Radiographic Projections & Positioning Guide: Imaging Procedures

Radiographic Projections &

Positioning Guide

Imaging Procedures

Olive Peart M.S. R.T. (R) (M)

Peltrovijan Publishing

P.O. Box 738

Greenbelt, MD 20768-0738

https://www.peltrovijan.com

The author does not guarantee and assumes no responsibility on the accuracy of any websites, links or other contacts contained in this book.

Radiographic Projections & Positioning

Imaging Procedures

All rights reserved.

Copyright © 2023 by Olive Peart

Smashwords eBook ISBN: 9798215123478

PRINTING HISTORY

Peltrovijan Publishing/2023

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ISBN: 978-1-937143-66-4  

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Table of Content

Acknowledgment

Preface

Radiographic Policies and Procedure

Chest and Upper Airway Imaging

Upper Extremity Imaging

Sholder Girdle

Lower Extremity Imaging

Bones of the Hip & Pelvis

Imaging the Bony Thorax

Imaging the Vertebral Spine

Imaging the Skull, Sinuses and Facial Bones

Bibliography

Work of Fiction by Olive Peart writing as Jo Dinage

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ACKNOWLEDGMENT

I would like to recognize my relatives, friends and many of the past students from the Stamford Radiology Program who helped me with patient positions. These include Kari Adams, Jennifer Ayaso, Yvonne Bijarro, Gregory Parry, George Peart, Jalal Shirazifard and Kevin Smith. I am extremely grateful for your help.

Thanks also to my husband, family and friends for their help and support.

Special thanks to Nupur Chakma, graduate of the Program in Radiology, Fortis College – Landover, class of 2021 ̶  cohort 2. Her timely suggestions and editing were greatly appreciated.

I also wish to acknowledge the help I received from the current students in the Fortis College-Landover radiologic technology program.  These willing and understanding models are Fransesco Bonilla, Lise Bosquet, Edna Brizuela, Keiry Castellon, Brittney Cooper, Ena Davis, Brian Dye, Kelly Fuentes and Hector Anderson Ortiz.

PREFACE

From its earliest beginning after its discovery in 1895, x-rays were recognized for their amazing ability to penetrate the human body and visualize the skeletal system. Since then, diagnostic imaging has undergone numerous changes in the methods of imaging, developing the image, image display, and image storage. However, throughout the ages there has been little change in the patient positioning aspect of diagnostic radiography. Despite the increasing importance of imaging modalities, such as CT, ultrasound, magnetic resonance (MR) and other molecular imaging studies, it is still essential to visualize the bones, joints and to image the contents of the thorax or abdomen on a two-dimensional image. General radiography often remains the first line of defense in medical diagnosis.

Radiographic imaging typically requires specific skills and positioning techniques. It is the effective use of these positioning skills that makes general radiography such a challenging and rewarding career option. In fact, poor image quality or poor positioning skills is sometimes a factor in the inability of radiographic imaging to diagnosis pathology, leading radiologists or physicians to seek alternative imaging modalities.

Turning to an alternative imaging modality should not be the result of poor image quality or poor positioning skills. It is understood that significant inaccuracies that can occur when the central ray is not perpendicular to the part, the image receptor (IR), the detector or cassette. In trauma situations, or if the patient cannot move, it is the responsibility of the imager to manipulate the central ray and the IR or cassette to produce an accurate representation of the part.

The desired outcome is a quality image and major contributing factor is the imager's competency and positioning skills. However, in addition to knowledge of positioning, another important role of the imaging professional is effective communication. The field of diagnostic radiography can be stimulating, especially from the patient care aspect. Specific verbal skills are necessary and required when interacting with the trauma or seriously ill patient, the intoxicated or mentally challenged patient, and even the overly anxious or the pediatric patient.

Finally, imaging professionals must use radiation wisely, practicing ALARA (As Low As Reasonably Achievable) at all times.

The positioning and procedure guide can help educators, students, recent graduates and experienced imagers with a comprehensive overview of routine imaging procedures and positioning terminology.

The guide includes is a summary of patient care in radiology, infection control, patient communication and digital technology.

Images and details of the fluoroscopy studies, Upper GI series, Barium Enema, Esophagram, Cystogram, ERCP, Myelogram, Arthrogram and Hysterosalpingogram are covered in the companion book, Radiographic Projections and Positioning Guide – Fluoroscopy studies.

Radiographic Policies and Procedures

Importance of Standard Precautions

Radiographic imaging must always be performed using standard precautions and the proper infection control techniques as outlined by the Centers for Disease Control & Prevention (CDC) and the Hospital Infection Control Practices Advisory Committee (HICPAC). Standard Precautions incorporates fluid and body precautions and body substance isolation. Standard Precautions are required whenever there is a possibility of contact with blood, body fluids, secretions, excretions, mucous membranes and nonintact skin. Standard Precautions must be applied to all patients.

Hand washing

Washing hands is a basic infection control technique. Washing hands and cleaning all areas of the x-ray table, erect stand and image plates or detectors before and after contact with the patient. Hand washing must take place even if gloves are worn.

Asepsis means the state of being free from germs. There are two types:

Surgical asepsis also referred to a sterile technique is the elimination of pathogens by sterilization.

Sterilization destroys microorganisms and their spores.

Sterilization is the absolute killing of all life forms.

Sterilization can be accomplished by autoclave (steam) gas, radiation or chemicals.

Sterility is an absolute state. - An object is either sterile or not.

Medical asepsis is also called clean technique.

