Predicting the developmental outcomes of very premature infants via ultrasound classification: A CONSORT - clinical study.

OBJECTIVE: This study aimed to assess the accuracy of ultrasonic grading in determining brain injury in very premature infants and analyze the affecting factors of these neonatal morbidity and mortality, and to investigate the relationship between serial cranial ultrasound (cUS) classification and Mental Developmental Index (MDI)/Psychomotor Developmental Index (PDI) in premature infants. METHODS: A total of 129 very preterm infants (Gestational Age ≤ 28 weeks) were subjected to serial cUS until 6 months or older and classified into 3 degrees in accordance with classification standards. The MDI and PDI (Bayley test) of the infants were measured until the infants reached the age of 24 months or older. The consistency between Term Equivalent Age (TEA)-cUS and TEA- magnetic resonance imaging (MRI) was calculated. Ordinal regression was performed to analyze the relationship among severe disease, early cUS classifications, psychomotor and mental development, and death. Operating characteristic curve were used to analyze the relationship between serial cUS grades and MDI/PDI scores. RESULTS: The mortality and survival rates of 129 very preterm infants were 32.8% and 67.3%, respectively. Among the 86 surviving infants, 20.9% developed mild cerebral palsy (CP) and 5.8% to 6.9% developed severe CP. The consistency between TEA-cUS and TEA-MRI was 88%. Grades 2 and 3 at first ultrasound were associated with adverse mental (OR = 3.2, OR = 3.78) and motor (OR = 2.25, OR = 2.59) development. cUS classification demonstrated high sensitivity (79%-96%). Among all cUS classifications, the specificity of the first cUS was the lowest and that of TEA-cUS was the highest (57% for PDI and 48% for MDI). CONCLUSIONS: Moderate and severe brain injury at first ultrasound is the most important factor affecting the survival rate and brain development of very premature infants. The cUS classification had high sensitivity and high specificity for the prediction of CP, especially in TEA-cUS.

Choroid plexus tumours on MRI: similarities and distinctions in different grades.

BACKGROUND: The therapeutic planning varies for different grades of choroid plexus tumours (CPTs). The aim of this study was to define the similarities and distinctions among MRIs for different grades of CPTs, providing more guidance for clinical decisions. METHODS: We reviewed the MRI findings in 35 patients with CPT verified by surgical pathology, including 18 choroid plexus papillomas (CPPs, grade I), 11 atypical choroid plexus papillomas (aCPPs, grade II), and 6 choroid plexus carcinomas (CPCs, grade III). Nonparametric testing based on ranks was performed to evaluate the association of pathological grade with MRI findings. RESULTS: Among the 35 CPTs, 29 were located in the ventricular system. The tumours were generally slightly hypo- or isointense on T1WI, slightly hyper- or isointense on T2WI, and moderately or strongly enhanced in post-contrast imaging. Twenty cases were accompanied by hydrocephalus. The median tumour longest diameters of CPPs, aCPPs, and CPCs were 28.6, 44.6, and 60.6 mm, respectively. Four cases were purely cystic, 6 were papillary, 10 were lobulated, and 2 were irregular. Three cases had necrosis. The median oedema diameters of CPPs, aCPPs, and CPCs were 0, 0, and 24.1 mm, respectively. The grades of CPTs were statistically associated with tumour longest diameter (rs = 0.68, P < 0.001), internal morphology (χ2 = 10.32, P = 0.016), necrosis (Z = 2.27, P = 0.023), and oedema diameter (rs = 0.72, P < 0.001). CONCLUSION: CPTs typically appeared as intraventricular papillary or lobulated lesions, often accompanied by hydrocephalus. Larger tumour, irregular or fuzzy internal morphology, presentation of necrosis and wide-ranging peritumoural oedema might increase the likelihood of malignancy.

Predictive Value of Cranial Ultrasound for Neurodevelopmental Outcomes of Very Preterm Infants with Brain Injury.

