PA Chest, Lateral Chest, PA Oblique Chest

ROOM SETUP

• Read patient's orders and history
• Clean room and set up for exam
• Make sure all equipment is working properly
• Have shielding, markers, cushioning blocks/triangles and any other items needed to aid the exam
• Wash your hands

PATIENT IDENTIFICATION

• Introduce yourself to the patient
• Ensure you have the correct patient by asking for: > Patient's name > Date of Birth > SSN > Exam > Correct anatomy and side being examined

Patient Identification

• For females between the ages of 12-55 ask if they are pregnant. They may need to fill out a pregnancy consent form depending on your facility. If patient is pregnant and you have the doctor's consent to perform the exam double shield the patient.

ANATOMICAL MARKING

• Make sure the marker is visualized in the collimated light field and it is not obscuring the area of interest
• The R or L on the marker corresponds with the correct side of the patient
• Marker includes tech's initials and may also include gravity beads or arrow

Anatomical marking

• The marker is positioned in the best location for the projection being presented such as: > AP/PA/Oblique films- marked anatomically to lateral aspect > Lateral films- marked side down, anteriorly > Decubitus films- marked anatomically side up > Cross table lateral films- marked anteriorly (when supine) and anatomically or side closest to film

-Artifacts- any artificial product that is not natural
-Artifacts degrade the image quality of radiographs produced by artificial mean which include: motion, foreign objects obscuring anatomy, vertical banding artifacts, etc.

TECHNICAL FACTORS

• Radiographic Contrast: The difference between the shades of gray visualized on a radiographic image
• Controlled by kVp (penetration)
• Cortical outlines: the outer layer of bone that is demonstrated on a radiograph of an anatomical structure
• High kVp results in low contrast/little difference between the shades of gray and lacks bright white shade
• Low kVp results in high contrast (black and white with very little gray)

Technical factors

• HELL: high kVp equals long scale low contrast
• LESH: low kVp equals short scale high contrast
• Radiographic Density: degree of blackness visualized on a radiographic image; controlled by mAs
• Trabecular patterns: the supporting material within cancellous bone. It's demonstrated radiographically as thin white lines throughout a bony structure
• Overexposure where all structures are too dark to evaluate
• Underexposure where structures are too light to evaluate

ADJUSTING TECHNICAL FACTORS

• kVp: adjust by 15% if the technique that was used was 70 kVp
• Overpenetrated: decrease technique by 15% > 70x0.15=10.5kVp 70-10.5=59.5kVp
• Underpenetrated: increase technique by 15% > 70x0.15=10.5kVp 70+10.5=80.5kvp

ADJUSTING TECHNICAL FACTORS

• mAs: adjust by 50% or 100% if technique used was 4mAs
• Overexposure: adjust technique by 50% > 4x.5=2mAs
• Underexposure: adjust technique by 100% > 4x4=16mAs

CENTERING

• Part/Film Centering > Ignore the collimated light field > Concentrate on the part > How is it centered to the film? > How is the space of the film utilized?
• Central Ray/ Part Centering > Focus on the collimated light field > How is the CR in relation to the part? > Four-sided visualization of collimation is needed to know where the CR is centered > Collimate down to the anatomy being exposed

ANATOMY of the THORAX

• BONY THORAX > Supports the walls of the pleural cavity > Protects the heart and lungs > Supports diaphragm

BONY THORAX

ANATOMY of the THORAx: THoracic Viscera

• Thoracic cavity contains the lungs and heart; organs of the respiratory, cardiovascular, and lymphatic systems; the inferior portion of the esophagus; and the thymus gland
• The cavity contains three separate chambers: a single pericardial cavity, and the right and left pleural cavities

ANATOMY of the THORAx: THoracic Viscera

IR: 14 x 17 in. lengthwise
Exposure Factors: 120 kVp @ 5 mAs
Patient Position: Have patient erect with chest touching the IR and weight distributed evenly on both feet
Part Position:
Center MSP of patient's body to midline of IR
Extend the patients chin up and have patient flex the arms rest the backs of the hands on the low hips
Depress the shoulders and roll them forward
Top of IR 1.5”-2” above the shoulders
CR: Perpendicular to the center of the IR and at the level of the T7
Collimation: Collimated to all 4 sides of the lungs
Respiration: Full inspiration. Expose at the end of the 2nd full inspiration

PA Chest Evaluation

Entire lung fields shown
No rotation
Trachea visible in midline
Scapulae projected outside the lung fields
Ten posterior ribs visible above the diaphragm
Sharp outlines of the heart and diaphragm
Lung markings visible from the hilum to the periphery of the lung
Clavicles below apices of lungs
Visible ID markers

LATERAL CHEST
IR: 14 x 17 in. lengthwise
Exposure Factors: 125 kVp @ 5 mAs
Patient Position: Have patient erect with left side touching IR to view left lung and heart. Have right side touching IR if viewing right lung.
Weight distributed on both feet evenly
Part Position: Patient is in a true lateral where the MSP is parallel with the IR
Have patient move their arms above their head with elbows flexed and grabbing opposite arms
Patient needs to raise and extend their chin
Top of IR 1.5”-2” above the shoulders
CR: Perpendicular to center of the IR at level of T7
Collimation: Collimated to all 4 sides of lungs
Respiration: Full inspiration. Expose at the end of the 2nd full inspiration

