Click for new scientific resources and news about Corona[COVID-19]

Paper Information

Journal:   IRANIAN JOURNAL OF RADIOLOGY   2005 , Volume 3 , Number 1 (SUPPLEMENT); Page(s) 7 To 7.


Author(s):  OGHABIAN M.A.*

Introduction & Background: Conventional imaging modalities of CT, MRI, ultrasound, radionuclide, and even metabolic PET are insensitive to reveal tumor and metastasis of less than few millimeters containing not much fewer than 500,000 cells. At this size, a tu-mor has effectively undergone about 20 cell dou-blings, and is sufficiently stuffed with gene defects and likely to metastasize. New techniques generally known as molecular imaging lead to a patient-specific approach based on physiologic, antigenic, molecular, and genetic disease markers. In this article, Current and the near term trends and techniques in early de-tection of cancer using gene specific, cell specific, or even patient specific approaches are summarized. A number of markers are used for cancer imaging. Anatomic markers show cell morphology defects at the sub-10-µm level on CT, MRI, and OCT (Optical Coherence Tomography). These techniques often fail to provide accurate and basic information necessary to manage the patient’s disease such as true metastatic extent. Functional markers use dynamic features, such as capillary leak (using ICG, IndoCyanine Green), lymphatic transport (by colloid, or Tc-Sestamibi), blood oxygenation, and blood flow. The features provide signal by a bulk phenomenon, and hence are still insensitive. More specifically, anti-genic probes, such as targeted antibodies have been demonstrated effectively in vivo for both diagnostic and therapeutic purposes, such as PSMA in the pros-tate cancer, CEA in colorectal cancer, and HER-2/neu in breast cancer. Metabolic probes accumulate at the site of a specific metabolic activity, and rely on imag-ing agents involving certain enzymatic pathways or transport functions of the cell. Examples are 18FDG (18F-fluoroDeoxyGlucose) in PET and 11C-thymidine. Recent spectroscopy techniques do not need such labeled probes. The common method for in-vivo spectroscopy is MRSI (Proton Magnetic Resonance Spectroscopy) that can demonstrate Cho-line (Cho), Creatine (Cr), and N-acetyl aspartate (NAA). Molecular probes seek to identify small mole-cules and targets involved in cell signaling and physi-ology. Molecular imaging is defined as an in vivo im-aging, characterization, and measurement of biologic processes at the cellular and molecular level. It is dif-ferentiated from antigenic imaging in the way that the pathways themselves are investigated in molecu-lar imaging rather than the surface markers. More-over, since molecules are much smaller than antibod-ies, they achieve a better distribution more quickly. In the current work, we used USPIO (Ultrasmall Su-per Paramagnetic Iron Oxide) to explore lymphatic system after being uptaken by macrophage cells. Other tumor targeted imaging is under our investiga-tion using monoclonal antibody conjugated with nano particle agents (USPIO) as a specific tumor marker. 

  • ندارد
  Yearly Visit 71
Latest on Blog
Enter SID Blog