A distinct phenotypic change in gliomas at the time of magnetic resonance imaging detection

Object Although gliomas remain refractory to treatment, it is not clear whether this characteristic is fixed at the time of its origin or develops later. The authors have been using a model of neurocarcinogenesis to determine whether a time exists during a glioma's evolution during which it is detectable but still curable, thus providing a justification for exploring the clinical merits of an early detection and treatment strategy. The authors recently reported the presence of 2 distinct cellular subsets, 1 expressing nestin and the other both glial fibrillary acidic protein (GFAP) and osteopontin (OPN), within all examined gliomas that developed after in utero exposure to ethylnitrosourea. Methods In this study, the authors used magnetic resonance (MR) imaging to assess when these 2 subpopulations appeared during glioma evolution. Results Using T2-weighted and diffusion-weighted MR imaging, the authors observed that gliomas grew exponentially once detected at rates that were location-dependent. Despite large differences in growth rates, however, they determined by correlating histochemistry with imaging in a second series of animals, that all lesions initially detected on T2-weighted images contained both subsets of cells. In contrast, lesions containing only nestin-positive cells, which appeared on average 40 days before detection on MR images, were not detected. Conclusions The sequential appearance of first the nestin-positive cells followed several weeks later by those expressing GFAP/OPN suggests that all gliomas arise through common early steps in this model. Furthermore, the authors hypothesize that the expression of OPN, a molecule associated with cancer aggressiveness, at the time of T2-weighted detection signals a time during glioma development when the lesion becomes refractory to treatment.

Download Full-text

Magnetic Resonance Imaging with Maximum Contrast between Two Selected Tissues Composed of Recordings with Three Repetition Times

Acta Radiologica ◽

10.1177/028418518802900129 ◽

1988 ◽

Vol 29 (1) ◽

pp. 140-142

Author(s):

B. Jung ◽

A. Ericsson ◽

A. Hemmingsson ◽

G. O. Sperber ◽

K.-Å. Thuomas

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Liver Metastases ◽

Normal Liver ◽

Liver Parenchyma ◽

Intensity Difference ◽

Resonance Imaging ◽

Mr Images ◽

Imaging Parameters

A method is presented which in a composed image maximizes the image intensity difference between two selected tissues. The composition is made from several magnetic resonance (MR) images from the same slice but with different MR imaging parameters. The method is illustrated with a patient with liver metastases for whom the technique was used to emphasize metastases above normal liver parenchyma.

Download Full-text

Syringomyelia-Chiari complex: magnetic resonance imaging and clinical evaluation of surgical treatment

Journal of Neurosurgery ◽

10.3171/jns.1990.73.1.0064 ◽

1990 ◽

Vol 73 (1) ◽

pp. 64-68 ◽

Cited By ~ 76

Author(s):

Jesús Vaquero ◽

Roberto Martínez ◽

Alicia Arias

Keyword(s):

Magnetic Resonance ◽

Mr Imaging ◽

Posterior Fossa ◽

Surgical Techniques ◽

Posterior Fossa Decompression ◽

Subjective Improvement ◽

Resonance Imaging ◽

Mr Images ◽

Content Type ◽

Spinal Cord Damage

✓ Thirty patients with syringomyelia-Chiari complex who underwent posterior fossa decompression or syringosubarachnoid shunting were studied clinically and by magnetic resonance (MR) imaging to assess the changes in the syrinx and in their clinical picture after surgery. When symptoms of posterior fossa compression were present, posterior fossa decompression was performed; however, when symptoms of posterior fossa compression were absent, the choice of posterior fossa decompression or syringosubarachnoid shunting depended, respectively, on whether the syrinx was narrow or wide on MR imaging. At least 1 year after surgery, subjective improvement or arrest of disease was recorded in 73% of the patients. The present study suggests that: 1) the symptoms attributed to spinal cord damage have no significant relationship to the size of the syrinx on MR images; 2) the surgical techniques employed in this series (posterior fossa decompression or syringosubarachnoid shunt) were equally useful in inducing syrinx collapse; and 3) when posterior fossa decompression is performed, plugging of the obex is not necessary for syrinx collapse.