BACKGROUND: Compared with full-term infants, very preterm infants are more vulnerable to injury and long-term disability and are at high risk of death. The predictive value of ultrasound and imaging on the neurodevelopment is one of the hot topics. This study aimed to investigate the relationship between cranial ultrasound (cUS) variables and neurodevelopmental outcomes of very preterm infants. METHODS: Totally 129 very preterm infants (gestational age ≤28 weeks) in neonatal intensive care unit of Hunan Children's Hospital between January 2012 and November 2014 were included in this retrospective study. Serial cUS (weekly before discharge and monthly after discharge) was performed on the infants until 6 months or older. Magnetic resonance imaging (MRI) was performed on the infants at approximately the term-equivalent age. The mental developmental index (MDI) and psychomotor developmental index (PDI) were followed up until the infants were 24 months or older. The relationship between brain injury and MDI/PDI scores was analyzed. RESULTS: The consistency rate between cUS and MRI was 88%. At the first cUS, germinal matrix hemorrhage (GMH) Grades 3 and 4, hospitalization duration, and weight are significantly correlated with MDI/PDI and prognosis (MDI: odds ratio [OR] = 8.415, 0.982, and 0.042, P = 0.016, 0.000, and 0.004; PDI: OR = 7.149, 0.978, and 0.012, P = 0.025, 0.000, and 0.000, respectively). At the last cUS, gestational age, extensive cystic periventricular leukomalacia (c-PVL), and moderate and severe hydrocephaly are significantly correlated with MDI (OR = 0.292, 60.220, and 170.375, P = 0.004, 0.003, and 0.000, respectively). Extensive c-PVL and moderate and severe hydrocephaly are significantly correlated with PDI (OR = 76.861 and 116.746, P = 0.003 and 0.000, respectively). CONCLUSIONS: Very premature infants with GMH Grades 3 and 4, short hospitalization duration, and low weight have low survival rates and poorly developed brain nerves. Cerebral palsy can result from severe cerebral hemorrhage, moderate and severe hydrocephaly, and extensive c-PVL. The sustained, inhomogeneous echogenicity of white matter may suggest subtle brain injury.

Quantitative Assessment of Airway Pathology in Subjects With COPD Using Low-Dose High-Resolution Computed Tomography.

BACKGROUND: The purpose of this study was to correlate airway parameters of COPD determined by low-dose high-resolution computed tomography (HRCT) with pulmonary function testing (PFT) results. METHODS: PFT data were collected for subjects with COPD and healthy controls. All subjects received inspiratory and expiratory phase low-dose HRCT. Bronchi in the apical segment of the right upper lobe (RB1), posterior segment of the right lower lobe (RB6), and lower lingual segment of the left upper lobe (LB5) were the target bronchi. Software automatically calculated airway wall area, inner area, and airway wall area percentage (percentage wall area for bronchial external area). RESULTS: A total of 75 COPD and 20 control subjects were included. The subjects with COPD were classified according to COPD stage, with 20 grade I, II, and III subjects, respectively, and 15 grade IV subjects. In COPD grade II, residual volume/total lung capacity was negatively correlated with airway wall area in LB5 (r = -0.51). In COPD grade III, FVC was negatively correlated with airway wall area percentage in LB5 (r = -0.49) but positively correlated with airway wall area in RB6 (r = 0.52); percent-of-predicted FEV1 was negatively correlated with airway wall area percentage in RB1 (r = -0.49); residual volume was negatively correlated with airway wall area (r = -0.47), and total lung capacity was negatively correlated with airway wall area in RB1 (r = -0.52) (all, P < .001). CONCLUSIONS: The results of this study suggest that airway parameters in different COPD grades have no uniform tendency of correlation with PFT, but some HRCT parameters are correlated to some PFT parameters.

Abnormal baseline brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy revealed by resting-state functional MRI.

