Thoracic Imaging and EKG Review

Flashcards covering key concepts from Thoracic Imaging (CXR indications, densities, positions, terminology, normal findings, landmarks, artificial airways, and common findings in pulmonary diseases like pulmonary edema, atelectasis, ARDS, pleural effusion, pneumonia, pneumothorax, and tuberculosis), as well as advanced imaging techniques (CT, MRI, V/Q Scan), and Electrocardiograms (EKG lead placement, waveform interpretation, rate calculation, and common arrhythmias).

What are some indications for performing a Chest X-ray (CXR)?

Abnormal breath sounds, increased work of breathing (WOB), shortness of breath (SOB), injury, pulmonary infection (sputum production, cough, fever), or recent intubation.

When is a CXR contraindicated due to the need for immediate intervention?

Tension pneumothorax, cardiac arrest, severe hypoxia, or severe/marked stridor/distress.

What are the 4 basic radiographic densities seen on a CXR, from darkest to lightest?

Air (black/radiolucent), Fat (dark gray), Soft Tissue/Water (gray), Bone/Calcium (white/radiopaque).

Which CXR position is best for a standard view?

PA (posterior to anterior).

What CXR position is used for bedridden patients?

AP (anterior to posterior).

What does 'radiolucent' mean in CXR terminology?

A dark pattern of air.

What does 'radiodense/opacity' indicate on a CXR?

A white pattern of solids, bones, or fluids.

What does 'consolidation' refer to on a CXR?

A solid white area.

What are the characteristics of a normal CXR regarding the diaphragm and trachea?

Both hemidiaphragms are rounded (dome-shaped), the right hemidiaphragm is slightly higher, and the trachea is midline.

What does 'obliterated, blunted, or blurred costophrenic angles' indicate, and what follow-up CXR is needed?

It indicates a pleural effusion, and a lateral decubitus CXR is indicated.

What does a flattened diaphragm often indicate on a CXR?

COPD (Chronic Obstructive Pulmonary Disease).

What does an increase in the cardiac shadow or silhouette (cardiomegaly) suggest on a CXR?

Congestive Heart Failure (CHF) or pericardial effusion.

What do crowding of ribs and straight/horizontal ribs suggest on a CXR?

Crowding of ribs is associated with atelectasis and restrictive processes; straight/horizontal ribs are associated with air trapping (obstructive diseases like COPD or acute asthma).

Where should the tip of an endotracheal tube ideally be positioned on a CXR?

Approximately 2-6 cm above the carina, at the level of the aortic knob or aortic arch (T4-T6 vertebral position).

Where should a central venous catheter tip rest on a CXR?

In the superior vena cava or right atrium of the heart (4th intercostal space, right of sternum).

What can a Lateral Neck X-Ray be used to identify in children?

Upper airway obstruction, such as croup or epiglottitis.

What are common CXR descriptions for Pulmonary Edema?

Fluffy infiltrates, butterfly pattern, batwing pattern, Kerley B Lines.

What are common CXR descriptions for Atelectasis?

Patchy infiltrates, platelike infiltrates, crowded pulmonary vessels, crowded air bronchograms, hilum displaced upwards, tenting of diaphragm.

What are common CXR descriptions for Acute Respiratory Distress Syndrome (ARDS)?

Ground glass appearance, honeycomb pattern, diffuse bilateral radiopacity, whiteout.

What are common CXR descriptions for Pleural Effusion?

Blunting/obliteration of the costophrenic angle, basilar infiltrates with meniscus sign, concave superior interface/border.

What are common CXR descriptions for Pneumonia?

Air bronchogram, increased density from consolidation.

What are common CXR descriptions for Pneumothorax?

Deep sulcus sign, arch.

What are common CXR descriptions for Tuberculosis?

Cavity formation, often in upper lobes.

What is Computed Tomography (CT) useful for detecting?

Mediastinal, pleural, and parenchymal masses, pulmonary nodules, lesions not visualized on CXR, and can diagnose bronchiectasis or pulmonary embolus (with contrast).

What is Magnetic Resonance Imaging (MRI) particularly useful for?

Determining thoracic aneurysms, congenital anomalies of the aorta and major thoracic vessels, and the precise position of tumors or soft tissue abnormalities without radiation.

What is a key consideration for patients requiring mechanical ventilation during an MRI?

Fluidic (non-electric, gas-powered) ventilators must be used, and all materials near the machine must be non-ferrous.

What does a normal ventilation scan with an abnormal perfusion scan on a V/Q scan indicate?

A pulmonary embolism.

What is the difference between an electrode and a lead in EKG terminology?

An electrode is an object placed on the skin to conduct current, while a lead is a displayed movement of electricity from one electrode to another (a view or angle).

Where is the V1 chest electrode placed?

4th intercostal space on the right side of the sternum.

Where is the V4 chest electrode placed?

5th intercostal space, left mid-clavicular line.

Which EKG waveform represents atrial depolarization?

The P wave.

Which EKG complex represents ventricular depolarization?

The QRS complex.

Which EKG waveform represents ventricular repolarization?

The T wave.

How is heart rate estimated using the 'Big Box Method' on an EKG?

Count the number of large boxes between two consecutive R waves. If 1 box = 300 bpm, 2 boxes = 150 bpm, 3 boxes = 100 bpm, etc.

What is the EKG rhythm with a heart rate greater than 100 bpm and normal P-waves, QRS complexes, and T-waves?

Sinus Tachycardia.

What is the EKG rhythm with a heart rate less than 60 bpm and normal P-waves, QRS complexes, and T-waves?

Sinus Bradycardia.

What EKG finding defines a First-Degree Heart Block?

A prolonged PR interval (greater than 0.20 seconds) with every P wave followed by a QRS complex.

What EKG finding defines Atrial Flutter?

Sawtooth P waves (flutter waves) typically with a regular ventricular rhythm.

What EKG finding defines Atrial Fibrillation?

Irregularly irregular rhythm with no discernible P waves and a wavy baseline.

What is the EKG rhythm characterized by wide, bizarre QRS complexes occurring prematurely, not preceded by a P wave?

Premature Ventricular Contractions (PVCs).

What does 'Ischemia' mean in the context of cardiac events?

Reduced blood flow to tissue.

What does 'Infarction' mean in the context of cardiac events?

Necrosis or death of tissue, often the end result of ischemia and injury.

What is the immediate treatment for an Acute Myocardial Infarction (MI), acronym MONA?

Morphine, Oxygen, Nitroglycerin, Aspirin.

What EKG rhythm is characterized by a complete absence of electrical activity (a flat line)?

Asystole.