A radiological insight into various musculoskeletal complications in patients suffering from AIDS and how it'll affect the management of the patient. A must know for all Radiologists.

1. Imaging Findings in
Musculoskeletal
Complications
of AIDS
Dr.Suhas B
MD Radio-Diagnosis

2. Introduction
• South & South East Asia is the second most affected; in 2010 this
region contained an estimated 4 million cases or 12% of all people
living with HIV resulting in approximately 250,000 deaths.
Approximately 2.4 million of these cases are in India.
• Central nervous system (CNS), pulmonary, and abdominal
complications affecting patients with HIV infection and AIDS have
been extensively documented and discussed in the literature. However,
musculoskeletal complications in this population are less well
described.

3. Introduction (contd.)
• Although musculoskeletal abnormalities in patients with HIV infection
and AIDS are not as common as pulmonary and CNS disorders, a
wide variety of osseous, articular, and soft tissue diseases may be
encountered.
• In this article, we review a wide spectrum of musculoskeletal disorders
and their imaging appearances in patients with AIDS.Many of these
conditions are not specific for HIV infection and AIDS and can be seen
in other forms of immunosuppression, but others have been more
specifically associated with this particular immunodeficiency.

4. Infectious Processes
• Infection is the most common musculoskeletal complication in patients with
AIDS. The immunocompromised patient is susceptible to opportunistic and
non-opportunistic infections affecting the skin, underlying soft tissues, bones,
and joints. Soft-tissue infections include superficial and deep cellulitis,
necrotizing and non-necrotizing fasciitis, soft-tissue abscesses, and pyomyositis.
• Osteomyelitis and septic arthritis are typical examples of infectious
involvement of the bones and joints, respectively. The most frequently cultured
bacterial agent is Streptococcus aureus, but multiple other organisms have also
been reported.
• The key elements that allow differentiation are (a) the depth of soft-tissue
involvement and (b) the presence of necrosis.
• Cross-sectional imaging techniques make such differentiation possible through
analysis of compartmental anatomy.

5. Cellulitis
• Cellulitis is an acute inflammatory condition of the skin that is
characterized by swelling, erythema, calor, and localized pain in the
affected area.
• In superficial cellulitis, CT and MR imaging demonstrate inflammatory
changes that involve the subcutaneous fat but do not extend beyond the
superficial fascia.

6. Cellulitis (contd.)
• Abnormal imaging findings include thickening of
the skin, septation of the subcutaneous fat, and
thickening of the underlying superficial fascia,
with scattered ill-defined hypointense areas on
T1-weighted MR images, a striated pattern of
hyperintensity on T2-weighted images, and
moderate diffuse enhancement on contrast
material–enhanced images.
• The MR imaging findings in cellulitis and
fasciitis are different from those in primary
bacterial myositis: Disproportionate involvement
of the muscles compared with subcutaneous tissue
or muscle compromise without associated
subcutaneous tissue involvement suggests the
diagnosis of bacterial myositis.
Superficial and deep cellulitis and myositis in a
42-year-old man. Axial CT scan obtained at the
level of the middle third of the leg shows
inflammatory changes in the subcutaneous soft
tissues, with fluid collections surrounding the
intramuscular compartments in the lateral aspect
of the leg adjacent to the tibialis anterior muscle
and in the medial compartment adjacent to the
soleus muscle (solid arrows). Inflammatory
changes consistent with myositis are also seen
within the soleus muscle (open arrow).

7. Necrotising Fasciitis
• Necrotising fasciitis is a relatively rare but rapidly
progressing infection tha represents a life-threatening
surgical emergency. It is characterized by extensive necrosis
of the superficial and deep anatomic planes, usually
accompanied by severe systemic toxicity.
• MR imaging is useful in differentiating necrotizing fasciitis
from severe cellulitis with or without secondary abscess
formation and pyomyositis
• The presence of deep fascial involvement at MR imaging
favors a diagnosis of necrotizing fasciitis.

8. Necrotising Fasciitis (contd.)
• The imaging findings in necrotizing fasciitis are similar to those in cellulitis
but are more severe with deeper involvement.
• Necrotizing fasciitis typically does not enhance after administration of
gadolinium-based contrast material. MR imaging and, to a lesser extent, CT
are useful in assessing the extent and depth of the inflammatory process and
the involvement of adjacent osseous structures.

