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Objective: The main purpose of this experiment include: 1, observed in rat liver cancer model in the conditions of joint use of Gd-DTPA and SPIO contrast agent, hepatocellular carcinoma lesions enhanced features, and with the use of Gd-DTPA and SPIO contrast agent compared; 2, observed after injection of SPIO contrast agent enhanced features of hepatocellular carcinoma, cirrhosis, regenerative nodules, focal nodular hyperplasia lesions, evaluation of superparamagnetic iron oxide on focal liver lesions display and qualitative diagnostic role; 3, observe the scan sequence hepatocellular carcinoma lesions enhanced features, the pros and cons of the scan sequence to identify the best option. Materials and Methods: 1, in vitro experiments is divided into two groups. A group: SPIO were diluted by 2.5,5,10,15,20,25,30 and 40μ mol Fe / ml concentration (n = 8), select the distilled water as a blank control; group B: 1mol/ml Gd -DTPA with different concentrations of SPIO mixing equal amounts (5,10,20,30,40,50,60,80 micromol Fe / ml, n = 8), select the distilled water as a blank control. A, B groups the SE T 1 weighted (390ms/14ms) scan, a temperature of 20 ° C, the signal strength between two groups. 2, animal experiments, the production of 30 diethyl nitrosamine-induced rat liver cancer model, enhanced before and after MR scan, the scan sequence SE T 1 -weighted (390ms/14ms), TSE T 2 weighted (4100ms/99ms) SE double echo proton density-weighted and of T 2 weighted (1800ms/20ms/70ms) gradient echo FLASH T 2 * the weighted (600ms/15ms/15 °), gradient echo FLASH T 1 -weighted (150ms/14ms/70 °). 30 rats were divided into four groups: A group of Gd-SPIO-enhanced group of 10 rats were first given the contrast agent Gd-DTPA, line SE, GRE T 1 WI scan, followed by given SPIO contrast agent, the scan sequence with the plain; B group for SPIO-Gd enhancement group of 10 rats, first giving the SPIO contrast agent, the line SE, GRE T 1 WI scan, 12 minutes given after Gd-DTPA scan sequence with the plain; C, D groups were given alone Gd-DTPA and SPIO (n = 5), the same as in the scan sequence plain. In addition, we also selected 20 normal rats as control separately given Gd-DTPA SPIO and Gd SPIO and SPIO Gd (, n = 5), the scan sequence and buy the same experimental group. MR scan is complete, the experimental animals were sacrificed, do take the diseased tissue paraffin section, HE staining and Prussian blue iron staining, optical microscope observation. Results: l A group of in vitro parts: the door): from 2.5 U mol the Fe / INL concentration from SPIO showing positive reinforcement; With the the SPIO concentration increased, the signal strength worse. (2) Group B: When Gd-DTPA with SPIO mixture, concentration of 0. the smol Gd / ml, 2.5 u mol Fe / Inl, showing the positive reinforcement;, signal strength, but decreased with the increased concentrations of SPIO. B group of a mixture of various concentrations of the signal strength is higher than that corresponding to the signal strength of the A group. 2, animal experiments, the: (1) Note SPIO atmosphere, the signal strength of the normal liver tissue and liver cirrhosis declined to GRE t. \) of Gd-SPIO, or SPIO-Gd joint-enhanced group, in Tiwi the the liver lesions signal-to-noise ratio (SN'R) the lesions - the liver parenchyma contrast (CN'R,), respectively, greater than the unenhanced, Gd-DTPA control group and SPIO the after The control group; TZWI, liver lesions SNR or CNR with SPIO control group there was no significant difference. spoon) injection SPIO contrast agent, HCC, regenerative nodules, focal nodular hyperplasia in TIWIM appears positive reinforcement; in TZWI, HCC remains high signal intensity, while the regenerative nodules, FNH negative reinforcement phenomenon. SPIO enhanced after GRE T WI HCC CNR higher than other scanning sequence, TSE and conventional SE T. WI As in HCC the SNR, CN'R no significant difference. the discovery of the sensitivity of the lesions. SPIO contrast agent in TI TZWI enhanced features contribute to significant focal liver lesions. 3. Shown is of great significance for the diagnosis of benign and malignant nodules. SPIO enhanced detection of liver lesions various NlL scan sequence found gradient echo (GRE) T. The right sequence is the most sensitive sequence; proton density-weighted spin-echo old E) and T. -Weighted sequences can show lesions on SPIO-enhanced fast spin-echo sequence (TSE) is less sensitive.
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