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Objective This study aimed to ascertain the minimum gadolinium dosage on contrast-enhanced (CE) T2 fluid-attenuated inversion recovery (FLAIR) at appropriate imaging time. Methods Different dosages of gadodiamide were imaged with a 3.0-T magnetic resonance scanner for T2-FLAIR and T1WI. Twenty glioma-induced rat models were randomly assigned into 4 groups (1/2, 1/4, 1/6, 1/8 of routine dosage) and imaged for T2-FLAIR and T1WI preinjection and postinjection of gadodiamide. Contrast-enhanced T2-FLAIR was acquired for 8 repetitions postinjection. Enhancement effects were assessed by calculating contrast-noise ratio and contrast ratio using Kruskal-Wallis and Mann-Whitney rank sum test. Results The in vitro experiment showed that gadodiamide at 1/4 of the T1WI dosage presented the best contrast on CE-T2-FLAIR. For in vivo study, the best enhancement effect on CE-T2-FLAIR was achieved at 1/2 of the routine dosage at 8 to 12 minutes of delayed scanning. Compared with CE-T1WI at routine dosage, CE-T2-FLAIR at 1/2 gadodiamide dosage presented similar enhancement effects with no statistical difference (P = 0.244 and 0.090 for contrast-noise ratio and contrast ratio, respectively). Conclusions Contrast-enhanced T2-FLAIR imaging with half of T1WI routine gadodiamide dosage can produce similar enhancement effects to CE-T1WI when characterizing brain gliomas. The cut-down of contrast agent dosage may help reduce gadolinium accumulation in certain tissues.

BackgroundSolitary intracranial hypothalamic mass occurs rarely. The etiological diagnosis of solitary hypothalamus lesion is challenging and often unachievable. Although previous studies indicated that lesions affecting the hypothalamus often cause significant metabolic disorders, few reports about the metabolic disturbances of patients with solitary hypothalamic mass have been reported.MethodTwenty-five patients with solitary hypothalamus lesions who had been evaluated and treated in Huashan Hospital from January 2010 to December 2020 were retrospectively enrolled. The clinical manifestations, radiological features, endocrine and metabolic disorders, and pathology were analyzed.ResultsThe male to female ratio was 5/20. The median age of onset was 22 (19, 35) years old. The most common initial symptom was polydipsia/polyuria (19/25, 76.0%) and amenorrhea (9/20, 45.0%). A high prevalence of hypopituitarism of different axes was found, with almost all no less than 80%. Central hypogonadism (21/22, 95.5%) and central diabetes insipidus (19/21, 90.5%) were the top two pituitary dysfunctions. Conclusive diagnoses were achieved by intracranial surgical biopsy/resection or stereotactic biopsy in 16 cases and by examining extracranial lesions in 3 cases. The pathological results were various, and the most common diagnoses were Langerhans cell histiocytosis (7/19) and hypothalamitis (5/19). The mean timespan from onset to diagnosis in the 19 cases was 34 ± 26 months. Metabolic evaluations revealed remarkable metabolic disorders, including hyperlipidemia (13/16, 81.3%), hyperglycemia (10/16, 62.5%), hyperuricemia (12/20, 60%), overweight/obesity (13/20, 65.0%), and hepatic adipose infiltration (10/13, 76.6%).ConclusionEither surgical or stereotactic biopsy will be a reliable and relatively safe procedure to help to confirm the pathological diagnosis of solitary hypothalamic mass. Metabolic disorders were severe in patients with solitary hypothalamic mass. The management of such cases should cover both the treatment of the primary disease, as well as the endocrine and metabolic disorders

OBJECTIVE To explore the value of magnetic resonance imaging (MRI) textures and its correlation with histopathological malignancy of gliomas by magnetic resonance (MR) navigated stereotactic biopsy. METHODS A total of 36 diffuse glioma cases and 64 puncture targets were included. All patients underwent a preoperative MR scan and intraoperative MR-navigated stereotactic biopsy. The histopathological diagnosis was grade II or grade III diffuse glioma. Regions of interest consistent with puncture targets were delineated on T1-weighted brain volume with gadolinium contrast enhancement images, and textures were extracted using Omni Kinetics software. Mann-Whitney rank sum test was used to analyze texture differences between grade II and grade III samples. False discovery rate (FDR) correction was applied to correct for multiple comparisons. Receiver operating characteristic curves evaluated the diagnostic value of textural analysis for grading gliomas. Correlation between MRI textures and histopathology was examined by Spearman correlation test. RESULTS Texture features, including max intensity, 95th quantile, range, variance, standard deviation, sum variance, and cluster prominence were higher in grade III glioma targets than grade IIs, grade II gliomas showed increased uniformity and short run low gray-level emphasis values (P and qFDRcorr < 0.05). Area under the curve was 0.887 (95% confidence interval, 0.805-0.969; P < 0.001) with combined textures in glioma grading. The listed first-order and gray-level cooccurrence matrix textures were correlated with Ki-67 labeling index. Gray-level cooccurrence matrix and gray-level run length matrix textures were correlated with isocitrate dehydrogenase 1 mutation. CONCLUSIONS Textures on T1-weighted brain volume with gadolinium contrast enhancement images differ between grade III and II gliomas and are correlated with Ki-67 labeling index and isocitrate dehydrogenase 1 mutation.

BackgroundMultimodal CT, including CT angiography (CTA) and CT perfusion (CTP), was increasingly used in stroke triage. This study was to determine the relationship between a new integrated parameter—both collateral circulation and relative permeability surface (PS)—and the hemorrhagic transformation (HT) in acute ischemic stroke (AIS) with middle cerebral artery occlusion (MCAO).MethodsWe retrospectively reviewed consecutive AIS patients with MCAO who underwent baseline CTA/CTP within 4 h of symptom onset and follow-up susceptibility-weighted imaging (SWI) within 3 weeks. Collateral circulation was assessed on the baseline CTA. Baseline CTP data were postprocessed to generate PS parameter. The patients with poor collateral circulation and at the same time with high relative PS were classified as the group of both poor collateral circulation and high relative PS. HT was defined according to European Cooperative Acute Stroke Study II criteria on follow-up SWI imaging. Multivariate logistic regression analysis was performed using HT as an outcome variable.ResultsThe group of patients with both poor collateral circulation and high relative PS was thirteen and thirty-three (52%) developed HT of the final cohort sixty-three AIS patients with MCAO. Multivariate logistic analysis revealed the new integrated parameter—both collateral circulation and relative PS (odds ratio, 16.59; 95% confidence interval, 13.09–19.10; P < 0.001) was independent predictor of HT. The area under the curve was 0.85 (95% confidence interval, 0.81–0.89). The sensitivity was 57%, specificity 97% and positive predictive value 92%, negative predictive value 58%.ConclusionsFor AIS patients with MCAO, these with poor collateral circulation on CTA and at the same time with high relative PS on CTP were at high risk for HT.

