Imaging features of sinonasal tumors on positron emission tomography and magnetic resonance imaging including diffusion weighted imaging: A pictorial review

Introduction: Sinonasal inflammatory conditions account for a major component of head and neck pathologies, whereas neoplasms involving the sinonasal region make up only 2-3% of all head and neck lesions. The symptoms of sinonasal tumors are nonspecific; imaging plays a critical role in distinguishing benign and malignant disease and may illustrate characteristic radiological features of specific sinonasal tumors. Objective: Aim was to determine the utilization of multimodality imaging, specifically the metabolic information provided by 18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET/CT) and diffusivity characteristics seen with diffusion weighted images (DWI) of magnetic resonance imaging (MRI), in a wide range of benign and malignant sinonasal tumors drawn from over 200 sinonasal lesions from our institution and supplemented by the literature. Conclusion: In this pictorial essay, we have reviewed common imaging characteristics of frequently encountered in sinonasal tumors and divided them into benign and malignant categories to facilitate creation of focused differential diagnoses

Preliminary experience with intravenous gadoxetate disodium as a craniospinal MR contrast agent

Gadoxetate disodium is a gadolinium-based contrast agent (GBCA) typically used for body imaging, as about 50% of its excretion is via the liver. Its use for craniospinal MRI has not been reported. Over a 3 years period, 31 adults underwent postcontrast MRI using gadoxetate disodium, each of whom had a relative contraindication to a GBCA, but a GBCA was deemed necessary by the clinical service to direct therapy. Postcontrast T1WI included either gradient-echo (GET1WI, n=12) or spin-echo (SET1WI, n=13) imaging. The contraindication in 29 patients was stage 3-5 chronic kidney disease (CKD) or acute kidney injury (AKI); the other two had normal kidney function, but a history of a reaction to another GBCA (vomiting in one and hypersensitivity in the other). Over a 3 years period, in those patients in whom a GBCA was both deemed necessary and had an estimated GFR (eGFR) of <40 ml/min/1.73 m(2) (i.e., stage 3-5 CKD), both informed consent and nephrology consultation was obtained. A 10 ml dose was given for cranial (n=23), spinal (n=9), and neck/face MRI (n=3), as well as craniocervical MRA (n=6). Three neuroradiologists separately evaluated for normal enhancement in 11 structures. The contrast enhancing percentage (CE%) was measured in 3 structures, and in enhancing lesions, if present. The pre-MRI eGFR was not significantly different from that at 30-90 days (p=0.522) in the 23 patients with an available eGFR at >90 days post-MRI; no patients developed acute kidney injury post-MRI, nor nephrogenic systemic fibrosis. Of the 11 intracranial structures scored, the superior sagittal sinus, pituitary stalk, and atrial choroid plexus enhanced in all 23 patients who underwent brain MRI, with CE%'s of 171.0%, 73.0%, and 69.8%, respectively. The number of patients with enhancing lesions were 3/23 brain MRI's, 8/9 spinal MRI's, 3/3 neck MRI's, and 2/6 craniocervical MRA/MRV's. In 9 spinal MRI's, the basivertebral plexus CE% was 213.7%; in the 7 with spondylodiscitis, the CE% measured 125.8% in enhancing epidural tissue, with a contrast-to-noise ratio (CNR) of 98.0%. This preliminary report describes the use of gadoxetate disodium as an alternative GBCA for craniospinal MRI and MRA in the renally impaired, but its efficacy in this regard must be further evaluated prospectively

Neurosarcoidosis Masquerading as Cavernous Sinus Meningioma

Neurosacroidosis can mimic intracranial tumors resulting in a diagnostic and therapeutic challenge 1-4. We present a case of right cavernous sinus and superior orbital fissure sarcoidosis masquerading as meningioma on MRI and associated with bilateral optic neuropathy that caused serious vision loss

MRI in differentiating malignant versus benign portal vein thrombosis in patients with hepatocellular carcinoma: Value of post contrast imaging with subtraction