Used to limit the number and prevent the spread of infectious microorganisms.

Microbes are not eliminated, just reduced or their environment altered so it is nonconductive to growth and reproduction.

Specific Transmission-Based Precautions are applied whenever a patient is infected with a pathogenic organism or a communicable disease, also for patients at risk for infections (immunosuppressed).

Airborne Precautions

Organisms remain suspended in the air for extended periods of time e.g., tuberculosis (TB).

Infected patients are placed in a negative-pressure isolation room with the door closed.

Healthcare providers should wear respiratory protection (filtered mask) on entering patient’s room.

Patient leaving room must wear a surgical mask.

Droplet Precautions

Pathogens spread through large droplets expelled when patient coughs, sneezes or talks. Droplets travel about 3 feet (91.5 cm) and infection occurs through contact with mouth, nasal mucosa or conjunctiva.

Patients are placed in private rooms with doors closed.

Healthcare provider should wear a mask within 3 feet (91.5cm) of patient.

Patient should wear mask on leaving the room.

Contact Precautions

Infections spreads through direct contact with patient or a contaminated object (formite) e.g., bed rails.

Clean all contaminated equipment after leaving room.

Health care providers should wear gloves and wash hands before entering and after leaving the room.

Impervious gown needed only if contact with patient is possible, and a face mask is suggested to avoid contaminating the nasal mucosa.

Patients leaving room should wear an impervious gown and face mask.

Clinical History Documentation

Reasons include for documentation:

Aids in diagnosis and prevents misdiagnosis

The radiologist may never see the patient. Clinical documentation is therefore especially helpful. The technologist can locate the actual injury site or foreign body markers be used to indicate the location of a penetrating injury.

Allow modification of exposure

Additive versus destructive pathologies or the presence of a prostatic device can require changes in the normal technical factors. A clinical history will allow for changes before the exposure.

Rule out errors

The wrong body part may be indicated on the requisition, or the imaging could be contraindicated because of poor internal preparation, allergies or preexisting medical history. Good clinical history documentation would highlight the error or specific problem and allow corrections.

Necessary for legal coding

In many cases, the clinical history is necessary to determine the correct diagnostic code. This can be critical for medical research and in billing and insurance reimbursement.

Patient Communication

Communicating specific breathing instructions is important in controlling motion. Patient motion control is critical to producing a high-quality radiograph.

Involuntary motion

Best controlled by using short exposure times. They are outside of a patient's control and include peristalsis.

Voluntary motion

Best control by communicating instructions clearly, by providing the patient with a warm and comfortable imaging experience, by using support devices when necessary and by using immobilization devices as a last resort.

Breathing instructions are necessary when imaging the thorax and abdomen. It is often not necessary when imaging the skull or extremities. However, even when breathing instruction is not required for imaging, telling a child or anxious adult to stop breathing during an exposure can aid in keeping them still.

General Imaging Rules

Proper use of anatomic side marker

The Right or Left side marker is required on all radiographic images before the exposure

Markers are not legally acceptable if written or digitally applied after the exposure

Markers should not obscure the anatomy or patient’s identification information

Palpation to identify landmarks

Applying light pressure with pad of fingers (not the tip/point of fingers and never with the whole hand).

Always advice patient before beginning palpations

Use of grid or Bucky device

Indications for Grid Use

Thickness of the part – most critical consideration

Body parts thicker than about 13 cm (5 inches)

The size of the field

Large field sizes of (14 X 17" or 35 X 43 cm), will more likely need a grid

kVp over 85kVp

kVp plays a minor role in scatter production in digital

Types of Grids

Stationary or Moving Grids (Bucky)

Parallel Grids

Focused Grids

Crossed Grids

Special Grids

Long dimension ̶  lead strips running parallel to the long axis of the grid

Can be used in portrait and landscape imaging

Short dimension ̶  lead strips running perpendicular to the long axis of the grid. Grid lines run across short axis of grid (versus the long axis)

Should be used only in landscape imaging

Grid Cutoff

Loss of density or exposure affecting a portion of the image or the whole image due to the absorption of the photons by the grid material.

Most common with parallel grids

Air Gap Technique – Alternative Grid Use

Increased OID allows the scatter to be dissipated in the air before reaching the image receptor

An OID of at least 6" (10-15 cm) is required to be effective

Similar to using 8:1 grid

Fig 1a Showing the placement and features of a parallel grid

Fig 1b  focused grid

Two (2) projections minimum

The two projections minimum is taken as near 90-degrees from each other as possible to:

Avoid superimposition of anatomic structures

Allow localization of lesion or foreign bodies

Show alignment of part

Determine alignment of fractures

Note: Three or more projections are often necessary with accurately visualizing joints

Fig. 2a (schematic drawing mimicking a fracture),

Fig.2b (Lateral radiograph of the part),

Fig.2c (AP radiograph of the part).

Fig. 2d (schematic drawing mimicking a fracture),

Fig.2e (Lateral radiograph of the part)

Fig.2f (AP radiograph of the part)

The 15% Rule

An increase in kVp of 15% is equivalent to doubling the mAs. This rule can be used to reduce the radiation dose to patients by increasing the kVp by 15% and reducing the mAs by ½.

Note: No amount of mAs increase can compensate for insufficient kVp.

Imaging Information

Cassettes are lightproof devices that hold the film in analog imaging. This terminology is often incorrectly used when referring to the image plate or detector in digital imaging.

Films are used to acquire the image, display the image and archive the image in analog imaging.

Image Plate (IP) holds the image receptor in digital photostimulable phosphor