OBJECTIVE Cushing disease is a potentially fatal endocrine disorder caused by adrenocorticotropin (ACTH)-secreting microadenomas in the pituitary gland. Accurate detection and localization of the adenomas is the key to clinical treatment. This study analysed the value of contrast-enhanced Sampling Perfection with Application-optimized Contrasts using different flip angle Evolutions (SPACE) sequence in magnetic resonance imaging (MRI) assessment of ACTH-secreting pituitary microadenomas. DESIGN AND PATIENTS We carried out a retrospective study in which 45 patients with ACTH-secreting pituitary microadenomas were enrolled. Dynamic contrast-enhanced (DCE) coronal T1-SE sequence was performed. A contrast-enhanced coronal SPACE sequence was added immediately after DCE MRI finished. Two independent observers assessed the tumour existence and location, then the results were compared with surgical findings. RESULTS Twenty-four lesions (53.3%) were detected by the DCE T1-SE sequence alone, while 35 lesions (80.0%) were detected with the addition of contrast-enhanced SPACE sequence. The sensitivity (58.5% vs. 85.3%; p

Rationale and Objectives The purpose of this study was to correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with data from a specific marker of hypoxia, hypoxia-inducible factor 1α (HIF-1α), in human gliomas on a point-to-point basis by using coregistered magnetic resonance imaging and frameless stereotactic biopsies. Materials and Methods Thirty-four patients with treatment-naive gliomas underwent DCE, axial T1-weighted, T2-weighted, T2-weighted fluid acquisition of inversion recovery, and three-dimensional T1-weighted brain volume with gadolinium contrast enhancement sequences on a 3.0-T magnetic resonance scanner before stereotactic surgery. Quantitative perfusion indices such as endothelial transfer constant, fractional extravascular extracellular space volume, fractional plasma volume, and reflux rate were measured at corresponding stereotactic biopsy sites. Each sample was considered an independent measurement, and its histology grade was diagnosed. HIF-1α expression was quantified from the point-to-point biopsy tissues. Analyses of receiver operating characteristic curves were done for HIF-1α to discriminate different grades of glioma. To look for correlations between immunohistochemical parameters and DCE indices, Spearman's correlation coefficient was used. Results Seventy biopsy samples from 34 subjects were included in the analysis. Mean immunoreactivity scores of HIF-1α were 2.75 ± 1.11 for grade II (n = 24), 6.20 ± 2.33 for grade III (n = 20), and 10.46 ± 2.42 for grade IV (n = 26). HIF-1α showed very good-to-excellent accuracy in discriminating grade II from III, III from IV, and II from IV (area under the curve = 0.838, 0.862, and 0.994, respectively). Endothelial transfer constant and fractional extravascular extracellular space volume showed a significantly positive correlation with HIF-1α expression (r = 0.686, P Conclusion Our study demonstrated HIF-1α to be a significant predictor of different grades of gliomas with high sensitivity and specificity. DCE-MRI is a useful, noninvasive imaging tool for quantitative evaluation of HIF-1α, and its parameters may be used as a surrogate for HIF-1α expression.

To explore the value of magnetic resonance textural analysis (MRTA) in assessing consistency of pituitary macroadenoma (PMA) based on contrast enhanced (CE) three-dimensional sampling perfection with application-optimized contrasts by using different flip angle evolution (3D-SPACE) images.Fifty-three patients with PMAs that underwent CE 3D-SPACE scanning by 3.0 T MRI and endoscopic trans-sphenoidal surgery were included in the present study. Consistency levels of PMAs were evaluated intraoperatively by two neurosurgeons. Each resection specimen was stained with HE and anti-collagen IV. MRTA was conducted and texture features were calculated. An unpaired t-test was used to analyze the differences of texture features between soft and hard PMAs. ROC curves by individual and combined features were used to calculate the diagnostic accuracy of MRTA in predicting PMA consistency.First-order energy and second-order correlation negatively correlated with hard PMAs, while first-order entropy and second-order variance, sum variance, and sum entropy positively correlated with stiffness. All showed significant differences between soft and hard PMAs (P 0.05). Diagnostic accuracy of combined negative features could achieve an AUC of 0.819, sensitivity of 88.9%, specificity of 61.5%, PPV of 70.6%, NPV of 84.2% and positive features could achieve an AUC of 0.836, sensitivity of 85.2%, specificity of 69.2%, PPV of 74.2%, NPV of 81.8% (P 0.001).MRTA using CE 3D-SPACE images is helpful for assessing PMA consistency preoperatively and noninvasively.

To predict silent corticotroph adenomas (SCAs) among non-functioning pituitary adenomas preoperatively using noninvasive radiomics. A total of 302 patients including 146 patients diagnosed with SCAs and 156 patients with non-SCAs were enrolled (training set: n = 242; test set: n = 60). Tumor segmentation was manually generated using ITK-SNAP. From T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and contrast-enhanced T1WI, 2550 radiomics features were extracted using Pyradiomics. Pearson’s correlation coefficient values were calculated to exclude redundant features. Several machine learning algorithms were developed to predict SCAs incorporating the radiomics and semantic features including clinical, laboratory, and radiology-associated features. The performance of models was evaluated by AUC. Patients in the SCA group were younger (49.5 vs 55.2 years old) and more female (85.6% vs 37.2%) than those in the non-SCA group (p

