ).The score of image quality of convexity group ( n =10) and parasagittal and falcine group ( n =39 ) was 2.2 ± 0.9 and 2.6 ± 0.6,and there was no significant difference between different location group ( Z =- 0.604,P ＞ 0.05).ConclusionsSimulation craniotomy can exactly display SCVs avoiding the influence of deep cerebral veins and skull veins.This simple technique can provide useful information about the SCVs and their relationships with cortical structures and tumors for preoperative surgical planning.

Objective To study the CT features and enhance the knowledge of peripheral primitive neuroectodermal tumors(pPNETs). Methods The CT appearances of 6 patients with pPNETs pathologically proved were analyzed retrospectively. Results The CT findings of 5 bone pPNETs were soft mass of homogeneous or heterogeneous density and osteolytic destruction without osteosclerosis, periosteum reaction and tumor bone formation. Follow up CT showed the mass shrunken significantly after radiotherapy in one case. In 1 patient of chest Askin tumor, the lesion appeared as a vast heterogeneous soft mass with moderate inhomogeneous enhancement. The mass invaded mediastinum and local bone destruction were not detected. Four months after operation, a small homogeneous tumor occurred in right chest wall with moderate homogeneous enhancement. Conclusion The manifestations of pPNETs on CT have no characteristics. However, CT can show the intra tumor structures and the extent of the tumor very well, which is helpful in differentiating diagnosis,predicting resectability, detecting distant metastases and evaluating the response to treatment.

PurposeCT myelography (CTM) and gadolinium-enhanced MR myelography (Gd-MRM) are essential methods used for localizing spinal cerebrospinal fluid leaks in patients with spontaneous intracranial hypotension (SIH) and are significant for diagnosis and guided epidural blood patches. This paper analyzes the rate and imaging features of unsuccessful myelography due to misinjection of contrast into epidural space to guide prompt and correct clinical judgment of unsuccessful myelography.Materials and Methods Myelography from 121 patients with SIH was retrospectively reviewed and the image features of the unsuccessful myelography were analyzed.Results A total of 128 myelography examinations were done. Contrast media was accidently injected into the epidural space in 33 examinations. The failure rate was 25.8%. In all 33 failed exams, bilateral spinal nerve roots on both sides of the dural sac passing through contrast media was observed without visualization of anterior and posterior nerve roots. Cauda equina was not seen within contrast media in 29 cases (87.9%); non-diffusion of contrast media into cisterns and ventricles in 26 cases (78.8%). Contrast was not continuous in spinal canal in 16 cases (48.5%), heterogeneous in 10 cases (30.3%). In 4 cases (12.1%) the inner contour of contrast was not smooth.Conclusion The unsuccessful rate of myelography is relatively high in SIH patients. A prompt and correct decision could be made based on the knowledge of contrast misinjection imaging features.

Objective To compare the diagnostic value between spinal MR myelography (MRM) and intrathecal Gadolinium MR myelography (GdM) in detecting spinal cerebrospinal fluid (CSF) leaks of spontaneous intracranial hypotension (SIH). Methods Retrospective analysis of imaging findings in 158 cases with SIH was performed. Both MRM and GdM were available in 24 cases, and MRM was performed first, followed by GdM within one week. Morphological abnormalities of nerve root, CSF leaks along the nerve roots, and abnormal CSF collections were observed and compared between the two methods by using McNemar statistics and Kappa test statistics. Results Morphological abnormalities of nerve root were detected in 176 lesions on GdM and 163 lesions on MRM, respectively, and GdM was more sensitive in the detection of morphological abnormalities of nerve root (χ2=6.26,P=0.011). CSF leaks along nerve roots were identified in 15 patients on both GdM and MRM while in 5 cases on neither GdM nor MRM, and identified in 4 patients on GdM but not on MRM. CSF leaks along the nerve roots were detected in 67 lesions on GdM and 55 lesions on MRM, respectively, and GdM was more sensitive in the detection of CSF leaks along nerve (χ2=6.05,P=0.012). MRM and GdM showed good consistency(Kappa =0.837,P=0.001)in detecting CSF leaks for patients with SIH. Six and 14 lesions of abnormal CSF collections in bony rims of spines were respectively detected by GdM and MRM, 12 and 28 lesions of abnormal CSF collections in bony rims of the ribs were respectively detected by GdM and MRM. MRM was more sensitive in the detection of abnormal CSF collections in bony rims of the spines and the ribs(χ2=6.13 ,14.06 ,P=0.008 ,0.001). Eleven and 10 lesions of CSF collections in epidural space were respectively detected by GdM and MRM, 1 and 3 lesions of CSF collections of C1—2 retrospinal space were respectively detected by GdM and MRM. No statistically significant differences existed between MRM and GdM in detecting CSF collections of epidural space and C1—2 retrospinal space (χ2=0.01,0.50,P=1.000,0.500). Conclusions MRM and GdM have their respective advantages in detecting spinal CSF leaks along the nerve roots, morphological abnormalities of nerve root and abnormal CSF collections. MRM combined with GdM can provide more information in localizing spinal CSF leaks for patients with SIH.

