LESSON 15
DIAGNOSTIC RADIOLOGY OF MUSCULOSKELETAL SYSTEM AND
ASSOCIATED DISEASES
Radiography
In examining a skeletal radiograph, it is important to begin by properly orienting
the image receptor and recognizing the radiographic projection. The radiographic
exposure technique selected is very important in achieving a proper diagnosis.
Proper technique is achieved when the soft tissues and bony structures of interest
are both adequately penetrated and the trabecular pattern is visible. Any motion of
the part in question impairs the visibility of the detail present.
Soft tissue areas often hold clues to the diagnosis and are examined by the
interpreting physician. Any signs of muscle atrophy, soft tissue swelling,
calcifications, opaque foreign bodies, or the presence of gas may indicate disease.
Analysis of the configuration of the bone and its relationship to other bones serves
to detect or exclude fractures, dislocations, congenital anomalies, or acquired
deformities.
The interface between cortical (compact) bone and soft tissue is also important.
Any periosteal new bone formation seen may be a response to trauma, tumors, or
infection. Juxtaarticular erosions are often seen in cases of arthritis. Cortical
resorption may be demonstrated as smudgy, irregular loss of the cortical margin. In
addition, the internal bone structure is important and should be examined for
abnormally altered texture, alterations in the amount of mineralization, or foci of
destruction. Careful consideration of all areas mentioned assists the physician in
arriving at the correct diagnosis.
For diagnose of bone density (e.g. osteoporosis)X ray densitometry is useful.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is an important modality used in imaging of
skeletal pathology, particularly in providing soft tissue detail because of its
superior contrast resolution. It is considered the modality of choice for detection
, and staging of soft tissue tumors involving the extremities. It is also extremely
useful in evaluation of joints, particularly the knee and the shoulder (Fig. 2-5).
Newer imaging techniques and improved equipment allow MRI to detect a greater
number of musculoskeletal subtleties with higher-resolution imaging (Fig. 2-6).
Sometimes these subtleties mimic bone pain but involve soft tissues instead, which
is an important distinction. Bone marrow imaging done with MRI is superior to
other modalities in visualizing subtle abnormalities within the musculoskeletal
system. Also, MRI may play a larger role in trauma medicine, particularly with the
refinement of open-bore and short-bore technologies.
Computed Tomography
Computed tomography (CT) is an important tool in skeletal imaging because with
newer technology the examination can be performed quickly and noninvasively,
even in cases of trauma. CT has the ability to define the presence and extent of
fractures or dislocations, to assess abnormalities in joints and associated soft
tissues, and to help diagnose spinal disorders Cortical bone gives no signal in MRI,
but CT provides ready visualization of bone details and is often used as a follow-
up to conventional radiographic imaging for improved detail. Bone tumors, in
particular, are now usually imaged with spiral or helical CT because of its
excellent ability to display bone margins and trabecular patterns and to assess both
bone and soft tissue involvement of tumors. Although CT results in greater contrast
resolution compared with radiography, much of the role for imaging other related
soft tissues has been usurped by MRI. Quantitative computed tomography (QCT)
is also used in evaluating bone mass loss, especially within the vertebral bodies of
the spine.
Nuclear Medicine Procedures
Nuclear medicine retains an advantage not offered by either MRI or CT in skeletal
imaging: the ability to look at the entire body at one time in a convenient fashion
(Fig. 2-8). It allows ready decision making as to whether any pathology shown is
an old injury or a new problem, with activity indicating that the bone involved is
affected by some new process. In addition, the bone scan is still the standard of
care for examination of metastatic processes because it demonstrates metabolic
reaction of the bone to the disease process and is more sensitive than comparative
DIAGNOSTIC RADIOLOGY OF MUSCULOSKELETAL SYSTEM AND
ASSOCIATED DISEASES
Radiography
In examining a skeletal radiograph, it is important to begin by properly orienting
the image receptor and recognizing the radiographic projection. The radiographic
exposure technique selected is very important in achieving a proper diagnosis.
Proper technique is achieved when the soft tissues and bony structures of interest
are both adequately penetrated and the trabecular pattern is visible. Any motion of
the part in question impairs the visibility of the detail present.
Soft tissue areas often hold clues to the diagnosis and are examined by the
interpreting physician. Any signs of muscle atrophy, soft tissue swelling,
calcifications, opaque foreign bodies, or the presence of gas may indicate disease.
Analysis of the configuration of the bone and its relationship to other bones serves
to detect or exclude fractures, dislocations, congenital anomalies, or acquired
deformities.
The interface between cortical (compact) bone and soft tissue is also important.
Any periosteal new bone formation seen may be a response to trauma, tumors, or
infection. Juxtaarticular erosions are often seen in cases of arthritis. Cortical
resorption may be demonstrated as smudgy, irregular loss of the cortical margin. In
addition, the internal bone structure is important and should be examined for
abnormally altered texture, alterations in the amount of mineralization, or foci of
destruction. Careful consideration of all areas mentioned assists the physician in
arriving at the correct diagnosis.
For diagnose of bone density (e.g. osteoporosis)X ray densitometry is useful.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is an important modality used in imaging of
skeletal pathology, particularly in providing soft tissue detail because of its
superior contrast resolution. It is considered the modality of choice for detection
, and staging of soft tissue tumors involving the extremities. It is also extremely
useful in evaluation of joints, particularly the knee and the shoulder (Fig. 2-5).
Newer imaging techniques and improved equipment allow MRI to detect a greater
number of musculoskeletal subtleties with higher-resolution imaging (Fig. 2-6).
Sometimes these subtleties mimic bone pain but involve soft tissues instead, which
is an important distinction. Bone marrow imaging done with MRI is superior to
other modalities in visualizing subtle abnormalities within the musculoskeletal
system. Also, MRI may play a larger role in trauma medicine, particularly with the
refinement of open-bore and short-bore technologies.
Computed Tomography
Computed tomography (CT) is an important tool in skeletal imaging because with
newer technology the examination can be performed quickly and noninvasively,
even in cases of trauma. CT has the ability to define the presence and extent of
fractures or dislocations, to assess abnormalities in joints and associated soft
tissues, and to help diagnose spinal disorders Cortical bone gives no signal in MRI,
but CT provides ready visualization of bone details and is often used as a follow-
up to conventional radiographic imaging for improved detail. Bone tumors, in
particular, are now usually imaged with spiral or helical CT because of its
excellent ability to display bone margins and trabecular patterns and to assess both
bone and soft tissue involvement of tumors. Although CT results in greater contrast
resolution compared with radiography, much of the role for imaging other related
soft tissues has been usurped by MRI. Quantitative computed tomography (QCT)
is also used in evaluating bone mass loss, especially within the vertebral bodies of
the spine.
Nuclear Medicine Procedures
Nuclear medicine retains an advantage not offered by either MRI or CT in skeletal
imaging: the ability to look at the entire body at one time in a convenient fashion
(Fig. 2-8). It allows ready decision making as to whether any pathology shown is
an old injury or a new problem, with activity indicating that the bone involved is
affected by some new process. In addition, the bone scan is still the standard of
care for examination of metastatic processes because it demonstrates metabolic
reaction of the bone to the disease process and is more sensitive than comparative
