Advances in diffuse glioma assessment: preoperative and postoperative applications of chemical exchange saturation transfer.

Chemical Exchange Saturation Transfer (CEST) is a technique that uses specific off-resonance saturation pulses to pre-saturate targeted substances. This process influences the signal intensity of free water, thereby indirectly providing information about the pre-saturated substance. Among the clinical applications of CEST, Amide Proton Transfer (APT) is currently the most well-established. APT can be utilized for the preoperative grading of gliomas. Tumors with higher APTw signals generally indicate a higher likelihood of malignancy. In predicting preoperative molecular typing, APTw values are typically lower in tumors with favorable molecular phenotypes, such as isocitrate dehydrogenase (IDH) mutations, compared to IDH wild-type tumors. For differential diagnosis, the average APTw values of meningiomas are significantly lower than those of high-grade gliomas. Various APTw measurement indices assist in distinguishing central nervous system lesions with similar imaging features, such as progressive multifocal leukoencephalopathy, central nervous system lymphoma, solitary brain metastases, and glioblastoma. Regarding prognosis, APT effectively differentiates between tumor recurrence and treatment effects, and also possesses predictive capabilities for overall survival (OS) and progression-free survival (PFS).

Transient partial regression of intracranial germ cell tumor in adult thalamus: A case report.

Background: Intracranial germ cell tumors (GCTs) are a relatively rare malignancy in clinical practice. Natural regression of this tumor is also uncommon. We describe a rare case of an intracranial GCT in the thalamus of an adult that showed spontaneous regression and recurrence after steroid therapy. Case description: A 38-year-old male patient's MRI of the head suggested space-occupying masses in the left thalamus and midbrain. MRI examination revealed demyelination or granulomatous lesions. After high dose steroid treatment, the symptoms improved. The lesions were significantly reduced on repeat MRI, and oral steroid therapy was continued after discharge. The patient's symptoms deteriorated 1 month prior to a re-examination with head MRI, which revealed that the mass within the intracranial space was larger than on the previous image. He revisited the Department of Neurosurgery of our hospital and underwent left thalamic/pontine mass resection on October 16, 2019, and the pathological results showed that the tumor was a GCT. Conclusion: Intracranial GCTs are rare in the adult thalamus but should be considered in the differential diagnosis. The intracranial GCT regression seen in this case may be a short-lived phenomenon arising from complex immune responses caused by the intervention.

Quantitative visual pathway abnormalities predict visual field defects in patients with pituitary adenomas: a diffusion spectrum imaging study.

OBJECTIVES: This study was to investigate clinical applicability of diffusion spectrum imaging (DSI) for quantitative detection of visual pathway abnormalities to predict the degree of visual field defects (VFD) in patients with pituitary adenomas. METHODS: Sixty-five patients with pituitary adenomas and 33 healthy controls underwent conventional MRI and DSI scanning that allowed high-angular-resolution fiber tracking. Optic chiasmal compression and VFD were confirmed in all patients via radiological and neuro-ophthalmological examinations. Quantitative assessments of chiasmal lift, VFD, and DSI parameters from the optic nerve, optic tract, and optic radiation were performed. Group comparisons and correlation analyses were conducted in patients and controls. Using the 5-fold cross-validation method, the support vector machine classifiers were constructed to predict the degree of visual defects. RESULTS: The mean values of quantitative anisotropy and generalized fractional anisotropy in optic nerve and optic tract showed significant differences between patients and controls (p < 0.05). These parameters were also significantly correlated with the chiasmal lift distance and degree of visual defects (p < 0.05). All patients were divided into mild (n = 42) and severe (n = 23) VFD groups, using the mean deviation value of -8 dB as the threshold. The classifiers achieved an accuracy of 0.83, sensitivity of 0.78, and specificity of 0.86 to discriminate patients with mild and severe visual defects. CONCLUSIONS: Using high-angular-resolution fiber tracking, DSI may provide quantitative information to detect visual pathway abnormalities and be a potential diagnostic tool for determining the degree of visual field defects in pituitary adenomas. KEY POINTS: • Abnormal QA and GFA values of optic nerve and optic tract in adenoma patients • Close relationship between DSI parameters and VFD degree in adenoma patients • The classifiers achieved an accuracy of 0.83, sensitivity of 0.78, and specificity of 0.86 to discriminate patients with mild and severe VFD.

