RADR 2217 Radiographic Pathology Chapter 9 The Hemopoietic System

He·mo·poi·e·sis (Variant of) Hematopoiesis: The production of all types of blood cells generated by a remarkable self-regulated system that is responsive to the demands put upon it. hematopoietic system n. The bodily system of organs and tissues, primarily the bone marrow, spleen, tonsils, and lymph nodes, involved in the production of blood.

Objectives Identify the major constituents of blood and describe the function of each constituent. Specify the various blood types. Explain the role of lymphatic systems in terms of immunity. Describe the pathogenesis, prognosis, and signs and symptoms of disease processes with regard to the hemopoietic system.

Overview Anatomy and Physiology of Blood Imaging Considerations Acquired Immune Deficiency Syndrome Neoplastic Diseases

Anatomy and Physiology of Blood

Hemopoietic System Blood Lymphatic tissue Bone marrow Spleen Components Blood Lymphatic tissue Bone marrow Spleen

Circulating Blood Components: Plasma Blood cells 55% of total blood volume 90% water 10% solutes Proteins Glucose Amino acids Lipids Blood cells 45% of total blood volume Erythrocytes Leukocytes Thrombocytes

Erythrocytes Red blood cells Small, biconcave disks Transport via Hemoglobin Transports oxygen & carbon dioxide to and from organs of the body May contain antigens to determine blood type Anemia: < 12 g/100ml; less than normal oxygen or carbon dioxide transportation Hematocrit – lab test to determine total % of RBCs in blood volume

Life of Erythrocytes Formed by Hemocytoblasts Red bone marrow Live approximately 120 days Aged RBCs are removed by the spleen, liver and the bone marrow. Phagocytosis Iron released & recycled in development of new RBCs Bilirubin formed & excreted in bile

Blood Types Types Type O Type AB O (no antigen) A antigen B antigen AB antigen Type O Universal donor Type AB Universal recipient Agglutination – clumping of RBCS when held together by antibodies

Rh Factor Discovered in blood of Rhesus monkey Types Rh positive 85% of population Rh negative Rh incompatibility requires immunization of mother prior to pregnancy (Rhogam shot) The above is true with 2nd pregnancy and subsequent pregnancies. 1st pregnancy progresses normally.

Leukocytes White blood cells; larger than RBCs Granular or nongranular Granular formed in red bone marrow may live 14 days Nongranular formed in lymph system may live for years WBCs “attack” & phagocytose foreign substances Changes in number often indicate disease process Usually 5000-9000 per ml normal range

Thrombocytes “Platelets” Necessary for proper blood clotting Respond within seconds to initiate coagulation Formed in myeloid tissue within red bone marrow Life span of 10 days

Lymphatic System Subsystem of circulatory system Assures immunity through production of lymphocytes and antibodies Responsible for fat absorption from intestinal tract Also responsible for manufacturing blood under certain circumstances

Lymphatic System Components Lymphatic vessels – contain lymph (milky liquid substance) Lymph nodes – small ovoid bodies (chained) along vessels Filter particles & foreign materials from blood Become enlarged when infection is present Regions include neck, mediastinum, axillary, retroperitoneal, & pelvic areas

Spleen Part of lymphatic system Produces lymphocytes and plasma cells Stores RBCs Functions in phagocytosis May be removed without detrimental effects May rupture with abdominal trauma

Lymphocytes Mature cells are most important in development of immunity Types T lymphocytes (derived from thymus gland B lymphocytes (derived from bone marrow) Ingest foreign substances Most radiosensitive blood cells Work with macrophages to ingest foreign substances & process specific foreign antigens Effect on organ transplants

Radiation Exposure Can have a harmful effect on blood marrow and lymphoid tissue Whole body dose of 0.5-0.75 Gy (50-75 rad) causes detectable change in blood cells Most radiosensitive blood cells: Lymphocytes Leukocytes Thrombocytes Radiation treatments may reduce patient immunity

Imaging Considerations

Imaging Considerations Radiography - limited role in diagnosis & treatment of hemopoietic conditions (skeletal & chest helpful) Abdomen CT - lymph node enlargement CT & MRI -Central nervous system & bone marrow imaging

Imaging Considerations Radiographer safety Standard precautions imperative for blood borne pathogens Gloves Gown Mask Face Shield Proper needle disposal Handwashing !!