Objective To investigate the pathogenesis, clinical manifestations, imaging features, and differential diagnosis of intraosseous ganglion. Methods Clinical and imaging features of 15 cases (5 men, 10 women; mean age 39.7 years) with intraosseous ganglia were retrospectively analyzed. There were 17 lesions, including 6 acetabula, 4 lunate, 3 proximal ends of tibia, 1 major tuberculum of humeral, 1 femoral head, 1 scaphoid, and 1 phalange. Results (1) Common radiological features included a unilocular or multilocular cyst surrounded by a full and thin rim of sclerotic bone in the subchondral epiphysis without any signs of degenerative joint disease. (2) Lesions were displayed as well defined round radiolucent defect or multi cystic changes with surrounding bony sclerosis or cystic and expansile change with irregular shape on CT scans. (3) CT showed an intraosseous ganglion communicating with adjacent joint in 1 patient. (4) CT values of the lesions were between 15- 80 HU. (5) Gas in the cyst could be seen in 3 cases. Conclusion Combined with patient′s age, lesion distribution, clinical manifestations, and imaging features, it is possible to make a correct diagnosis of intraosseous ganglion.

Objective To show the distinctive resonance pattern in 7 cases of intracranial abscess and 19 cases of cystic lesions as to evaluating these specific resonance peaks. Methods Characteristics of ~1H-MRS in 7 patients with brain abscesses and 19 with cystic or necrotic intracranial tumors were analyzed and compared. Peak assignment was based on reference values from in vivo and in vitro studies. Results Among 7 patients with brain abscesses, 6 showed the presence of cytosolic amino acid (AA) at 0.9 ppm, 5 showed alanine (Ala) at 1.5 ppm, 2 showed acetate (Ac) at 1.9 ppm and 1 patient showed succinate (Suc) at 2.4 ppm. None of the above resonances had been detected in spectra from 19 cases of cystic or necrotic intracranial tumors. Conclusions ~1H-MRS might reflect the different histochemical specificity of abscesses and cystic or necrotic tumors effectively. It should have special values in diagnosis and differential diagnosis of the brain abscess.

Objective To explore the value of time-invariant CTA in assessing collateral circulation of patients with acute ischemic stroke and assisting clinicians in predicting clinical outcomes.Methods The score of collateral circulation was compared between single-phase and time-invariant CTA.NIHSS score was calculated at admission and two weeks after admission.A 50% or greater decrease in NIHSS score over two weeks was considered as major neurologic improvement,which showed good clinical outcome;otherwise,it indicated bad outcome.The predictive ability of time-invariant CTA for clinical outcomes was assessed based on ROC curves.Results Compared with single-phase CTA,more collateral vessels could be viewed on time-invariant CTA.The average score of collateral circulation on time-invariant and single-phase CTA was 1.50±0.69 and 1.15±0.49 respectively (P=0.006<0.05 ).Time-invariant CTA had the moderate predictive ability for clinical outcomes in patients with acute ischemic stroke (AUC=0.810;P=0.032<0.05). Conclusion The time-invariant CTA showed potential value in assessing collateral circulation of patients with acute ischemic stroke and assisting clinicians in predicting clinical outcomes.

Objective To evaluate the correlation between intracranial hyperintense vessel sign (HVS) on fluid-attenuated inversion recovery(FLAIR) and the degree of the stenosis of internal carotid artery (ICA).The effect of carotid endarterectomy(CEA) on HVS was assessed.Methods A retrospective analysis of MR FLAIR sequence and cerebral-cervical computed tomography angiography(CTA) was performed in 1 total of 491 patients.Of the 491 patients,41 treated with CEA were evaluated using their pre-and post-operative image data.Patients were divided into ICA stenosis group and non-stenosis group according to the CTA imaging findings.The ICA stenosis group was subdivided into unilateral group and bilateral stenosis group.Furthermore,we measured and graded the ICA of the unilateral stenosis group into seven stenotic degrees,they were＜50％(n=40),50％-＜60％(n=15),60％-＜70％(n=17),70％-＜80％ (n=6),80％-＜90％ (n=7),90％-＜100％ (n=23),100％ (n=24),respectively.Chi square test was used to analyze the occurrence rates of HVS between ICA stenosis and non-stenosis group,and between ICA unilateral and bilateral stenosis group,respectively.Spearman rank correlation was performed to evaluate the correlation between the presence of HVS and stenotic degrees of the ICA.For the 41 patients who underwent CEA,pre-and post-operative image data were compared,focusing on the presence or disappearance of the HVS on MR FLAIR imaging.Results HVS on FLAIR images were observed in 81 of 177 patients(45.76％) with ICA stenosis,and in 59 of 314 patients(18.79％) without ICA stenosis.The occurrence rate of HVS was significantly higher in patients with ICA stenosis than those without ICA stenosis (x2=40.40,P＜0.01).There was no statistical significance in the occurrence rates of HVS between ICA unilateral stenosis group and bilateral stenosis group(x2=0.24,P＞0.05).The occurrence rates of HVS of ICA graded as the seven stenotic degrees were 22.00％(8/40),26.67％(4/15),35.29％(6/17),33.33％ (2/6),42.86％ (3/7),69.57％ (16/23),83.33％ (20/24),respectively.There was a significant positive correlation between the occurrence rates of HVS and the degrees of ICA stenosis(r=0.964,P＜0.01).HVS disappeared in 19(86.36％) out of 22 patients with HVS on pre-operative MR images after CEA in The remaining HVS in 3(13.64％) patients was attributed to the failure of completely recanalization of ICA.Conclusions A close relationship exists between HVS and ICA stenosis.The presence of HVS indicates a high probability of the existence of severe ICA stenosis.A further assessment for ICA stenosis is warranted.HVS disappearance after successful CEA indicates that HVS can be a useful marker for the the evaluation of consequence associated with CEA.

