A hot research topic in medical imageology is PET-CT. It is widely used in oncology. This article focuses on the role of PET-CT in tumor diagnosis and treatment, especially the applications and advantages of 18F-FDG PET-CT imaging in tumor staging, treatment strategies, curative effect and prognosis evaluations, radiotherapy planning, residual and recurrent monitoring and personalized therapy of tumor patient.

Objective　To evaluate the diagnostic value of 99Tcm-HL91 in experimental tumor and inflammation models comparing with 99Tcm-MIBI. Methods　Three kinds of solid neoplasm bearing mice (Ehrlich carcinoma bearing mice, H22 carcinoma bearing mice and human ovarian COC1 neoplasm bearing nude mice) and two inflammation models (chemical and bacterial inflammation) underwent static whole body planar imaging at 1 and 4 hours after injection of 99Tcm-HL91. Two kinds of neoplasm bearing mice (Ehrlich carcinoma bearing mice,H22 carcinoma bearing mice) and two inflammation models (chemical and bacterial inflammation) underwent static planar imaging after injection of 99Tcm-MIBI, at early phase (10～20 minutes) and delayed phase (2 h). All of the mice were sacrificed at 4 h. The tumors, or inflammatory lesions, blood and contralateral normal muscles served as controls were removed, weighted and the radioactivity was measured. ROIs were drawn around tumor, inflammatory lesions and contralateral muscles in planar images, and the radioactivity ratios of target (tumor or inflammatory lesions)-to-blood (T/B), target-to non target (contralateral muscles) i.e. T/NT were calculated. Results　Neoplasms were clearly visible in planar images at 1 and 4 h after injection of 99Tcm-HL91 in all tumor models. At the same time inflammatory lesions could not be seen clearly. Neoplasms were seen in delayed phase in 99Tcm-MIBI group, but it was not easy to distinguish them from inflammation. The T/B ratios and T/NT ratios of 99Tcm-HL91 tumor model groups were significantly higher than that of 99Tcm-MIBI tumor model groups. The T/NT ratios of tumors were significantly higher than that of inflammatory lesions in 99Tcm-HL91 groups. Conclusion　Compared with 99Tcm-MIBI imaging, 99Tcm-HL91 is of much more diagnostic value in detection of certain solid neoplasms, and can distinguish neoplasm from inflammation.

The potential of 99mTc labeled P1, P4-di (adenosine-5')-tetraphosphate (Ap4A) for imaging experimental atherosclerotic plaques was evaluated in New Zealand white (NZW) rabbits. To label the 99mTc to Ap4A, stannous tartrate solution was used. 99mTc-Ap4A was purified on a Sephadex G-25 column. The radiochemistry purities of 99mTc-Ap4A were 85% to 91%. Biodistribution study revealed 99mTc-Ap4A cleared from blood rapidly. Thirty min after 99mTc-Ap4A administrated on NZW atherosclerotic rabbits, lesion to blood (target/blood, T/B) ratio was 3.17 +/- 1.27, and lesions to normal (target/non-target, T/NT) ratio was 5.23 +/- 1.87. Shadows of atherosclerotic plaques were clearly visible on radioautographic film. Aortas with atherosclerotic plaques also could be seen on ex vivo gamma camera images. Atherosclerotic abdominal aortas were clearly visible on in vivo images 15 min to 3 h after 99mTc-Ap4A administration. 99mTc-labeled Ap4A can be used for rapid noninvasive detection of experimental atherosclerotic plaque.

The nanobody is a novel antibody fragment,which has beneficial biophysical and pharmacokinetic properties,such as the small molecular weight,high affinity and specificity for antigen.Nanobody is ideally suitable for molecular imaging as a targeting probe that could label antigen at nmol level in vitro.In animal models of xenografted tumor,atherosclerotic plaques and brain disorders,the target tissues were specifically and clearly detected and the high tumor-to-blood (T/B) ratios were obtained.Structural or chemical modified nanobodies will have higher affinity and retention to target tissues,and be convenient for the application of molecular imaging.With the development of the related research,nanobody-based molecular imaging will be gradually transformed into the clinical applications,and play an important role in early diagnosis and therapeutic assessment.

Objective To observe the change of 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging on lung tumors after treatment of Argon-Helium (Ar-He) cryoablation,and to search the measure for evaluating the short-term curative effect after treatment of Ar-He cryoablation.Methods 19 focuses of 15 patients had completed the treatment of Ar-He cryoablation.All of patients imaged with 18F-FDG PET-CT in six months after Ar-He cryoablation.7 patients of all imaged with 18F-FDG PET-CT pre- and after Ar-He cryoablation.The others only imaged with 18F-FDG PET-CT after cryoablation,but these focuses could compare with tissues near the focus or other tumors in themselves.Results 18F-FDG PET-CT imaging found that there was no accumulation of radionuclide in 13 of 19 focuses after cryoablation and there was no new tumor in follow-up.Two target region of cryoablation,which grew up in mediastinum,were found radiation defect with distinct boundary and expanding outward during 4 months.The other 4 focuses recurred during 6 months in which there was accumulation of radionuclide after cryoablation.There was significant change about SUVmax of focuses after cryoablation by qualitative and quantitative analysis (t =3.784,P ＜0.05).But the changes of SUVmax had no significant difference in different time,between cryoablation and PET-CT imaging (F =0.106,P ＞0.05).Conclusion 18F-FDG PET-CT imaging really reveals the range and effect of Ar-He cryoablation.It is an optimal measure for evaluating the short term curative effect after Ar-He cryoablation.