Download Full-text

Magnetic resonance imaging: an accurate method to evaluate arteriovenous malformations after stereotactic radiosurgery

Journal of Neurosurgery ◽

10.3171/jns.1996.85.6.1044 ◽

1996 ◽

Vol 85 (6) ◽

pp. 1044-1049 ◽

Cited By ~ 127

Author(s):

Bruce E. Pollock ◽

Douglas Kondziolka ◽

John C. Flickinger ◽

Atul K. Patel ◽

David J. Bissonette ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Cerebral Angiography ◽

False Negative ◽

Resonance Imaging ◽

Mr Images ◽

Content Type ◽

Fine Print

✓ To determine the accuracy of magnetic resonance (MR) imaging in comparison to cerebral angiography after radiosurgery for an arteriovenous malformation (AVM), the authors reviewed the records of patients who underwent radiosurgery at the University of Pittsburgh Medical Center before 1992. All patients in the analysis had AVMs in which the flow-void signal was visible on preradiosurgical MR imaging. One hundred sixty-four postradiosurgical angiograms were obtained in 140 patients at a median of 2 months after postradiosurgical MR imaging (median 24 months after radiosurgery). Magnetic resonance imaging correctly predicted patency in 64 of 80 patients in whom patent AVMs were seen on follow-up angiography (sensitivity 80%) and angiographic obliteration in 84 of 84 patients (specificity 100%). Overall, 84 of 100 AVMs in which evidence of obliteration was seen on MR images displayed angiographic obliteration (negative predictive value, 84%). Ten of the 16 patients with false-negative MR images underwent follow-up angiography: in seven the lesions progressed to complete angiographic obliteration without further treatment. Exclusion of these seven patients from the false-negative MR imaging group increases the predictive value of a negative postradiosurgical MR image from 84% to 91%. No AVM hemorrhage was observed in clinical follow up of 135 patients after evidence of obliteration on MR imaging (median follow-up interval 35 months; range 2–96 months; total follow up 382 patient-years). Magnetic resonance imaging proved to be an accurate, noninvasive method for evaluating the patency of AVMs that were identifiable on MR imaging after stereotactic radiosurgery. This imaging modality is less expensive, more acceptable to patients, and does not have the potential for neurological complications that may be associated with cerebral angiography. The risk associated with follow-up cerebral angiography may no longer justify its role in the assessment of radiosurgical results in the treatment of AVMs.

Download Full-text

Magnetic resonance imaging for detection of late meniscal tears in dogs following tibial tuberosity advancement for treatment of cranial cruciate ligament injury

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-13-08-0107 ◽

2014 ◽

Vol 27 (02) ◽

pp. 141-146 ◽

Cited By ~ 3

Author(s):

C. R. Lamb ◽

M. S. Tivers ◽

A. Li ◽

F. Taylor-Brown

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Cruciate Ligament ◽

Meniscal Tear ◽

Ligament Injury ◽

Meniscal Tears ◽

Resonance Imaging ◽

Mr Images ◽

Cranial Cruciate Ligament

SummaryTo document the use of and to estimate the accuracy of magnetic resonance (MR) imaging for detection of late meniscal tears in dogs with cranial cruciate ligament injury treated with tibial tuberosity advancement (TTA).Medical records of dogs that had TTA followed by stifle MR imaging for suspected meniscal tear and subsequent arthrotomy were reviewed retrospectively. Magnetic resonance images were reviewed independently by an observer blinded to clinical information who classified menisci as torn, abnormal but intact, or normal. Magnetic resonance and surgical findings were compared.Eight stifles from large breed dogs were included. Six stifles had a medial meniscal tear identified in MR images and later confirmed surgically. In the remaining two stifles, the menisci appeared intact in MR images and no tear was identified at subsequent arthrotomy. Lateral menisci in all stifles appeared intact in MR images and were considered normal at surgery. Susceptibility artefacts associated with TTA implants were present in all images but did not adversely affect interpretation of intra-articular structures.Magnetic resonance imaging appears to be accurate for diagnosis of late meniscal tears. Artefacts associated with TTA implants did not prevent evaluation of critical intra-articular structures. Further investigation with MR imaging should be considered when late meniscal tear is suspected following TTA.

