Current research progress of diagnosis of iliac vein stenosis based on multi-modal imaging / 国际外科学杂志

Iliac vein stenosis (IVS), known as iliac vein compression syndrome, refers to a series of diseases caused by iliac vein compression or intraluminal adhesions leading to lower extremity vein or pelvic vein drainage disturbance and other clinical manifestations which is quite common in vascular surgery. The vast majority of patients with symptoms of chronic venous insufficiency (CVI) have IVS. In clinical work, IVS does not typically appear as a single symptom, while often combining with other lesions, such as varicose veins of the lower extremities, skin pigmentation, ulcer formation. Studies on its aetiology and epidemiology have found a mean age of onset of 40 years, the age of onset in females is lower than that in males, and the average of stress in females is significantly higher than that in males. Typical IVS occurs mainly in the left lower extremity in young women of reproductive age, but exceptions remain. In summary, the importance of the diagnosis of IVS in clinical practical work can be seen. CVI is a general term for all diseases that affect the morphology and function of the venous system. Compared with chronic venous disease (CVD), CVI include venous system abnormalities without symptoms or signs. Thus, it more accurately describes the diagnosis and treatment of IVS that requires clinical guidance, so its concept is quoted. With the development and advancement of medical imaging, more and more techniques provide help in the diagnosis and treatment of IVS. Therefore, professionals in various specialties have made relevant studies about the benefits and drawbacks of imaging techniques for diagnosis, treatment modalities, and prognostic management of this disease, in order to improve the diagnostic efficacy. Consequently, this review is focused on the current situation of the diagnosis and treatment of IVS under multi-modal imaging, hoping to provide choices of medical imaging technologies for the different states, and to find a better and personalized plan for patients.

In vitro multi-modal imaging of magnetic targeted nanoparticles and their targeting effect on hepatic stellate cells / 中国组织工程研究

BACKGROUND: In recent years, molecular imaging combined with medical imaging technology and targeted molecular probes have gradually become a research focus. The targeted tissues at the molecular level can be observed using molecular imaging, medical imaging technology, and targeted molecular probes in combination to realize non-invasive imaging of the occurrence and development of the diseases. OBJECTIVE: To develop the magnetic targeted nanoparticle probes, observe the ultrasound/CT/MRI imaging properties in vitro, and investigate their targeting ability to rat hepatic stellate cells in vitro. METHODS: Taking poly(lactic-co-glycolic acid) (PLGA) polymer as the shell, cyclic arginine-glycine-aspartic acid (cRGD) octapeptide as the ligand, targeted magnetic nanoparticles with superparamagnetic Fe3O4 embedded in the shell and perfluorooctyl bromide(PFOB) loaded in the core were prepared by double emulsion evaporation method. The physical and chemical properties of the nanoparticles were detected. The ultrasound/CT/MRI multi-modal imaging properties of the nanoparticles at different concentrations diluted with double-distilled water were tested in vitro. Cyclic RGD peptide immobilization on PLGA-Fe3O4-PFOB NPs was completed through the amide condensation reaction. The conjugation efficiency of the cRGD on PLGA-Fe3O4-PFOB NPs and targeting ability of targeted magnetic nanoparticles in vitro were verified. Cytotoxicity experiments were used to measure the toxic effects of nanoparticles at different concentrations on BRL-3A cells in each group. RESULTS AND CONCLUSION: The targeted magnetic nanoparticles with the average size of (221. 5±60. 3) nm were uniform in dispersion and size. The prepared individual nanoparticle was spherical with the superparamagnetic Fe3O4 scattered on the shell. The encapsulation rate of Fe3O4 was 38%. In vitro ultrasound imaging and CT imaging signal decreased gradually as the concentrations of the nanoparticle suspension decreased. The T2-weighted signal of MRI decreased gradually with the increase of the concentrations of magnetic particle Fe3O4. Flow cytometry results showed that 94. 13% of the cRGD was bound to the nanoparticles. In vitro cell targeting experiments showed that compared to PLGA-Fe3O4-PFOB NPs, cRGD-PLGA-Fe3O4-PFOB NPs exhibited greater cell targeting and affinity efficiency to hepatic stellate cells. Cytotoxicity experiments results showed the nanoparticles had no significant influence on cell viability of the BRL-3A cells. These results suggest that targeted magnetic nanoprobe cannot only be used as a multi-modal imaging contrast agent for ultrasound/CT/MRI, but also exhibits a strong specific affinity to rat hepatic stellate cells in vitro. It has great potential for the early diagnosis of liver fibrosis.

Application of multi-modal and multi-functional molecular imaging based on near-infrared fluorescence dye in tumor models / 中国实验动物学报

Multi-modal fusion molecular imaging technology integrates the advantages of a variety of molecular imaging techniques,and has become a hotspot and trend in the field of molecular imaging. Heptamethine cyanine dye is a class of novel near-infrared fluorescence(NIRF)dye with tumor targeting properties. With its unique optical properties, the dye has broad application prospects in tumor molecular imaging, targeted therapy and drug delivery system. Nano-materials containing heptamethine cyanine dye can be used for NIRF/MRI dual-modal imaging. NIRF/PET dual-modal imaging can be achieved after labeling with nuclides. Conjugated with chemotherapy drugs,targeted delivery of anti-tumor drugs can also be achieved. Complexes of multiple heptamethine cyanine dyes have been used for multi-modal imaging as a new strategy for photothermal therapy,photodynamic therapy and combined treatment of tumors.

Intravenous thrombolysis for acute ischemic stroke / 中国实用内科杂志

Reperfusion therapies(thrombolysis,mechanical thrombectomy,or stenting,etc.) for acute ischemic stroke are the most effective therapy.Reperfusion therapy may limit ischemic tissue enlargement,leading to a reduced infarct size and favorable clinical outcome by restoring the blood flow before the salvageable penumbra became the progress of ischemic brain infarction.intravenous (IV) recombinant tissue plasminogen activator (rt-PA) therapy is the only proven effective treatment of acute ischemic stroke.Although thrombolytic therapy has matured,but the standard intravenous thrombolytic therapy (non-enhanced computed tomography (CT)-guided,3 h time window,the intravenous injection of tPA) have many restrictions,including a short therapeutic time window,recanalization rate was only 50 %,and the major dangers of symptomatic hemorrhagic transformation.As a result,currently in clinical practice,only a minority of patients (usually 1% to 3%) received thrombolytic therapy.So there are some issues still need to be further explored,such as the expansion of thrombolytic time window,a new thrombolytic drugs are used for more than 3h incidence of acute ischemic stroke patients,the evaluation of new reperfusion methods (in particular,multi-modal imaging technology),intravenous,and intra-arterial thrombolysis combined application of thrombolytic therapy,and new anti-platelet drug combination,and the application of mechanical devices or by transcranial Doppler ultrasound to promote the role of thrombolytic drugs.