医学教学课件：hematopoietic system and lymphoscintigraphy

1、Hematopoietic and lymphatic imaging,Bone marrow imaging Spleen imaging lymphoscintigraphy (FDG-PET/CT in lymphoma,Main contents,骨髓显像Bone marrow imaging,Bone marrow is found in the hollow spaces in the interior of bones, On average, bone marrow constitutes 4% of the total body mass of humans. . two t

2、ypes of bone marrow: red marrow and yellow marrow. The red marrow (active marrow) produces blood cells and clotting factors. The yellow marrow stores fat. At birth, all bone marrow is red. With age, more and more of it is converted to the yellow type; only around half of adult bone marrow is red,Ana

3、tomy & Physiology,In adults, red marrow is found mainly in the axial skeleton (vertebral bodies, pelvis, sternum, ribs, scapulae), and in the proximal one third of the femurs and humeri. Yellow marrow is found in the medullary cavity of the middle portion of long bones. In cases of severe blood loss

4、, the body can convert yellow marrow back to red marrow to increase blood cell production,Principle,Radionuclide bone marrow imaging is based on labeling one of the major components of bone marrow. ray can be detected from bone marrow by nuclear medicine imaging equipments, such as SPECT, camera,Rad

5、iopharmaceutics,52Fe （ferrum） erythropoiesis in connection with iron metabolism measuring the extent of erythropoietic marrow produced in a cyclotron with a half-life of 8.2h Its activity over the liver and the spleen is poor or absent, which makes it convenient to detect pathology in the bone marro

6、w over the thoracic and lumbar areas,99mTc-labeled colloids (e.g. 99mTc-PHY) When injected into blood, rapidly cleared by the phagocytic cells in the blood, bone marrow and liver and by the reticuloendothelial cells in the spleen. Bone marrow in the lower thoracic and upper lumbar spine cannot be pr

7、operly visualized by 99mTc-colloids imaging due to overlapping radioactivity over the liver and spleen,The lower thoracic and upper lumbar region of the spine are not well seen because of the intense activity in the liver and spleen,99mTc-monoclonal antibodies (99mTc-MAB) directed against nonspecifi

8、c iron-reacting antigen 95 (NCA-95), a differentiation antigen of granulopoiesis. clinically applied for the imaging of granulopoietic marrow. bone marrow scans of much-improved quality without significant superimposition of liver and spleen the radioactivity over the bone marrow was found to be 2-3

9、 times that with 99mTc-colloids,TechniquesHow is the procedure performed,Remove jewelry, or other metals (because they may interfere with the image), and lie supine on the table. Anterior and posterior whole-body static imagings were performed 30min after 10-15mCi (370-555MBq) radiotracers have been

10、 injected intravenously,A pregnant or breast-feeding woman is not suggested to perform the exam,Imaging Analysis,In normal adults, radiocolloids are mainly taken up by the axial skeleton ( vertebral bodies, pelvis, sternum, ribs, scapulae) the proximal one third of the femurs and humeri,In children,

11、 however, it is normal to see radioactivity in the axial skeleton and the whole long bone,Clinical application,1、Indicate the best sites for obtaining bone marrow sample Bone marrow biopsy are usually accurate techniques for evaluating the bone marrow. But this evaluation is limited to a small part

12、of bone marrow. Bone marrow imaging can provide information about the whole body distribution of functioning bone marrow in various clinical states. It is helpful to indicate the best sites for obtaining bone marrow sample and to reach the final diagnosis of the disease,2、Evaluate the amount of acti

13、ve marrow,Many tumor patients are treated with a combination of chemotherapy and radiation, both of which can have an adverse effect on bone marrow. In patients who have undergone these treatments and are being considered for additional therapy, bone marrow imaging can determine the amount of remain

14、ing functional tissue and show its distribution,the suppression of bone marrow activity in the axial skeleton and the long bone,3、Aplastic anemia evaluating the amount of active marrow in the whole body and following up after treatment,荒芜型（desolation） Few active marrow (remaining functional bone mar

15、row) could be detected in the axial skeleton and long bone,Aplastic anemia is a syndrome of bone marrow failure characterized by peripheral pancytopenia (deficiency of all three blood cell types ) and marrow hypoplasia,According to the amount of active marrow, aplastic anemia can be classified into

16、three types,Aplastic anemia,抑制型(suppression) Low active marrow in the axial skeleton and long bone,Aplastic anemia,正常型 (normal) Radiotracers are taken up by the axial skeleton ( vertebral bodies, pelvis, sternum, ribs, scapulae) and the proximal one third of the femurs and humeri,4、Leukemia evaluati

17、ng the amount of active marrow in the whole body, predicting prognosis and following up after treatment .,Low active marrow in the axial skeleton and expended peripheral bone marrow (PBM,In literatures reported, relapse rate within 10 months in expanded PBM patients (74.4 %) was significant higher t

18、han that in non-expanded PBM patients (13.6 ,5、bone marrow infarcts in Sickle Cell Anemia(SCA) . . Bone marrow infarcts are common in patients with SCA. Plain films are usually normal in acute bone marrow infarcts. The bone marrow scan, however, is a sensitive means of confirming bone marrow infarct

