Risk factors analysis of mirror aneurysms: A multi-center retrospective study based on clinical and demographic profile of patients.

As a special subgroup of multiple intracranial aneurysms, mirror aneurysms are located bilaterally on the corresponding intracranial arteries. The current study sought to compare the clinical and demographic features of patients harboring mirror aneurysm, and to elucidate the corresponding risk factors. We performed a retrospective cohort study of 2641 intracranial aneurysms patients, who were admitted to our hospitals between January 2005 and June 2014. Patients were subdivided into three groups based on the inclusion criteria: (i) single (n=2250); (ii) non-mirror multiple (n=285); and (iii) mirror aneurysms (n=106). Clinical and demographic files of the three groups were collected and compared, and medical histories including stroke, hyperlipemia, hypertension, hyperglycemia, valvular heart disease were considered as potential risk factors. Potential morphological reasons for mirror cerebral aneurysms rupture, including aneurysms size, irregular walls and cerebral hemispheric dominance, were also compared. Our data showed that the male to female ratio of mirror aneurysms patients was 1:3.61, which was significantly different from that of single aneurysm (1:1.27) and multiple aneurysms (1:2.00). The prevalence of mirror aneurysms in women is higher than that in men (P<0.001). Older patients (especially 60-69 years old) also appear to be more vulnerable to mirror aneurysm than single aneurysm (P<0.001). In 84 mirror aneurysm patients the aneurysms were located on the internal carotid arteries (79.2%), most typically at the PComA or in the Cavernous ICA. Patients with medical history of hyperlipemia appear to have an increased risk of harboring mirror aneurysms. Larger aneurysm size and presence of an irregular aneurysm wall appear to be the morphological factors that predispose for mirror aneurysms rupture.

Juxta-adrenal schwannoma: dynamic multi-slice CT and MRI findings.

BACKGROUND: We retrospectively analyzed the MSCT and MRI findings of three cases of juxta-adrenal schwannoma and reviewed literature. METHODS AND RESULTS: Three patients were male, and showed no signs for endocrine activity. The three cases of juxta-adrenal schwannoma were all well-circumscribed, oval masses with cystic components, and one case with hemorrhage. Hypointense signal capsules were observed on T2-weighted images in two cases, and the capsule in one case showed rim enhancement. The tumors displayed mild enhancement in the arterial phase and progressive enhancement during the portal venous phase and equilibrium phase. Computed tomography angiography clearly showed the tumor feeding vessels arising from the abdominal aorta. CONCLUSIONS: MSCT and MRI are valuable imaging modalities for diagnosis of juxta-adrenal schwannoma.

Human tissue kallikrein promoted activation of the ipsilesional sensorimotor cortex after acute cerebral infarction.

BACKGROUND/AIMS: Kallikrein, a serine proteinase, has been reported to have many functions, such as selectively dilating arterioles in the ischemic area and enhancing angiogenesis and neurogenesis. Therefore, it may promote cerebral poststroke reorganization. We observed the effect of human tissue kallikrein on the brain motor activation of acute ischemic stroke patients and evaluated patient condition severity and prognosis. METHODS: Forty-four cases suffering from cerebral infarction between 6 and 72 h of onset were randomly assigned into the kallikrein group (n = 24) and the control group (n = 20). The control group was given conventional treatment, whereas the kallikrein group was given both conventional treatment and human tissue kallikrein over the course of 12-14 days. The activation of the sensorimotor cortex (SMC) and cerebellum, the affected forefinger strength and the NIHSS scores were evaluated before and after treatment. The MBI and MRS scores were assessed at 30 and 90 days after stroke onset. RESULTS: There were no differences between the two groups in activation volume, patient condition and scores before treatment. After treatment, the ipsilesional SMC activation volume was significantly larger and the increase in the volume was significantly greater in the kallikrein group than in the control group (p < 0.05 for both). The NIHSS score was significantly smaller and the improvement in the score was significantly greater in the kallikrein group after treatment (p < 0.05 for both). Moreover, the MBI scores at 30 days were significantly higher, whereas the MRS scores at 30 days were significantly lower in the kallikrein group than in the control group (p < 0.05 for both). CONCLUSIONS: Kallikrein improved neural function effectively and quickly after stroke, and promoting cerebral reorganization might be an important mechanism for kallikrein in the treatment of acute cerebral infarction.

