Exosomes are small vesicles commonly found in bodily fluids such as blood, urine, ascites, and breast milk. As essential mediators of intercellular communication, exosomes play pivotal roles in physiological and pathological processes including material transport, signal transduction, homeostasis regulation, immune response, and angiogenesis. They are promising biomarkers for disease diagnosis and key carriers for therapeutic drug delivery. Longitudinal tracking of exosome biodistribution, elucidating their migratory routes and homing effects, determining optimal delivery routes and therapeutic dosages, and evaluating implantation in target tissues are crucial for better understanding their mechanisms of action and guiding clinical applications. Magnetic resonance imaging (MRI), as a non-invasive and repeatable imaging technique, offers an ideal approach for exosome tracking. By labeling exosomes with specific contrast agents or tracers and detecting them via MRI, researchers can trace exosomes in vivo. This facilitates advancements in exosome-based nanomedicine and accelerates the clinical translation of exosome diagnostics and therapeutics.
Exosomes/metabolism* ; Humans ; Magnetic Resonance Imaging/methods* ; Contrast Media ; Animals ; Tissue Distribution

OBJECTIVE: Bilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy. MATERIALS AND METHODS: Six patients who underwent hysterectomy and bilateral salpingo-oophorectomy were studied. At baseline, mean patient age was 49.5 years (range: 45-54 years). Third lumbar vertebral body BMD measurement using quantitative CT, marrow fat fraction (FF) using MR spectroscopy and marrow perfusion using dynamic contrast enhanced MRI were conducted immediately prior to surgery and at 3, 9, and 21 months after surgery. RESULTS: Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 +/- 7.2% in BMD (n = 6), a sharp increase of 92.2 +/- 46.3% (n = 6) in FF, a sharp decrease of 23.6 +/- 3.9% in maximum contrast enhancement (n = 5), and of 45.4 +/- 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05). CONCLUSION: Bilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.
Body Mass Index ; Bone Density ; Bone Marrow/*metabolism ; Contrast Media/diagnostic use ; Female ; Humans ; Hysterectomy ; Lipids/analysis ; Longitudinal Studies ; Lumbar Vertebrae/*radiography ; *Magnetic Resonance Imaging ; Middle Aged ; Ovariectomy ; Prospective Studies

OBJECTIVETo investigate the distribution of hyaluronic acid (HA) with iohexol tracing in the knee joint cavity of rabbits using CT plain scan, three-dimensional reconstruction and Χ-ray and observe how different injection sites affect HA distribution.

METHODSMixtures of HA and iohexol (tracer) were prepared that contained final iohexol concentrations of 2.5%, 5%, 10%, 20%, or 40%. The HA-iohexol mixtures (0.5 ml) were injected into rabbit knee joints, and the optimal iohexol concentration that allowed clear differentiation of the injected agents from the surrounding tissues was determined using dual-source CT plain scan and three-dimensional reconstruction technique. The HA-iohexol mixture (0.5 ml) containing the optimal concentration of iohexol was then injected into the knees of the rabbits either through the patella medial approach or the medial joint line approach, and HA distribution in the knee joint cavity was observed using CT scan and Χ-ray.

RESULTSThe CT value of HA-iohexol mixture increased progressively with the tracer concentration. After injection of the mixture containing 2.5%, 5%, 10%, 20%, and 40% iohexol, the CT value ratios of the soft tissue, HA-iohexol mixture and bone cortex were 2:7:46, 2:14:44, 2:28:44, 2:60:46, and 2:98:45, respectively, and a iohexol concentration of 5% was determined as optimal for differntiating the injected agents from the surrounding tissues. The HA-iohexol mixutre containing 5% iohexol injected through the medial-patellar approach was distributed mainly over the patello-femoral joint, and that injected through the joint line approach was found mainly over the tibio-femoral joint.

CONCLUSIONHA-iohexol mixture containing 5% iohexol allows clear differentiation of bone cortex and soft tissues in rabit knee joint from the injected agents on CT scan and Χ-ray, and the injection approach can influence HA distribution in the knee joint cavity.