To investigate the correlation between enhancement degrees of brain metastases on contrast-enhanced T2-fluid-attenuated inversion recovery (CE-T2 FLAIR) and vascular permeability parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Thirty-nine patients with brain metastases were prospectively collected. They underwent non-enhanced T2 FLAIR, DCE-MRI, CE-T2 FLAIR, and contrast-enhanced three-dimensional brain volume imaging (CE-BRAVO). Quantitative parameters of DCE-MRI were evaluated for all lesions, which included volume transfer constant (Ktrans), rate constant (Kep), and fractional volume of the extracellular extravascular space (Ve). Contrast ratio (CR) and percentage increase (PI) values of all lesions on CE-T2 FLAIR were also measured. The tumor enhancement degree on CE-T2 FLAIR in relation to CE-BRAVO was visually classified as higher (group A), equal (group B), and lower (group C). A total of 82 brain metastases were evaluated, including 31 in group A, 19 in group B, and 32 in group C. The Ktrans and Kep were negatively correlated with the CR (ρ = − 0.551, p

To evaluate for the first time the performance of a deep learning method based on no-new-Net for fully automated segmentation and volumetric measurements of intracerebral hemorrhage (ICH), intraventricular extension of intracerebral hemorrhage (IVH), and perihematomal edema (PHE) in primary ICH on CT. Three hundred and eighty primary ICH patients who underwent CT at hospital arrival were divided into a training cohort (n = 300) and a validation cohort (n = 80). An independent cohort with 80 patients was used for testing. Ground truth (segmentation masks) was manually generated by radiologists. Model performance on lesion segmentation and volumetric measurement of ICH, IVH, and PHE were evaluated by comparing the model results with the segmentations performed by radiologists. In the test cohort, the Dice scores of lesion segmentation were 0.92, 0.79, and 0.71 for ICH, IVH, and PHE, respectively. The sensitivities were 0.93 for ICH, 0.88 for IVH, and 0.81 for PHE. The positive predictive values were 0.92, 0.76, and 0.69 for ICH, IVH, and PHE, respectively. Excellent concordance (concordance correlation coefficients [CCCs] ≥ 0.98) of ICH and IVH and good concordance of PHE (CCCs ≥ 0.92) were demonstrated between manually and automatically measured volumes. The model took approximately 15 s to provide automatic segmentation and volume analysis for each patient. Our model demonstrates good reliability for automatic segmentation and volume measurement of ICH, IVH, and PHE in primary ICH, which can be useful to reduce the effort and time of doctors to calculate volumes of ICH, IVH, and PHE. • Deep learning algorithms can provide automatic and reliable assessment of intracerebral hemorrhage, intraventricular hemorrhage, and perihematomal edema on CT. • Non-contrast CT-based deep learning method can be helpful to provide efficient and accurate measurements of ICH, IVH, and PHE in primary ICH patients, thereby reducing the effort and time of doctors to segment and calculate volumes of ICH, IVH, and PHE in primary ICH patients.

The current positive computed tomography (CT) contrast agents (PCTCAs) including clinical iodides, present high CT density value (CT‐DV). However, they are incapable for the accurate diagnosis of some diseases with high CT‐DV, such as osteosarcoma. Because bones and PCTCAs around osteosarcoma generate similar X‐ray attenuations. Here, an innovative strategy of negative CT contrast agents (NCTCAs) to reduce the CT‐DV of osteosarcoma is proposed, contributing to accurate detection of osteosarcoma. Hollow mesoporous silica nanoparticles, loading ammonia borane molecules and further modified by polyethylene glycol, are synthesized as NCTCAs for the diagnosis of osteosarcoma. The nanocomposites can produce H2 in situ at osteosarcoma areas by responding to the acidic microenvironment of osteosarcoma, resulting in nearly 20 times reduction of CT density in osteosarcoma. This helps form large CT density contrast between bones and osteosarcoma, and successfully achieves accurate diagnosis of osteosarcoma. Meanwhile, The NCTCAs strategy greatly expands the scope of CT application, and provides profound implications for the precise clinical diagnosis, treatment, and prognosis of diseases., A negative computed tomography (CT) contrast agent based on hollow mesoporous silica nanoparticles@ammonia borane@polyethylene glycol nanocomposite can produce H2 in situ at osteosarcoma areas by responding to the acidic microenvironment of osteosarcoma, and prominently reduce the CT density of osteosarcoma, which can form large CT density difference contrast between bones and osteosarcoma, and further realize accurate diagnosis of malignant osteosarcoma.

Bismuth (Bi)‐based nanomaterials can exhibit characteristic attenuation depending on different levels of X‐ray energy, known as “energy‐dependent attenuation”. Liver‐fibrosis‐targeted Bi‐based nanomaterials, BiF(3)@PDA@HA, can exhibit characteristic attenuation on monoenergetic X‐ray, endowing the diagnosis of liver fibrosis via monoenergetic imaging of spectral computed tomography. More details can be found in article number 2002548 by Yan Zhou, Wenbo Bu, Zhenwei Yao and co‐workers. [Image: see text]

Background The genetic status of 1p/19q is important for differentiating oligodendroglioma, isocitrate-dehydrogenase (IDH)-mutant, and 1p/19q-codeleted from diffuse astrocytoma, IDH-mutant according to the 2016 World Health Organization (WHO) criteria. Purpose To assess the value of magnetic resonance textural analysis (MRTA) on T2 fluid-attenuated inversion recovery (FLAIR) images for making a genetically integrated diagnosis of true oligodendroglioma by WHO guidelines. Study type Retrospective case control. Subjects In all, there were 54 patients with a histopathological diagnosis of diffuse glioma (grade II). All were tested for IDH and 1p/19q. Field strength/sequence 3.0T, including T2 FLAIR sequence, axial T1 -weighted, and T2 -weighted sequence. Assessment MRTA on a representative tumor region of interest (ROI) was made on preoperative T2 FLAIR images around the area that had the largest diameter of solid tumor using Omni Kinetics software. Statistical tests Differences between IDH-mutant and 1p/19q-codeleted and IDH-mutant and 1p/19q-intact gliomas were analyzed by the Mann-Whitney rank sum test. Receiver operating characteristic curves (ROC) were created to assess MRTA diagnostic performance. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated with a cutoff value according to the Youden Index. Results Comparisons demonstrated significant differences in kurtosis (P = 0.007), energy (0.008), entropy (0.008), mean deviation (MD) ( 0.7. MD had the highest diagnostic performance, with AUC = 0.878, sensitivity = 94.1%, specificity = 75.0%, PPV = 86.5%, and NPV = 88.2%. Data conclusion MRTA on T2 FLAIR images may be helpful in identifying oligodendroglioma, IDH-mutant, and 1p/19q-codeleted. Level of evidence 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.