Neurocognitive dysfunction of varying degrees is common in patients with hepatitis B virus-related cirrhosis (HBV-RC) without overt hepatic encephalopathy (OHE). However, the neurobiological mechanisms underlying these dysfunctions are not well understood. We sought to identify changes in the neural activity of patients with HBV-RC without OHE in the resting state by using the amplitude of low-frequency fluctuation (ALFF) method and to determine whether these changes were related to impaired cognition. Resting-state functional MRI data from 30 patients with HBV-RC and 30 healthy controls matched for age, sex, and years of education were compared to determine any differences in the ALFF between the two groups. Cognition was measured with the psychometric hepatic encephalopathy score (PHES), and the relationship between these scores and ALFF variation was assessed. Compared with controls, patients showed widespread lower standardized ALFF (mALFF) values in visual association areas (bilateral lingual gyrus, middle occipital gyrus, and left inferior temporal gyrus), motor-related areas (bilateral precentral gyrus, paracentral lobule, and right postcentral gyrus), and the default mode network (bilateral cuneus/precuneus and inferior parietal lobule). Higher mALFF values were found in the bilateral orbital gyrus/rectal gyrus. In patients, mALFF values were significantly positive correlated with the PHES in the right middle occipital gyrus and bilateral precentral gyrus. Our findings of resting-state abnormalities in patients with HBV-RC without OHE suggest that neurocognitive dysfunction in patients with HBV-RC without OHE may be caused by abnormal neural activity in multiple brain regions.

1H-MR spectroscopy and diffusion tensor imaging of normal-appearing temporal white matter in patients with nasopharyngeal carcinoma after irradiation: initial experience.

PURPOSE: To detect radiation-induced changes of temporal lobe normal-appearing white mater (NAWM) following radiation therapy (RT) for nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Seventy-five H(1)-MR spectroscopy and diffusion-tensor imaging (DTI) examinations were performed in 55 patients before and after receiving fractionated radiation therapy (total dose; 66-75GY). We divided the dataset into six groups, a pre-RT control group and five other groups based on time after completion of RT. N-acetylaspartic acid (NAA)/choline (Cho), NAA/creatine (Cr), Cho/Cr, mean diffusibility (MD), functional anisotropy (FA), radial diffusibility (λ(⊥)), and axial diffusibility (λ(||)) were calculated. RESULTS: NAA/Cho and NAA/Cr decreased and λ(⊥) increased significantly within 1 year after RT compared with pre-RT. After 1 year, NAA/Cho, NAA/Cr, and λ(⊥) were not significantly different from pre-RT. In all post-RT groups, FA decreased significantly. λ(||) decreased within 9 months after RT compared with pre-RT, but was not significantly different from pre-RT more than 9 months after RT. CONCLUSION: DTI and H(1)-MR spectroscopy can be used to detect early radiation-induced changes of temporal lobe NAWM following radiation therapy for NPC. Metabolic alterations and water diffusion characteristics of temporal lobe NAWM in patients with NPC after RT were dynamic and transient.

[Application of dynamic contrast-enhanced magnetic resonance imaging in evaluating liver fibrosis].

OBJECTIVE: To analyze the value of time-signal intensity curve (TIC) in dynamic contrast-enhanced magnetic resonance imaging (DEC-MRI) in the evaluation of liver fibrosis. METHODS: Thirty-six consecutive patients and healthy volunteers were divided into 4 groups according to the stages of fibrosis, namely the normal group (n=9), mild fibrosis group (n=5), moderate to severe fibrosis group (n=7), and liver cirrhosis group (n=15). All the subjects underwent conventional and DEC-MRI, and the TIC was generated automatically to evaluate the peak height, TTP, MSI and MSD. The correlations between the TIC parameters and the stage of fibrosis were assessed. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the value of the TIC parameters in the evaluation of fibrosis stage. RESULTS: Moderate but significant inverse correlations of the peak height, MSI, and to fibrosis stage were noted in these patients (P<0.05); the peak time was positively correlated to the fibrosis stage (P<0.05). In patients with a fibrosis stage ≥1, the AUC of the measured TIC parameters ranged from 0.747 to 0.783, with the MSD of the spleen had the highest AUC (0.783). For a fibrosis stage ≥3, the AUC of the indices ranged between 0.728 and 0.877, highest for liver MSI of the arterial phase, followed by the portal vein MSI, liver MSI of portal venous phase, liver MSD, splenic MSI of arterial phase and splenic MSD. In the diagnosis of liver cirrhosis, the AUC (range 0.742-0.821) decreased in the order of liver MSI of the portal venous phase, liver MSD, liver MSI of the arterial phase, the portal vein MSI, splenic MSI of the arterial phase and splenic MSD. CONCLUSION: TIC of DEC-MRI can be used to evaluate hemodynamic changes in the liver, and may serve as a practical non-invasive functional imaging modality for assessing the severity of liver fibrosis.

