Comparison of Contrast-Enhanced T2 FLAIR and 3D T1 Black-Blood Fast Spin-Echo for Detection of Leptomeningeal Metastases

Purpose: Imaging plays a significant role in diagnosing leptomeningeal metastases. However, the most appropriate sequence for the detection of leptomeningeal metastases has yet to be determined. This study compares the efficacies of contrast-enhanced T2 fluid attenuated inversion recovery (FLAIR) and contrast-enhanced 3D T1 black-blood fast spin echo (FSE) imaging for the detection of leptomeningeal metastases. Materials and Methods: Tube phantoms containing varying concentrations of gadobutrol solution were scanned using T2 FLAIR and 3D T1 black-blood FSE. Additionally, 30 patients with leptomeningeal metastases were retrospectively evaluated to compare conspicuous lesions and the extent of leptomeningeal metastases detected by T2 FLAIR and 3D T1 black-blood FSE. Results: The signal intensities of low-concentration gadobutrol solutions (< 0.5 mmol/L) on T2 FLAIR images were higher than in 3D T1 black-blood FSE. The T2 FLAIR sequences exhibited significantly greater visual conspicuity scores than the 3D T1 black-blood sequence in leptomeningeal metastases of the pial membrane of cistern (P = 0.014). T2 FLAIR images exhibited a greater or equal extent (96.7%) of leptomeningeal metastases than 3D T1 black-blood FSE images. Conclusion: Because of its high sensitivity even at low gadolinium concentrations, contrast-enhanced T2 FLAIR images delineated leptomeningeal metastases in a wider territory than 3D T1 black-blood FSE.ope

Metastatic breast cancer from rhabdomyosarcoma mimicking normal breast parenchyma on sonography

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Late-Developing Metastatic Malignant Melanoma in the Thoracic Spine Originating from Choroidal Melanoma.

A 54-year-old woman visited Gangnam Severance Hospital for left side flank pain. She had a history of total removal of malignant melanoma on the left eye ball 20 years prior. No evaluation had been performed since then. A paravertebral mass at thoracic ninth level (T9) was discovered on spinal magnetic resonance imaging, and pathology confirmed malignant melanoma. Following positron emission tomography-computed tomography, no other metastasis was discovered. After removal of the paravertebral mass, palliative chemotherapy (dacabarzine + tamoxifene) was administered in 3 cycles over 2 months. Radiotherapy with simultaneous integrated boost technique was performed at 4,350 cGy total over 15 days, 290 cGy per delivery, and was administered with the first cycle of palliative chemotherapy. Despite this treatment, multiple metastases developed throughout her body 7 months later, and the patient is continuing chemotherapy.ope

Subtypes of breast cancer show different spatial distributions of brain metastases.

The aim of our study was to test the hypothesis that the spatial distribution of breast cancer brain metastases (BM) differ according to their biological subtypes. MR images of 100 patients with BM from primary breast cancer were retrospectively reviewed. Patients were divided according to the biological subtype of the primary tumor, (triple-negative: 24, HER2 positive: 48, luminal: 28). All images marked with BMs were standardized to the human brain MRI atlas provided by the Montreal Neurological Institute 152 database. Distribution pattern of BM was evaluated with intra-group and intergroup analysis. In intra-group analysis, hot spots of metastases from triple-negative are evenly distributed in the brain, meanwhile BMs from HER2 positive and luminal type occur dominantly in occipital lobe and cerebellum. In intergroup analysis, BMs from triple-negative type occurred more often in frontal lobe, limbic region, and parietal lobe, compared with other types (P < .05). Breast cancer subtypes tend to demonstrate different spatial distributions of their BMs. These findings may have direct implications for dose modulation in prophylactic irradiation as well as for differential diagnoses. Thus, this result should be validated in future study with a larger population.ope

Dynamic Contrast-Enhanced MRI and Its Applications in Various Central Nervous System Diseases

Dynamic contrast-enhanced MRI (DCE-MRI) is a noninvasive imaging technique used to evaluate tissue vascularity/permeability features through consecutive imaging acquisitions after gadolinium-based contrast agent administration. Over the past several decades, techniques and protocols for DCE-MRI have evolved, leading to growing applications of DCE-MRI for different neurological disorders. Although most established applications of DCE-MRI are for studying tumors, an increasing number of studies have been evaluating the use of this technique for neurodegenerative and other miscellaneous diseases. The purpose of this article was to provide an overview of DCE-MRI and its clinical applications in various neurological diseases.ope

The Added Value of Double Dose Gadolinium Enhanced 3D T2 Fluid-Attenuated Inversion Recovery for Evaluating Small Brain Metastases

