Zachary D. Grossman

Functional magnetic resonance (fMR) imaging of a rat brain tumor model: implications for evaluation of tumor microvasculature and therapeutic response

Functional MR (fMR) imaging techniques based on blood oxygenation level dependent (BOLD) effects were developed and applied to a rat brain tumor model to evaluate the potential utility of the method for characterizing tumor growth and regression following treatment. Rats bearing 9L brain tumors in situ were imaged during inhalation of room air and after administration of 100% oxygen + acetazolamide (ACZ) injected 15 mg/kg intravenously. Pixel-to-pixel fMR maps of normalized signal intensity change from baseline values were calculated from T2 weighted spin echo (SE) images acquired pre- and post- oxygen + ACZ administration. Resultant fMR maps were then compared to gross histological sections obtained from corresponding anatomical regions. Regions containing viable tumor with increased cellular density and localized foci of necrotic tumor cells consistent with hypoxia were visualized in the fMR images as regions with decreased signal intensities, indicating diminished oxyhemoglobin concentration and blood flow as compared to normal brain. Histological regions having peritumor edema, caused by increased permeability of tumor vasculature, were visualized in the fMR images as areas with markedly increased signal intensities. These results suggest that fMR imaging techniques could be further developed for use as a non-invasive tool to assess changes in tumor oxygenation/hemodynamics, and to evaluate the pharmacologic effect of anti-neoplastic drugs.

Gadopentetate dimeglumine is potentially an alternative contrast agent for three-dimensional computed tomography angiography with multidetector-row helical scanning.

Objective To demonstrate that gadopentetate dimeglumine is potentially an alternative contrast medium for computed tomographic angiography (CTA). Methods One 12.2-kg Beagle dog was studied as proof of principle; the cervical vessels of three adult human patients were imaged for presurgical planning of the neck. Gadopentetate dimeglumine, 0.5 mol/l (Berlex Laboratories, Wayne, NJ, U.S.A.), a LightSpeed QX/i CT (General Electric Medical Systems, Milwaukee, WI, U.S.A.), and an Ultra Sparc II (SUN Microsystems, Santa Clara, CA, U.S.A.) running Advantage Windows 3.1 (General Electric Medical Systems) were used. Results Sufficient enhancement for CTA of the thoracic aorta, cervical vessels, and abdominal vessels was produced in the experimental dog, and the cervical vessels were clearly defined in all three patients. Conclusion In that subset of patients with contraindications to iodinated contrast medium and for whom magnetic resonance angiography is inappropriate, gadopentetate dimeglumine may be an alternative contrast medium for CTA.

Application of Ruppert’s reagent in preparing novel perfluorinated porphyrins, chlorins and bacteriochlorins

A first report to demonstrate the utility of (trifluoromethyl)trimethylsilane as an efficient reagent for the synthesis of perfluorinated porphyrins, chlorins and bacteriochlorins is presented.

Isolated extramedullary relapse of acute lymphoblastic leukemia in the breast of an adolescent girl: radiologic findings and discussion

We report a case of isolated extramedullary leukemia relapse in the breast of an adolescent girl. A 13-year-old girl with acute lymphoblastic leukemia in remission, post-chemotherapy and unrelated cord blood transplant, presented with a breast lump. US and mammography demonstrated a large hypervascular heterogeneous mass. Examination of tissue provided by US-guided core biopsy confirmed focal leukemic relapse. US is a commonly used diagnostic tool in children and adolescents with a breast mass, for both characterization and guided biopsy.

A 15-year-old girl with a right leg mass

A l!%year-old white girl noticed pain in the right knee and a lump medial to her right knee after a field hockey injury. Over the course of several months, physical therapy relieved most of the pain, and the lump began to shrink but did not completely resolve. Six months after the initial injury occurred, the mass became more tender and swollen. She referred herself to an orthopedic surgeon at the State University of New York (SUNY) Health Science Center at Syracuse. On examination the patient walked without a limp and was able to toe walk, heel walk, and jump without discomfort in the right knee. A firm, tender mass approximately 4 cm in diameter was palpated on the medial aspect of the right knee, just posterior to the medial collateral ligament. There was no evidence of ligamentous instability or joint effusion. Plain films and magnetic resonance (MR) images of the knee were obtained. A bone scan appeared normal.