9. Necrotising Fasciitis (contd.)
Necrotizing fasciitis in a 45-year-old male
intravenous drug abuser. Coronal (a) and axial
(b) fat suppressed T2- weighted MR images
show high-signal-intensity inflammatory changes
involving both the subcutaneous fat in the medial
surface (arrow in a) and the gastrocnemius
and soleus muscles (arrows in b) of the left
leg. This hyperintensity is consistent with
deep-seated infection or necrotizing fasciitis.

10. Soft-Tissue Abscesses
• MR imaging will show a well-demarcated fluid collection that is
hypointense on T1-weighted images, is hyperintense on T2-weighted
images, is surrounded by a low-signal-intensity pseudocapsule with all
sequences, and demonstrates peripheral rim enhancement after
intravenous administration of gadolinium-based contrast material.
These features are useful in differentiating abscesses from cellulitis or
fasciitis.
• When an abscess is suspected, needle aspiration is mandatory.
Treatment includes antibiotics and percutaneous drainage.

11. Soft-tissue abscess in a 21-year-old man with a history of intravenous drug abuse. Axial
unenhanced (a) and contrast-enhanced (b) fat-suppressed T1-weighted MR images of the hand
show extensive inflammatory changes and abscess formation within the muscles and soft
tissues of the thenar and palmar region. An abscess is seen within the first dorsal interosseous
and adductor pollicis muscles (arrow). This fluid collection has low signal intensity on the
unenhanced image and peripheral ring enhancement with central low signal intensity on the
contrast-enhanced image. The absence of tendon sheath and bursal involvement helped rule
out the presence of horseshoe abscess formation.

12. Pyomyositis
• Pyomyositis, or bacterial myositis, is characterized by pyogenic
inflammation of the muscle and, musculoskeletal complications of AIDS.
• CT demonstrates areas of muscle enlargement with decreased attenuation
of the muscle secondary to edema. Intramuscular fluid collections may also
be observed. Intravenous administration of contrast material can help
differentiate necrotic from viable musculature because the nonviable tissue
will demonstrate lack of enhancement.

13. Pyomyositis (contd.)
• MR imaging is more sensitive than CT in the detection of inflammatory changes
within the muscles. On T1-weighted images, pyomyositis may appear as a central area
of low signal intensity within the muscle, in some cases surrounded by a peripheral rim
of high signal intensity that probably represents blood products. Pus inside the abscess
can be either isointense or hyperintense with T1-weighted sequences depending on the
proteinaceous content of the fluid collection. On T2-weighted and short inversion time
inversion-recovery (STIR) images, the abscessed collection is hyperintense.
• Areas of abnormal high signal intensity in adjacent muscles represent unorganized
phlegmonous collections, edema, or hyperemia. After contrast material injection,
necrotic tissue manifests as a low-signal intensity area surrounded by a hyperintense
enhancing rims. Abnormal gas in the necrotic tissue is easily identified at radiography
CT, and MR imaging.

14. Pyomyositis in a 23-year-old man with AIDS
and a history of intravenous drug abuse.
Radiograph demonstrates multiple gas
collections (arrows) within the soft tissues of
the medial and posterior left thigh.
Pyomyositis in a 25-year-old woman.
Axial contrast-enhanced CT scan of the
lower neck demonstrates multiple
abscesses in the soft tissues and muscles
of the supraclavicular space and neck
(arrows). Results of aspiration confirmed
M tuberculosis myositis and lymph node
involvement.

15. Pyomyositis with myonecrosis in a 38-year-old man. (a) Coronal T1-weighted MR image shows extensive
myonecrosis affecting the medial compartments of the lower extremities, with bilateral hypointense fluid collections
(arrows). (b) On a coronal fat-suppressed T2-weighted MR image, the bilateral fluid collections demonstrate
high signal intensity. The multiple round, ill-defined low-signal-intensity areas within the necrotic collection on the
left side (arrows) represent abnormal gas bubbles. (c) Axial contrast-enhanced fat-suppressed T1-weighted MR image
shows intense peripheral rim enhancement surrounding the bilateral fluid collections (arrows) and the gas
bubbles within the necrotic tissue on the left side.