PURPOSE: Single dose gadolinium (Gd) enhanced fluid-attenuated inversion recovery (FLAIR) is helpful for visualizing superficial parenchymal metastases. However, the usefulness of FLAIR with a higher dose of Gd is uncertain. The aim of our study was two-folds: first, to prove that the signal to noise ratio (SNR) of small brain metastases is higher than large brain metastases on double-dose (DD) enhanced FLAIR and, second, to explore the added value of DD Gd enhanced FLAIR in relation to T1 GRE for evaluating small brain metastases. MATERIALS AND METHODS: For the first purpose, 50 pairs of small (2 mm5 mm) were included. The difference in the SNR and contrast ratio (CR) between small and large metastases on DD Gd-enhanced 3D T2 FLAIR was compared by Wilcoxon signed-rank tests. For the second purpose, a total of 404 small metastases were included. The diagnostic sensitivities between 3D T1 gradient echo (GRE) alone and combined results of 3D T1 GRE and 3D T2 FLAIR were compared with McNemar test. RESULTS: The SNR and CR of small brain metastases were significantly higher than those of large brain metastases (p<0.001). In qualitative analysis, the diagnostic sensitivities for small brain metastases were significantly higher for 3D T1 GRE plus 3D T2 FLAIR than 3D T1 GRE alone regardless of scan time (p<0.001). CONCLUSION: Small brain metastases showed higher signal intensity than large brain metastases on the DD Gd enhanced 3D T2 FLAIR images. DD Gd enhanced 3D T2 FLAIR imaging may have a complementary role to 3D T1 GRE for evaluating small brain metastases.ope

Assessment of Meningeal Lymphatics in the Parasagittal Dural Space: A Prospective Feasibility Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

Objective: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. Materials and Methods: Eighteen participants (26–71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. Results: The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD washout rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01–0.15) than that of younger participants (median, 0.32; IQR, 0.07–0.45) (P = 0.040). Conclusion: This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.ope

Clinical Features Indicating Nigrostriatal Dopaminergic Degeneration in Drug-Induced Parkinsonism

Objective : Patients with drug-induced parkinsonism (DIP) may have nigrostriatal dopaminergic degeneration. We studied the clinical features that may indicate nigrostriatal dopaminergic degeneration in patients with DIP. Methods : Forty-one DIP patients were classified into normal and abnormal [18F] FP-CIT scan groups. Differences in 32 clinical features and drug withdrawal effects were studied. Results : Twenty-eight patients had normal (Group I) and 13 patients had abnormal (Group II) scans. Eight patients of Group I, but none of Group II, had taken calcium channel blockers (p = 0.040). Three patients of Group I and six of Group II had hyposmia (p = 0.018). After drug withdrawal, Group I showed greater improvement in Unified Parkinson’s Disease Rating Scale total motor scores and subscores for bradykinesia and tremors than Group II. Only hyposmia was an independent factor associated with abnormal scans, but it had suboptimal sensitivity. Conclusion : None of the clinical features were practical indicators of nigrostriatal dopaminergic degeneration in patients with DIP.ope

Asymmetric Parkinsonism With Progressive Nigrosomal Change Secondary to Kernohan's Notch Phenomenon

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Apparent diffusion coefficient histogram in breast cancer brain metastases may predict their biological subtype and progression.

Our aims for this study were to investigate the relationship between diffusion weighted image (DWI) parameters of brain metastases (BMs) and biological markers of breast cancer, and moreover, to assess whether DWI parameters accurately predict patient outcomes. DWI data for 34 patients with BMs from breast cancer were retrospectively reviewed. Apparent diffusion coefficient (ADC) histogram parameters were calculated from all measurable BMs. Two region of interest (ROI) methods are used for the analysis: from the largest BM or from all measurable BMs per one patient. ADC histogram parameters were compared between positive and negative groups depending on ER/PR and HER2 statuses. Overall survival analysis after BM (OSBM) and BM-specific progression-free survival (BMPFS) was analyzed with ADC parameters. Regardless of ROI methods, 25th percentile of ADC histogram was significantly lower in the ER/PR-positive group than in the ER/PR-negative group (P < 0.05). Using ROIs from all measurable BMs, Peak location, 50th percentile, 75th percentile, and mean value of ADC histogram were also significantly lower in the ER/PR-positive group than in the ER/PR-negative group (P < 0.05). However, there was no significant difference between HER2-postive and negative group. On univariate analysis, using ROIs from all measurable BMs, lower 25th percentile, 50th percentile and mean of ADC were significant predictors for poor BMPFS. ADC histogram analysis may have a prognostic value over ER/PR status as well as BMPFS.ope