DOPPLER ECHOCARDIOGRAPHY

DOPPLER ECHOCARDIOGRAPHY

pediagenosis    May 30, 2025    Comment   

DOPPLER ECHOCARDIOGRAPHY

Plate 3-13
PRINCIPLES OF DOPPLER ECHOCARDIOGRAPHY

Echocardiography with Doppler ultrasound is based on the principle of estimating velocity and direction of blood flow by using moving red blood cells as a target (see Plate 3-13). There are two types of Doppler US: continuous wave and pulse wave. With the continuous wave technique the transducer can be aimed along the long axis of the ventricle of the aorta and can record all flow patterns encountered. The pulse wave technique allows simultaneous recording of the Doppler and 2D echocardiography. The pulsed technique allows the localization of a Doppler sample in the area of interest (e.g., mitral and aortic valves). Using these Doppler techniques, a transvalvular gradient across the aortic or mitral valves can be derived, as well as estimation of the pressure and severity of mitral, aortic, and tricuspid valve regurgitations.

TRANSTHORACIC CARDIAC ULTRASOUND

TRANSTHORACIC CARDIAC ULTRASOUND

pediagenosis    May 30, 2025    Comment   

TRANSTHORACIC CARDIAC ULTRASOUND

Plate 3-12
TRANSDUCER POSITIONS IN ECHOCARDIOGRAPHIC EXAMINATION

Understanding  cardiac  ultrasound  (US)  requires knowing cardiac anatomy and physiology. In addition, performing echocardiography requires considerable experience to develop the necessary technical skills. Cardiac US records reflected sound waves from blood tissue interfaces within the heart and great vessels, thus visualizing the complex cardiac anatomy and providing a remarkably detailed image of heart motion and structure during all phases of the cardiac cycle (see Plate 3-12). Transthoracic cardiac US is one of the most useful diagnostic tests available.

INTRAVASCULAR ULTRASOUND

INTRAVASCULAR ULTRASOUND

pediagenosis    May 30, 2025    Comment   

INTRAVASCULAR ULTRASOUND

Plate 3-11

Intravascular ultrasound (IVUS) uses high-frequency sound waves to acquire 3D images to determine the extent and composition of the atherosclerotic lesions in the coronary vessels. IVUS is an invasive technique used in the catheterization laboratory to complement catheter based coronary angiography and thus requires cardiac catheterization.

CATHETER BASED CORONARY ANGIOGRAPHY

CATHETER BASED CORONARY ANGIOGRAPHY

pediagenosis    May 22, 2025    Comment   

CATHETER BASED CORONARY ANGIOGRAPHY

Plate 3-9
RIGHT CORONARY ARTERY: ARTERIOGRAPHIC VIEWS

Until recently, diagnosis of human coronary atherosclerosis depended primarily on the physician’s ability to interpret the significance of chest pain described by patients who experience infinitely variable subjective responses to stress. Objective confirmation hinged on the recognition of transient or persistent electrocardiographic changes, which usually indicate the presence of myocardial ischemia, necrosis, or scar tissue replacement of functioning myocardium. Therefore the pres- ence of coronary atherosclerosis could be recognized in a patient only after the disease process had progressed to a point where arterial obstructions were so severe as to cause transient or permanent secondary changes in the myocardium (ischemia or infarction).

RADIOLOGY AND CATHETER BASED ANGIOCARDIOGRAPHY

RADIOLOGY AND CATHETER BASED ANGIOCARDIOGRAPHY

pediagenosis    May 22, 2025    Comment   

RADIOLOGY AND CATHETER BASED ANGIOCARDIOGRAPHY

FRONTAL PROJECTION

RADIOLOGY

Radiologic examination is an essential part of the evaluation of cardiac disease. The size of the heart and identification of chamber enlargement and pericardial, cardiac, and coronary calcification, as well as information on heart function and hemodynamics, can be determined from chest radiography, fluoroscopic examination, and angiocardiographic observations.

INFECTIONS OF THE HAND

INFECTIONS OF THE HAND

pediagenosis    May 18, 2025   

INFECTIONS OF THE HAND

Before the introduction of antibiotics, infections of the hand often led to prolonged morbidity, severe deformity, amputation, and even death. Kanavel’s classic article in 1939 on the pathways of purulent infection within the anatomic compartments of the hand opened the modern era of treatment for these problems. Although injuries in the industrial workplace are less prevalent than in Kanavel’s time, wounds of the hand still account for a large percentage of hand infections. A high incidence of hand infections is also associated with societal problems, such as intravenous injection of drugs with contaminated needles, wounds inflicted with various weapons in gang-related incidents, and complications of treatment with immunosuppressive agents. Human and animal bites may also have severe consequences.

Lymphatic Drainage of Mouth and Pharynx

Lymphatic Drainage of Mouth and Pharynx

pediagenosis    May 18, 2025   

Lymphatic Drainage of Mouth and Pharynx

Lymphatic fluid, carried by the lymphatic capillaries in the tissues of the mouth and pharynx, is all eventually taken by the lymphatic vessels, either directly or with the interruption by interposed lymph nodes, to the chain of lymph nodes lying along the internal jugular vein. The efferent vessels from these nodes enter into the formation of the jugular lymphatic trunk, which, characteristically, on the left side empties into the thoracic duct near its termination and on the right side into the right lymphatic duct. The thoracic duct and the right lymphatic duct pour their lymph into the bloodstream at the junction of the internal jugular and subclavian veins on the respective side. On either side the jugular trunk may empty directly into the veins near this site.

MUSCLES OF THE HAND

MUSCLES OF THE HAND

pediagenosis    May 17, 2025   

MUSCLES OF THE HAND

INTRINSIC MUSCLES

The interosseous muscles occupy the intermetacarpal intervals and are of two types: dorsal and palmar. Each intermetacarpal space contains one palmar and one dorsal interosseous muscle. The four dorsal interosseous muscles are abductors of the digits and are bipennate; the three palmar interosseous muscles are adductors and are unipennate. The plane of reference for abduction and adduction of the fingers is the midplane of the third digit. This is evident on simultaneously spreading and then approximating the extended digits. The placement of these muscles follows from the above considerations of actions and reference plane for abduction and adduction.

EFFECTS OF PITUITARY TUMORS ON THE VISUAL APPARATUS

EFFECTS OF PITUITARY TUMORS ON THE VISUAL APPARATUS

pediagenosis    May 16, 2025    Comment   

EFFECTS OF PITUITARY TUMORS ON THE VISUAL APPARATUS

The optic chiasm lies above the diaphragma sellae. The most common sign that a pituitary tumor has extended beyond the confines of the sella turcica is a visual defect caused by the growth pressing on the optic chiasm. The most frequent disturbance is a bitemporal hemianopsia, which is produced by the tumor pressing on the crossing central fibers of the chiasm and sparing the uncrossed lateral fibers. The earliest changes are usually enlargement of the blind spot; loss of color vision, especially for red; and a wedge-shaped area of defective vision in the upper-temporal quadrants, which gradually enlarges to occupy the whole quadrant and subsequently extends to include the lower temporal quadrant as well.

Pancreas Anatomy

Pancreas Anatomy

pediagenosis    May 16, 2025    Comment   

Pancreas Anatomy

The pancreas is both an exocrine and an endocrine gland. Most of its substance is involved in producing pancreatic juice, which is conveyed by a duct system into the descending duodenum. In addition, microscopic clumps of endocrine tissue, the pancreatic islets (islets of Langerhans), are dispersed throughout the gland.