Radiographic Techniques for Abdominal Imaging

Radiographic Techniques

• Radiographic techniques are used to diagnose or treat patients by recording images of the internal structure of the body to assess the presence or absence of disease, foreign objects, and structural damage or anomaly.

Larynx & Pharynx

• Plain radiography is used to investigate soft-tissue swellings and foreign bodies in the air passages, as well as laryngeal trauma.
• Tomography, CT, MRI may be needed for a full evaluation of disease processes.
• Two projections (anteroposterior and lateral) are commonly used.
• Anteroposterior (AP): Patient supine, chin raised, image receptor centered at the 4th cervical vertebra, X-ray beam directed 10° cranially, collimated from occipital bone to 7th cervical vertebra.
• Lateral: Patient standing or sitting with shoulder against the CR cassette or vertical Bucky, jaw slightly raised, image receptor centered at the level of the thyroid cartilage, X-ray beam horizontally collimated from mastoid process, through 4th cervical vertebra.

Thorax: Lungs

• Radiographic examination of the lungs is used for various medical conditions, including primary lung disease and pulmonary effects of other organ systems.
• Positioning is primarily determined by patient condition; erect position is preferred in healthy patients, and supine/semi-erect is used for immobile/very ill patients.
• Images are typically acquired on arrested deep inspiration.
• Exposure needs to be optimized to avoid masking pulmonary detail or artificially enhancing markings.

Radiographic Anatomy of Lungs

• The lungs are found within the thoracic cavity.
• The right lung is typically larger due to the heart's position.
• Upper, middle, and lower lobes divide the right lung; upper and lower lobes divide the left lung.
• The trachea divides at the 4th thoracic vertebra into right and left main bronchi, the right being wider and more vertical than the left.
• Hilar regions (where major pulmonary vessels branch) are areas of increased radio-opacity.

Radiographic Considerations for Thorax

• Careful patient preparation is critical; removal of radiopaque objects and managing chest tubes are important.
• Exposure needs to be optimized to visualize laryngeal cartilages, soft tissues, and foreign bodies.

Positioning for the Chest

• Anteroposterior (AP) Erect: Patient stands erect, facing the image receptor.Feet slightly apart, the median sagittal plane is adjusted at right angles to the receptor, the collimated horizontal beam is directed at right angles to the receptor and centred at the level of the 8th thoracic vertebra.
• Lateral: Patient, the median sagittal plane is adjusted at right angles to the receptor, patient's shoulders are lowered and pushed forward to project the scapula outside of the lung fields. The collimated horizontal beam is directed at right angles to the sternum with centre midway between the sternal notch and
• Posterior Anterior (PA): Patient facing the receptor. Scapular and arms away from the lung fields. The collimated horizontal beam is directed at right angles to the receptor and centred at the level of the 8th thoracic vertebra.

Posteroanterior (PA)

• The patient is positioned erect, facing the image receptor, feet slightly apart, the median sagittal plane is adjusted at right angles to the receptor, the collimated horizontal beam is directed at right angles to the receptor and centred at the level of the 8th thoracic vertebra.
• The exposure is made in full normal arrested inspiration.

Radiographic Anatomy of the Heart and Aorta

• The heart and aorta are assessed through radiographic studies to evaluate heart size and the gross anatomy of blood vessels.
• Common examination types include posteroanterior projections of the chest.
• The structures, like the aortic knuckle, can help demonstrate cardiac disease or dilation.

Radiographic Considerations for the Heart and Aorta

• Specific patient preparation is important, especially if there's cardiovascular disease or the use of external devices like pacemakers.
• Exposure is critical to ensure the visualization of detail, including the mediastinum and the cardiac structures.
• In supine posture, cardiac orientation might appear more horizontal.

Radiographic Considerations for Lungs

• Patient preparation should minimize the obscuring of specific regions like the apical regions.
• Respiratory conditions for the imaging need appropriate measures.
• Exposures should be optimized and avoiding factors resulting to artifacts is critical.

Typical Imaging Protocols for Abdomen

• Common reasons for abdominal radiographic examinations include bowel obstruction, acute abdominal pain, perforations, renal issues, foreign body localization, and detection of calcification or gas collections.
• Specific image orientations (e.g., AP supine, erect, oblique, decubitus) can aid in visualizing the abdominal organs and structures, as well as in the detection of abnormalities.

Radiology Considerations for Abdomen

• Adequate preparation includes checking the presence of foreign objects and assuring that the urinary tract is empty.
• Patient positioning and exposure are critical for a clear image.
• The imaging process should be optimized and appropriate exposure measures need to be taken into consideration.

Mammography Techniques

• Mammography is a low kVp radiography of breast tissue for detecting pathologies.
• Common projections used include 45-degree medio-lateral oblique (MLO) and craniocaudal (CC).

Radiographic Considerations for Mammography

• Lesions are assessed based on size, shape, margin, and density.
• Calcifications are assessed based on size, shape, number, grouping, and orientation.
• Architectural distortion is often associated with carcinoma.
• Focal increase in density can sometimes be seen in malignancy.
• Other techniques (e.g., ultrasound, MRI) can provide additional information in ambiguous cases.

Additional Points

• Exposure time, beam direction, and cassette positioning significantly impact image quality.
• Proper patient positioning are necessary to avoid artifacts on the images and allow clear visualization of structures of interest.
• Specific protocols are needed to manage specific medical conditions.