Purpose: The author compared three-dimensional computed tomographic angiography with combined volume rendering technique (3D-CTA VR) with three-dimensional digital subtraction angiography (3D-DSA) in the detection and characterization of intracranial aneurysms, in order to assess the diagnostic capability of 3DCTA VR. Materials and Methods: This study included 50 patients with suspected intracranial aneurysm who underwent both 3D-CTA VR and 3D-DSA, and who were subsequently confirmed as having aneurysms by intracranial operation or other neurointerventional procedures. The detectability and the characteristics of the aneurysms, such as their aneurysmal neck, direction, and vasospasm of the adjacent vessels, were evaluated retrospectively. Results: Sixty-five intracranial aneurysms were detected through surgery or other interventional procedures. 3D-DSA was more sensitive (96.92%) than 3D-CTA VR in the detection of the aneurysms. All of the aneurysms that were more than 3mm in size were detected with both techniques. 3D-DSA failed to reveal one posterior communicating artery aneurysm, while 3D-CTA VR missed three aneurysms. The aneurysmal necks were clearly visualized in 58 of 61 aneurysms (95.1%) on 3D-CTA VR, but all of the aneurysmal necks(100%) were clearly identified on 3D-DSA. Conclusion: 3D-CTA combined with VR technique showed good sensitivity for the depiction of intracranial aneurysms greater than 3 mm in size, and its usefulness in characterizing the aneurysms for surgical or endovascular treatment planning was equal to or less than that of 3D-DSA.
The choice of surgical treatment for meningiomas is affected by the subtype and clinical characteristics. Therefore, an accurate preoperative diagnosis is essential. Current magnetic resonance imaging (MRI) technology is unable to distinguish between meningioma subtypes. In the present study, we compared and evaluated the utility of conventional MRI, magnetic resonance fingerprinting (MRF), and diffusion-weighted imaging (DWI) in differentiating World Health Organization grade I transitional and fibrous meningiomas from meningothelial meningiomas.Forty-six patients with pathologically confirmed meningiomas (15 meningothelial, 18 transitional, and 13 fibrous) were enrolled in the present study. All patients underwent conventional MRI, MRF, and DWI scans before surgery using a 3T scanner. The Jonckheere-Terpstra test was used to analyze differences in the signal and enhancement characteristics of the three groups from T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI). To investigate the difference in quantitative T1 and T2 values derived from MRF and apparent diffusion coefficient (ADC) values between the three groups using the Kruskal-Wallis test, regions of interest (ROIs) were manually drawn on the parenchymal portion of the tumors; P<0.017 was considered statistically significant after Bonferroni correction for multiple comparison. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performances of the different parameters.Meningothelial meningiomas had significantly higher T1 and T2 values than transitional and fibrous meningiomas (all P<0.017). ROC analysis results revealed that the combination of T1 and T2 values had the largest area under the curve (AUC). The AUC for the combination of T1 and T2 values was 0.826 between meningothelial and transitional meningiomas, and the AUC for the combination of T1 and T2 values between meningothelial and fibrous meningiomas was 0.903. No significant differences were found in the T1 and T2 values between transitional and fibrous meningiomas. There were also no statistically significant differences in the conventional MRI (including T1WI, T2WI, and contrast-enhanced T1WI) and ADC values between the three meningioma subtypes (all P>0.05).MRF may provide more quantitative information than either conventional MRI or DWI for differentiating transitional and fibrous meningiomas from meningothelial meningiomas. T1 and T2 values derived from MRF may distinguish transitional and fibrous meningiomas from meningothelial meningiomas, and the combination of T1 and T2 values provides the highest diagnostic efficacy.
Objective To study the tumor border patterns of hepatocellular carcinoma (HCC) on lower field MRI and its pathological basis. Method Tumor border patterns on MRI of 33 cases of HCC were analyzed, and MRI pathologic correlation study of 24 resected HCC specimens were performed. Results ①The tumor border patterns of the 33 HCC on T 2WI were divided into three groups:well defined nonlobular margin (82/132 quadrants; 62.1%),well defined lobular margin (20/132 quadrants; 15.2%) and ill defined margin (30/132 quadrants;22.7%). ②The rate of same tumor border pattern of the in vivo and in vitro MRI HCC was 79.2%. ③Correlation between patterns of tumor border on MR scan and the pathological capsular patterns:most of the tumors with well defined nonlobular borders(88.2%) had complete capsules. Tumors with incomplete or irregular capsules were most commonly seen as well defined, lobular borders (67.5%) whereas most tumors without capsules had ill defined borders (66.7%). Correlation between the patterns of tumor border on MR studies and incidences of tumor invasion of surrounding hepatic tissues:scattered tumor cells in the surrounding hepatic tissues were found in 12/85(88.2%) areas with well defined nonlobular borders; 17/40(42.5%) areas with well defined, lobular borders; 25/45(55.6%) areas with ill defined borders. Conclusion The patterns of tumor borders on lower field MRI can accurately reflect circumstance of the tumor capsules, the tumor cell classification and the incidences of tumor invasion of surrounding hepatic tissue.