Lateral Chest Evaluation

Both lungs in their entirety
Entire lung field
Superimposition of the ribs posterior to the vetebral column
Arm or its soft tissues not overlapping the superior lung field
Long axis of the lung fields demonstrated in vertical position
Lateral sternum with no rotation
Visible ID markers

PA OBLIQUE CHEST (LAO/RAO)
IR: 14 x 17 in. lengthwise
Exposure Factors: 125 kVp @ 5 mAs
Patient Position: Have patient erect and facing the IR. Turn them 45 degrees toward the left side for an LAO and 45 degrees to the right side for an RAO
Part Position: Rotate patient 45 degrees to place right/left shoulder against the grid and center thorax to IR.
Instruct patient to place right/left on corresponding hip with palm out. Have them raise the opposite arm to shoulder level and grasp top of IR for support.
Top of IR 1.5”-2” above the vertebral prominens
CR: Perpendicular to center of IR at the level of T7
Collimation: Collimated to all 4 sides of the lungs
Respiration: Full inspiration. Expose at the end of the 2nd inspiration

PA Oblique Chest LAO/RAO Evaluation

Both lungs in their entirety
Trachea filled with air
Heart and mediastinal structure within the lung field of the elevated side in oblique images of 45 degrees
Maximum area of the right lung on the LAO
Maximum are of the left lung on the RAO

CHEST PATHOLOGIES

PNEUMONIA

• Pneumonia: lung inflammation caused by bacterial or viral infection, in which the air sacs fill with pus and may become solid. Inflammation may affect both lungs (double pneumonia), one lung (single pneumonia), or only certain lobes (lobar pneumonia)
• Signs & Symptoms: Changes in mental status, loss of appetite. nausea or vomiting, fever and/or chills, productive cough (often severe and may be green in color, shortness of breath difficulty breathing, chest pain when coughing or breathing deeply, feeling weak and feeling tired

PNEUMONIA

• Treatments: The most important treatment for pneumonia is to recognize the symptoms of pneumonia and contact your doctor. Depending on the cause of the pneumonia treatment often requires antibiotics or other prescription medications

PNEUMONIA

Pneumonia Radiograph

Anatomy of main concentration:
Costophrenic angles
Pleural spaces and surfaces
Diaphragmatic margins
Cardiothymic silhouette
Pulmonary vasculature
Right major fissure
Air bronchograms overlying the cardiac shadow
Lung expansion
Patterns of aeration

PNEUMOTHORAX

• Pneumothorax: the presence of air or gas in the cavity between the lungs and the chest wall, causing collapse of the lung
• Signs & Symptoms: sudden onset of chest pain that may lead to tightness in chest, shortness of breath, rapid heart rate, rapid breathing, cough, fatigue, and cyanosis may occur due to decreases in blood oxygen levels
• Diagnosis: Examination of the chest with a stethoscope reveals decreased or absent breath sounds over the affected lung. Diagnosis confirmed by chest X-ray

PNEUMOTHORAX

• Treatments: If only a small area of the lung is collapsed then it will be monitored until the air is absorbed and also supplemental oxygen may be used. For a larger area of the lung collapsing it is likely that a needle or chest tube will be used to vacuum suction the air out. Surgery is the last option if none of the above works.

PNEUMOTHORAX

Signs of pneumothorax

Visible visceral pleural edge seen as very thin, sharp white line
No lung markings are seen peripheral to this line
The peripheral space is radiolucent compared to adjacent lung
The lung may be completely collapsed
The mediastinum should not shift away from the pneumothorax unless a tension pneumothorax is present

PLEURAL EFFUSION

• Pleural effusion: a buildup of fluid in the pleural space, an area between the layers of tissue that line the lungs and the chest cavity
• Signs & Symptoms: chest pain, difficulty breathing, painful breathing, cough, fever chills and loss of appetite
• Diagnosis: a doctor may suspect pleural effusion based on the symptoms and physical examination. Doctors may use auscultation and percussion tests when a pleural effusion is suspected. Chest X-rays are often the first step in identifying pleural effusion. If pleural effusion is likely, decubitus chest X-rays are ordered

PLEURAL EFFUSION

• Treatments: treatment for pleural effusions may often mean treating the medical condition causing the pleural effusion. Such as, giving antibiotics for pneumonia or giving diuretics for CHF. Large, infected, or inflamed pleural effusions often require drainage (thoracentesis)

PLEURAL EFFUSION

Pleural Effusion Radiograph

Signs of pleural effusion:
Blunting of costophrenic angle
Blunting of the cardiophrenic angle
Fluid within the horizontal or oblique fissures
With large volume effusions, mediastinal shift occurs away from the effusion

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