Predictive Role of the Apparent Diffusion Coefficient and MRI Morphologic Features on IDH Status in Patients With Diffuse Glioma: A Retrospective Cross-Sectional Study.

PURPOSE: To evaluate isocitrate dehydrogenase (IDH) status in clinically diagnosed grade II~IV glioma patients using the 2016 World Health Organization (WHO) classification based on MRI parameters. MATERIALS AND METHODS: One hundred and seventy-six patients with confirmed WHO grade II~IV glioma were retrospectively investigated as the study set, including lower-grade glioma (WHO grade II, n = 64; WHO grade III, n = 38) and glioblastoma (WHO grade IV, n = 74). The minimum apparent diffusion coefficient (ADCmin) in the tumor and the contralateral normal-appearing white matter (ADCn) and the rADC (ADCmin to ADCn ratio) were defined and calculated. Intraclass correlation coefficient (ICC) analysis was carried out to evaluate interobserver and intraobserver agreement for the ADC measurements. Interobserver agreement for the morphologic categories was evaluated by Cohen's kappa analysis. The nonparametric Kruskal-Wallis test was used to determine whether the ADC measurements and glioma subtypes were related. By univariable analysis, if the differences in a variable were significant (P<0.05) or an image feature had high consistency (ICC >0.8; κ >0.6), then it was chosen as a predictor variable. The performance of the area under the receiver operating characteristic curve (AUC) was evaluated using several machine learning models, including logistic regression, support vector machine, Naive Bayes and Ensemble. Five evaluation indicators were adopted to compare the models. The optimal model was developed as the final model to predict IDH status in 40 patients with glioma as the subsequent test set. DeLong analysis was used to compare significant differences in the AUCs. RESULTS: In the study set, six measured variables (rADC, age, enhancement, calcification, hemorrhage, and cystic change) were selected for the machine learning model. Logistic regression had better performance than other models. Two predictive models, model 1 (including all predictor variables) and model 2 (excluding calcification), correctly classified IDH status with an AUC of 0.897 and 0.890, respectively. The test set performed equally well in prediction, indicating the effectiveness of the trained classifier. The subgroup analysis revealed that the model predicted IDH status of LGG and GBM with accuracy of 84.3% (AUC = 0.873) and 85.1% (AUC = 0.862) in the study set, and with the accuracy of 70.0% (AUC = 0.762) and 70.0% (AUC = 0.833) in the test set, respectively. CONCLUSION: Through the use of machine-learning algorithms, the accurate prediction of IDH-mutant versus IDH-wildtype was achieved for adult diffuse gliomas via noninvasive MR imaging characteristics, including ADC values and tumor morphologic features, which are considered widely available in most clinical workstations.

Quantitative susceptibility-weighted imaging in amyotrophic lateral sclerosis with 3.0 T magnetic resonance imaging.

OBJECTIVE: To evaluate alterations in phase-shift values in the gray matter of patients with amyotrophic lateral sclerosis (ALS) using susceptibility-weighted imaging (SWI). METHODS: Twenty patients with definite or probable ALS and 19 age- and sex-matched healthy controls were enrolled. SWI was performed using a 3.0 T magnetic resonance imaging scanner. Phase-shift values were measured in corrected phase images using regions of interest, which were placed on the bilateral precentral gyrus, frontal cortex, caudate nucleus, globus pallidus, and putamen. RESULTS: Phase-shift values of the precentral gyrus were significantly lower in ALS patients (-0.176 ± 0.050) than in the control group (-0.119 ± 0.016) on SWI. The average phase-shift values of the frontal cortex, caudate nucleus, globus pallidus, and putamen in ALS patients (-0.089 ± 0.023, -0.065 ± 0.016, -0.336 ± 0.191, and -0.227 ± 0.101, respectively) were not significantly different from those in the healthy controls (-0.885 ± 0.015, -0.079 ± 0.018, -0.329 ± 0.136, and -0.229 ± 0.083, respectively). CONCLUSIONS: Compared with healthy controls, ALS patients had a lower phase-shift value in the precentral gyrus, which may be related to abnormal iron overload. Thus, SWI is a potential method for identifying ALS patients.