Gd3+-based contrast agents (CAs) are the most prevailing and widely used for enhanced magnetic resonance imaging (MRI). Numbers of approaches have been developed to regulate the key parameters in order to obtain high-relaxivity CAs, according to the classic Solomon–Bloembergen–Morgen theory. Herein, a method of controlling oxygen vacancies in inorganic nanosized CAs has been developed for largely accelerated proton relaxation to obtain a high r1 value. Such a strategy is verified on oxygen-deficient PEG-NaxGdWO3 nanorods, which exhibit a remarkable r1 value up to 80 mM–1 s–1 (at 0.7 T) and a high r1 value of 32.1 mM–1 s–1 on a clinical 3.0 T scanner, offering an excellent blood pool MRI performance at a low dose. Meanwhile, free electrons and/or oxygen-vacancy-induced small polarons can endow PEG-NaxGdWO3 nanorods with significant photothermal conversion for MRI-guided photothermal therapy.

OBJECTIVE The study aimed to characterize magnetic resonance imaging (MRI) findings of solitary hypothalamitis and evaluate their clinical value in diagnosis. METHODS Magnetic resonance imaging scans, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and contrast-enhanced T1-weighted sequences, of 8 biopsy-proven hypothalamitis lesions were retrospectively analyzed along with MRI features including size, shape, signal intensity, enhancement pattern, correlation with adjacent tissues, and changes in infundibular stalk and sella turcica. RESULTS Of 8 patients, 5 were diagnosed with lymphoplasmacytic proliferative inflammation, 2 with Langerhans cell histocytosis, and 1 with Rosai-Dorfman disease. Solitary hypothalamitis predominantly demonstrated mild hypointensity/isointensity in T1WI and mild hyperintensity in T2-weighted imaging. In contrast-enhanced T1WI, all lesions showed heterogeneous but primarily peripheral enhancement patterns. Seven cases showed the polygon sign. In T1WI, the normal high signal intensity of neurohypophysis was absent from all patients, with no infundibular stalk thickening. Seven patients presented with optic chiasma edema, and 5 with edema-like changes along the optic tract (OTE), but most showed no visual impairment (n = 7). CONCLUSIONS Magnetic resonance imaging, particularly postcontrast MRI, is the optimal modality for assessment of hypothalamic lesions. Peripheral enhancement with polygon sign and optic tract or chiasm edema without visual impairment are highly suggestive of hypothalamitis.

BackgroundIt is difficult to distinguish atypical cancerous nodule from cirrhosis nodule.PurposeTo investigate the value of spectral computed tomography (CT) imaging parameters in differentiating h...

Multimodal magnetic resonance (MR) imaging, including MR angiography (MRA) and MR perfusion (MRP), plays a critical role in the diagnosis and surveillance of acute ischemic stroke. However, these techniques are hindered by the low T1 relaxivity, short circulation time, and high leakage rate from vessels of clinical Magnevist. To address these problems, nontoxic polyethylene glycol (PEG)ylated upconversion nanoprobes (PEG-UCNPs) are synthesized and first adopted for excellent MRA and MRP imaging, featuring high diagnostic sensitivity toward acute ischemic stroke in high-resolution imaging. The investigations show that the agent possesses superior advantages over clinical Magnevist, such as much higher relaxivity, longer circulation time, and lower leakage rate, which guarantee much better imaging efficiency. Remarkably, an extremely small dosage (5 mg Gd kg(-1) ) of PEG-UCNPs provides high-resolution MRA imaging with the vascular system delineated much clearer than the Magnevist with clinical dosage as high as 108 mg Gd kg(-1) . On the other hand, the long circulation time of PEG-UCNPs enables the surveillance of the progression of ischemic stroke using MRA or MRP. Once translated, these PEG-UCNPs are expected to be a promising candidate for substituting the clinical Magnevist in MRA and MRP, which will significantly lengthen the imaging time window and improve the overall diagnostic efficiency.

CT angiography (CTA) and CT perfusion (CTP) imaging can play important roles in the workup of acute ischemic stroke. However, these techniques are hindered by the large amounts of contrast agents (CAs) required, high doses of X-ray radiation exposure, and nephrotoxicity of the clinical used iodinated CAs. To address these problems, we synthesized and validated a novel class of CT CAs, PEGylated BaHoF5 nanoparticles (NPs), for CTA and CTP imaging, which can greatly enhance the diagnostic sensitivity and accuracy of ischemic stroke. These agents have unique advantages over conventional iodinated CT agents, including much lower dosage required, major metabolism through liver and better imaging efficiency at different voltages. Once translated, these PEGylated BaHoF5 NPs can replace iodine-based CAs for diagnostic contrast-enhanced imaging of patients with kidney/heart diseases and improve the overall diagnostic index with negligible side effects.

Background The diagnosis of a tumor depends on accurate identification of the target area for biopsy. However, tumor heterogeneity and the inability of conventional structural data for identifying the most malignant areas can reduce this accuracy. Purpose To evaluate the feasibility and practicality of magnetic resonance spectroscopy (MRS)- and arterial spin labeling (ASL)-guided MRI navigation for needle biopsy of intracranial tumors. Material and Methods Thirty patients with intracranial tumors who underwent intraoperative stereotactic biopsy were retrospectively analyzed. Contrast-enhanced 3D-BRAVO or 3D-T2FLAIR structural data, combined with MRS and ASL data, were used to identify the target area for biopsy. High-choline or high-perfusion sites were chosen preferentially, and then the puncture trajectory was optimized to obtain specimens for histopathologic examination. Results Twenty-two specimens were collected from 20 glioma patients (two specimens each were collected from two patients) and ten specimens were collected from ten lymphoma patients. The diagnosis rate after the biopsy was 93.3% (28/30). Two gliomas were initially diagnosed as gliosis and subsequently diagnosed correctly after the collection of a second biopsy specimen. Combined MRS and ASL helped target selection in 23 cases (76.7%), including three cases each of low-enhancing and non-enhancing gliomas. In two cases, the target selection decision was changed because the areas initially chosen on the basis of positron emission tomography data did not match the high-perfusion areas identified with ASL. Conclusion Compared with conventional MRI, combined MRS and ASL improved the accuracy of target selection for the stereotactic biopsy of intracranial tumors.