16. Pyomyositis in a 35-year-old man.
(a) Axial contrast-enhanced fat-
suppressed T1-weighted MR image
demonstrates extensive inflammatory
changes involving the deep muscles of
the right midthigh, with enhancement
within the vastus intermedius muscle that
extends into the adductor muscles
(arrows). Note the increased diameter of
the right thigh compared with the left
thigh.
(b) On an axial fat-suppressed T2-
weighted MR image, there is extensive
cellulitis of the superficial and deep
compartments with diffuse myositis of
almost all the right-sided
muscles, with less diffuse involvement of
the left thigh. Note also the bilateral fluid
collections superficial to the vastus
lateraliis muscles (arrows).

17. Osteomyelitis
• Osteomyelitis is infection of the bone and a common infectious cause of
musculoskeletal complications in AIDS patients.
• Radiography is not sensitive in the detection of early osteomyelitis because it does
not demonstrate changes until 10–14 days after the onset of the infectious process,
when lytic lesions or periosteal reaction is evident. Technetium-99m methylene
diphosphonate (MDP) bone scintigraphy and gallium-67 and indium- 111–labeled
WBC scintigraphy are the most sensitive methods for the detection of early
osteomyelitis.

18. Osteomyelitis (contd.)
• CT of the affected region may demonstrate soft-tissue swelling and
periosteal reaction, medullary changes, and focal cortical erosions or
trabecular coarsening.
• T1-weighted images demonstrate low signal intensity in the affected bone
whereas on T2-weighted images the corresponding areas have high signal
intensity.
• MR imaging with intravenously administered gadolinium-based contrast
material offers comprehensive depiction of the extent of both bone and soft-
tissue infection; it also helps identify areas of devitalized tissue.

19. Chronic osteomyelitis in a 41-
year-old man.
Anteroposterior
(a) and lateral (b)
radiographs show
extensive soft-tissue
ulceration of the distal
forearm associated with
periosteal reaction of the
distal ulna and, to a lesser
extent, of the distal radius
projecting into the
interosseous space. Results
of pathologic analysis proved
extensive necrotic changes,
but no definitive bacteria or
infectious agent could be
identified.

20. Osteomyelitis (contd.)
• Tuberculosis infection and bacillary angiomatosis are two specific forms of
osteomyelitis that have been observed with increasing frequency in HIV-infected and
AIDS patients.
• Radiography demonstrates erosion of the anterior vertebral bodies with deformity.
An adjacent soft-tissue mass may be seen. CT is useful for detecting destructive
changes involving the cortical bone of the vertebral bodies. Calcifications in the
paravertebral soft tissues with fluid collections are frequently seen, findings that are
consistent with abscess formation.
• MR imaging is the preferred modality for imaging the spine. T1-weighted images
demonstrate decreased signal intensity within the vertebral marrow secondary to
edema, with corresponding high signal intensity on T2- weighted images. Epidural
extension manifests as posterior displacement of the thecal sac and deformity of the
spinal cord. Arachnoiditis manifests as thickened nerve roots that enhance with
contrast material administration.

21. Osteomyelitis in a 41-year-old woman.
Coronal contrast-enhanced fat-suppressed T1-
weighted MR image demonstrates osteomyelitis
of the right wing of the sacrum and septic
arthritis of the right sacroiliac joint. Abscesses
with peripheral rim enhancement are seen
within the right iliac and gluteal muscles and
the sacrum. Aspiration and culture
demonstrated M Tubeculosis .
Osteomyelitis and septic sacroiliitis in a
46-year-old female intravenous drug abuser
with septic endocarditis. Axial T1-weighted MR
image demonstrates a hypointense lesion in
the right sacroiliac joint (arrow) with extension
into the right iliac bone and sacrum. Pathologic
analysis demonstrated S pyogenes.

22. Osteomyelitis (contd.)
• Bacillary angiomatosis is an unusual form of osteomyelitis that
specifically affects the HIV infected population.
• Radiography usually demonstrates osteolytic foci that may range from
well-circumscribed lytic lesions involving the cortex to ill-defined
lesions with extensive cortical destruction, medullary permeation, and
periosteal reaction.
• Bone scintigraphy reveals increased radiotracer uptake in the affected
areas. CT demonstrates well-defined nonsclerotic lytic lesions. MR
imaging shows well-defined lytic lesions with low and high signal
intensity on T1- and T2-weighted images, respectively.