Objective
To investigate the cerebral blood flow in migraine without aura with three-dimensional arterial spin labeling technology.
Methods
From January 2013 to February 2016, magnetic resonance perfusion imaging was operated in 20 migraine patients without aura and 20 healthy controls by using arterial spin labeling, to determine their regional cerebral blood flow (rCBF) during migraine attacks and attack-free period. The significant difference was analyzed in rCBF between the two groups.
Results
The rCBF was significantly lower at the headache side during migraine period ((52.77±5.97) ml·100 g-1·min-1) than symmetrical side in the migraine patients without aura ((62.72±6.65) ml·100 g-1·min-1,t=3.780, P<0.01). The rCBF of temporosphenoid lobe in headache side in the migraine patients without aura ((53.97±5.87) ml·100 g-1·min-1) was significantly lower than corresponding region in the control group ((59.21±2.35) ml·100 g-1·min-1,t=4.449, P=0.001). And no significant difference in rCBF was found in migraine patients without aura under attack-free period.
Conclusions
Three-dimensional arterial spin labeling could quantitatively analyze the cerebral blood flow. Monitoring the perfusion difference in migraine patients could provide some references in the pathogenesis research and therapy.
Key words:
Migraine; Cerebral blood flow; Magnetic resonance imaging, arterial spin labeling; Case control study
Background The detection rate of lung nodules has increased considerably with CT as the primary method of examination, and the repeated CT examinations at 3 months, 6 months or annually, based on nodule characteristics, have increased the radiation exposure of patients. So, it is urgent to explore a radiation‐free MRI examination method that can effectively address the challenges posed by low proton density and magnetic field inhomogeneities. Purpose To evaluate the potential of zero echo time (ZTE) MRI in lung nodule detection and lung CT screening reporting and data system (lung‐RADS) classification, and to explore the value of ZTE‐MRI in the assessment of lung nodules. Study Type Prospective. Population 54 patients, including 21 men and 33 women. Field Strength/Sequence Chest CT using a 16‐slice scanner and ZTE‐MRI at 3.0T based on fast gradient echo. Assessment Nodule type (ground‐glass nodules, part‐solid nodules, and solid nodules), lung‐RADS classification, and nodule diameter (manual measurement) on CT and ZTE‐MRI images were recorded. Statistical Tests The percent of concordant cases, Kappa value, intraclass correlation coefficient (ICC), Wilcoxon signed‐rank test, Spearman's correlation, and Bland–Altman. The p ‐value <0.05 is considered significant. Results A total of 54 patients (age, 54.8 ± 11.9 years; 21 men) with 63 nodules were enrolled. Compared with CT, the total nodule detection rate of ZTE‐MRI was 85.7%. The intermodality agreement of ZTE‐MRI and CT lung nodules type evaluation was substantial (Kappa = 0.761), and the intermodality agreement of ZTE‐MRI and CT lung‐RADS classification was moderate (Kappa = 0.592). The diameter measurements between ZTE‐MRI and CT showed no significant difference and demonstrated a high degree of interobserver (ICC = 0.997–0.999) and intermodality (ICC = 0.956–0.985) agreements. Data Conclusion The measurement of nodule diameter by pulmonary ZTE‐MRI is similar to that by CT, but the ability of lung‐RADS to classify nodes from MRI images still requires further research. Level of Evidence 2 Technical Efficacy Stage 2
Purpose: Acute mesenteric ischemia (AMI) is one of the most dramatic abdominal emergencies. The most common cause of AMI is a thrombo-embolism of the mesenteric artery or vein. The aim of this study was to evaluate the feasibility of CT angiography for evaluating mesenteric vascular steno-occlusive lesion in AMI. Materials and Methods: Fifteen patients with clinically and angiographically proven AMI underwent a twophase CT. The CT angiographic images were reconstructed using a 3D rendering algorithm, such as the maximum intensity projection and volume-rendering. All the CT angiographic images were reviewed with respect to stenosis or occlusion of mesenteric vessel by the consensus of two radiologists, and were correlated with the findings of digital subtraction angiography. Results: Digital subtraction angiography (DSA) visualized 60 mesenteric vessels including the superior mesenteric artery (n=15) and vein (n=15), and the inferior mesenteric artery (n=15) and vein (n=15). DSA showed steno-occlusive lesions in 16 mesenteric vessels (13 superior mesenteric arteries, two superior mesenteric veins, and one inferior mesenteric artery). CT angiography detected steno-occlusive lesions in 16 mesenteric vessels (12 superior mesenteric arteries, one superior mesenteric vein, and three inferior mesenteric arteries). The sensitivity, specificity, and accuracy of CT angiography for evaluating mesenteric vascular steno-occlusive lesion were 87.5%, 95.4%, and 93.3%, respectively. Conclusion: CT angiography is an useful adjunct to abdominal CT in an AMI setting on account of its ability to detect the causes of AMI such as a steno-occlusive lesion of the mesenteric vessel.