[Value of Minimum Apparent Diffusion Coefficient in Peritumoral Edema in the Differential Diagnosis between Primary Central Nervous System Lymphoma and Glioblastoma].

Objective To evaluate the role of minimum apparent diffusion coefficient(MinADC) values in peritumoral edema based on magnetic resonance diffusion weighted imaging in the differential diagnosis between primary central nervous system lymphoma(PCNSL) and glioblastoma(GBM).Methods ADC values in peritumoral edema were measured in 16 patients with PCNSL(diffuse large B cell lymphoma) and 31 patients with GBM(WHO grade 4) confirmed by pathology.Regions of interests were manually drawn on ADC maps on peritumoral edema regions to obtain the MinADC value.Independent samples t-test and receiver operating characteristic analysis were performed for statistical analysis.Results The MinADC value [(1.20-1.45)×10-3 mm2/s,mean(1.35±0.68)×10-3 mm2/s] in PCNSL was significantly higher than that in GBM [(0.95-1.31)×10-3 mm2/s,mean(1.12±0.09)×10-3 mm2/s](t=9.977,P=0.000).The area under the receiver operating characteristic curve was 0.986,and the cutoff value of MinADC was 1.245×10-3 mm2/s for the differentiation between PCNSL and GBM,with the best combination of sensitivity(94.1%) and specificity(94.1%).Conclusion MinADC value can be a simple and effective measure for the differential diagnosis between PCNSL and GBM.

Differentiation between radiation-induced brain injury and glioma recurrence using 3D pCASL and dynamic susceptibility contrast-enhanced perfusion-weighted imaging.

PURPOSE: This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma. METHODS: Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions. The included patients were classified into a radiation-induced brain injury group (n = 34) and a glioma recurrence group (n = 35) based on subsequent pathologic analysis or clinical-radiological follow-up. Lesion perfusion parameter values (CBF and nCBF on pCASL, nrCBV and nrCBF on DSC-PWI) were measured and compared between the two groups using Student's t test. Pearson correlation analysis was performed to evaluate the correlation between pCASL (CBF and nCBF) and DSC-PWI (nrCBV and nrCBF) values in the contrast-enhanced lesions and in the perifocal edema regions. RESULTS: For the contrast-enhanced lesions, the CBF, nCBF, nrCBV, and nrCBF (29.46 ±â€¯15.08 ml/100 g/min, 1.11 ±â€¯0.50, 1.39 ±â€¯1.15, and 1.30 ±â€¯0.74) in the radiation-induced brain injury group were significantly lower than those (64.52 ±â€¯33.92 ml/100 g/min, 2.73 ±â€¯1.71, 3.39 ±â€¯2.12, and 3.20 ±â€¯1.95) in the glioma recurrence group (P < 0.001). The CBF and nCBF demonstrated strong correlation with nrCBV and nrCBF in the contrast-enhanced lesions. CONCLUSION: Radiation-induced brain injury and glioma recurrence can be reliably distinguished using both 3D pCASL and DSC-PWI. Contrast-free 3D pCASL is a suitable alternative to DSC-PWI for long-term follow-up in glioma patients with postoperative radiotherapy.

Differential diagnosis of mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and ischemic stroke using 3D pseudocontinuous arterial spin labeling.

PURPOSE: To evaluate the efficacy of 3D pseudocontinuous arterial spin labeling (3D pCASL) in the differential diagnosis between mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and acute ischemic stroke (AIS). MATERIALS AND METHODS: Conventional magnetic resonance imaging (MRI) including T2 -weighted imaging (T2 WI) and diffusion-weighted imaging (DWI), and 3D pCASL perfusion data were obtained on a 3.0T MR scanner in 16 newly appearing lesions in nine patients with MELAS and 14 acute lesions in 12 patients with AIS. A postlabeling delay (PLD) time of 2025 msec was applied. The cerebral blood flow (CBF) values were measured in the central part and the peripheral part of the lesions and the CBF values were compared between MELAS and AIS patients. RESULTS: The lesions of both MELAS and AIS showed high signal intensity on T2 WI and demonstrated hyperintensity on DWI. Compared with the perfusion defects or hypoperfusion in all AIS, hyperperfusion was revealed in 16 acute MELAS lesions, especially in the peripheral part of the lesions. The CBF values of 16 lesions in MELAS were 11.20-73.11 ml/100g/min in the central part and 65.33-169.11 ml/100g/min in the peripheral part. The CBF values of 14 lesions in AIS were 12.32-19.94 ml/100g/min in the central part and 11.66-18.37 ml/100g/min in the peripheral part. The CBF value of the peripheral part (119.80 ± 35.41) in MELAS was significantly higher than that (14.66 ± 2.61) in AIS (P = 0.0001). CONCLUSION: The whole-brain 3D pCASL technique might be useful in differentiating MELAS from AIS. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:199-206.

Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging.

OBJECTIVES: We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. METHODS: Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. RESULTS: The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 × 10(-3) mm(2)/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. CONCLUSIONS: pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. KEY POINTS: • pCASL shows positive correlation with DSC-PWI in astrocytic tumour grading. • ADC values based on ADC histograms can be an objective method. • Combination of DWI and pCASL or DSC-PWI can improve grading accuracy.

The role of magnetic resonance diffusion-weighted imaging and three-dimensional arterial spin labelling perfusion imaging in the differentiation of parasellar meningioma and cavernous haemangioma.

OBJECTIVE: To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. METHODS: Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T1- and T2-weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. RESULTS: MinADC was significantly lower and nCBF significantly higher in meningioma (n = 19) than cavernous haemangioma (n = 15). There was a significant negative correlation between minADC and nCBF (r = -0.605). CONCLUSION: DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous.

[Association of myocardial bridge of the left anterior descending coronary artery with coronary atherosclerotic stenosis in the segment proximal to the site of bridge].

OBJECTIVE: To investigate whether myocardial bridging (MB) is independently associated with coronary atherosclerosis proximal to MB in the left anterior descending coronary artery (LAD) identified by computed tomographic coronary angiography (CCTA). METHODS: From March 2011 to December 2012, patients (n=9 862) with suspected coronary disease underwent CCTA using dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack, and body mass index) and the results of CCTA were reviewed. Two radiologists evaluated the coronary artery for MB and coronary atherosclerosis stenosis (CAS) in LAD and made a diagnosis by consensus. Significant independent risk factors for CAS were investigated by multivariate logistic regression analysis. RESULTS: A total of 3 182 (32.3%) cases of MB and 3 359 cases of CAS of LAD were identified. No patient with CAS in the tunneled segment was found. The mean length of bridges and the mean thickness of the overlying myocardium was (17.3±5.2) mm and (1.2±0.9) mm, respectively. There were 1658 MB cases in 3 359 cases of LAD stenosis and 1 524 MB cases in 6 503 cases of no LAD stenosis (χ(2)=681.12, P<0.05). Logistic regression analysis showed that MB in the LAD were significantly associated with CAS in the proximal LAD (OR=3.07, 95%CI=2.81-3.37, P<0.001), and after final adjustment for age, gender, body mass index, family history of heart attack, smoking, hypertension, dyslipidemia, diabetes mellitus, and resting heart rate (OR=2.86, 95% CI=2.60-3.16, P < 0.001). CONCLUSION: MB in the LAD is independently associated with CAS in the proximal segment to MB.

[Differentiation between glioma recurrence and radiation-induced brain injuries using perfusion-weighted magnetic resonance imaging].

