MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility of MR fingerprinting in differentiating common types of adult intra-axial ...brain tumors.
MR fingerprinting acquisition was performed in 31 patients with untreated intra-axial brain tumors: 17 glioblastomas, 6 World Health Organization grade II lower grade gliomas, and 8 metastases. T1, T2 of the solid tumor, immediate peritumoral white matter, and contralateral white matter were summarized within each ROI. Statistical comparisons on mean, SD, skewness, and kurtosis were performed by using the univariate Wilcoxon rank sum test across various tumor types. Bonferroni correction was used to correct for multiple-comparison testing. Multivariable logistic regression analysis was performed for discrimination between glioblastomas and metastases, and area under the receiver operator curve was calculated.
Mean T2 values could differentiate solid tumor regions of lower grade gliomas from metastases (mean, 172 ± 53 ms, and 105 ± 27 ms, respectively;
= .004, significant after Bonferroni correction). The mean T1 of peritumoral white matter surrounding lower grade gliomas differed from peritumoral white matter around glioblastomas (mean, 1066 ± 218 ms, and 1578 ± 331 ms, respectively;
= .004, significant after Bonferroni correction). Logistic regression analysis revealed that the mean T2 of solid tumor offered the best separation between glioblastomas and metastases with an area under the curve of 0.86 (95% CI, 0.69-1.00;
< .0001).
MR fingerprinting allows rapid simultaneous T1 and T2 measurement in brain tumors and surrounding tissues. MR fingerprinting-based relaxometry can identify quantitative differences between solid tumor regions of lower grade gliomas and metastases and between peritumoral regions of glioblastomas and lower grade gliomas.
BACKGROUND: Current MR imaging allows primarily qualitative distinctions between the signal intensities of various T1 or T2 weighted imaging paradigms. Magnetic Resonance Fingerprinting (MRF) ...represents a novel framework for simultaneous, and precise quantitation of multiple MR tissue properties. Here we assess the capability of MRF based T1 and T2 relaxometry to evaluate different types of intra-axial brain tumors. MATERIALS AND METHODS: 20 patients including 10 glioblastoma multiforme (GBM), 5 oligodendrogliomas (OG) and 5 metastases (METS) were scanned using a MRF protocol. Imaging was acquired through representative areas of brain and quantitative T1 and T2 maps were generated. T1 and T2 quantification of solid tumor component, immediate perilesional white matter (PWM) within 1 cm of enhancing margin, and contralateral white matter (CWM) was performed using ROI analysis. Student's t-test was used for statistical analysis. RESULTS: Solid tumor T1, T2 were distinct from T1, T2 of CWM (n = 20, p < 0.001). There were differences between T1, T2 of PWM of GBMs and METS as compared to their CWM (n = 15, p < 0.001, p < 0.001). Also, there were differences between the T1, T2 of both the solid and PWM regions of GBMs and METS (p < 0.01; p < 0.05 respectively). T2 relaxometry revealed difference between GBMs and OGs (p < 0.02). CONCLUSIONS: MRF can simultaneously measure T1, T2 values of brain tumors and surrounding tissues distinguishing various tumor types and their associated PWM changes from CWM with high statistical significance. Preliminary data supports using MRF to identify regions of infiltrative edema in GBM, and differentiation of tumor types and grades. Statement of Clinical Relevance: Our preliminary data suggests MRF may have a role in non-invasively distinguishing various types intracranial masses, delineate tumor margins, and possibly characterize therapeutic response.
The use of magnetic resonance imaging (MRI) for prostate cancer imaging has been an area of burgeoning research activity with a goal of finding imaging characteristics that will allow for improved ...diagnosis and surveillance of prostate cancer. This article will review the MRI sequences currently used for imaging the prostate and describe the scoring and reporting system used by radiologists for prostate MRI known as the Prostate Imaging Reporting and Data System (PI-RADS). Current research regarding the role of prostate MRI for patients without prior biopsy, with prior negative biopsy and elevated PSA, and on active surveillance protocols will also be reviewed.
Molecular diffusion plays an important role in many biologic phenomena. The ability to study diffusion, therefore, is extremely useful in physiology and medicine. MRI offers a non-invasive window to ...diffusion, particularly water self-diffusion. MRI techniques, which provide diffusion sensitivity or quantitation (diffusion tensor MRI DTI), have found widespread application in neuroscience and medicine, including the evaluation of stroke, brain development, tumor imaging, and demyelinating disorders. We discuss the tensor nature of diffusion and provide an overview of how DTI offers unique information on tissue organization, water mobility, and disease states, particularly those of neuro-ophthalmologic interest.
Hypertension and a missing kidney Raina, Rupesh; Gulani, Vikas; Mehta, Lina ...
Clinical kidney journal
5, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Standard initial assessment via ultrasound of a 4-year-old girl with hypertension revealed the absence of one kidney. Instead of cross-sectional imaging of the retroperitoneal space, a functional ...(nuclear) study was performed. This revealed a malformed kidney within the chest. Though systemic levels of renin and aldosterone were not elevated, removal of the malformed kidney normalized the blood pressure. The presence of prominent smooth muscle nodules surrounding the arteries was seen in the malformed kidney. Initial attempts to avert surgery by pharmacologically reducing blood flow to the malformed kidney were unsuccessful. The review of the literature offers little evidence to support such a strategy.
A new imaging sequence for rapid determination of the apparent self‐diffusion tensor of water was developed and tested on fixed excised rat spinal cords. To reduce the time required to determine the ...tensor, the sequence utilized a new single‐shot approach with multiple spin echoes. An assumption of cylindrical symmetry in the sample was made, thus requiring the measurement of only four of the six unique elements of the tensor. This assumption was found experimentally to be valid, and the results obtained using the new sequence were found to be quantitatively the same as results obtained using a standard spin‐echo sequence.
PDF