Animals ; Contrast Media ; Hyaluronic Acid ; metabolism ; Iohexol ; Knee Joint ; Rabbits ; Tissue Distribution ; Tomography, X-Ray Computed

OBJECTIVE: To investigate the diagnostic significance of basophil activation test (BAT) in anaphylaxis to non-ionic contrast media through testing the content of CD63, mast cell-carboxypeptidase A3 (MC-CPA3), and terminal complement complex SC5b-9 of the individuals by testing their levels in the normal immune group and the anaphylaxis groups to β-lactam drugs and non -ionic contrast media. METHODS: The CD63 expression of basophilic granulocyte in blood was detected by flow cytometry. The levels of MC-CPA3 in blood serum and SC5b-9 in blood plasma were detected by ELISA. RESULTS: The CD63 expression of basophilic granulocyte in blood, the levels of MC-CPA3 and SC5b-9 of anaphylaxis to non-ionic contrast media and β-lactam drugs were significantly higher than that in normal immune group (P < 0.05). CONCLUSION There is activation of basophilic granulocytes, mast cells and complement system in anaphylaxis to non-ionic contrast media. BAT can be used to diagnose the anaphylaxis to non-ionic contrast media.
Anaphylaxis/diagnosis* ; Basophils/cytology* ; Carboxypeptidases A/metabolism* ; Complement Membrane Attack Complex/metabolism* ; Contrast Media ; Flow Cytometry ; Granulocytes/cytology* ; Humans ; Mast Cells/cytology* ; Tetraspanin 30/metabolism*

OBJECTIVETo evaluate the role of 2-deoxy-D-glucose (2-DG) modified supermagnetic iron oxide nanoparticles (SPIO) (γ-Fe2O3@DMSA-DG NPs) in tumor detection as a magnetic resonance imaging (MRI) contrast agent.

METHODSγ-Fe2O3@DMSA-DG NPs was prepared. The degree of A549 cells targeted absorption of γ-Fe2O3@DMSA-DG NPs was detected by Prussian blue staining, colorimetric assay, T2W and multi-echo sequence MRI. γ-Fe2O3@DMSA NPs was used as a control agent, and free D-glucose as a competitive inhibitor. Human lung adenocarcinoma A549 xenograft tumor was prepared in nude mice. Sterile aqueous suspension of γ-Fe2O3@DMSA NPs or γ-Fe2O3@DMSA-DG NPs was injected into the tail vein of nude mice. Before and 6, 12, 24, 48 h after injection, MRI imaging of the mice was performed. T2 signal intensity of the tumor, brain, liver and thigh skeletal muscles, and T2 values of the tumors were measured.

RESULTSThe average diameter of the particles was about 10 nm, and there were no significant differences between the diameters of γ-Fe2O3@DMSA NPs and γ- Fe2O3@DMSA-DG NPs. The IR spectra showed the C-N retractable vibration peak at γ-Fe2O3@DMSA-DG NPs surface, indicating that 2-DG was conjugated to the γ-Fe2O3@DMSA NPs. The Prussian blue staining, colorimetric assay, MRI T2 signal intensity and T2 values revealed that γ-Fe2O3@DMSA-DG NPs were significantly more absorbed by A549 cells at growth peak than γ-Fe2O3@DMSA NPs, and the absorption of γ-Fe2O3@DMSA-DG NP was inhibited by free D-glucose. The results of in vivo examination showed that before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA-DG NPs, the mean T2 signal intensities of the tumors were (326.00 ± 16.26)s, (276.40 ± 5.13)s, (268.40 ± 30.58)s, (240.40 ± 25.93)s, (262.20 ± 30.04)s, respectively, and the T2 values of the tumors were (735.80 ± 20.93) ms, (645.80 ± 69.58) ms, (615.00 ± 124.61) ms, (570.60 ± 67.78) ms, and (537.80 ± 105.29) ms, respectively. However, before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA NPs, the mean T2 signal intensities of the tumors were (335.60 ± 4.93)s, (290.80 ± 5.93)s, (273.40 ± 15.08)s, (327.40 ± 16.65)s, and (313.20 ± 20.45)s, respectively, and T2 values were (686.00 ± 21.44)ms, (617.80 ± 69.93)ms, (645.20 ± 85.89)ms, (669.40 ± 13.72)ms, and (608.80 ± 61.90)ms, respectively. The T2 signal intensity and T2 value of the tumors were not declined generally after injection. The liver T2 signal intensity was decreased after injection of both γ-Fe2O3@DMSA-DG NPs and γ-Fe2O3@DMSA NPs, and T2 signal intensity of the brain and muscle did not show significant changes.