[Value of multi-slice spiral CT in the diagnosis and therapeutic effect evaluation of gastrointestinal stromal tumors].

OBJECTIVE: To analyze the CT manifestations of gastrointestinal stromal tumors, and explore the value of CT in the diagnosis and therapeutic effect evaluation of these tumors. METHODS: A retrospectively analysis of the medical imaging data was conducted in 39 cases of gastrointestinal stromal tumors confirmed by surgery and pathology in comparison with the pathological findings. RESULTS: Of the 39 patients with gastrointestinal stromal tumors, 2 had esophageal stromal tumors, 23 had gastric stromal tumor, 7 had duodenal stromal tumor, 4 had jejunal stromal tumors, 2 had ileal stromal tumors, and 1 had colon stromal tumor. Twenty-five patients were found to have highly malignant tumors, and 11 had low-grade tumors, with the other 3 having tumors of unidentifiable nature. CT displayed exogenous or endogenous mass in these cases, and the tumors had a maximum diameter ranging from 3 to 45 cm (<5 cm in 12 cases and >or=5 cm in 27 cases). Of the 27 cases with a tumor diameter over 5 cm, 23 had malignant stromal tumors, and the tumor mass showed heterogeneous density with central necrosis and cystic and the solid portion of the tumor exhibited mild to moderate enhancement. Six patients were found to have intratumoral punctate calcification, and 17 with malignant tumors showed high peripheral enhancement, with the solid portion of the tumors showing delayed enhancement. The 6 patients with unresectable tumors received chemotherapy resulting in significantly reduced tumor diameter and cystic and necrotic foci in the tumor. CONCLUSION: Multi-slice spiral CT allows precise localization and qualitative assessment of gastrointestinal stromal tumors, and also helps in the evaluation of the therapeutic effect.

[Characteristic imaging features of primary central nervous system lymphoma in comparison with pathological findings].

OBJECTIVE: To investigate the imaging features of primary central nervous system lymphoma (PCNSL). METHOD: The imaging and pathological findings in 13 patients with pathologically confirmed PCNSL were analyzed retrospectively. Of these patients, 5 underwent CT scan, 6 had magnetic resonance imaging (MRI) examination, 1 patient underwent both CT and MRI examinations, and another had both MRI and PET/CT examinations. RESULTS: Among the 13 patients with PCNSL, 11 were identified to have solitary tumor foci and the other 2 had multiple lesions. Supratentorial tumors were found in 9 patients, infratentorial tumors in 3 patients, and both supratentorial and infratentorial tumors in 1 patient. In 6 cases, the tumor presented isodensity or slight hypodensity on plain CT images, with mild or moderate enhancement after contrast agent injection. The lesions showed isointense or hypointense signals on T1WI and isointense or slightly hypointense signals on T2WI in 7 cases, with obvious homogenous enhancement in 5 cases and microcystic foci in 2 cases after gadolinium injection. Five patients showed the "angular sign" and 4 the "hilar depression sign". All the patients presented with mild or moderate peritumoral edema and space-occupying mass except for 1 patient with diffuse lesions, who showed hypointense signals on T1WI and hyperintense signals on T2WI with obvious nodular enhancement after gadolinium injection and high 18F-FDG uptake on PET/CT. Pathologically, the tumors appeared pinkish or grey-white, soft, with rich blood supply and without capsules. The tumor cells were found to cluster around the blood vessels under microscope. CONCLUSIONS: PCNSL may present with typical imaging features which can be suggestive of the diagnosis. Stereotactic biopsy can be performed when necessary to obtain a definite diagnosis.