Early diagnosis and accurate staging are important for planning therapeutic intervention to improve outcomes in patients with malignant melanoma (MM).Noninvasive molecular imaging has been extensively studied in cancer diagnosis,staging,therapeutic evaluation,and prognosis.Several radiopharmaceuticals have been developed to diagnose and treat MM,such as monoclonal antibodies,melanocortin receptors,benzamide (BZA) and BZA analogs.In this review,the characteristics and limitations of these radionuclide molecular probes are summarized and discussed.

To study the changes in every part of the beta-adrenergic signal transduction pathway and their effects on ischemic preconditioning of rat myocardium in vivo. SD rats were divided into three groups: IP group, I/R group and CON group. The IP group was further divided into PC1-, 2-, 3-, and PC1+, 2+, 3+ groups according to preconditioning procedure. The rats received surgical procedure and underwent left coronary artery occlusion and reperfusion. We analyzed the infarct size by TTC staining, measured serum myocardial enzymes, studied the beta-AR Bmax and Kd by radioligand binding assay of receptors, checked the activity of AC and PKA by the method of biochemistry and examined the content of cAMP by radioimmunoassay. The infarct area was much smaller in the IP group than in the I/R group (P < 0.001), while the enzymes were significantly higher in I/R (P < 0.001). The Bmax of beta-AR in IP was much higher than that in I/R (P < 0. 001), but no difference in Kd could be seen between IP and I/R groups. In IP, the activity of AC and PKA and the content of cAMP were higher than those in I/R (P < 0.05, 0.002 and 0.001, respectively). In the procedure of preconditioning, the content of cAMP and the activity of PKA showed the characteristic of cyclic fluctuation. Ischemic preconditioning can protect the heart from necrosis and reduce endo-enzyme leakage. The system of beta-adrenergic signal transduction pathway probably takes part in the protection effect of the IP, which might be elicited by the PKA.
Ischemic Preconditioning, Myocardial ; Myocardium/*metabolism ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta/*physiology ; Signal Transduction

Optical imaging is one of the molecular imaging modalities,and it consists of three imaging methods (fluorescence,bioluminescence and diffusion imaging).For fluorescence imaging,quantum dots (QDs) are inorganic semiconductor nanocrystals with a diameter from 2 to 100 nm.Compared with organic fluorescent dye,QDs have several unique optical properties,such as wide and continuous excitation spectra,narrow and symmetrical emission spectrum,strong fluorescence intensity and high resistance to photobleaching.This article reviews the optical properties of QDs and their development in the field of molecular imaging from in vitro and in vivo applications,as well as the limitations and problems.

Objective To screen out single chain variable fragment antibody (scFv)specific to vascular cell adhesion mole‐cule 1(Vcam‐1)from phage recombinant antibody library ,and to evaluate its activity and compare its activity with full‐length monoclonal antibody.Methods Amplification of Vcam‐1 was performed by PCR and Vcam‐1 gene plasmid was transferred into eukaryotic cells to express Vcam‐1 antigen protein.Immune cuvette was coated with purified Vcam‐1 antigen ,and the positive clones were screened out by 4 rounds of “adhesion‐elution‐proliferation” process with gradually increasing pressure.The posi‐tive clones were tested by ELISA method and high titer clones were chosen for gene sequencing.Then the high‐titer clones were transferred into E.coli ,and the clone with the highest expression was regarded as the final requisite one.Competent cells were infected by the final requisite clone and scFv was expressed.After purification ,the activity of scFv was tested by ELISA and its affinity was evaluated.Results Molecular weight of Vcam‐1 antigen protein was 85-90 kD.Positive clones were screened out by taking Vcam‐1 protein as the antigen ,and 9 high titer clones were obtained by single phage ELISA.Gene sequencing of these clones was carried out and 3 sequences were obtained ,1 of which got the highest expression.Molecular weight of the expressed scFv was about 30 kD.The scFv got high affinity to Vcam‐1 antigen according to ELISA ,in spite of its lower activity than full‐length monoclonal antibody.Conclusion scFv antibody specific to Vcam‐1 was successfully obtained from phage display librar‐y ,which laid the foundation of subsequent in vivo diagnosis and therapy.

Objective To investigate a myocutaneous flap method for eyelid baggy plasty conforming to the medical aesthetic requirements. Methods Before operation the amount of the lower eyelid skin excised should be determined. Asking the patient to look upward at supine position, the operator lifted properly the lower eyelid skin using fine forceps without teeth at the results of smooth superficialness at this region and slight ectropion. The incision lines were marked along the print pinched by forceps and the trace 2 to 3 mm below the ciliary margin. Intra-operatively severing soft issues to the inferior orbital fringe just on the sub-orbicularis level, the skin-muscle flap was made. Then the excessive muscle was removed in the light of the incision lines. The orbital fat teased out resected or filled up the concavity along the lower orbital edge. Results The tense and smooth appearance of lower eyelid was archived in 900 cases received in our hospital except 2 temporary ectropion cases and 2 temporary double vision cases. We repaired the 15 ectropions using adjacent skin flap, tarsal reduction, skin soft tissue expansion, or superficial temporary fascia sling suspension, eliminated 28 haematomaes and made the excision of scar and wound suture for a hypertrophic scar case in the 150 complications from other hospitals. The crow wrinkles were improved apparently. Conclusion The amount of skin excision determined pre-operatively, which not only successfully refrains interfering elements from blooding and swelling but also avoids giving rise to ectropion, is accurate than that performed during operation. Natural appearance after operation becomes better and lasting because of orbicularis raised which strengthens the anterior wall of orbital septum.