Small hepatocellular carcinoma with bile duct tumor thrombi: CT and MRI findings.

BACKGROUND: Small hepatocellular carcinoma (sHCC) with bile duct tumor thrombi (BDTT) is rare and easily misdiagnosed as cholangiocarcinoma. This study was to analyze the imaging features of sHCC with BDTT. PATIENTS AND METHODS: CT and/or MRI examinations were performed on seven patients who had sHCC with BDTT. One patient received CT scan, one received CT and MR scan, and five received MR scan. Magnetic resonance cholangiopancreatography (MRCP) was performed in five patients. The diagnosis of sHCC with BDTT was based on surgical specimens in all patients. RESULTS: The sHCC lesions and BDTT were presented on CT or MRI scans in all the seven cases. The BDTT is presented as soft tissue mass in the bile duct with biliary dilatation above the obstruction. In the two patients who had received dynamic contrast CT scan, the sHCC lesions showed atypical enhancement pattern of HCC. The BDTT showed similar enhancement pattern as sHCC in one of the two patients. The sHCC and BDTT showed homogenous hypointense signals on T1W images and hyperintense signals on T2W images in all six cases. In the three patients who had received dynamic enhancement MR scan, the enhancement patterns of sHCC lesions and BDTT were similar. Early enhancement of sHCC lesion and BDTT at hepatic arterial phase with hyperintense signals was observed in one patient, while two other patients had no early enhancement. All sHCC lesions and BDTT showed hypointense signals at portal venous phase, equilibrium phase, and delayed phase. Six patients showed hyperintense signal of hemorrhage in the dilated bile ducts on both T1W and T2W images. Five cases of BDTT presented as filling defect in the bile ducts on MRCP. The BDTT were directly connected with sHCC lesions in all the seven patients, without bile duct wall thickening or extra-bile duct invasion. CONCLUSION: CT or MRI is a safe, reliable, and valuable method for the detection and diagnosis of sHCC with BDTT.

[Diagnosis of recurrent or residual nasopharyngeal carcinomas in the skull base area with F-18-fluoro-deoxyglucose positron emission tomography].

OBJECTIVE: To investigate the diagnostic value of F-18-fluoro-deoxyglucose positron emission tomography (FDG-PET) for the recurrent or residual nasopharyngeal carcinomas in the skull base area. METHODS: Nine post-irradiation nasopharyngeal carcinoma patients did FDG-PET scanning, CT/MRI imaging and underwent nasopharynx and skull base-biopsy under endoscopy. The results of FDG-PET were evaluated and compared with CT/MRI studies and biopsies. RESULTS: In 9 cases of post-irradiation nasopharyngeal carcinoma, CT/MRI detected 7 recurrent cases and 2 suspected recurrent cases in occipital bone and clivus. All 9 cases had accumulated FDG in nasopharynx and cranial base. A definite diagnosis was made by biopsy, 3 cases were confirmed recurrence, and others 6 cases were proved mucous chronic inflammation and (or) osteoradionecrosis. The accuracy of FDG-PET was 33.3% (3/9), and the false positive rate was 66.7% (6/9). CONCLUSIONS: Diagnosis of recurrent or residual nasopharyngeal carcinomas in the skull base area with FDG-PET had high false-positive rate, final diagnosis must depend on histopathologic examination under endoscopy.

[MRI performance and diagnosis of schwannomas from cranial nerves in posterior cranial fossae].