Background The aim of this study was to assess the diagnostic accuracy of diffusion kurtosis magnetic resonance imaging parameters for differentiating high-grade gliomas (HGGs) from primary central nervous system lymphomas (PCNSLs). Methods Diffusion parameters, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ//), radial diffusivity (λ⊥); and kurtosis parameters, including mean kurtosis (MK), axial kurtosis (K//), and radial kurtosis (K⊥), were normalized to contralateral normal-appearing white matter (NAWMc) to decrease inter-individual and inter-regional changes across the entire brain, and then compared with the solid parts of 20 HGGs and 11 PCNSLs [median 95% confidence interval (CI), P

// Tong Tong 1 , Zhong Yang 2 , John W. Chen 3 , Jianming Zhu 4 , Zhenwei Yao 2 1 Department of Radiology, Fudan University Shanghai Cancer Center, Shanghai, China 2 Department of Radiology, Fudan University Huashan Hospital, Shanghai, China 3 Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA 4 Department of Radiation Oncology, The University of North Carolina, Chapel Hill, NC, USA Correspondence to: Zhenwei Yao, e-mail: aocnhnr@126.com John W. Chen, e-mail: jwchen@mgh.harvard.edu Keywords: clinical paper, magnetic resonance imaging, magnetic resonance spectroscopy, glioma, differential diagnosis Received: May 18, 2015 Accepted: August 07, 2015 Published: August 20, 2015 ABSTRACT Purpose: To determine whether the changes of [Cho/NAA] ratio in patients with glioma, measured by dynamic 1 H-MRS can be used to differentiate between high-grade and low-grade gliomas. Materials and Methods: This prospective study was approved by the institutional ethics committee. Written informed consent was obtained. Forty-nine patients with biopsy-proven glioma and 20 normal control subjects were recruited in this study. The maximum [Cho/NAA] ratios, acquired at 0 min, and at 6 min, were calculated and assessed from volume of interests (VOI) in the tumor areas and in the surrounding normal tissue for each patient. Absolute difference in the [Cho/NAA] ratios, from MRS acquired at 0 and 6 min, in high-grade glioma, low-grade glioma, and control subjects were compared. Results: The maximum [Cho/NAA] ratio acquired from the tumor area at the 0 min is 6.08 ± 2.02, which was significantly different ( p = .017) from that acquired after 6 min, 4.87 ± 2.13. The [Cho/NAA] ratio from the surrounding normal tissue area did not change significantly from spectra acquired at different times (0 min, 6 min). Absolute difference in [Cho/NAA] ratios acquired at 0 and 6 min time points were significantly higher ( P < 0.001) in high-grade glioma (= 3.86 ± 3.31) than in low-grade glioma (= 0.81 ± 0.90), and control subjects (0.061 ± 0.026, P = 0.000), while there was no significantly difference in low-grade glioma and control subjects. Conclusions: Dynamic 1 H-MRS can be useful for differential diagnosis between high-grade and low-grade gliomas as well as insight into the heterogeneity within the tumor.

OBJECTIVETreatment with a BRAF mutation inhibitor might shrink otherwise refractory craniopharyngiomas and is a promising preoperative treatment to facilitate tumor resection. The aim of this study was to investigate the noninvasive diagnosis of BRAF-mutated craniopharyngiomas based on MRI characteristics.METHODSFifty-two patients with pathologically diagnosed craniopharyngioma were included in this study. Polymerase chain reaction was performed on tumor tissue specimens to detect BRAF and CTNNB1 mutations. MRI manifestations—including tumor location, size, shape, and composition; signal intensity of cysts; enhancement pattern; pituitary stalk morphology; and encasement of the internal carotid artery—were analyzed by 2 neuroradiologists blinded to patient identity and clinical characteristics, including BRAF mutation status. Results were compared between the BRAF-mutated and wild-type (WT) groups. Characteristics that were significantly more prevalent (p < 0.05) in the BRAF-mutated craniopharyngiomas were defined as diagnostic features. The minimum number of diagnostic features needed to make a diagnosis was determined by analyzing the receiver operating characteristic (ROC) curve.RESULTSEight of the 52 patients had BRAF-mutated craniopharyngiomas, and the remaining 44 had BRAF WT tumors. The clinical characteristics did not differ significantly between the 2 groups. Interobserver agreement for MRI data analysis was relatively reliable, with values of Cohen κ ranging from 0.65 to 0.97 (p < 0.001). A comparison of findings in the 2 patient groups showed that BRAF-mutated craniopharyngiomas tended to be suprasellar (p < 0.001), spherical (p = 0.005), predominantly solid (p = 0.003), and homogeneously enhancing (p < 0.001), and that patients with these tumors tended to have a thickened pituitary stalk (p = 0.014). When at least 3 of these 5 features were present, a tumor might be identified as BRAF mutated with a sensitivity of 1.00 and a specificity of 0.91. The area under the ROC curve for the sum of all 5 diagnostic criteria was 0.989 (p < 0.001).CONCLUSIONSThe BRAF mutation status of craniopharyngiomas might be predicted using certain MRI features with relatively high sensitivity and specificity, thus offering potential guidance for the preoperative administration of BRAF mutation inhibitors.

Background and Purpose— Permeability surface (PS) on computed tomographic perfusion reflects blood–brain barrier permeability and is related to hemorrhagic transformation (HT). HT of deep middle cerebral artery (MCA) territory can occur after recanalization of proximal large-vessel occlusion. We aimed to determine the relationship between HT and PS of deep MCA territory. Methods— We retrospectively reviewed 70 consecutive acute ischemic stroke patients presenting with occlusion of the distal internal carotid artery or M1 segment of the MCA. All patients underwent computed tomographic perfusion within 6 hours after symptom onset. Computed tomographic perfusion data were postprocessed to generate maps of different perfusion parameters. Risk factors were identified for increased deep MCA territory PS. Receiver operating characteristic curve analysis was performed to calculate the optimal PS threshold to predict HT of deep MCA territory. Results— Increased PS was associated with HT of deep MCA territory. After adjustments for age, sex, onset time to computed tomographic perfusion, and baseline National Institutes of Health Stroke Scale, poor collateral status (odds ratio, 7.8; 95% confidence interval, 1.67–37.14; P =0.009) and proximal MCA-M1 occlusion (odds ratio, 4.12; 95% confidence interval, 1.03–16.52; P =0.045) were independently associated with increased deep MCA territory PS. Relative PS most accurately predicted HT of deep MCA territory (area under curve, 0.94; optimal threshold, 2.89). Conclusions— Increased PS can predict HT of deep MCA territory after recanalization therapy for cerebral proximal large-vessel occlusion. Proximal MCA-M1 complete occlusion and distal internal carotid artery occlusion in conjunction with poor collaterals elevate deep MCA territory PS.