This study explored the feasibility of reducing the scan time of Patlak parametric imaging on the uEXPLORER.A total of 65 patients (27 females and 38 males, age 56.1 ± 10.4) were recruited in this study. 18F fluorodeoxyglucose was injected, and its dose was adjusted by body weight (4.07 MBq/kg). Total-body dynamic scanning was performed on the uEXPLORER total-body Positron emission tomography/computed tomography (CT) scanner with a total scan time of 60 min from the injection. The image derived input function (IDIF) was obtained from the aortic arch. The voxelwise Patlak analysis was applied to generate the Ki images designated as GIDIF with different acquisition times (20-60, 30-60, 40-60, and 44-60 min). The population-based input function (PBIF) was constructed from the mean value of the IDIF from the population, and Ki images designated as GPBIF were generated using the PBIF. Nonlocalmeans (NLM) denoising was applied to the generated images to get two extra groups of (NLM-designated) images: GIDIF+NLM and GPBIF+NLM . Two radiologists evaluated the overall image quality, noise, and lesion detectability of the Ki images from different groups. The 20-60 min scans in GIDIF were selected as the gold standard for each patient. We determined that image quality is at sufficient level if all the lesions can be recognized and meet the clinical criteria. Ki values in muscle and lesion were compared across different groups to evaluate the quantitative accuracy.The overall image quality, image noise, and lesion conspicuity were significantly better in long time series than short time series in all four groups (all p < 0.001). The Ki images in the GIDIF and GPBIF groups generated from 30-min scans showed diagnostic value equivalent to the 40-min scans of GIDIF . While the image quality of the 16-min scans was poor, all lesions could still be detected. No significant difference was found between Ki values estimated with GIDIF and GPBIF in muscle and lesion regions (all p > 0.5). After applying the NLM filter, the coefficient of variation could be reduced on the order of (1%, 15%, 19%, and 37%) and (110%, 125%, 94%, and 69%) with four acquisition time schemes for lesion and muscle. The reduction percentage did not have a substantial difference in IDIF and PBIF group. The Ki images in the GIDIF+NLM and GPBIF+NLM groups generated from the 20-min acquisitions showed acceptable quality. All lesions could be found on the NLM processed images of the 16-min scans. No significant difference was found between Ki values produced with GIDIF+NLM and GPBIF+NLM in muscle and lesion regions(all p > 0.7).The Ki images generated by the PBIF-based Patlak model using a 20-min dynamic scan with the NLM filter achieved a similar diagnostic efficiency to images with GIDIF from 40-min dynamic data, and there is no significant difference between Ki images generated using IDIF or PBIF (p > 0.5).
【Objective】 To evaluate clinical value of diffusion weighted 3.0T MR imaging in detecting lesions and metastasis in malignant tumors of female pelvic. 【Methods】 3.0T MR imaging of 26 female patients with malignant masses of pelvic were retrospectively analyzed, including 17 cervix carcinoma (14 preoperative and 3 recurrence of postoperative), 7 endometrial cancer (5 preoperative and 2 recurrence of postoperative), 1 colon cancer (recurrence of postoperative), and 1 ovarian cancer (recurrence of postoperative). Apparent diffusion coefficient (ADC) of all the primarily lesions and metastasis were measured and compared with the ADC of normal tissue (internal obturator muscle). Conventional 3.0T MRI and DWI combined with conventional MRI were compared in detecting lesions. 【Results】 1) Measurement and comparison of the ADC value of malignant lesions and normal tissue: the difference was statistically significant among the primarily lesions, metastasis and internal obturator muscle(P = 0.024). The difference was statistically significant between the primarily lesions and internal obturator muscle (P = 0.012). The difference was statistically significant between the metastasis and internal obturator muscle (P = 0.021). The difference was not statistically significant between the primarily lesions and metastasis (P = 0.402). 2) Comparison of the ability of the conventional 3.0T MRI and DWI combined with conventional MRI in detecting malignant lesions: there were 43 and 88 lesions detected by conventional MR group and DWI combined with conventional MR group respectively. The difference was statistically significant between the two groups (P 0.001). 【Conclusion】 The ADC value of the diffusion weighted 3.0T MRI could reflect the diffusion limited of the lesions quantitatively, and identify the benign and malignant lesions. Diffusion weighted imaging with background suppression could display the malignant lesions in female pelvic clearly and directly with the high resolution and high clinical value.
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