Download Full-text

Gd3+-DTPA-Meglumine-Anionic Linear Globular Dendrimer G1: Novel Nanosized Low Toxic Tumor Molecular MR Imaging Agent

ISRN Pharmaceutics ◽

10.1155/2013/378452 ◽

2013 ◽

Vol 2013 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Tahmineh Darvish Mohamadi ◽

Massoud Amanlou ◽

Negar Ghalandarlaki ◽

Bita Mehravi ◽

Mehdi Shafiee Ardestani ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Citric Acid ◽

Magnetic Resonance ◽

Early Diagnosis ◽

Mr Imaging ◽

Contrast Media ◽

Cancer Treatment ◽

Diagnostic Methods ◽

Resonance Imaging ◽

Mr Images

Despite the great efforts in the areas of early diagnosis and treatment of cancer, this disease continues to grow and is still a global killer. Cancer treatment efficiency is relatively high in the early stages of the disease. Therefore, early diagnosis is a key factor in cancer treatment. Among the various diagnostic methods, molecular imaging is one of the fastest and safest ones. Because of its unique characteristics, magnetic resonance imaging has a special position in most researches. To increase the contrast of MR images, many pharmaceuticals have been known and used so far. Gadopentetate (with commercial name Magnevist) is the first magnetic resonance imaging contrast media that has been approved by the US Food and Drug Administration. In this study, gadopentetate was first synthesized and then attached to a tree-like polymer called dendrimer which is formed by polyethylene glycol core and surrounding citric acid groups. Stability studies of the drug were carried out to ensure proper synthesis. Then, the uptake of the drug into liver hepatocellular cell line and the drug cytotoxicity were evaluated. Finally, in vitro and in vivo MR imaging were performed with the new synthetic drug. Based on the findings of this research, connecting gadopentetate to dendrimer surface produces a stronger, safer, and more efficient contrast media. Gd(III)-diethylenetriamine pentaacetate-meglumine-dendrimer drug has the ability to enter cells and does not produce significant cytotoxicity. It also increases the relaxivity of tissue and enhances the MR images contrast. The obtained results confirm the hypothesis that the binding of gadopentetate to citric acid dendrimer produces a new, biodegradable, stable, and strong version of the old contrast media.

Download Full-text

Thoracic calcifications on magnetic resonance imaging: correlations with computed tomography

Jornal Brasileiro de Pneumologia ◽

10.1590/1806-3713/e20180168 ◽

2019 ◽

Vol 45 (4) ◽

Author(s):

Juliana Fischman Zampieri ◽

Gabriel Sartori Pacini ◽

Matheus Zanon ◽

Stephan Philip Leonhardt Altmayer ◽

Guilherme Watte ◽

...

Keyword(s):

Magnetic Resonance ◽

Mr Imaging ◽

Signal Intensity ◽

Ct Scans ◽

Rio Grande Do Sul ◽

Resonance Imaging ◽

Mr Images ◽

Hyperintense Lesion ◽

Neoplastic Lesions ◽

T1 And T2

ABSTRACT Objective: To identify the characteristics of thoracic calcifications on magnetic resonance (MR) imaging, as well as correlations between MR imaging and CT findings. Methods: This was a retrospective study including data on 62 patients undergoing CT scans and MR imaging of the chest at any of seven hospitals in the Brazilian states of Rio Grande do Sul, São Paulo, and Rio de Janeiro between March of 2014 and June of 2016 and presenting with calcifications on CT scans. T1- and T2-weighted MR images (T1- and T2-WIs) were semiquantitatively analyzed, and the lesion-to-muscle signal intensity ratio (LMSIR) was estimated. Differences between neoplastic and non-neoplastic lesions were analyzed. Results: Eighty-four calcified lesions were analyzed. Mean lesion density on CT was 367 ± 435 HU. Median LMSIRs on T1- and T2-WIs were 0.4 (interquartile range [IQR], 0.1-0.7) and 0.2 (IQR, 0.0-0.7), respectively. Most of the lesions were hypointense on T1- and T2-WIs (n = 52 [61.9%] and n = 39 [46.4%], respectively). In addition, 19 (22.6%) were undetectable on T1-WIs (LMSIR = 0) and 36 (42.9%) were undetectable on T2-WIs (LMSIR = 0). Finally, 15.5% were hyperintense on T1-WIs and 9.5% were hyperintense on T2-WIs. Median LMSIR was significantly higher for neoplastic lesions than for non-neoplastic lesions. There was a very weak and statistically insignificant negative correlation between lesion density on CT and the following variables: signal intensity on T1-WIs, LMSIR on T1-WIs, and signal intensity on T2-WIs (r = −0.13, p = 0.24; r = −0.18, p = 0.10; and r = −0.16, p = 0.16, respectively). Lesion density on CT was weakly but significantly correlated with LMSIR on T2-WIs (r = −0.29, p < 0.05). Conclusions: Thoracic calcifications have variable signal intensity on T1- and T2-weighted MR images, sometimes appearing hyperintense. Lesion density on CT appears to correlate negatively with lesion signal intensity on MR images.

