Comparison of Gadomer-17 and gadopentetate dimeglumine for differentiation of benign from malignant breast tumors with MR imaging.

Rationale And Objectives: This study compared gadopentetate dimeglumine (molecular weight, 0.5 kD), a standard contrast medium, and Gadomer-17 (apparent molecular weight, approximately 35 kD), a new, clinically applicable, large-molecular contrast medium, with respect to their microvascular characterizations of experimentally induced breast tumors at magnetic resonance (MR) imaging.

Materials And Methods: A spectrum of breast tumors, benign through highly malignant, was induced in Sprague-Dawley rats (n = 30) by intraperitoneal administration of N-ethyl-N-nitrosourea (ENU), a potent carcinogen.

Histopathological study of experimental poststreptococcal pneumonia in mice. Group A, type 50, streptococcal infection of murine nares controls with Staphylococcus aureus and E. coli.

Microscopic methods (light and electron microscopy, histochemistry, immunohistochemistry) have been used to assess previously unknown pulmonary inflammatory responses of specific pathogen-free (SPF) mice secondary to infection via the nares by group A, type 50, streptococci suspended in saline ("strep group mice"). As controls for the strep group mice, the animals were either injected with saline alone via nares (no lesions were seen), or with Staphylococcus aureus in saline ("staph group mice") or with E. coli ("E.

Correlation of dynamic contrast-enhanced MR imaging with histologic tumor grade: comparison of macromolecular and small-molecular contrast media.

Objective: The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic MR imaging were correlated with histopathologic grade in mammary soft-tissue tumors.

Materials And Methods: A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N-ethyl-N-nitrosourea, a potent carcinogen.

Histologic confirmation of microvascular hyperpermeability to macromolecular MR contrast medium in reperfused myocardial infarction.

A macromolecular MR contrast medium (MMCM) designed to permit histochemical staining and specific tissue localization, albumin-(biotin)10-(Gd-DTPA)25 (Bio-Alb-Gd), was used in a rat model of reperfused myocardial infarction to confirm the presence and distribution of microvascular hyperpermeability. T1-weighted spin-echo images were acquired before and after administration of Bio-Alb-Gd. An avidin-biotin-complex (ABC) stain, specific for the biotinylated MR contrast medium, was used to define the MMCM distribution and to detect any regional change in microvascular permeability related to infarction.

Disseminated neocortical and subcortical encephalopathy (DNSE) with widespread activation of brain macrophages: a new dementia disorder? Autopsy reports of two postmenopausal women from families with mitochondrial DNA mutations.

In this study we present 2 postmenopausal women who showed clinical symptoms that resembled those of a rather well-defined group of vascular dementia disorders, termed subcortical dementia (Binswanger disease, CADASIL). Patient 1 exhibited mitochondrial DNA (mtDNA) variants in the ND5 gene at position 13,708 and the Cytb gene at position 15,257. These DNA variants have been described in a number of neurologic disorders, but their pathogenetic potential is unclear.

Correlation of dynamic contrast-enhanced magnetic resonance imaging with histologic tumor grade: comparison of macromolecular and small-molecular contrast media.

Background: The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic magnetic resonance imaging (MRI) were correlated with histopathologic grade in mammary soft tissue tumors.

Materials And Methods: A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N -ethyl-N -nitrosourea (ENU), a potent carcinogen.

[Macromolecular contrast media for MR mammography. A new approach to characterizing breast tumors].

The value of macromolecular contrast agents (MMCM) for the characterization of benign and malignant breast tumors will be demonstrated in this review. Animal studies suggest a high potential of MMCM to increase the specificity of MR-mammography. The concept of tumor differentiation is based on the pathological hyperpermeability of microvessels in malignant tumors.

Osteogenic sarcoma: noninvasive in vivo assessment of tumor necrosis with diffusion-weighted MR imaging.

Purpose: To evaluate diffusion-weighted magnetic resonance (MR) imaging for detecting tumor necrosis in an animal model of osteogenic sarcoma.

Materials And Methods: Twelve rats with osteogenic sarcoma underwent T1-weighted unenhanced and gadolinium-enhanced spin-echo and diffusion-weighted spin-echo MR imaging. Histologic correlation was performed.

Definition of liver tumors in the presence of diffuse liver disease: comparison of findings at MR imaging with positive and negative contrast agents.

Purpose: The potential to define liver tumors at magnetic resonance (MR) imaging was compared with a positive and a negative contrast agent (gadoxetic acid disodium, or gadolinium EOB-DTPA [a hepatocyte-directed agent], and ferumoxides, or superpara-magnetic iron oxide particles [a Kupffer cell-directed agent], respectively) in normal rats and in rats with induced acute hepatitis, fatty liver, or cirrhosis.