Acquired Immune Deficiency Syndrome

AIDS First recognized in 1981 Acquired Immune Deficiency Syndrome First recognized in 1981 Caused by 2 related human immunodeficiency retroviruses (HIV-1 and HIV-2) Presence of unusual opportunistic infections Directly linked to increased incidence of malignancies Most common disease associated with lymphocytopenia or lymphocyte depletion

Inhibits body’s response to presence of various diseases HIV-1 and HIV-2 Inhibits body’s response to presence of various diseases HIV-1 Identified in 1984 Paralyzes normal immune mechanisms in body Results in severe immunosuppression (AIDS) Responsible for most cases in Western Hemisphere More virulent than HIV-2 HIV-2 Principal agent of AIDS in West Africa

HIV-AIDS Signs & Symptoms Lymphadenopathy Malaise Fever Joint pain Weight loss Nausea & vomiting Diarrhea Leukopenia Anemia Thrombocytopenia

HIV-AIDS May affect anyone; most frequent in homosexual & bisexual men and IV drug users Virus transmitted by sexual contact & exposure to infected blood & body fluids One of most common infections is TB Pneumocystis carinii and bacterial pneumonias are also common

Kaposi’s Sarcoma Most common malignancy in AIDS (25-30% of patients) Also affects connective tissue Most often affects Skin lymph nodes GI system Radiographically presents as hilar adenopathy, nodular pulmonary infiltrates, & pleural effusion Endobronchial Kaposi’s is frequent

Neoplastic Disease

Multiple Myeloma Disease of plasma cells resulting in cell proliferation Unknown etiology & usually confined to bone marrow Abnormal plasma cells produce large amounts of protein Forms discrete tumors that weaken affected bone & disrupts normal renal function Typically seen over 40 years of age

Multiple Myeloma Most frequently affects pelvis, spine, ribs, and skull 90% have bone involvement Patient presents with bone pain, anemia, fatigue, bleeding disorders, renal problems, hypercalcemia, recurrent bacterial infections Poor prognosis with survival usually 2-3 years

Multiple Myeloma Imaging Demonstrates Punched-out, osteolytic regions Diffuse osteoporosis May demonstrate pathologic & vertebral compression fractures MRI more useful in early stages of disease (30% bone loss needed for conventional)

Leukemia Disease of leukocytes resulting in overproduction of white blood cells Unknown etiology May be associated with exposure to irradiation & certain chemicals; also with genetic defects & Epstein-Barr May lead to anemia bleeding infection

Leukemia Classified as acute or chronic Account for 35% of all cancer deaths in children under 15 years All forms require cell destruction by irradiation or antileukemic drug therapy Bone marrow transplants may be attempted Survival depends on complete remission Radiography role is limited

Non-Hodgkin’s Lymphoma Malignancy of lymph cells Most common lymphoma Incidence increases with age Unknown etiology Found in Lymph nodes Bone Marrow Spleen Liver GI system

Non-Hodgkin’s Lymphoma Patient presents with lymphadenopathy & possible anemia Diagnosis with CT of abdomen & pelvis Bone biopsy may be performed Treatment includes chemotherapy & radiation therapy

Hodgkin’s Disease Type of lymphoma affecting lymphoid tissue Node distribution is usually retroperitoneal Unknown etiology Commonly affects ages 20-40 & those over 60 More often affects men

Hodgkin’s Disease Patient presents with malaise, fever, anorexia, enlarged lymph nodes Staged according to extent of disease most often with CT Commonly treated with radiation & chemotherapy