Download Full-text

Comparison of atlas- and magnetic resonance imaging—based stereotactic targeting of the globus pallidus internus in the performance of deep brain stimulation for the treatment of dystonia

Journal of Neurosurgery ◽

10.3171/jns.2002.96.4.0673 ◽

2002 ◽

Vol 96 (4) ◽

pp. 673-679 ◽

Cited By ~ 53

Author(s):

Nathalie Vayssiere ◽

Simone Hemm ◽

Laura Cif ◽

Marie Christine Picot ◽

Nina Diakonova ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Deep Brain Stimulation ◽

Magnetic Resonance ◽

Mr Imaging ◽

Resonance Imaging ◽

Mr Images ◽

Content Type ◽

Significant Difference ◽

Fine Print ◽

Deep Brain

Object. To assess the validity of relying on atlases during stereotactic neurosurgery, the authors compared target coordinates in the globus pallidus internus (GPi) obtained using magnetic resonance (MR) imaging with those determined using an atlas. The targets were used in deep brain stimulation (DBS) for the treatment of generalized dystonia. Methods. Thirty-five patients, who were treated using bilateral DBS of the GPi, were included in this study. The target was selected on three-dimensional MR images by direct visual recognition of the GPi. The coordinates were automatically recorded using dedicated software. They were translated into the anterior commissure—posterior commissure (AC—PC) coordinate system by using a matrix transformation process. The same GPi target was defined, based on the locations of brain structures shown in the atlases of Schaltenbrand and Talairach. Magnetic resonance imaging—based GPi target coordinates were statistically compared with the corresponding atlas-based coordinates by applying the Student t-test. A significant difference (p < 0.001) was demonstrated in x, y, and z directions between MR imaging—based and Schaltenbrand atlas—derived target coordinates. The comparison with normalized Talairach atlas coordinates demonstrated a significant difference (p < 0.01) in the y and z directions, although not in the x direction (p = 0.12). No significant correlation existed between MR imaging—based target coordinates and patient age (p > 0.1). No significant correlation was observed between MR imaging—based target coordinates and patient sex in the y and z directions (p > 0.9), although it was significant in the x direction (p < 0.05). A significant variation in coordinates and the length of the AC—PC line was revealed only in the y direction (p < 0.005). Conclusions. A significant difference was found between target coordinates obtained by direct visual targeting on MR images (validated by postoperative clinical results) and those obtained by indirect targeting based on atlases.

Download Full-text

A Gadolinium(III) Complex Based on the Thymine Nucleobase with Properties Suitable for Magnetic Resonance Imaging

International Journal of Molecular Sciences ◽

10.3390/ijms22094586 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4586

Author(s):

Marta Orts-Arroyo ◽

Amadeo Ten-Esteve ◽

Sonia Ginés-Cárdenas ◽

Isabel Castro ◽

Luis Martí-Bonmatí ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Mr Imaging ◽

Lesion Detection ◽

Resonance Imaging ◽

X Ray Diffraction ◽

Functional Images ◽

High Relaxivity ◽

Contrast Enhanced ◽

Phantom Studies

The paramagnetic gadolinium(III) ion is used as contrast agent in magnetic resonance (MR) imaging to improve the lesion detection and characterization. It generates a signal by changing the relaxivity of protons from associated water molecules and creates a clearer physical distinction between the molecule and the surrounding tissues. New gadolinium-based contrast agents displaying larger relaxivity values and specifically targeted might provide higher resolution and better functional images. We have synthesized the gadolinium(III) complex of formula [Gd(thy)2(H2O)6](ClO4)3·2H2O (1) [thy = 5-methyl-1H-pyrimidine-2,4-dione or thymine], which is the first reported compound based on gadolinium and thymine nucleobase. 1 has been characterized through UV-vis, IR, SEM-EDAX, and single-crystal X-ray diffraction techniques, and its magnetic and relaxometric properties have been investigated by means of SQUID magnetometer and MR imaging phantom studies, respectively. On the basis of its high relaxivity values, this gadolinium(III) complex can be considered a suitable candidate for contrast-enhanced magnetic resonance imaging.

Download Full-text