BACKGROUND & OBJECTIVE: Cranial nerve schwannomas originate frequently in posterior cranial fossae and have various and complex MRI performances, some of which are still not well known. This study was to explore MRI performances and features of schwannomas from cranial nerves in posterior cranial fossae. METHODS: The MRI performances of 75 cases of schwannoma from cranial nerves in posterior cranial fossae, including trigeminal (n=9), facial (n=1), acoustic (n=53), 9th-11th (n=9) and hypoglossal (n=3) schwannomas, confirmed by surgical and pathologic findings, were analyzed retrospectively. RESULTS: Most of schwannomas in posterior cranial fossae were solid-cystic lesions when their sizes were larger than 1.5 cm in diameter. Small lesions (less than 1.5 cm in diameter) may be completely solid, which were closely related to cranial nerves. On T1WI, the solid part of tumor appeared iso- or slightly hypointense, while cystic part was hypointense. On T2WI, solid part appeared high or slightly high signal intensity, but cystic part appeared very high signal intensity. On contrast-enhanced T1WI, there was obvious enhancement in the solid part, but not in the cystic part. Some typical signs were very useful to infer tumor origin, such as, dumbbell-shaped trigeminal schwannoma extended across the middle and posterior cranial fossa, enlargement of internal auditory canal, widened jugular foramen and hypoglossal foramen caused by acoustic schwannoma, the 9th-11th shcwannoma, and hypoglossal schwannoma, respectively. The correct ratio for qualitative diagnosis of schwannoma was 92% using MRI, but the incorrect ratio for identifying the nerve of tumor origin was 8.7%. CONCLUSION: MRI is a good method in qualitative diagnosis of schwannoma and identifying cranial nerves of tumor origin in posterior cranial fossae.

[Preliminary application of functional magnetic resonance imaging to neurosurgery].

BACKGROUND & OBJECTIVE: Motor functional deficit may be caused by surgery resection of brain tumors around the central sulcus. This study was to evaluate the application of functional magnetic resonance imaging (fMRI) to neurosurgery through identifying motor hand functional cortex and depicting the relationship between the cortex and tumor with fMRI before surgery. METHODS: Routine MRI and fMRI were performed on 31 patients with brain tumor around the central sulcus. Of the 31 cases of brain tumor, 10 were metastases, 11 were gliomas, 6 were meningiomas, 2 were arterial-venal malformation (AVM), and 2 were arachnoid cysts. fMRI was performed using FFE-EPI sequence. Sixteen continuent slices with 4 mm thickness and 0 gap parallel to bicommissural line were scanned during the rest, and actions of opening and closing of hand were imaged. A total of 1,280 functional original pictures and statistical Z-score maps were obtained. RESULTS: The activation areas of motor hand functional cortex were showed in all patients except 2 whose heads moved obviously during the scanning. The minimal distance between the functional cortex and tumor was measured. There were 3 types of activation of motor hand functimal cortex, including activation spots in or near the tumor, deformation and shift of cortex activation area, normal shape and location of cortex activation area. Other activation areas in different places of brain in individual patients were also appeared. CONCLUSION: fMRI may help to identify the relationship between the brain tumors near central sulcus and the location of motor hand functional cortex, therefore, provide reference for neurosurgery.

[Significance of dynamic enhanced MRI in differential diagnosis of radiofibrosis and recurrent nasopharyngeal carcinoma at the basilar clivus].

BACKGROUND & OBJECTIVE: Basilar clivus is a common site of recurrent nasopharyngeal carcinoma (RNPC). Biopsy of the basilar clivus is seldom done because of its deep location and complex anatomic structure, therefore, early differential diagnosis of radiofibrosis (RF) and RNPC at the basilar clivus is very difficult. This study was designed to investigate the characteristics of radiofibrosis and RNPC at the basilar clivus on dynamic enhanced magnetic resonance imaging (DMRI) for differential diagnosis. METHODS: A total of 38 NPC patients, treated in Cancer Center and the Second Affiliated Hospital of Sun Yat-sen University with follow-up of 1-5 years, were divided into 2 groups: 22 in RF group and 16 in RNPC (RNPC at the basilar clivus) group. After conventional plain MRI scan of nasopharynx, DMRI and conventional contrast enhanced T(1)-weighted imaging (T1WI) were performed. Maximal contrast enhancement ratio (MCER), time to MCER (Tmax), and contrast enhancement ratio at the 40th second of DMRI (CER(40s)) of basilar clivus, condylar process, and nasal concha were measured. RESULTS: The MCER and CER(40s) of RF at the basilar clivus were lower, and the Tmax was longer than those of RNPC at the basilar clivus. When CER40s > or =150%, CER40s of basilar clivus > or = CER(40s) of nasal concha, and the combination of these 2 indexes were respectively set as the DMRI diagnostic criteria of RNPC at the basilar clivus, the diagnostic sensitivity of the second criterion was the highest (81.3%), and the diagnostic specificity of the third criterion was also the highest (86.4%). CONCLUSIONS: DMRI is helpful for differential diagnosis of radiofibrosis and RNPC at the basilar clivus. RNPC at the basilar clivus is highly suggested when it meet the criteria of both CER(40s) > or =150% and CER(40s) of basilar clivus > or = CER(40s) of nasal concha. When the 2 criteria are conflictive, the latter is more accurate, MCER and Tmax of the basilar clivus should be took into consideration.