•Enhancement accurately differentiates benign from malignant portal vein thrombus.•High accuracy is achieved at arterial, portal venous, and delayed phase imaging.•Subtracted and nonsubtracted images demonstrate similarly high diagnostic accuracy.•Sensitivity and specificity of 20% enhancement on subtracted later phases was >90%. To evaluate MR imaging parameters including quantitative multiphasic post-contrast enhancement with subtraction and qualitative diffusion weighted imaging (DWI) in differentiating benign versus malignant portal venous thrombosis (PVT) in patients with hepatocellular carcinoma (HCC). Radiology reports over a 6-year period ending February 2016 were searched for key words indicating presence of both HCC and PVT on abdominal MRI. 39 patients were identified with PVT characterized as benign or malignant based on pathologic data or serial imaging growth criteria. Image review was performed by two subspecialized radiologists blinded to the diagnosis and medical chart. Signal intensity for regions of interest were recorded within the portal vein thrombus as well as the portal vein on pre-contrast and dynamic post-contrast phases without and with subtraction. Qualitative parameters for DWI and presence of PV expansion were also evaluated. Percent enhancement generated high area under the curve (AUC) for both readers on all non-subtraction phases: arterial (0.95/0.98), portal venous (0.97/0.97) and delayed phase (0.96/0.99) and subtraction phases: arterial (0.91/0.96), portal venous (0.94/0.99) and delayed phases (0.96/0.97). Statistically significant differences were observed between benign and malignant PVT for both readers for PV expansion (p= <0.001/0.006). No qualitative DWI parameter reached statistical significance for both readers. Post-contrast and subtraction MRI can reliably distinguish malignant from benign PVT in patients with HCC using subtracted or non-subtracted images and at arterial, portal venous, or delayed phase timing

MRI in differentiating malignant versus benign portal vein thrombosis in patients with hepatocellular carcinoma: Value of post contrast imaging with subtraction

Purpose: To evaluate MR imaging parameters including quantitative multiphasic post-contrast enhancement with subtraction and qualitative diffusion weighted imaging (DWI) in differentiating benign versus malignant portal venous thrombosis (PVT) in patients with hepatocellular carcinoma (HCC)

Reversing the effects of androgen-deprivation therapy in men with metastatic castration-resistant prostate cancer

OBJECTIVE: To investigate whether bipolar androgen therapy (BAT), involving rapid cyclic administration of high-dose testosterone, as a novel treatment for metastatic castration-resistant prostate cancer (mCRPC) promotes improvements in body composition and associated improvements in lipid profiles and quality of life. PATIENTS AND METHODS: Men from two completed trials with computed tomography imaging at baseline and after three cycles of BAT were included. Cross-sectional areas of psoas muscle, visceral and subcutaneous fat were measured at the L3 vertebral level. Functional Assessment of Chronic Illness Therapy - Fatigue questionnaire and 36-item short-form health survey were used to assess quality of life. RESULTS: The 60 included patients lost a mean (sd) of 7.8 (8.2)% of subcutaneous fat, 9.8 (18.2)% of visceral fat, and gained 12.2 (6.7)% muscle mass. Changes in subcutaneous and visceral fat were positively correlated with each other (Spearman\u27s correlation coefficient 0.58, 95% confidence interval 0.35-0.71) independent of the effects of age, body mass index, and duration of androgen-deprivation therapy. Energy, physical function, and measures of limitations due to physical health were all significantly improved at 3 months. The improvements in body composition were not correlated with decreases in lipid levels or observed improvements in quality of life. CONCLUSIONS: In the present study, BAT was associated with significant improvements in body composition, lipid parameters, and quality of life. This has promising implications for the long-term health of men with mCRPC

Intravenous Ferumoxytol Allows Noninvasive MR Imaging Monitoring of Macrophage Migration into Stem Cell Transplants

PurposeTo develop a clinically applicable imaging technique for monitoring differential migration of macrophages into viable and apoptotic matrix-associated stem cell implants (MASIs) in arthritic knee joints.Materials and methodsWith institutional animal care and use committee approval, six athymic rats were injected with intravenous ferumoxytol (0.5 mmol iron per kilogram of body weight) to preload macrophages of the reticuloendothelial system with iron oxide nanoparticles. Forty-eight hours later, all animals received MASIs of viable adipose-derived stem cells (ADSCs) in an osteochondral defect of the right femur and mitomycin-pretreated apoptotic ADSCs in an osteochondral defect of the left femur. One additional control animal each received intravenous ferumoxytol and bilateral scaffold-only implants (without cells) or bilateral MASIs without prior ferumoxytol injection. All knees were imaged with a 7.0-T magnetic resonance (MR) imaging unit with T2-weighted fast spin-echo sequences immediately after, as well as 2 and 4 weeks after, matrix-associated stem cell implantation. Signal-to-noise ratios (SNRs) of viable and apoptotic MASIs were compared by using a linear mixed-effects model. MR imaging data were correlated with histopathologic findings.ResultsAll ADSC implants showed a slowly decreasing T2 signal over 4 weeks after matrix-associated stem cell implantation. SNRs decreased significantly over time for the apoptotic implants (SNRs on the day of matrix-associated stem cell implantation, 2 weeks after the procedure, and 4 weeks after the procedure were 16.9, 10.9, and 6.7, respectively; P = .0004) but not for the viable implants (SNRs on the day of matrix-associated stem cell implantation, 2 weeks after the procedure, and 4 weeks after the procedure were 17.7, 16.2, and 15.7, respectively; P = .2218). At 4 weeks after matrix-associated stem cell implantation, SNRs of apoptotic ADSCs were significantly lower than those of viable ADSCs (mean, 6.7 vs 15.7; P = .0013). This corresponded to differential migration of iron-loaded macrophages into MASIs.ConclusionIron oxide loading of macrophages in the reticuloendothelial system by means of intravenous ferumoxytol injection can be utilized to monitor differential migration of bone marrow macrophages into viable and apoptotic MASIs in a rat model