The aim of this study is to determine if contrast enhanced (CE) sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) images can provide clearer pituitary adenoma margin than conventional CE T1-weighted spin echo (T1-SE) sequence for cavernous sinus (CS) invasion evaluation. 21 healthy volunteers were preformed with SPACE scans before and after administration of gadopentetate dimeglumine at different time points (1, 7 and 13 min). Signal intensity (SI) of regions of interest was plotted in SI/time curves for bilateral CS, pituitary and temporal lobe. 35 patients with pituitary adenoma (≥1 cm) were performed CE T1-SE and CE SPACE scans. Two observers made the visual assessment of the tumor margin delineation and CS invasion evaluation on both SPACE and T1-SE images. Surgical findings were compared with the invasion assessment results. At 1, 7 and 13 min after enhancement, SI of left CS increased 6.7, 9.5 and 11.2 % respectively compared with unenhanced images (all p

Purpose To evaluate the use of endoglin-targeted paramagnetic liposomes in delineating the glioma margins using magnetic resonance (MR) angiogenesis imaging in a rat model. Materials and Methods Four liposome preparations, including nontargeted paramagnetic liposomes (Gd-SLs), isotype control IgG-coupled paramagnetic liposomes (IgG-Gd-SLs), endoglin monoclonal antibody coupled paramagnetic liposomes (MAb-Gd-SLs), and biotinylated antibodies (Bio-MAb)/streptavidin-coupled paramagnetic liposomes (SAv-Gd-SLs) for two-step pretargeting imaging, were formulated. All animal experiments were carried out with the approval of the Shanghai Animal Care. C6 glioma-bearing Sprague-Dawley rats were intravenously injected with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) or the previously mentioned liposomes (n = 5) and imaged with MR. T1-weighted MRI was performed before and dynamically repeated after different contrast agents were injected. The enhancement features of the tumors were compared. Results The signal enhancement of the tumor in the two-step pretargeting group increased by 117.9 ± 5.3% at the periphery and 109.2 ± 3.5% in the center (P = 0.032) at the 8-hour timepoint after SAv-Gd-SLs injection. Ring-like enhancement margins were demonstrated at the periphery of the tumor in the two-step targeted group. The specificity of the targeted liposomes was supported by the competitive study. The signal of peak enhancement using MAb-Gd-SLs was 59% less than that of the two-step group and only slightly higher than the non-targeted groups. Conclusion The two-step endoglin-targeted imaging using biotin-streptavidin interaction was demonstrated to induce intense enhancement of the tumor periphery, which implies that this advanced MR molecular contrast agent may be suitable for accurately delineating glioma tumor margins. J. Magn. Reson. Imaging 2015;41:1056–1064. © 2014 Wiley Periodicals, Inc.

INTRODUCTION To ascertain if the volume transfer constant (Ktrans ) derived from T1 dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) correlates with the immunohistological markers of angiogenesis in high-grade gliomas. METHODS Fifty-one image-guided biopsy specimens in 34 patients with newly presenting high-grade gliomas (grade III = 16; grade IV = 18) underwent preoperative imaging (conventional imaging and T1 DCE-MRI). We correlated vascular endothelial growth factor (VEGF) expression and the microvessel density (MVD) of MRI-guided biopsy specimens with the corresponding DCE-derived Ktrans . Histological sections were stained with VEGF and CD34, and examined under light microscopy. These histological and molecular markers of angiogenesis were correlated with the Ktrans of the region of interest corresponding to the biopsy specimen. RESULTS The Ktrans showed a significant positive correlation with VEGF expression (ρ = 0.582, P = 0.001) but not with MVD stained with CD34 antibody (ρ = 0.328, P = 0.072). CONCLUSION The Ktrans derived from DCE-MRI can reflect the VEGF expression of high-grade gliomas but not the MVD.

The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly.

Cerebral proliferative angiopathy (CPA) is a rare cerebral vascular lesion characterized by diffuse vascular abnormalities with intermingled normal brain parenchyma. Cerebral proliferative angiopathy has a complex clinical presentation, and many patients present with ischemic symptoms. We described a case of a 6 year old boy presenting with transient dizziness with weakness of left limbs. MRI showed the presence of a diffusely dilated extensive vascular lesion mainly located in the corpus callosum, right frontal and temporal lobes. Digital subtraction angiography (DSA) revealed a large hypervascular lesion with a diffuse arterial supply. 99mTc-ECD SPECT cerebral blood flow perfusion image revealed decreased perfusion in right frontal and parietal lobe. A surgical procedure of encephaloduromyosynangiosis (EDMS) was performed on the patient, and the patient exhibited disappearance of TIAs during the follow-up period. There is no consensus on treatment of cerebral proliferative angiopathy, but the hemodynamic characteristics of CPA were more similar to moyamoya disease in the PWI-MR study. Furthermore, we speculated that increased regional cerebral blood flow perfusion may relieve clinical symptoms and improve prognosis of patient with CPA. Therefore, we performed encephaloduromyosynangiosis (EDMS) on this pediatric CPA patient with ischemic symptoms. 99mTc-ECD SPECT obtained 6 months after operation showed significant improvement of right frontal and parietal blood perfusion. MR perfusion at follow-up period demonstrated the range and blood flow of vascular lesion decreased significantly compared with preoperative MR perfusion. Follow-up angiography studies showed well compensation by profound neovascularization through the superficial temporal artery, and vascular malformation disappeared around the region supplied from the ECA. EDMS procedure may be a reasonable and effective treatment for patients with ischemia associated with CPA.

The aim of this study was to explore x-ray computed tomography (CT) and magnetic resonance imaging (MRI) characteristics specific to granular cell tumors (GCTs) of the neurohypophysis. The clinical and imaging data of 6 patients with operation-proven GCTs of the neurohypophysis were analyzed retrospectively. There were 6 patients with GCTs of the neurohypophysis confirmed pathologically. Five of the tumors were purely suprasellar lesions distinct from the intrasellar pituitary gland. One tumor was both intra- and suprasellar. Solid tumors were hyperattenuated and enhanced homogeneously on CT, while showing isointensity on T1WI and heterogeneous hypointensity on T2WI, with homogeneous (4/5) or inhomogeneous (1/5) enhancement. The cystic tumor showed hypointensity on T1WI and hyperintensity on T2WI, with ring enhancement. “Star-like crack sign” was seen in 2 larger solid cases. Calcification was absent in all cases. Well-circumscribed intra and/or suprasellar masses, hyperattenuated and homogeneously enhancing on CT, hypointensity on T2WI, rarely seen calcification, should arouse suspicion of GCTs of the neurohypophysis.