[Magnetic resonance imaging manifestations of radiation injury in brain stem and cervical spinal cord of nasopharyngeal carcinoma patients after radiotherapy].

BACKGROUND & OBJECTIVE: It is very important to diagnose the radiation injury in brain stem and cervical spinal cord of patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Magnetic resonance imaging (MRI) manifestations of radiation encephalopathy have been widely reported, while those of radiation injury in brain stem and cervical spinal cord have been seldom reported. This study was to analyze the MRI characteristics of radiation injury in brain stem and cervical spinal cord of patients with NPC after radiotherapy. METHODS: MRI was performed in 60 NPC patients 6 months to 5 years after radiotherapy. The imaging sequences included T(1)-weighted image (T(1)WI), T2-weighted image (T(2)WI), fluid attenuated inversion recovery (FLAIR). All patients received T(1)WI contrast-enhanced scanning. RESULTS: Of the 60 patients, 6 had lesions in cervical spinal cord, 54 had lesions in brain stem. Of the 54 cases of radiation injury in brain stem, most lesions located in pons (20 cases), basis pons and medulla oblongata (26 cases), others located in mesencephalon (3 cases), medulla oblongata (5 cases). All lesions showed hypo- or iso-intense signal on T(1)WI, and hyper-intense signal on T(2)WI. After contrast-enhanced scanning, 11 cases (18.3%) had no enhancement; 49 (81.7%) markedly enhanced with 21 cases (42.9%) of homogenous patchy enhancement, and 28 cases (57.1%) of hetergenerous ringed and patchy enhancement. CONCLUSION: MRI shows clearly the radiation injury in brain stem and cervical spinal cord of NPC patients after radiotherapy.

[Magnetic resonance imaging diagnosis of cervical lymph node metastasis from lingual squamous cell carcinoma].

BACKGROUND & OBJECTIVE: The identification of cervical lymph node metastasis is very important for the treatment and prognosis prediction of lingual squamous cell carcinoma. Simple palpation is unsatisfactory for the accurate diagnosis of cervical lymph node metastasis. Magnetic resonance imaging (MRI) has been increasingly used to evaluate cervical lymph node status. This study was to explore MRI features of cervical lymph nodes metastasis from lingual squamous cell carcinoma, and to investigate the role of MRI in diagnosing this kind of metastasis. METHODS: The MR images of 448 nodal levels in 92 patients with lingual squamous cell carcinoma were analyzed, and compared with their pathologic diagnoses. RESULTS: Of the 488 nodal levels, 166 (37.1%) were proved pathologically as metastases, level II was the most commonly involved. False-positive and false-negative rates of MRI diagnoses were higher in levels I, and II than in levels III, IV, and V. There is no statistical difference in the incidence of cervical lymph nodes metastases of different nodal levels between squamous cell carcinoma of corpus linguae and that of radix linguae. Obvious central nodal necrosis was seen in 76 nodal levels at MR images,which were proved pathologically as metastatic nodes. Extracapsular nodal invasions in 34 nodal levels had irregular contour, and infiltration of adjacent fat tissues around lymph nodes, among which carotid artery walls were encased in 2 cases. With the diagnostic criteria of metastasis as the minimal nodal diameter of >/= 8 mm or central nodal necrosis, the diagnostic sensitivity, specificity, and accuracy of MRI were 79.5%, 90.4%, and 86.4%, respectively. CONCLUSIONS: The incidence of cervical lymph nodes metastasis from lingual squamous cell carcinoma is highest in level II. MRI diagnostic criteria of cervical lymph nodes metastasis are nodal size, central nodal necrosis, and irregular contour of lymph nodes. MRI may diagnose lymph node metastasis in levels III-V with high accuracy, While its diagnosis accuracy on levels I-II is affected by the sites, which weakens its clinical value.