[Optic radiation in normal adults: a study using magnetic resonance diffusion tensor imaging and diffusion tensor tractography].

OBJECTIVE: To study the fractional anisotropy (FA) and the architecture of the optic radiation fiber tracts of normal adults with magnetic resonance (MR) diffusion tensor imaging (DTI). METHODS: Diffusion tensor images were obtained from 30 healthy volunteers without any cerebral abnormalities on conventional MRI. FA and the mean diffusivity (MD) of the optic radiation were measured in the directional encoded color (DEC) maps. The architecture of the optic radiation fiber tracts were displayed with the software of diffusion tensor fiber tracking. RESULTS: In all subjects, the optic radiation could be readily identified in the DEC maps. The FA value was 0.509-/+0.029 in the left and 0.502-/+0.026 in the right, with the MD value of (0.763-/+0.050) x10(-3) and 0.748-/+0.052)x10(-3) mm2/s, respectively. No significant differences were found in the FA or MD value of the bilateral optic radiation (P>0.05). Diffusion tensor tractography (DTT) demonstrated that the 3 bundles of the optic radiation fibers were located in the lateral sagittal stratum, passing from the lateral geniculate body of the thalamus to the primary visual cortex. The dorsal and lateral bundles passed posteriorly to the superior bank of the calcarine cortex, while the ventral bundle passed anteriorly before making a sharp turn, known as the Meyer loop, and subsequently coursed posteriorly to terminate in the inferior margin of the calcarine cortex, which was consistent with the results of classic anatomical studies. CONCLUSION: As a novel method to study the relationship between visual function and optic pathway, DTI and DTT can show the FA and architecture of the optic radiation.

[Association of polymorphism of Met764Thr locus allele in ADAM33 gene with bronchial asthma and lung function of asthmatic subjects].

OBJECTIVE: To analyze the association of the polymorphism of Met764Thr with bronchial asthma and lung function of asthmatic subjects of Han nationality in Southern China. METHODS: In 164 unrelated patients with asthma and 112 unrelated healthy controls, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing were used to determine polymorphism of Met764Thr locus allele in ADAM33 gene. The clinical indexes associated with lung function (FVC%, FEV(1)%) were compared among the three genotypes (Met764/Met764, Met764/Thr764, Thr764/Thr764) in asthmatic subjects. RESULTS: No significant difference was found in the allele (Met764, Thr 764) frequency among populations in UK, US, German, Korean, and Southern China (chi(2) = 6.77, P > 0.05). The frequencies of the genotypes (Met764/Met764, Met764/Thr764, Thr764/Thr764) were respectively 78.7% (129), 18.3% (30), 3.0% (5) in 164 asthmatic subjects and respectively 91.1% (102), 6.3% (7), 2.7% (3) in the 112 controls. There was a significant difference in the distributions of the genotypes (Met764/Met764, Met764/Thr764, Thr764/Thr764) between asthmatic subjects and controls (chi(2) = 8.46, P < 0.05). The frequencies of alleles (Thr764) were respectively 12.2% in the asthmatic subjects and 5.8% in the controls. Significant difference was observed in the allele (Met764, Thr 764) frequency between the two groups (chi(2) = 6.27, P < 0.05). The presence of Thr764 allele of ADAM33 gene was found to be a greater risk factor in asthmatic subjects than in controls. The odds ratio (OR) of Met764/Thr764 and Met764/Thr764 + Thr764/Thr764 were 3.389 (1.430 - 8.030), 2.767 (1.308 - 5.854), respectively. When compared with Met764/Met764 genotype, all P < 0.05. There was a significant decrease in the FVC% and FEV(1)% levels of Met764/Thr764, Thr764/Thr764 and Met764/Met764 genotype. CONCLUSIONS: These results suggest that Met764Thr locus genetic polymorphism is associated with susceptibility of asthma and clinical indexes of lung function of asthmatic subjects of Han nationality in Southern China.

