Principles of 2D and M-Mode Echo (Continued) Flashcards
Calculate the reflection co-efficient for the muscle air interface.
0.0004 x106 + 1.71x106
In echocardiography or medical ultrasound imaging in general, we encounter various types of reflectors, some of which are specular (reflecting waves in a specific direction) and others are non-specular (reflecting waves in multiple directions). Here are some examples:
Specular Reflectors:
Heart valve leaflets: These thin structures within the heart can produce specular reflections due to their smooth surfaces.
Diaphragm: The diaphragm separating the chest and abdominal cavities can produce specular reflections, especially in cases of pleural effusion or pneumothorax.
Bone surfaces: Bone surfaces can act as specular reflectors, particularly when the ultrasound beam encounters cortical bone interfaces.
Non-Specular Reflectors:
Myocardium: The muscular tissue of the heart can produce non-specular reflections due to its irregular structure and varying orientation of muscle fibers.
Blood cells: Within the bloodstream, red blood cells can scatter ultrasound waves in multiple directions, leading to non-specular reflections.
Liver parenchyma: Liver tissue can produce non-specular reflections due to its heterogeneous structure and presence of blood vessels.
What position should the patient typically lay in to obtain the left parasternal views?
Correct answer:
left lateral decubitus
Semi-fowler
, Not Selected
right lateral decubitus
, Not Selected
Supine
What structures are visualised in the left parasternal long axis view of the left ventricle?
Correct answer:
Left ventricular outflow tract
Left atria
Mitral valve
What left ventricle wall is visualised in the left parasternal long axis view of the left ventricle?
Posterior
What anatomical structure is best visualised from the high left parasternal view?
Proximal ascending aorta
What normal variants can be seen in the right atria from the right ventricular inflow tract view?
Correct answer:
Chiari network
Eustachian valve
What are these: Review
Chiari network:
Moderator band (Septomarginal trabecula)
Atrial appendage
Eustachian valve (Valve of the inferior vena cava)
Chiari network: This is a reticulated network of fibers or strands in the right atrium. The Chiari network is a web-like structure of fibers or strands found in the right atrium of the heart, thought to be a remnant of embryonic development, which may play a role in directing blood flow during fetal circulation. In adults, it typically has no significant physiological function but may be observed incidentally during imaging studies or cardiac procedures.
Moderator band (Septomarginal trabecula): This is a muscular band of tissue found in the right ventricle. While not directly visible in the right atrium.
The moderator band, also known as the septomarginal trabecula, is a muscular structure found in the right ventricle of the heart, extending from the interventricular septum to the base of the anterior papillary muscle. It contains the right bundle branch of the cardiac conduction system and helps coordinate ventricular contraction, contributing to efficient pumping of blood from the right ventricle.
Atrial appendage: The right atrial appendage is a small, ear-shaped pouch-like structure extending from the right atrium.
The atrial appendage assists in optimizing atrial function by increasing atrial capacity and aids in preventing blood stasis by serving as a reservoir for blood, thus reducing the risk of clot formation in the atria.
Eustachian valve (Valve of the inferior vena cava): This is a fold of tissue at the opening of the inferior vena cava into the right atrium.
The Eustachian valve is a fold of tissue located at the opening of the inferior vena cava into the right atrium of the heart, directing oxygenated blood towards the foramen ovale during fetal development. In adults, it may have a minimal physiological role, potentially influencing blood flow dynamics in certain clinical conditions such as atrial septal defects.
In the left parasternal long axis view of the left ventricle, the left ventricle should be —————– to the sound beam and be —————– in the sector.
–Perpendicular–
–Horizontal–
The interatrial septum can be best visualised in which of the following parasternal views?
Parasternal short axis of the aortic valve
Axial resolution is the:
A)Minimum reflector spacing along the axis of an ultrasound beam that results in separate distinguishable echos being displayed
B)Minimum reflector spacing perpendicular to the axis of an ultrasound beam that results in separate distinguishable echos being displayed
C) Ability to accurately image moving structures
D) Smallest variation in echo level that can be distinguished as a shade of grey on B-mode
Minimum reflector spacing along the axis of an ultrasound beam that results in separate distinguishable echos being displayed
Lateral resolution is the:
A)Minimum reflector spacing along the axis of an ultrasound beam that results in separate distinguishable echos being displayed
B)Minimum reflector spacing perpendicular to the axis of an ultrasound beam that results in separate distinguishable echos being displayed
C) Ability to accurately image moving structures
D) Smallest variation in echo level that can be distinguished as a shade of grey on B-mode
Correct answer:
Minimum reflector spacing perpendicular to the axis of an ultrasound beam that results in separate distinguishable echos being displayed
Contrast resolution is the:
A)Minimum reflector spacing along the axis of an ultrasound beam that results in separate distinguishable echos being displayed
B)Minimum reflector spacing perpendicular to the axis of an ultrasound beam that results in separate distinguishable echos being displayed
C) Ability to accurately image moving structures
D) Smallest variation in echo level that can be distinguished as a shade of grey on B-mode
D) Smallest variation in echo level that can be distinguished as a shade of grey on B-mode
Temporal resolution is the:
A)Minimum reflector spacing along the axis of an ultrasound beam that results in separate distinguishable echos being displayed
B)Minimum reflector spacing perpendicular to the axis of an ultrasound beam that results in separate distinguishable echos being displayed
C) Ability to accurately image moving structures
D) Smallest variation in echo level that can be distinguished as a shade of grey on B-mode
C) Ability to accurately image moving structures
In order for two reflectors to be displayed as two separate reflectors in the axial plane what must be true?
They must be separated by spatial pulse length
They must be separated by less than one wave length
They must be separated by less than one spatial pulse length
They must be separated by one wave length
Answer,
They must be separated by less than one spatial pulse length