CONCLUSIONSγ-Fe2O3@DMSA-DG NPs has an ability to target glucose receptors overexpressed in tumors, and may serve as a MRI contrast agent for tumor detection.

Adenocarcinoma ; diagnosis ; metabolism ; pathology ; Animals ; Cell Line, Tumor ; Colorimetry ; Contrast Media ; chemistry ; pharmacokinetics ; Deoxyglucose ; chemistry ; pharmacokinetics ; Ferric Compounds ; chemistry ; pharmacokinetics ; Humans ; Image Enhancement ; Lung Neoplasms ; diagnosis ; metabolism ; pathology ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Particle Size

Splenic hamartoma is a very rare benign tumor, which is usually found incidentally after splenectomy or autopsy. Although percutaneous needle biopsy can be performed, it carries a high risk of bleeding after the procedure. Therefore, diagnosis is usually made by surgical resection. Herein, we report a case of splenic hamartoma diagnosed by magnetic resonance imaging and contrast-enhanced ultrasonography, which enables visualization of the unique signals of microbubbles in the vessels in real time. Relevant literature is also reviewed.
Adult ; Antigens, CD31/metabolism ; Antigens, CD34/metabolism ; Contrast Media ; Female ; Hamartoma/*diagnosis/pathology/ultrasonography ; Humans ; Immunohistochemistry ; Magnetic Resonance Imaging ; Splenic Diseases/*diagnosis/pathology/ultrasonography ; Tomography, X-Ray Computed

OBJECTIVETo evaluate whether garlicin can prevent reperfusion no-reflow in a catheter-based porcine model of acute myocardial infarction (AMI).

METHODSTwenty-two male Chinese mini swines were randomized into 3 groups: sham-operation group (n=6), control group (n=8), and garlicin group (n=8). The distal part of left anterior descending coronary artery (LAD) in swines of the latter two groups was completely occluded by dilated balloon for 2 h and a successful AMI model was confirmed by coronary angiography (CAG) and electrocardiograph (ECG), which was then reperfused for 3 h. In the sham-operation group, balloon was placed in LAD without dilatation. Garlicin at a dosage of 1.88 mg/kg was injected 10 min before LAD occlusion until reperfusion for 1 h in the garlicin group. To assess serial cardiac function, hemodynamic data were examined by catheter method before AMI, 2 h after occlusion and 1, 2, and 3 h after reperfusion. Myocardial contrast echocardiography (MCE) and double staining with Evans blue and thioflavin-S were performed to evaluate myocardial no-reflow area (NRA) and risk area (RA).

RESULTSLeft ventricular systolic pressure and left ventricular end-diastolic pressure significantly improved in the garlicin group after reperfusion compared with the control group P<0.05) and 2 h after AMI (P<0.05). MCE showed garlicin decreased reperfusion NRA after AMI compared with the control group (P <0.05). In double staining, NRA/RA in the garlicin group was 18.78%, significantly lower than that of the control group (49.84%, P<0.01).

CONCLUSIONSGarlicin has a preventive effect on the porcine model of myocardial infarction reperfusion no-reflow by improving hemodynamics and decreasing NRA.