Three-dimensional Radiologic Assessment of Chemotherapy Response in ă Ewing Sarcoma Can Be Used to Predict Clinical Outcome

International audiencePurpose: To compare the agreement of three-dimensional (3D) tumor ă measurements for therapeutic response assessment of Ewing sarcoma ă according to the Children's Oncology Group (COG) criteria, ă one-dimensional (1D) Response Evaluation Criteria in Solid Tumors ă (RECIST), and two-dimensional (2D) measurements defined by the World ă Health Organization (WHO) with tumor volume measurements as the standard ă of reference and to determine which method correlates best with clinical ă outcomes. ă Materials and Methods: This retrospective study was approved by the ă institutional review board of three institutions. Seventy-four patients ă (mean age +/- standard deviation, 14.5 years +/- 6.5) with newly ă diagnosed Ewing sarcoma treated at three medical centers were evaluated. ă Primary tumor size was assessed on pre-and posttreatment magnetic ă resonance images according to 1D RECIST, 2D WHO, and 3D COG ă measurements. Tumor responses were compared with the standard of ă reference (tumor volume) on the basis of RECIST, COG, and WHO ă therapeutic response thresholds. Agreement between the percentage ă reduction measurements of the methods was assessed with concordance ă correlation, Bland-Altman analysis, and Spearman rank correlation. ă Agreement between therapeutic responses was assessed with Kendall tau ă and unweighted kappa statistics. Tumor responses were compared with ă patient survival by using the log-rank test, Kaplan-Meier plots, and Cox ă regression. ă Results: Agreement with the reference standard was significantly better ă for 3D measurement than for 1D and 2D measurements on the basis of ă RECIST and COG therapeutic response thresholds (concordance correlation ă of 0.41, 0.72, and 0.84 for 1D, 2D, and 3D measurements, respectively; P ă < .0001). Comparison of overall survival of responders and nonresponders ă demonstrated P values of .4133,.0112,.0032, and .0027 for 1D, 2D, 3D, ă and volume measurements, respectively, indicating that higher ă dimensional measurements were significantly better predictors of overall ă survival. ă Conclusion: The 3D tumor measurements according to COG are better ă predictors of therapeutic response of Ewing sarcoma than 1D RECIST or 2D ă WHO measurements and show a significantly higher correlation with ă clinical outcomes. (C) RSNA, 201

Magnetic Resonance Imaging of Ferumoxide-Labeled Mesenchymal Stem Cells in Cartilage Defects: In Vitro and in Vivo Investigations

The purpose of this study was to (1) compare three different techniques for ferumoxide labeling of mesenchymal stem cells (MSCs), (2) evaluate if ferumoxide labeling allows in vivo tracking of matrix-associated stem cell implants (MASIs) in an animal model, and (3) compare the magnetic resonance imaging (MRI) characteristics of ferumoxide-labeled viable and apoptotic MSCs. MSCs labeled with ferumoxide by simple incubation, protamine transfection, or Lipofectin transfection were evaluated with MRI and histopathology. Ferumoxide-labeled and unlabeled viable and apoptotic MSCs in osteochondral defects of rat knee joints were evaluated over 12 weeks with MRI. Signal to noise ratios (SNRs) of viable and apoptotic labeled MASIs were tested for significant differences using t -tests. A simple incubation labeling protocol demonstrated the best compromise between significant magnetic resonance signal effects and preserved cell viability and potential for immediate clinical translation. Labeled viable and apoptotic MASIs did not show significant differences in SNR. Labeled viable but not apoptotic MSCs demonstrated an increasing area of T 2 signal loss over time, which correlated to stem cell proliferation at the transplantation site. Histopathology confirmed successful engraftment of viable MSCs. The engraftment of iron oxide–labeled MASIs by simple incubation can be monitored over several weeks with MRI. Viable and apoptotic MASIs can be distinguished via imaging signs of cell proliferation at the transplantation site