Diffusion Spectrum Imaging of Corticospinal Tracts in Idiopathic Normal Pressure Hydrocephalus.

Purpose: The purpose of this study was to measure the diffusion spectrum imaging (DSI) parameters of corticospinal tracts (CSTs) and evaluate diffusional changes in CSTs in patients with idiopathic normal pressure hydrocephalus (iNPH) by DSI. Methods: Twenty-three iNPH patients and twenty-one healthy controls (HCs) were involved in this study. Brain DSI data for all participants were collected through the same MR scanning procedure. The diffusion parameters measured and analyzed included quantitative anisotropy (QA), the isotropic diffusion component (ISO), general fractional anisotropy (GFA), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of corticospinal tracts. Results: The QA and ISO values of corticospinal tracts in iNPH patients were significantly lower than those in HCs (PLQA = 0.008, PRQA = 0.016, PLISO = 0.024, PRISO = 0.016). The mean MD, AD, and RD values in iNPH patients were significantly higher than those in HCs (PMD = 0.032, PAD = 0.032, PRD = 0.048,). No significant differences in GFA and FA values were noted between iNPH patients and HCs. Conclusion: Decreased QA and ISO values of corticospinal tracts were found in iNPH patients. Quantitative CST evaluation using DSI may lead to information that can improve the present understanding of the disease mechanism.

Trigeminal Nerve White Matter Fiber Abnormalities in Primary Trigeminal Neuralgia: A Diffusion Spectrum Imaging Study.

OBJECTIVE: Diffusion spectrum imaging (DSI) was used to quantitatively study the changes in the trigeminal cistern segment in patients with trigeminal neuralgia (TN) and to further explore the value of acquiring DSI data from patients with TN. METHODS: To achieve high-resolution fiber tracking, 60 patients with TN and 35 healthy controls (HCs) were scanned with conventional magnetic resonance imaging (MRI) and DSI. The patients and the members of the control group were compared within and between groups. The correlations between quantitative parameters of DSI and the visual analog scale (VAS), and symptom duration and responsible vessel types were analyzed. RESULTS: Compared with unaffected side of patients in the TN group, the affected side showed significantly decreased quantitative anisotropy (QA) (p < 0.001), fractional anisotropy (FA) (p = 0.001), and general FA (GFA) (p < 0.001). The unaffected side exhibited significantly decreased QA (p + 0.001), FA (p = 0.001), and GFA (p < 0.001) and significantly increased axial diffusivity (AD) (p = 0.036) compared with the affected side of patients in the TN group and the average values of HCs. There were significantly decreased QA (p = 0.046) and FA (p = 0.008) between the unaffected side of patients and the average values of HCs. GFA can evidently distinguish arteries, veins, and features of unaffected side in TN patients. CONCLUSION: Using high-resolution fiber tracking technology, DSI can provide quantitative information that can be used to detect the integrity of trigeminal white matter in patients with TN and can improve the understanding of the disease mechanism.

Comparative Analysis of the MRI Characteristics of Meningiomas According to the 2016 WHO Pathological Classification.