[Imaging findings of craniopharyngioma in relation to its surgical management: a retrospective analysis].

OBJECTIVE: To analyze the CT and magnetic resonance imaging (MRI) findings of craniopharygioma and explore the correlation between the pathological findings and clinical features of the disease. METHODS: The CT and MRI findings of 123 pathologically confirmed craniopharygioma cases were reviewed retrospectively in conjunction with the pathological findings and surgical data. RESULTS: This patient cohort consisted of 70 male and 53 female patients with their age ranging from 1 to 72 years (mean 23.82 years). Of the 123 craniopharyngioma patients, 59 were found to have adamantinous craniopharyngiomas, 41 had papillary squamous craniopharyngiomas, and 23 had mixed tumors. Solid tumor was found in 18 cases, cystic tumor in 38 cases, and calcification in 78 cases; in 23 cases, the posterior of the tumor did not exhibit clear boundary from the wall of the three cerebral ventricles, and in 11 cases CT and MRI displayed hypophysial stalk, which was found intraoperatively in 53 cases. CONCLUSIONS: MRI allows clear vision of the range of craniopharyngioma involvement and the anatomical structures surrounding the tumor. CT, on the other hand, shows better performance in displaying the calcification foci. Accurate identification of the site, dimension, calcification patterns and relation between the hypophysial stalk and hypothalamus by the imaging modalities significantly benefits the optimization of the surgical plan for the tumor.

[Association between ADAM33 gene polymorphism and bronchial asthma in South China Han population].

OBJECTIVE: To investigate the association between the polymorphism of T(1) locus allele in ADAM33 gene and bronchial asthma in South China Han population. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing were used to determine the polymorphism of T(1) locus allele in ADAM33 gene in 160 unrelated patients with asthma and 95 unrelated healthy controls from South China Han population. RESULTS: No significant difference was found in T(1) locus allele distribution frequency in populations of UK, US, Germany, Korea, and South China (Chi(2)=9.085, P=0.109). The frequencies of the genotypes (TT, TC, CC) were 80.6% (n=129), 16.9% (n=27) and 2.5% (n=4) in the 160 asthmatic patients and 94.7% (n=90), 3.2% (n=3) and 2.1% (n= 2) in the 95 controls, respectively, showing a significant difference in the distribution of the genotypes (TT, TC, CC ) between asthmatic patients and healthy controls (Chi(2)=10.955, P<0.05). The frequencies of the alleles (T, C) were 0.891 and 0.109 in the asthmatic patients and 0.963 and 0.037 in the controls, respectively, showing also a significant difference in the allele frequency between them (Chi square =8.299, P<0.05). The presence of C allele of ADAM33 gene T1 locus was found to be a greater risk factor in asthmatic patients than in the healthy controls. The odds ratio (OR) of TC and TC+CC were 6.279 (1.849-21.328) and 4.326 (1.620-11.550), respectively, with P value of 0.001 and 0.002, respectively, in comparison with TT genotype. CONCLUSION: The polymorphism of T(1) locus allele in ADAM33 gene is associated with the susceptibility to asthma in South China Han population.

[High-field MRI and pathological diagnosis of supratentorial primitive neuroectodermal tumors].

OBJECTIVE: To analyze the magnetic resonance imaging (MRI) features of supratentorial primitive neuroectodermal tumors (sPNET) and improve the diagnosis of this disease. METHODS: MRI manifestations of 14 cases of PNET were retrospectively analyzed and compared with their pathological features. RESULTS: The supratentorial lesions involved the occipital lobe in 4, frontal lobe in 3, fronto-occipital lobe in 2, temporo-occipital lobe in 3, lateral ventricle in 1 case and the saddle region in 1. All the lesions were large in volume and most of them presented heterogeneous signals in MRI. Of the 14 cases, 12 showed cystic degeneration and necrosis, 2 had hemorrhage and 6 showed signs of emptied small blood vessels. Twelve cases had heterogeneous enhancement and 2 had moderate enhancement. Pathologically, 10 cases of neuroblastomas were identified, along with 3 ganglioneuroblastomas and 1 atypical rhabdoid tumor. CONCLUSION: MRI findings of PNET are rather characteristic to assist in the diagnosis and treatment of the disease, but a final definite diagnosis still relies on pathological examination.