OBJECTIVE: To evaluate the role of perfusion weighted imaging (PWI) in the differentiation between recurrent glioma and radiation-induced brain injuries. METHODS: Twenty-three patients with previously resected and irradiated glioma, presenting newly developed abnormal enhancement, were included in the study. The final diagnosis was determined either histologically or clinicoradiologically. PWI was obtained with a gradient echo echo-planar-imaging (GRE-EPI)technique. The normalized relative cerebral blood volume (rCBV) ratio [rCBV (abnormal enhancement)/rCBV (contralateral tissue)], relative cerebral blood flow (rCBF) ratio [rCBF (abnormal enhancement)/rCBF(contralateral tissue)], mean transit time(MTT) ratio [MTT (abnormal enhancement)/MTT(contralateral tissue)],time to peak(TTP)ratio[TTP(abnormal enhancement)/TTP(contralateral tissue)],and bolus arrive time(BAT)ratio[BAT(abnormal enhancement)/BAT(contralateral tissue)] were calculated. The regions of interest (ROIs) consisting of 20-40mm(2) were placed in the abnormal enhanced areas on postcontrast T1-weighted images.Ten ROIs measurements were performed in each lesion.T test was used to determine whether there was a difference in the rCBV/rCBF/rMTT/rTTP/rBAT ratios between recurrent glioma and irradiated injuries.Significance was set to a P value <0.05. RESULTS: Thirteen of the 23 patients were proved recurrent glioma and 10 were proved radiation-induced brain injuries. The rCBV ratio (3.60±3.86 vs. 0.82 ± 0.74, P = 0.000)and rCBF ratio (2.88 ± 2.27 vs. 0.84 ± 0.80, P = 0.000) in glioma recurrence were markedly higher than those in radiation injuries. The areas under rCBV and rCBF ROC curve were both 0.8763. rMTT (P=0.204), rTTP (P=0.260), and rBAT (P=0.071) ratios showed no statistical difference between the two groups. CONCLUSION: PWI is an effective technique in distinguishing glioma recurrence from radiation injuries,and the ratios of rCBV and rCBF ratio differential diagnosis of critical value to 1.3088 and 1.1235, respectively, can be used as a reliable clinical indicator.

Mastoid surgery for secretory otitis media with mixed hearing loss / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the therapeutic effect of mastoid surgery for secretory otitis media with mixed hearing loss.</p><p><b>METHODS</b>A retrospective analysis was conducted of the data from 26 cases (43 ears) of secretory otitis media with bone conduction hearing loss collected from 2001 to 2008. Thirty-two ears were treated with mastoid surgery and myringotomy with insertion of ventilation tubes. All the patients received medications after the operation.</p><p><b>RESULTS</b>All the patients showed obvious improvement after mastoid surgery. The average pure tone of air conduction hearing threshold was about 25 dB after the surgery, with the average pure tone of bone conduction hearing threshold of about 15 dB. The patients were followed up for 1-2 years during which no significant change in hearing was recorded, and no middle ear effusion in the tympanic cavity was found after removal of the ventilation tubes.</p><p><b>CONCLUSION</b>Persistent secretory otitis media can be associated with mixed hearing loss, and mastoid surgery can significantly enhance the hearing level to produce positive therapeutic effects.</p>

Audiological assessment in 88 patients with otosclerosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the clinical data of the hearing in otosclerosis patients and explore their association with the clinical manifestations.</p><p><b>METHOD</b>A retrospective analysis of 88 otosclerosis cases (162 ears) was performed. Pure tone audiometry was performed in all the cases 1 to 3 days before the operation for speech analysis at the frequencies of 500, 1 k, 2 kHz and to determined the average pure-tone hearing threshold (PTA) and gas Bone gap (ABG). The incidence of carhart notch was observed in patients with simple conductive hearing loss and mixed hearing loss, and in the early, middle and late stage of otosclerosis.</p><p><b>RESULTS</b>Carhart notch occurred at significant higher incidence in patients with simple conductive hearing loss and in early otosclerosis (P<0.05).</p><p><b>CONCLUSION</b>For common otosclerosis, the lesion invades initially the vestibular window, round ligament and stapes floor, followed by the base of the cochlea, and therefore observation of the carhart notch may help determine the disease course.</p>

Therapeutic effects of small fenestra stapedotomy with semiconductor diode laser: a comparison with microdrill / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the effects of small fenestra stapedotomy with semiconductor diode laser and microdrill in patients with otosclerosis.</p><p><b>METHODS</b>Twenty-six patients (29 ears) undergoing stapedotomy with semiconductor diode laser and 19 patients (21 ears) with microdrill were compared for the hearing results and complication rates.</p><p><b>RESULTS</b>No statistically significant differences were found in postoperative speech frequency and high frequency pure tone average in closing the air-bone gap between the two groups. The ears treated by stapedotomy with semiconductor diode laser showed significantly better preoperative minus the postoperative air-bone gap and milder dizziness.</p><p><b>CONCLUSION</b>In spite of the good hearing outcomes in both groups, small fenestra stapedotomy with semiconductor diodelaser can achieve better results and reduce the incidence of complications.</p>