19、,In normal individuals, active bone marrow is confined to the proximal portions of the humeri and femurs, but in patients with SCA the marrow expands peripherally to the distal end of the long bones, especially around the knees. Areas of infarction appear as cold areas surrounded by increased uptake

20、 in the surrounding active marrow,A) Small defect in distal humerus (B) Defects in both femora,D) Distal tibial infarct. (E) Infarcts in proximal right tibia and distal left femura,6、avascular necrosis of the hips It is important to make an early diagnosis of avascular necrosis of the hip, especiall

21、y after trauma, so that appropriate therapy can be instituted,Radiocolloid scan in a trauma patient show decreased activity in the right femoral head. Surgery confirmed avascular necrosis,7、Multiple myeloma exploring the lesion areas involved and following up after treatment,Bone marrow metastasis f

22、rom tumors : diffuse asymmetric increased radiotracer uptake in the axial skeleton and expanded PBM,8、Others,真性红细胞增多症(polycythemia vera), 骨髓增生异常综合征(myelodysplastic syndrome), 慢性溶血性贫血(chronic hemolytic anemia), 慢性失血性贫血(chronic hemorrhagic anemia), 缺铁性贫血(iron-deficiency anemia,Low active marrow in the

23、 partial axial skeleton ( ribs and scapulaes) and expanded PBM (femurs and humeri,Iron-deficiency anemia,Advantage of bone marrow scintigraphy Compared with other Techniques （biopsy and MRI） Bone marrow biopsy is an excellent techniques for evaluating bone marrow and can provide a specific clinical

24、diagnosis. But this evaluation is limited to a small part of bone marrow. Radionuclide bone marrow imaging is a simple noninvasive technique that provides information about the whole body distribution of functioning bone marrow in various clinical states. Magnetic resonance imaging (MRI) is a highly

25、 sensitive technique for evaluating bone marrow and can predict differences between fatty, cellular, and fibrotic marrow. However bone marrow scintigraphy is preferred when whole body screening is desired, since the cost of MRI limits its use for this purpose,脾显像Spleen imaging,Radiotracer and Princi

26、ple,99mTc sulfur colloid (99mTc-SC) is the most commonly used radiopharmaceutical for spleen imaging. Following intravenous administration, it is rapidly removed from the blood by the reticuloendothelia system of the liver, spleen. The spleen can be adequately visualized and separated from the adjac

27、ent liver in patients with normal upper abdominal anatomy. In certain disease states, whenever there is reasonable double about the ability to establish the presence or absence of splenic, 99mTc labeled heat-denatured RBCs imaging is recommended as an imaging method complementary to the SC scan,Norm

28、al image,Clinical application,establish the presence or absence of splenic tissue and evaluate its function diagnose accessory spleen Diagnose auxiliarily spleen infarction and spleen trauma Detect the planted spleen Distinguish tumors in the spleen from those on the left abdomen,淋巴显像Lymphoscintigra

29、phy,a network of small channels similar to blood vessels that circulate the lymph fluid and lymphocytes of the immune system throughout the body. Lymph nodes, which act like a filter for foreign bodies such as germs, viruses, are located along this network,Radiotracer and Principle,Radiocolloid is p

30、hysiologically transported from an appropriate interstitial injection site to the drainage lymph nodes. And the image can provide functional, as well as anatomic and morphological data of lymph system,45nm 颗粒直径 100nm,Methods,The type of study you are having will determine the location of your inject

31、ion and the number of scans performed,Breast cancer The radiotracer may be injected in multiple sites near the tumor and/or around the nipple. The breast, chest and underarm regions will be imaged. Imaging usually is completed within 30 minutes to one hour, but may take up to two or more hours. Arm

32、or leg edema The radiotracer is injected between the first and second fingers or toes of each hand or foot. Both the swollen and healthy arm or leg will be imaged so that the two sides can be compared. Depending on the degree of lymphatic obstruction and the cause, imaging may take 30 minutes to sev

33、eral hours,Image analysis,We include the internal mammary lymphoscintigraphy as an example of how to analyze the image data,A B,C D,A, normaldiscrete lymphatic aggregated with good bilateral radiocolloid uptake B, suspicious of abnormality diminished radiocolloid uptake in the upper left parasternal

34、 nodes C, abnormalthe left parasternal lymphatics have been disrupted with ill-defined aggregates of radiocolloid along the parasternal border and substernally D, abnormalcomplete obliteration of the right parasternal nodes,Clinical application,Identify the sentinel lymph node（SLN）, or the first nod

35、e to receive the lymph drainage from a tumor Sentinel node scanning has become widely accepted in breast cancer, malignant melanoma，head and neck cancer, thyroid cancer, non-small cell lung cancer, gastric cancer, penile cancer, and vulvar cancers. The Relevance ratio of SLN in breast cancer is 92%9

36、8%, and its coincidence ratio is 90%100%. Over 50% patients avoid axillary lymph node dissection after SLN scanning The Relevance ratio of SLN in melanoma is 80%98,Contraindications Absolute contraindications include clinically positive (N1) axilla and allergy to component used. Relative contraindications include the following ： Prior biopsy (especially excisional biopsy) Previous breast and axillary surgery Advanced disease (associated with fatty degeneration of nodes with reduced function) Neoadjuvant chemotherapy Multicentric and multifocal disease Du