Proton magnetic resonance spectroscopy for radiation encephalopathy induced by radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: To understand the metabolic patterns of NAA, Cr and Cho in radiation encephalopathy (RE) induced by radiotherapy for nasopharyngeal carcinoma detected by proton magnetic resonance spectroscopy (1H-MRS), and provide useful evidence for early diagnosis of this disease. METHODS: Chemical shift imaging 1H-MRS was performed for 10 healthy volunteers (control group) and 21 patients with pathologically confirmed nasopharyngeal carcinomas, who developed RE after radical radiotherapy as diagnosed on the basis of clinical symptoms and imaging findings. The contents of NAA, Cr and Cho in the pixels were observed, the metabolic maps generated, and NAA/Cr and NAA/Cho ratios calculated for all the subjects. RESULTS: The concentrations of NAA, Cr and Cho were rarely observed in the necrosis and liquefaction foci in the patients, nor were any signals displayed on their metabolic maps. In the visible lesions, with the exception of the necrosis and liquefaction foci, the content of NAA increased slightly, whereas that of Cr or Cho decreased obviously or even became absent. An area around the lesion was identified where NAA content decreased but Cr or Cho increased. The signal in the metabolic maps appeared indistinguishable. The NAA/Cr and NAA/Cho ratios were less than 1. Farther away from the visible lesions, the NAA, Cr and Cho contents remained normal with NAA/Cr and NAA/Cho ratios of less than 1. CONCLUSION: 1H-MRS is capable of displaying the patterns of metabolite changes in RE induced by radiotherapy, and identifying larger area of abnormal metabolism in RE than the visible lesion in MRI, which suggests the possibility of earlier detection of RE with 1H-MRS.

Magnetic resonance imaging findings in comparison with histopathology of heroin-associated encephalopathy.

OBJECTIVE: To review the magnetic resonance imaging (MRI) features and explore the histopathological basis of heroin-associated encephalopathy (HE). METHODS: The data were collected from 34 established HE cases diagnosed with epidemiological evidence, clinical manifestations, MRI findings and laboratory examination. Histopathological sections were obtained in 10 cases. All patients were examined with T1WI, T2WI and FLAIR using 1.5T MRI scanner. Four patients died and autopsy was performed in 2 of them. Eight patients underwent stereotactic cerebral biopsy and the results of pathological examination were compared with the MRI findings. RESULTS: All the 34 cases had low signals in T1WI but high signals in T2WI. Extensive involvement of the hemispheres beyond the cerebellar tentorium, brain stem and cerebellum was identified in 85.3% of the cases, and less than 10% had lesions involving only one of these three structures. Most of the lesions involved mainly the white matter, and 91.2% of the cases showed involvement of the bilateral hemispheres. Specific MRI features were found to help in HE diagnosis: lesions compromising the hemispheres beyond the cerebellar tentorium presented with the pattern resembling the Chinese character "eight", a hollow pattern was found in brain stem involvement, and "butterfly wing" pattern in cerebellar involvement. The abnormal signals were caused mainly by demyelination and vacuole formation in the white matter, and these vacuoles resulted in the sponge-like appearance of the white matter containing fluid. CONCLUSION: MRI can provide strong evidence for HE diagnosis and can be informative of the involvement, position and aggravation of the lesions with some characteristic MRI features. In most of the cases, a MRI-based diagnosis can be consistent with histopathological diagnosis.

Phase-contrast magnetic resonance angiography for assessment of intracranial venous sinus lesions.