[MRI performance and diagnosis of meningioma--a report of 126 cases].

BACKGROUND & OBJECTIVE: In MRI study of meningioma, it was lack of large group of patients to evaluate MRI qualitative diagnosis, and no consensus had been achieved concerning problems such as peritumoral edema in meningioma. This study was to summarize main clues for diagnosing meningioma through analyzing MRI performance of 126 patients with meningioma. METHODS: Among 126 patients with meningioma, 32 were syncytial, 35 were fibroblastic, 24 were psammomatous, 9 were angioblastic, 18 were transitional, 3 were papillary, and 5 were malignant. All patients were scanned with T1, T2-weighted imaging (T1WI, T2WI), and contrast-enhanced T1WI. RESULTS: Convexity of brain was more likely to be involved, among 126 cases of meningioma, 45 (35.7%) tumors located at convexity of brain. The size of tumor ranged from 1.4 to 9.9 cm. Eighty-one percent of tumors were round or oval in shape. Isointensity or slight hyperintensity of T2WI signals detected in 70.6% patients. The rates of tail sign, and pseudo-capsule were 62.7%, and 49.2%. Extruding sign of brain parenchyma was observed in 83.8% (57/68)of patients with tumor size of > 4 cm. Significantly even and increasing sign in contrast-enhanced T1WI were observed in 104 patients (82.5%). Peritumoral edema occurred in 57 patients (45.1%), and related to tumor size. Other rare signs included cystic changes, bleeding, calcification, osteal changes, and introtumoral vessel symptoms. The correct rate of diagnosis was 95.2%. CONCLUSIONS: MRI performances of meningioma are various. Judgment of extra-brain tumor, typical T2WI signals, tail sign, and significantly even and increasing sign are key factors for diagnosing meningioma.

[MR cholangiopancreatography and MR imaging in the diagnosis of extrahepatic cholangiocarcinoma].

OBJECTIVE: To evaluate the imaging features of MR Imaging (MRI) and MR cholangiopancreatography (MRCP) and their clinical value in the diagnosis of extrahepatic cholangiocarcinoma. METHODS: MRI was performed in 54 patients with extrahepatic cholangiocarcinoma proved surgically and pathologically, MRCP in 44 patients, Gadolinium-enhanced in 29 patients. MRI, MRCP and pathological findings were analyzed retrospectively. RESULTS: By MRI, the mass was shown (n = 39) and all bile duct thickened (n = 13) in extrahepatic cholangiocarcinoma. Gadolinium-enhanced ones revealed calcified focus (n = 22). By MRCP, interrupted, abruptly cut-off or cone-like changes of the bile duct (n = 16), beak-like or mouse tail changes (n = 26) or tumbler mouth appearance (n = 2) were shown. The bile duct distal to the obstruction was observed in 29 patients. Of the 54 patients examined by MRI in combination with MRCP, correct tumor localization was made in 52 (96.3%) and correct judgement of tumor nature in 50 (92.6%). CONCLUSION: Conventional MRI is an effective supplement to MRCP in the diagnosis of extrahepatic cholangiocarcinoma. MRCP combined with MRI is able to significantly improve the diagnostic accuracy of MR examination.

[Preliminary study of astrocytic tumors by diffusion tensor imaging].