Materials And Methods: Rats with implanted liver adenocarcinomas were divided into four groups: no diffuse liver disease ("normal" [n = 6]) and diffuse liver diseases (induced acute hepatitis [n = 6], fatty liver [n = 6], or cirrhosis [n = 6]). Rats first received gadoxetic acid disodium (50 mumol/kg) and then, 45 minutes later, ferumoxides (10 mumol/kg).

Monitoring neovascularity as an indicator to response to chemotherapy in osteogenic and Ewing sarcoma using magnetic resonance angiography.

Histologic studies on resected specimen have shown that tumor neovascularity is related to prognosis and response to therapy in a variety of human neoplasms. In nine patients with osteogenic or Ewing sarcoma, we evaluated the use of magnetic resonance angiography (MRA) to assess neovascularity non-invasively in vivo and to monitor response to chemotherapy. Seven patients with osteosarcoma and two patients with Ewing sarcoma were studied before and after chemotherapy by MRA (2-D time-of-flight gradient-echo sequence, TR = 50 msec, TE = 9.

Early detection of acute tubular injury with diffusion-weighted magnetic resonance imaging in a rat model of myohemoglobinuric acute renal failure.

We evaluated the feasibility of magnetic resonance imaging (MRI) for early detection of tubular injury by monitoring changes in the apparent diffusion coefficient (ADC) of renal water in a rat model of myohemoglobinuric glycerol-induced acute renal failure (ARF). Diffusion-weighted MRI was performed concurrently with measurements of serum creatinine and blood urea nitrogen (BUN), evaluation of renal perfusion with dynamic contrast-enhanced MRI, and renal morphological examination. ADC values in the cortex and outer medulla significantly declined within minutes after the glycerol administration (70-75% of control at 4 min and 50-60% of control at 15 min).

Musculoskeletal neoplasm: perineoplastic edema versus tumor on dynamic postcontrast MR images with spatial mapping of instantaneous enhancement rates.

Purpose: To evaluate the utility of fast, contrast-enhanced, sequential magnetic resonance (MR) imaging in differentiating between extraosseous tumor and perineoplastic edema.

Materials And Methods: Fourteen patients underwent sequential MR imaging (3.5 seconds per image) after bolus administration of gadopentetate dimeglumine.

[CT and MRI in elastofibroma. A rare, benign soft tissue tumor].

Elastofibroma is a rare, benign soft-tissue tumor that occurs along the chest wall in the periscapular region. We identified five patients with a surgical diagnosis of elastofibroma who had had CT and/or MR scans. CT and MR imaging were compared to histologic findings in two patients.

Primary bone tumors: value of MR angiography for preoperative planning and monitoring response to chemotherapy.

Objective: The purposes of our study were to investigate the use of MR angiography with two- (2D) and three-dimensional (3D) displays in evaluating vascular morphology of musculoskeletal neoplasms for preoperative planning of limb-salvage surgery and to assess the use of MR angiography for monitoring changes in neovascularity and evaluating response to chemotherapy.

Subjects And Methods: We used MR angiography (2D time-of-flight) to study 13 patients with primary bone tumors (nine osteogenic sarcomas, two Ewing's sarcomas, and two primary lymphomas of bone) at the time of initial presentation. Eight patients (all of whom had osteogenic sarcoma) also underwent MR angiography following chemotherapy before limb-salvage surgery.

Cellular proliferation in prostatic adenocarcinoma as assessed by bromodeoxyuridine uptake and Ki-67 and PCNA expression.

Prostatic carcinomas vary in their biological potential, even when stratified by grade and stage. Measurement of cellular proliferation by various methods has been shown to correlate with outcome for several human cancers, including prostatic carcinoma. Uptake of bromodeoxyuridine (BrdUrd), a thymidine analogue, has been accepted as a measure of cellular proliferative rate.

Radiation-induced telangiectasia in the brain simulates cryptic vascular malformations at MR imaging.

Purpose: To analyze the magnetic resonance (MR) imaging, clinical, and pathologic features of radiation-induced telangiectasia of the brain.

Materials And Methods: The clinical and radiation therapy records were reviewed of 20 patients who developed focal hypointense lesions on T2-weighted MR images obtained after radiation therapy of the central nervous system. Pathologic material was reviewed in six patients.

Contrast-enhanced magnetic resonance imaging estimation of altered capillary permeability in experimental mammary carcinomas after X-irradiation.

Rationale And Objectives: Dynamic magnetic resonance imaging (MRI) enhanced with a macromolecular contrast medium, albumin-(Gd-DTPA)35, was used to detect changes in microvascular characteristics in R3230 mammary adenocarcinomas induced by x-irradiation.

Methods: Tumors were implanted in either flank in nine rats. One of the tumors was exposed to single-dose x-irradiation (30 Gy) 3 days before MRI.