NMR characteristics of rat mammary tumors

Conference · Sun Jan 01 00:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:7087916

Osbakken, M; Kreider, J; Taczanowsky, P

12 rats were injected intradermally with 13762A rat mammary adenocarcinoma (1 x 10/sup 6/ cells). 3 rats died before completion of the study and 2 rat had tumor regression; the first 3 were excluded from data analysis. NMR imaging with a 1.5K gauss resistive magnet at 2, 3, 4, and 5 weeks after injection demonstrated increasing tumor mass. Saturation recovery (SR), inversion recovery (IR), and spin echo (SE) pulse sequence images and T/sub 1/ calculation were done for tumor characterization. (Tumor size was too small to identify at 2 weeks.) 3 rats were sacrificed after the last 3 imaging periods for histological studies, done to distinguish solid tumor mass from necrosis. Planimetry of tumor areas showed that as tumors grew in size, the ratio of necrotic area to area of solid tumor increased (week 3 = .3 +- .11; week 4 = .45 +- .07; week 5 = .51 +- 05); simultaneous calculated T/sub 1/ values also increased (week 3 = .35 +- .15; week 4 = .45 +- .06; week 5 = .42 +- 03). Qualitative NMR image T/sub 1/ values also increased as evidenced by progression of SR and IR tumor image intensity from very bright compared to the rest of the body at week 3 to less intense than other structures at week 5. These findings indicate that change in T/sub 1/ may be secondary to the pathophysiological change in the tumor (the increasing in necrosis, associated with increased free water). Thus, the range of T/sub 1/ values obtained in tumors in this study (and in previous studies) may be due to change in tumor physiology and anatomy. Careful correlation of histological with NMR data may allow ultimate use of NMR relaxation characteristics for determination of the physiological state of tumors.

• Research Organization: Pennsylvania State Univ., Hershey Medical Center, Hershey, PA
• OSTI ID: 7087916
• Report Number(s): CONF-840619-; TRN: 87-008919
• Journal Information: J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
NMR IMAGING
MAMMARY GLANDS
ANATOMY
EXPERIMENTAL NEOPLASMS
INJECTION
MAGNETS
MONITORING
PATHOLOGY
PHYSIOLOGY
RATS
ANIMALS
BODY
DIAGNOSTIC TECHNIQUES
DISEASES
GLANDS
INTAKE
MAMMALS
NEOPLASMS
ORGANS
RODENTS
VERTEBRATES
550602* - Medicine- External Radiation in Diagnostics- (1980-)