It is well-known that multimodal imaging can integrate the advantages of different imaging modalities by overcoming their individual limitations. As ultra-high field magnetic resonance imaging (MRI) will be inevitably used in future MRI/X-ray computed tomography (CT) scanner, it is highly expected to develop high-performance nano-contrast agents for ultra-high field MR and CT dual-modality imaging, which has not been reported yet. Moreover, specific behavior of nano-contrast agents for ultra-high field MRI is a challenging work and still remains unknown. Herein, a novel type of NaHoF4 nanoparticles (NPs) with varied particle sizes were synthesized and explored as high-performance dual-modality contrast agents for ultra-high field MR and CT imaging. The specific X-ray absorption and MR relaxivity enhancements with varied nanoparticle diameters (3 nm, 7 nm, 13 nm and 29 nm) under different magnetic field (1.5/3.0/7.0 T) are investigated. Based on experimental results and theoretical analysis, the Curie and dipolar relaxation mechanisms of NaHoF4 NPs are firstly separated. Our results will greatly promote the future medical translational development of the NaHoF4 nano-contrast agents for ultra-high field MR/CT dual-modality imaging applications.

It is a common view that consistency and blood supply of pituitary adenoma (PA) can influence the surgical effect. The aim of this study was to determine whether MRI signal intensity (SI) was correlated to the consistency or blood supply of pituitary macroadenoma.Forty eight pituitary macroadenoma patients were underwent preoperative MRI, including precontrast and contrast-enhanced (CE) T1-spin echo (T1-SE) imaging, CE-sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) imaging, and perfusion-weighted imaging (PWI). The tumor consistency and blood supply were determined by neurosurgeons. The expression of collagen IV and MIB-1 was detected with immunohistology. The correlation of the relative SI (rSI) values (tumor to normal frontal white matter SI) and PWI data to the tumor consistency, blood supply, and the expression level of collagen IV and MIB-1 was statistically studied by Kruskal-Wallis rank test (K-W test).A significant correlation was observed between the tumor consistency and the rSI on precontrast T1-SE imaging (P = 0.004) but not on CE T1-SE and CE SPACE imaging. The expression of collagen IV was also significantly associated with rSI on T1-SE imaging (P = 0.010). The blood supply was correlated with the relative CBV (rCBV) (P = 0.030). In addition, the expression of MIB-1 was correlated with rSI of CE T1-SE imaging (P = 0.007).Our results suggest that T1-SE imaging may be a simple and useful method for predicting consistency of PA. CBV value can provide helpful information for assessing the blood supply of pituitary macroadenoma.

To analyze extracerebral cavernous malformation located in the cavernous sinus and correlate their magnetic resonance imaging (MRI) features to pathological findings.Nineteen patients (5 men and 14 women; mean age, 50.6 years; range, 32-71 years) with surgically verified cavernous malformations in the cavernous sinus were reviewed. MRI including T1-weighted, T2-weighted, and postcontrasted T1-weighted imaging was carried out in all instances with a 1.5-T superconductive system (Signa; General Electric Medical Systems, Milwaukee, WI).All these lesions measured from 2.5 cm to 6 cm (average, 4.3 cm) with 13 lesions located to the right side and 6 to the left side. Magnetic resonance images showed that 18 cases were hypointense to white matter on T1-weighted images with only one case showed mixed hypointensity and hyperintensity. On T2-weighted images, 17 cases showed marked homogeneous hyperintensity, 1 case showed marked hyperintensity with some signal void structures and 1 with mixed intensity. Marked homogeneous enhancement after contrast material administration was found in 7 cases, and the remaining 12 showed marked heterogeneous enhancement. Pathologically, these lesions can be classified as type A, type B, and type C. Type A was sponge-like with intact pseudocapsule; type B was mulberry-like with the pseudocapsule incomplete or absent; and type C was composed of both mulberry-like composition and sponge-like composition. Lesions with homogeneous contrast enhancement on MRI correlated with type A pathological findings, whereas those with heterogeneous enhancement correlated with type B and type C pathological findings. Asymmetrical dumbbell-shaped masses of 13 cases involving the sellar and round masses of 6 cases with 2 protruding into the sellar were found. All of the cavernous malformations displaced the adjacent temporal lobe without adjacent brain edema. The internal carotid arteries were displaced or encased in all cases.If a well-demarcated, homogeneous high signal intensity lesion on T2-weighted images with a dumbbell configuration involving both parasellar and sellar regions with marked heterogeneous or homogeneous enhancement is found, the diagnosis of cavernous sinus cavernous malformation should be entertained.

Colon cancer (CC) is one of the most common intestinal malignancies and is difficult to detect in its early stage by magnetic resonance imaging (MRI) with currently used contrast agents (CAs). The development of targeted CAs contributes to the early diagnosis of CC and thereby enables early intervention and timely therapy. Considering the outstanding performance of upconversion nanoprobes (UCNPs) in high-performance MR and fluorescence imaging, a new type of nanoprobes with considerably enhanced imaging performance is developed herein. Carcinoembryonic antigen (CEA) antibody is conjugated onto the surface of UCNPs to achieve the targeted imaging of early CC tumors, which overexpress CEA. Both toxicity tests and histological/hematological examinations demonstrate the excellent biocompatibility of these CC-targeting nanoprobes, which possess great potential for clinical application in the early diagnosis of CC.