Allyl Compounds ; pharmacology ; therapeutic use ; Animals ; Cardiotonic Agents ; pharmacology ; therapeutic use ; Contrast Media ; Disease Models, Animal ; Disulfides ; pharmacology ; therapeutic use ; Hemodynamics ; drug effects ; Male ; Myocardial Infarction ; complications ; diagnostic imaging ; drug therapy ; pathology ; Myocardial Reperfusion ; No-Reflow Phenomenon ; complications ; diagnostic imaging ; drug therapy ; pathology ; Swine ; Swine, Miniature ; Thiazoles ; metabolism ; Ultrasonography

Herein, we report the case of a large benign insulinoma in an obese young man with a three-year history of asymptomatic hypoglycaemia. He presented to our outpatient department with a two-week history of dizziness and morning cold sweats. A random serum glucose test revealed hypoglycaemia. Upon admission, computed tomography and magnetic resonance imaging of the abdomen with intravenous contrast media showed an enhancing mass lesion in the uncinate process of the pancreas. To confirm the diagnosis, an intra-arterial calcium stimulation test with hepatic venous sampling was performed for preoperative localisation and to exclude the presence of occult insulinomas. The patient underwent an exploratory laparotomy, with successful resection of the pancreatic head tumour. Histology confirmed the diagnosis of insulinoma. The patient's postoperative recovery was uneventful, and he has not developed further episodes of hypoglycaemia three years post surgery.
Adult ; Blood Glucose ; analysis ; Calcium ; metabolism ; Contrast Media ; chemistry ; Hepatic Veins ; pathology ; Humans ; Insulinoma ; blood ; complications ; diagnosis ; Magnetic Resonance Imaging ; Male ; Obesity ; blood ; complications ; Pancreatic Neoplasms ; blood ; complications ; diagnosis ; Tomography, X-Ray Computed

OBJECTIVE: Suspicious incidental gastrointestinal FDG uptake during positron-emission tomography/computed tomography (PET/CT) examinations can be caused by different diseases, including malignancies. However, differentiation with PET alone is difficult. The aim of this study was to investigate the potential of PET alone, contrast-enhanced CT (ceCT), and low-dose CT (ldCT) in routine PET/CT protocols for differentiation of incidental gastrointestinal lesions. MATERIALS AND METHODS: Sixty patients with incidental gastrointestinal lesions who underwent a routine PET/CT protocol with ldCT and ceCT were retrospectively analysed. The PET lesions were evaluated regarding their FDG uptake patterns and the standard uptake value. The anatomical correlates in both CT protocols were compared in regard to the correct lesion classification with the reference standard endoscopy. RESULTS: Sixty-two lesions were found in 60 patients (17 malignant, 10 premalignant, 5 benign, 13 inflammatory, 17 physiological). The differentiation of the FDG uptake patterns did not enable reliable lesion classification. The positive predictive value for pathology was 0.81 for ceCT in PET/CT and 0.70 for ldCT. Malignancies were detected in 100% of the patients by ceCT vs. 29.4% by ldCT. The false negative rate of ceCT for all pathologies was 31.1%, vs. 68.9% for ldCT. False positive results (17/62) could not be excluded sufficiently by either CT protocol. CONCLUSION: PET/ceCT protocols provide additional benefit especially in detecting gastrointestinal malignancies as a cause of suspicious incidental gastrointestinal FDG uptake. However, since follow-up endoscopy cannot be forgone due to the considerable false negative rate even with ceCT, the addition of ceCT to a routine PET/ldCT protocol cannot be recommended for this purpose.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use/pharmacokinetics ; Female ; Fluorodeoxyglucose F18/*diagnostic use/pharmacokinetics ; Follow-Up Studies ; Gastrointestinal Diseases/*diagnosis/metabolism ; Gastrointestinal Tract/*metabolism/radiography/radionuclide imaging ; Humans ; Male ; Middle Aged ; Positron-Emission Tomography/*methods ; Reproducibility of Results ; Retrospective Studies ; Tomography, X-Ray Computed/*methods

No abstract available.
Antigens, CD34/metabolism ; Carcinoma, Hepatocellular/pathology/*radiography ; Contrast Media/chemistry/diagnostic use ; Gadolinium DTPA/chemistry/*diagnostic use ; Humans ; Immunohistochemistry ; Liver Neoplasms/pathology/*radiography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Tomography, X-Ray Computed