BACKGROUND & OBJECTIVE: Diffusion tensor imaging (DTI) is an advanced quantitative form of diffusion-weighted imaging. It could be used to calculate not only the apparent diffusion coefficient (ADC) of average water diffusion for each vowel, but also the diffusion anisotropic index of diffusion. Diffusion-weighted imaging is used in most of the studies of the brain tumors abroad. We used DTI method to measure the ADC, fractional anisotropy (FA) and relative anisotropy (RA), values of different tumor tissues and to evaluate the usefulness of ADC, FA, and RA in differentiating solid tumor, necrotic region, edema region, normal brain tissue, and in grading the malignancy of cerebral astrocytomas. METHODS: Fourteen cases of astrocytomas diagnosed (10 cases of grade 1-2 astrocytomas and 4 cases of grade 3-4 astrocytomas) were studied by DTI. ADC, FA, and RA values of different tumor tissue were measured. RESULTS: When all cases were analyzed as a group, significant differences of ADC were found in enhancing solid tumor (1.14+/-0.13x10(-3) mm(2)/s), necrotic region (2.04+/-0.50x10(-3) mm(2)/s), edema region (1.55+/-0.19x10(-3) mm(2)/s) compared with normal brain tissue (0.74+/-0.08x10(-3) mm(2)/s)(P< 0.05). Significant differences of ADC were also found in solid tumor (enhancing tissue:1.14+/-0.13x10(-3) mm(2)/s, non-enhancing tissue:1.01+/-0.25x10(-3) mm(2)/s) compared with necrotic region and edema region, respectively (P< 0.05). Significant differences of FA and RA were found in solid enhancing region (FA:0.21+/-0.08; RA:0.23+/-0.07), necrotic region (FA: 0.14+/-0.06, RA: 0.16+/-0.07), edema region (FA:0.16+/-0.04, RA:0.16+/-0.02) compared with normal brain tissue (FA: 0.37+/-0.06, RA: 0.38+/-0.07) (P< 0.05). No difference of FA and RA was found in solid tumor (including enhancing and non-enhancing tissue). Significant differences of ADC (P< 0.05), not FA and RA, were found between grade 1-2 astrocytomas (1.07+/-0.04x10(-3) mm(2)/s) and grade 3-4 astrocytomas (1.32+/-0.08x10(-3) mm(2)/s). CONCLUSION: Determination of ADC can be used to differentiate normal brain tissue from enhancing solid tumor, necrotic region, and edema region. Determination of FA and RA can be used to differentiate solid enhancing tumor, necrotic region, and edema region from normal brain tissue, but can not be used to differentiate solid tumor, necrotic region, and edema region. The ADC values, not FA and RA, may predict the degree of malignancy of astrocytic tumors.

[Correlation between SPIO-enhanced magnetic resonance imaging (MRI) and histological grading in hepatocellular carcinoma].

BACKGROUND & OBJECTIVE: Hepatocellular carcinoma(HCC) is one of the most common tumors in the world. The diagnosis of HCC is very difficult.This study was designed to evaluate the role of SPIO(superparamagnetic iron oxide)-enhanced magnetic resonance imaging (MRI) in diagnosing hepatocellular carcinoma and its correlation with histological grading. METHODS: Conventional plain and Feridex-enhanced MRI scanning was performed in 30 patients with suspected hepatic lesions. The signal intensity and Kupffer-cell-count of lesions and nontumorous area was observed. SPIO intensity ratio and the ratio of Kupffer-cell-count were analyzed. RESULTS: Ratio of Kupffer-cell-count in well-differentiated HCC (1.05+/-0.12) was higher than those in moderately and poorly-differentiated HCC (0.38+/-0.21 and 0.15+/-0.14, respectively) (P< 0.01). The ratio of the intensity of tumor lesions to that of nontumor area on SPIO-enhanced MRI inversely related to Kupffer-cell-count ratio in hepatic lesions (r=0.064,P< 0.01). CONCLUSION: SPIO-enhanced MRI may reflect Kupffer-cell- count in HCC and dysplastic nodules and is useful for estimation of histological grading in HCC.