Diagnostic Tests and Imaging Methods for Disease Detection
Diagnostic Tests: Detecting Disease in the Body
Diagnostics play a crucial role in identifying diseases and monitoring their progression. Accurate diagnostic reports are essential for effective treatment. Diagnostic procedures include:
- Physical Examinations: Assessing vital signs like blood pressure, heart rate, body temperature, and performing auscultation (listening to internal sounds).
- Blood Tests: Analyzing blood samples to detect infections (via leukocyte counts) and measure cholesterol, glucose levels, etc.
- Urinalysis: Examining urine samples to assess kidney and urinary tract function, although it provides less information than blood tests.
- Cell Cultures: Growing cells from biopsies to determine if they are benign or malignant.
- Biopsies: Extracting tissue samples for detailed analysis.
- Imaging Diagnostic Methods
Imaging Diagnostic Methods
Imaging techniques have significantly advanced in recent years, enabling faster and more precise disease detection. These methods include:
Radiography (X-rays)
Uses X-rays to create images on a photographic plate. Dense structures (bones) block X-rays, while softer tissues (muscles) allow them to pass through. Commonly used in traumatology, and for detecting lung cancer and some tumors.
CT Scan (Computed Tomography)
Uses X-rays to create cross-sectional images of the body. Useful for visualizing tumors and injuries in areas like knees and ligaments.
MRI (Magnetic Resonance Imaging)
Uses powerful magnets and radio waves to generate images. Hydrogen atoms absorb and release energy, which is processed to create detailed images. Excellent for visualizing soft tissues.
PET Scan (Positron Emission Tomography)
Uses a radioactive tracer substance administered to the patient. Detects metabolic activity and helps identify problems in organs and tissues, such as blood flow and kidney function.
Gammagraphy (Scintigraphy)
Uses radioactive isotopes that emit gamma radiation. Sensors detect the radiation to identify metabolic issues.
Ultrasound
A less invasive technique using high-frequency sound waves. A device emits ultrasound and captures the echoes to create images. Safe for use in many applications, including prenatal care.
Cancer
Cancer is a group of diseases characterized by uncontrolled cell growth, forming a tumor. This often results from a loss of control in certain genes. While not directly inherited, a genetic predisposition can increase risk. There are two main types of tumors, identified through biopsy:
- Benign: Localized tumors that do not invade other tissues.
- Malignant: Tumors that invade surrounding tissues and can spread (metastasize) through the bloodstream or lymphatic system.
Causes of Cancer:
- Chemical substances (asbestos, benzene, nickel, tobacco smoke).
- Radiation (ultraviolet rays, X-rays, nuclear radiation).
- Viruses (Human Papillomavirus, Hepatitis C).
- Genetic predisposition.
Cancer Treatment:
- Anti-cancer substances in foods (fresh fruits, vegetables, olive oil).
- Chemotherapy: Intravenous drugs that inhibit cell division (antimitotics).
- Radiotherapy: Using radiation to destroy tumor cells.
- Bone marrow transplantation (for leukemia).
- Monoclonal antibodies: Antibodies designed to target and eliminate cancer cells.
- Surgery.
Leukemia
Leukemia is a blood cancer characterized by an uncontrolled increase in immature white blood cells.
- Acute Leukemia: Rapidly progressing and requires immediate treatment.
- Chronic Leukemia: Evolves slowly, with periods of increased and normal activity.
Symptoms: High fever, fatigue, loss of appetite, impaired white blood cell function, thrombocytopenia (low platelet count) leading to petechiae (small red spots), and anemia (low red blood cell count).
Treatment: Chemotherapy, radiotherapy, and bone marrow transplantation (from umbilical cord blood banks or bone marrow donors).
Causes: Genetic alterations and environmental factors (diet, chemical exposure).