OBJECTS: To evaluate the performance of preoperative magnetic resonance imaging (MRI) in evaluating diagnoses, operation methods and recurrence of meningiomas according to the World health organization (WHO) pathological classification. METHODS: MRI characteristics of 127 meningioma patients were retrospectively analysed according to pathological results (WHO grade) and their association with Simpson's grades (resection) and recurrence. RESULTS: The T1-weighted imaging (T1WI) signal intensity of WHO grade I meningiomas was slightly hypointense or isointense gray, while the T2-weighted imaging (T2WI) signal intensity was isointense or slightly hyperintense. The T1WI and T2WI signal intensity in WHO grade II and III meningiomas was isointense gray. The enhancement degree and patterns, lobulation, flowing voids, dural tail, maximum diameter, peritumoural oedema, ADC values and margin were significantly different between any 2 grades (P < 0.05). The ADC values were higher for WHO grade I tumors than for WHO grade II and III tumors (P < 0.001). Among all the analyzed characteriscs, ADC values, peritumoural oedema, and margin effectively predicted the diagnosis according to the WHO classification. The operation method and surgical resection were different between WHO grade Ⅰ and WHO grade Ⅱ/Ⅲ meningiomas (P < 0.05). The recurrence rate increased with tumor grade, but there was no statistical difference among the 3 types(P> 0.05). CONCLUSIONS: WHO grades and pathological subtypes of meningiomas can generally be determined based on their MRI characteristics. In addition, MRI provides significant guidance for the grading of surgical success and prognosis.

A rare case of giant cystic adamantinomatous craniopharyngioma in an adult.

Craniopharyngioma is an uncommon intracranial tumor that primarily occurs in the sella turcica. Giant cystic craniopharyngioma is rare in general and extremely rare in adults. We report a rare case of giant cystic craniopharyngioma in the anterior pontine cisterna and suprasellar cisterna. A 27-year-old man presented with double vision, and craniocerebral MRI revealed cystic masses in the anterior pontine cisterna and suprasellar cisterna. The masses were removed surgically and diagnosed as large cystic craniopharyngiomas by pathology and MRI. Giant cystic craniopharyngioma is rare in adults. Through this case report, we hope to increase awareness of this disease among various clinicians, including radiologists.

Corona Virus International Public Health Emergencies: Implications for Radiology Management.

The outbreak of 2019 novel coronavirus (2019-nCoV) pneumonia was reported in Wuhan, Hubei Province, China in December 2019 and has spread internationally. This article discusses how radiology departments can most effectively respond to this public health emergency.

CT Imaging and Differential Diagnosis of COVID-19.

Since the beginning of 2020, coronavirus disease 2019 (COVID-19) has spread throughout China. This study explains the findings from lung computed tomography images of some patients with COVID-19 treated in this medical institution and discusses the difference between COVID-19 and other lung diseases.

Compromised Air Quality and Healthcare Safety from Smoking inside Hospitals in Shantou, China.

Achieving smoke-free healthcare facilities remains a great challenge in countries with a high smoking prevalence and weak regulation. Assessment of the impact of environmental tobacco smoke (ETS) and its constituent PM2.5 on the air quality in Chinese hospitals has not been reported. In this study, we conducted air quality surveys by measuring real-time PM2.5 concentrations with Dylos Air Quality Monitors in five tertiary hospitals in Shantou, China during summer (July-August 2016) and winter (November-February 2017). Twenty-eight-day surveys inside the hospitals showed median PM2.5 concentrations above the China Air Quality Standard in elevator lobbies (51.0 µg/m3, IQR 34.5-91.7), restrooms (40.2, 27.1-70.3), and corridors (36.5, 23.0-77.4). Evidence of tobacco smoking was significantly associated with PM2.5 spikes observed in all the survey locations, contributing to the air quality undesirable for health in 49.1% of total survey hours or 29.3% of summer and 75.4% of winter survey hours inside the buildings, and 33.5%, 25.7%, and 6.8% of survey hours in doctor offices, nurse stations, and patient rooms, respectively. In conclusion, smoking inside hospitals induces PM2.5 spikes that significantly compromise the air quality and impose significant health risk to the hospital inhabitants. Reinforcing comprehensive smoking ban with the vested interest of all stakeholders followed by creative disciplinary actions are suggested to ensure healthcare safety.