Diagnostic imaging techniques

Imaging Studies X-Rays X-rays are waves of electromagnetic energy. They behave in much the same way as light rays, but at much shorter wavelengths.

Omar Diagnostic imaging of the foot and ankle has made numerous advancements in the last 25 to 30 years and allows rapid, noninvasive, high-resolution depiction of anatomy and pathology. Technical advances in magnetic resonance imaging MRIincluding faster gradients, higher field strength magnets, and better coils; in computed tomography, including the advent of helical acquisition and multidetector capabilities; and in ultrasound, including higher frequency transducers, have allowed better understanding of foot and ankle pathology and associated findings.

For example, high frequency ultrasound is well suited to examine superficial structures commonly encountered in the musculoskeletal system like peripheral nerves, tendons, and ligaments and visualization of structures during real-time scanning can be used to give physiologic or biomechanical information such as detecting abnormal tendon subluxation or ligament insufficiency during dynamic or stress maneuvers.

There are numerous small structures in close proximity with complex, nonlinear courses, such as the lateral ankle ligaments and intrinsic musculature, which can be difficult to distinguish without thorough understanding of the anatomy. Many of these structures are difficult to see without proper patient positioning, optimization of the plane of scanning to image the desired anatomy, or adjusting image acquisition parameters to obtain the highest possible resolution.

Furthermore, patient positioning and imaging planes may not be standardized between institutions which may cause differences in the appearance and orientation of structures. Therefore, imagers must be aware of these differences in the appearances of certain structures based on patient positioning in order to avoid misinterpretation.

Moreover, on cross-sectional imaging, there is no consensus on nomenclature of standard orthogonal imaging planes, especially in the forefoot. However, in the forefoot, some imagers refer to the short axis as the axial plane, whereas others refer to it as the coronal plane.

This may cause confusion when reported findings are communicated to others. Thus, it is important to describe suspected sites of pathology on several planes whenever possible.

Finally, ultrasound in particular is highly dependent on probe positioning and often relies on smaller field-of-view images than other imaging modalities. This makes sonographic images difficult to reproduce and may not allow the study interpreter to adequately place suspected pathology within an anatomic context.

However, with increasing utilization of diagnostic imaging in the foot and ankle, imagers and clinicians are becoming more aware of these considerations.

This will help to mitigate the impact the issues may have and further improve the diagnostic capabilities of noninvasive imaging. First, this modality has superior spatial resolution of osseous structures compared to MRI and offers strong contrast resolution to discriminate between bone, metal, calcification, fat, and soft tissues.

Therefore, it provides a detailed anatomic assessment of the bones to help diagnose fractures, identify and characterize areas of periosteal reaction and osteolysis, and evaluate osseous alignment in order to suggest biomechanical alterations or sites of related injuries. Moreover, radiographs can depict areas of soft-tissue swelling or calcifications, which often allows diagnosis of specific pathologies or limits the differential diagnosis to help guide further diagnostic testing.

Additionally, radiographs can be obtained fairly quickly and inexpensively, which helps clinicians and imagers to make decisions and initiate therapy in a timely manner.

The Future of Medical Imaging: 4 Meaningful Innovations for 2017

Furthermore the images are reproducible, with most institutions obtaining standard views of the foot and ankle, including anteroposterior AP Fig. Additional standard radiographic protocols are available for bones like the calcaneus Figs. In a standard anteroposterior image of the ankle the patient is imaged with the leg extended and the patient supine.

The foot is positioned so its long axis is approximately perpendicular to the long axis of the lower extremity. The x-ray beam is centered between the malleoli at the tibiotalar joint. The image should include the distal third of the tibia and fibula to the proximal metatarsals.

The talar dome is seen in profile. There is mild overlap of the lateral malleolus and the lateral talus whereas the medial tibiotalar joint is open.

Weight-bearing views are also commonly performed. In this instance the patient is erect on the platform with the heels abutting the image receptor IR and the toes directed forward. Both feet are often included on the same image for comparison.

On the lateral radiograph either mediolateral ML or lateromedial LM images can be performed. In the ML image the lateral margin of the foot is placed against the image receptor IR with the long axis of the IR parallel to the long axis of the lower extremity.

As in the anteroposterior view the foot is positioned so its long axis is approximately perpendicular to the long axis of the lower extremity. Alternatively, the LM view is performed with the medial portion of the foot against the IR.

Although the ML view is generally more comfortable, the LM view more commonly represents a true lateral of the foot and ankle in which there is greater superimposition of the metatarsals. The beam is centered about 2 cm above the inferior tip of the lateral malleolus.Numerous diagnostic imaging techniques may be used to supplement history, physical examination, and laboratory tests in the evaluation of bone and joint disease.

The choice of the imaging techniques to use and in what sequence depends on the sensitivity and specificity of the technique for a particular problem, on the availability, cost, and risk, and experience in its use.

X-ray based methods of medical imaging include conventional X-ray, computed tomography (CT) and mammography. To enhance the X-ray image, contrast agents can be .

A radiologist is a doctor who specializes in imaging techniques. He or she is the person who usually reads (interprets) the images made during the test. The radiologist writes a report on the findings and sends the report to your doctor.

Diagnostic Imaging Techniques of the Foot and Ankle Imran M. Omar Diagnostic imaging of the foot and ankle has made numerous advancements in the last 25 to 30 years and allows rapid, noninvasive, high-resolution depiction of anatomy and pathology.

Diagnostic Imaging Diagnostic imaging plays a critical role in initial cancer diagnosis, treatment planning, and palliative therapies through interventional techniques and cancer monitoring. The Department of Radiology offers state-of-the-art clinical care and recently has expanded to enhance its services.

Diagnostic Imaging Techniques of the Foot and Ankle Imran M. Omar Diagnostic imaging of the foot and ankle has made numerous advancements in the last 25 to 30 years and allows rapid, noninvasive, high-resolution depiction of anatomy and pathology.