Purpose To evaluate the correlation between T2-FLAIR hyperintense vessel sign (HVS) and the stenotic degree of internal carotid artery (ICA) and assess the HVS changes after the carotid endarterectomy (CEA). Materials and Methods Fifty-one patients with CEA were retrospectively enrolled. The stenosis of the bilateral ICA were as:≥90%, and<90%. The distribution of HVS locations was classified as three regions:sylvian fissure, sulci of temporo-occipital lobe and other areas. The presence and the location of HVS were counted. The extrension of HVS on T2-FLAIR were graded as:I:the presence of HVS was<1/3 of the MCA territory, II:the presence of HVS was≥1/3 of the MCA territory.χ2-test was performed for correlation between HVS and ICA stenosis. The difference of HVS and stenosis of ICA and their effects on CEA was accessed. Results HVS was significantly higher in the ICA stenosis more than 90%group than in the less than 90% group (χ2=23.584, P<0.001). The frequencies of HVS were 12, 34 and 15 in sylvian fissure, sulci of temporo-occipital lobe and other area, respectively. The proportion of grade II HVS was higher in the ≥ 90% group than in the<90% group (χ2=8.395, P<0.05). After CEA, HVS on 29 affected hemispheres were showed to be disappeared (n=24) or remained (n=5) in the treated side. Conclusion The presence and the grade of HVS were correlated with the stenotic degree of ICA. In the patients with ICA stenosis, HVS was most frequently found in the sulci of temporal lobe and occipital lobe, and seldom found in sylvian fissure. HVS disappeared after CEA indicating that HVS can be considered as a marker for CEA treatment.

Objective To compare the uniformity between spine MRI and 18F-FDG PET/CT in detection of spinal metastatic tumor, and to analyze the reasons for the discrepancy between them.Methods Data of 42 malignant tumor patients underwent spine MRI and 18F-FDG PET/CT were analyzed retrospectively.And the two tests were underwent within 30 days.The author censused and analyzed the number of centrums with metastatic tumor detected by spine MRI and 18F-FDG PET/CT,and supposed that 18F-FDG PET/CT was gold standard,to evaluate the sensitivity and specificity of spine MRI.The inconsistent between two tests was analysed.Results The study included 509 centrums of 42 patients.123 positive centrums (24.2%) were detected on spine MRI,and 114 positive centrums (22.4%) on 18F-FDG PET/CT(P=0.22>0.05).The uniformity between two tests was good (Kappa=0.76).Supposing that 18F-FDG PET/CT was gold standard,the sensitivity,specificity,positive predictive value, negative predictive value,false negative rate and false positive rate of spine MRI was 85.1%(97/114),93.4%(369/395),85.1%(97/114),93.4% (369/395),14.9%(17/114) and 6.6%(26/395) respectively.43 centrums of 14 patients were diagnosed inconsistently by spine MRI and 18F-FDG PET/CT.The main reasons for the inconformity were as following: types of primary tumors, insensitivity of spine MRI for diffuse scattered spinal metastatic tumors, the existence of misdiagnosis on spine MRI, misdiagnosis of spine MRI for metastatic lesions located in the vertebral appendix and paramedian vertebral body,misdiagnosis of 18F-FDG PET/CT for metastatic lesions located in the sacral centrum, existence of false positive on 18F-FDG PET/CT and so on.Conclusion The uniformity between spine MRI and 18F-FDG PET/CT is good.The inconformity still existes in some cases.Carefully comparative analysis of them contributes to find metastatic lesions.