Surgical resection, one of the main clinical treatments of intracranial glioblastoma, bears the potential risk of incomplete excision due to the inherent infiltrative character of the glioblastoma. To maximize the accuracy of surgical resection, the magnetic resonance (MR) and fluorescence imaging are widely used for the tumor preoperative diagnosis and intraoperative positioning. However, present commercial MR contrast agents and fluorescent dyes can only function for single mode of imaging and are subject to poor blood-brain barrier (BBB) permeability and nontargeting-specificity, resulting in the apparent risks of inefficient diagnosis and resection of glioblastoma. Considering the unique MR/upconversion luminescence (UCL) bimodal imaging feature of upconversion nanoparticles (UCNPs), herein, we have developed a dual-targeting nanoprobe (ANG/PEG-UCNPs) to cross the BBB, target the glioblastoma, and then function as a simultaneous MR/NIR-to-NIR UCL bimodal imaging agent, which showed a much enhanced imaging performance in comparison with the clinically used single MRI contrast (Gd-DTPA) and fluorescent dye (5-ALA). Moreover, their biocompatibility, especially to brains, was systematically assessed by the histological/hematological examination, indicating a negligible in vivo toxicity. As a proof-of-concept, the ANG/PEG-UCNPs hold the great potential in MR diagnosis and fluorescence positioning of glioblastoma for the efficient tumor surgery.

Meningioangiomatosis (MA) is a rare, benign, hamartomatous lesion of leptomeninges and underlying cerebral cortex. Preoperative diagnosis is difficult and challenging due to its diverse clinical, pathological and imaging features. Imaging findings of this disease including computed tomography (CT) and magnetic resonance imaging (MRI) are reviewed in this chapter. CT findings include focal extensively calcified lesions, lesions with patchy calcification, and no apparent calcification. MRI findings include predominantly hypointensity on T1-weighted images and hyperintensity on T2-weighted images, and gyriform hyperintensity on FLAIR sequences. After contrast material administration, the majority of the lesions show heterogeneous enhancement. Occasionally, a non-enhancing lesion on MRI may be seen due to extensive calcification on CT. Gyriform hyperintensity on FLAIR sequence is the unique MRI feature of meningioangiomatosis, which correlates with proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex on pathology.

Abnormalities in diffusion-weighted and perfusion-weighted magnetic resonance images not only occur in stroke patients but also in transient ischemic attack patients. We found magnetic resonance images were abnormal in 28 patients (68%): 15 had diffusion-weighted imaging abnormalities, 7 had both diffusion-weighted imaging and perfusion-weighted imaging defects and 6 had an isolated perfusion-weighted imaging abnormality. Patients with shorter onset to magnetic resonance imaging, large artery atherothrombosis, coronary artery disease, hyperlipidemia and hemiparesis were more likely to show perfusion-weighted imaging abnormalities. Compared with patients who had a good prognosis, in poor prognosis patients, the relative cerebral blood flow and relative cerebral blood volume was significantly higher. The data suggest that transient ischemic attack patients are more likely to have a poor prognosis when white matter of the symptomatic side shows hyperperfusion within 24 h of symptom onset; however, patients are more likely to have a good prognosis when white matter of the symptomatic side shows hypoperfusion.

Purpose Meningioangiomatosis (MA) is a rare benign localized lesion of leptomeninges and underlying cerebral cortex. Preoperative diagnosis is difficult and challenging because of its diverse clinical, pathological, and imaging features. We retrospectively analyzed 7 cases of MA to explore their imaging features and correlate with pathological findings. Materials and methods Imaging studies including computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively reviewed in 7 patients with surgically and pathologically verified intracranial MA (not associated with neurofibromatosis). Computed tomography studies were performed in axial plane without iodinated contrast-material administration; magnetic resonance studies consisted of axial T1-weighted, T2-weighted, Fluid attenuated Inversion Recovery (FLAIR), and postcontrast T1-weighted sequences and coronal or sagittal precontrast and postcontrast T1-weighted sequences. Results Computed tomography showed focal extensively calcified lesions in 3 cases, lesions with patchy calcification in 2 cases, and no apparent calcification in 2 cases. Magnetic resonance imaging demonstrated predominantly hypointensity on T1-weighted images and hyperintensity on T2-weighted images. Six of 7 cases exhibited gyriform hyperintensity on FLAIR sequences, which correlated with proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex on histopathological analysis. After contrast-material administration, all but 1 showed heterogeneous enhancement. The nonenhancing lesion on MRI was completely calcified on CT. Conclusion Gyriform hyperintensity on FLAIR sequence is the main MRI feature of MA, which correlates with proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex on pathological analysis. Plain CT scan is essential to demonstrate the extent of calcification of these lesions.

The aim of this study was to compare the efficacy and safety of macrocyclic gadobutrol (1.0 M) with linear gadopentetate dimeglumine (0.5 M) for contrast-enhanced magnetic resonance imaging (MRI) of central nervous system (CNS) lesions in Chinese patients (N = 147) with known or suspected CNS lesions, who were enrolled in this single-blind, randomized, parallel-group study. Three blinded independent readers evaluated all efficacy variables. The primary efficacy variable was the difference between the two agents for the change in contrast-to-noise ratio (CNR) between non-enhanced and contrast-enhanced scans of lesions. Secondary outcomes included mean change in number of lesions detected before and after contrast enhancement, diagnostic confidence, and safety and tolerability parameters. Gadobutrol was non-inferior to gadopentetate dimeglumine in respect to the difference in the mean change in CNR (6.94; 95% confidence interval [CI] lower limit: -3.90; predefined maximum 95% CI lower limit: -6.52). The mean change in the number of CNS lesions detected was greater with gadobutrol versus gadopentetate dimeglumine (1.2 vs. 0.2 lesions). Diagnostic confidence was classified as ‘high’ for more patients with gadobutrol versus gadopentetate dimeglumine by the investigators (58.8% vs. 55.4%) and by the three blinded readers (63.6% vs. 55.7%, 23.7% vs. 18.0% and 81.7% vs. 81.0%). Both agents were well tolerated by participating patients. We concluded that in Chinese patients with CNS lesions, gadobutrol (1.0 M) was as effective and well tolerated in contrast-enhanced MRI as gadopentetate dimeglumine (0.5 M). Gadobutrol provided improved visualization of CNS lesions compared with gadopentetate dimeglumine, with a comparable tolerability profile.

Spontaneous extravasation of urine (SUE) is a rare urologic manifestation. Predisposing conditions of SUE include ureteric calculus, retrograde pyelography, pregnancy, abdominal aorta aneurysm, tumors, or enlargement of the prostate gland. Usually, SUE is a self-limiting condition that mandates differentiaton from other catastrophic conditions of pelviureteric ruptures. Most reported cases of SUE based on urograms are unilateral in presentation. Herein, we report a case of bilateral SUE evident on computed tomography urography in a patient with benign prostatic hyperplasia. We also review the literature briefly.