Langerhans Cell Histiocytosis
Overview Definition Langerhans cell histiocytosis (LCH) is a rare, idiopathic neoplastic disorder of dendritic cells (Langerhans cells), which are involved in antigen presentation to T cells. Epidemiology Classification The Histiocyte Society and WHO both have classifications for histiocyte disorders. Histiocyte Society classification The Histiocyte Society divides the histiocytic disorders into 5 categories based on the […]
Mpox (Monkeypox)
Overview Mpox (formerly known as monkeypox) is a viral zoonotic disease caused by the mpox virus. Mpox has a clinical profile similar to that of smallpox, but is less often fatal. Virology Epidemiology Transmission Clinical Presentation General Invasion period (0–5 days) Symptoms occurring during this period may include: Cutaneous manifestations The course of illness is followed […]
Cranial Nerve Palsies
Overview Definitions Overview of CNs The table below summarizes the functions of the 12 CNs. Table: Functions of the 12 CNs CN Name Function Type I Olfactory Olfaction (smell) Sensory II Optic Vision Sensory III Oculomotor Eye movement Pupillary constriction Accommodation Eyelid opening Motor IV Trochlear Eye movement (superior oblique muscle) Motor V Trigeminal Facial […]
Pulmonary Function Tests
Overview Definition Examples Indications Contraindications Lung Volumes Lung volumes are measured by: Lung volumes: Lung capacities: Spirometry Spirometry records the volume of air moving in and out of an individual’s lungs. Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) Table: Parameters of obstructive and restrictive lung disease Parameter Obstructive lung disease Restrictive lung disease […]
Pediatric Gastrointestinal Abnormalities
Introduction Key considerations in pediatric imaging Several additional issues must be considered during pediatric imaging, including: Preparatory steps prior to image analysis Prior to the interpretation of any image, the physician should take certain preparatory steps. The same systematic approach should always be followed: Radiography/Fluoroscopy Indications Advantages Disadvantages Exam technique Interpretation/evaluation Images should always be […]
Imaging of the Intestines
Introduction Imaging modalities The common radiologic modalities used to evaluate the intestines are the following: Preparation and orientation Prior to interpretation of any image, the physician should take certain preparatory steps. The same systematic approach should be followed every time: Determine the orientation of the image: Radiography (X-ray) Overview Exam technique General positioning: Positioning for […]
Cancer Immunotherapy
Tumor Immunology Immune system The immune system provides defense (immunity) against invading pathogens ranging from viruses to parasites, and components are interconnected by blood and the lymphatic circulation. The 2 lines of defense (that overlap): Tumor recognition Over 20,000 DNA-damaging events occur each day, which undergo repair via specific pathways, thus causing no lasting effect. […]
Volume Depletion and Dehydration
Definitions and Etiology Definitions Dehydration refers only to a loss of water, while volume depletion refers to a loss of both water and Na+. Etiology Pathophysiology The relative differences between losses of water and Na determine how water shifts between the fluid compartments of the body. With volume depletion and dehydration, there are fluid shifts […]
Imaging of the Liver and Biliary Tract
Introduction Imaging methods Preparation and orientation Prior to interpretation of any image, the physician should take certain preparatory steps. The same systematic approach should be followed every time. Ultrasonography Overview Exam technique Interpretation and evaluation Report includes: Normal findings CT Overview Exam technique Interpretation and evaluation Normal findings MRI Overview Exam technique Table: General principles […]
Imaging of the Urinary System
Introduction Imaging methods The common radiologic methods in use to evaluate the urinary tract are: Preparation and orientation Radiography Overview Exam technique Interpretation and evaluation As the obtained image contains multiple organs and structures (and not just the urinary tract), an inside-out approach (central to peripheral) is taken to provide interpretation: Normal findings AP view: […]