OBJECTIVE: To review the presentations of intracranial venous sinus lesions in phase-contrast (PC) magnetic resonance angiography (MRA) and discuss the diagnostic value of this imaging modality for these lesions. METHODS: This study involved 52 patients with intracranial venous sinus lesions, including 21 with dural venous sinus malformation, 7 dural arteriovenous fistula (6 caroticocaveneous fistula, CCF), 5 venous sinus thrombus and 19 meningioma invading the venous sinuses. All patients underwent PC and time-of-flight (TOF) MRA with a 1.5 Tesla MR scanner, with 28 of them undergoing subsequent digital subtraction angiography (DSA). RESULTS: PC MRA showed extensive hyperintense signals that identified the lesions, feeding arteries, deferent veins and venous sinuses in 21 cases of dural arteriovenous fistula, but the lesion signals appeared homogeneous. In these cases, PC and TOF MRA had equally good performance in displaying the feeding arteries with success in 20 of the 21 cases (95.2%), whereas the former resulted in a greater rate of deferent vein display [90.5% (19/21)] than the latter [76.2% (16/21), P<0.05]. The 6 CCF cases showed ipsilateral cavernous sinus expansion and upper ophthalmic vein dilations. In the 5 cases of venous sinus thrombis, 4 had transverse sinus thrombus and 1 superior sagittal sinus thrombus. All the cases presented signal disappearance in the sinuses in PC MRA and hyperintense signals in MRI, and some cases had also cerebral superficial hemorrhage and edema. The 19 cases of meningioma invading the venous sinus displayed sinus shift, stenosis and occlusion in PC MRA. CONCLUSION: PC MRA has great advantages in displaying the anatomical structure and lesions of the venous sinuses.

[MRI features of 13 cases of intracranial ependymoma].

OBJECTIVE: To improve the accuracy of qualitative diagnosis of intracranial ependymomas by analyzing their magnetic resonance (MR) images. METHODS: The MR images of 13 cases of intracranial ependymomas confirmed by pathological examinations were investigated retrospectively. RESULTS: In the 10 cases of ventricle ependymomas, the tumors were identified in the fourth ventricle in 3 cases and in the lateral ventricle in 7 cases. The T(1)-weighted MR images presented isointense or hypointense signals and T(2)-weighted images showed inhomogeneous hyperintense ones. No edema occurred around these tumors, and the contrast-enhanced scans presented inhomogeneous enhancement. In the other 3 cases of ependymomas in the brain parenchyma, including 2 cases of supratentorial and 1 subtentorial ependymomas. The tumor parenchyma presented hypointense signals in T(1)-weighted MR images as compared to the signals of the brain parenchyma, and in T(2)-weighted images, the signals intensities were similar to or higher than those of the gray matter. Mild edema could be seen around the tumors. Enhanced scans of the tumor parenchyma showed mild to moderate enhancement. CONCLUSION: MR examination may help in the preoperative detection of intracranial ependymomas.

[Role of magnetic resonance imaging in the diagnosis of intracranial germinoma].

OBJECTIVE: To investigate the value of magnetic resonance imaging (MRI) in the diagnosis of intracranial germinoma. METHODS: A retrospective analysis of the MRI features was conducted in 19 cases of pathologically confirmed intracranial germinoma. RESULTS: The lesion was located in the sellar region in 10 cases, in the pineal region in 6 and in the thalamus and basal ganglia in 3. The characteristic MRI of intracranial germinoma included the following features: (1) In T1-weighted images (T1WI), the lesions were isointense or slightly hypointense, which appeared isointense or slightly hyperintense in T2-weighted images (T2WI). The germinoma in the sellar region and pineal region showed no edema, but those in the thalamus and basal ganglia showed minimal or moderate edema with space-occupying effect. (2) Homogeneous or inhomogeneous Gd-DTPA enhancement was observed in most of the tumors. CONCLUSION: Multiplanar imaging and Gd-DTPA enhancement in MRI are helpful in the diagnosis and differential diagnosis of intracranial germinoma, which presents features characteristic of the gender and age of the patients with the disease, location, size, form and image intensity of the lesion, and therefore, preoperative MRI diagnosis of the tumor can be possible.