23. Acute spondylodiskitis and vertebral osteomyelitis in a 46-year-old woman. (a) Sagittal T1-weighted
MR image shows acute spondylodiskitis and vertebral osteomyelitis with epidural collections (open arrow)
and dural enhancement (solid arrows) at the C5-C6 level. These inflammatory findings are nonspecific and
can be observed in a variety of granulomatous, fungal, and bacterial infections. One week later, the patient
developed extensive wedge deformity and collapse of C5 and C6. (b) Axial contrast-enhanced T1-
weighted MR image demonstrates abnormal dural enhancement and cord compression secondary to the
epidural fluid collections (arrows).

24. Septic Arthritis
• Infection of joints can arise from hematogenous spread or contiguous
extension from neighboring soft-tissue infection or osteomyelitis.
• Radiography may reveal joint effusion, bone erosion, osteoporosis, and
indistinct margins of the joint with joint space narrowing.
• MR imaging is more sensitive in the detection of early changes in septic
arthritis, revealing signal intensity abnormalities in the bone marrow and
soft tissues, both of which have edema-like signal intensity (ie, are
hypointense on T1-weighted images and hyperintense on fat suppressed T2-
weighted images or STIR images).
• Extension of infection from the joint space into surrounding bursae is also
easily recognized at MR imaging.

25. Septic arthritis and bursitis in a 42-year-old woman. (a) Coronal fat-suppressed T2-
weighted MR image shows extensive fluid collections within the bursae around the
shoulder, especially the subacromial (subdeltoid) bursa (arrows). (b) On a sagittal
contrast-enhanced fat-suppressed T1-weighted MR image, the fluid collections
(arrows) exhibit low signal intensity with no enhancement.

26. Inflammatory Processes
• The most common rheumatic manifestation associated with HIV infection is
arthralgia.
• The arthritides most commonly associated with HIV infection are articular
pain syndrome, Reiter syndrome, psoriatic arthritis, and the syndromes of
oligoarthritis and polyarthritis.
• Polymyositis is the most common muscular manifestation in HIV-infected
patients and must be distinguished from pyomyositis, which is its most
important differential diagnosis, because their treatments differ.

27. Arthritis
• Reiter syndrome has been described in HIV-infected patients following
infection with Yersinia, Salmonella, and Shigella species.
• Classic radiographic features of Reiter syndrome include asymmetric
alterations of synovial joints, symphyses, and entheses; bone erosion with
adjacent bone proliferation; and paravertebral ossification. The calcaneus,
ankle, knee, and sacroiliac joints are usually involved (42). These features
do not appear to be different from those seen in non–HIV-infected
individuals.

28. Arthritis (contd.)
• Psoriatic arthritis has a higher prevalence among HIV-infected
and AIDS patients than in the general population.
• The rheumatologic characteristics of psoriatic arthritis are
similar to those of Reiter syndrome, except there is a greater
predilection for the small articulations of the wrist and hand.
• Psoriatic arthritis tends to be polyarticular and asymmetric, in
which case it rapidly progresses to a deforming and
incapacitating form of the disease. Involvement of the sacroiliac
joint and spine is rare.

29. 34 year old male with psoriatic arthropathy
showing ‘pencil in cup deformity’ of distal
phalanges with multiple erosive lesions
along metacarpals and phalanges.
27 year old patient with Reiter
syndrome with retrocalcaneal bursa
erosive disease.

30. Arthritis (contd.)
• Radiographic findings include osteopenia, soft-tissue swelling, joint
effusions, joint space narrowing, marginal erosions, periosteal reaction, and
joint deformities such as flexion contractures, ulnar deviations, and swan
neck deformities. Features that help differentiate symmetric polyarthritis
from classic rheumatoid arthritis are proliferative bone formation and
periostitis.
• HIV-associated arthritis can also occur. This arthritis is oligoarticular,
asymmetric, and peripheral. This arthritis has a short duration of 1–6
weeks. Radiography may reveal a joint effusion in some cases.

31. Arthritis (contd.)
• Arthralgia and painful articular syndrome are the most common
rheumatic manifestations of HIV infection.
• Radiographic features are nonspecific and range from no abnormality
to joint effusions with or without periarticular osteopenia.
• The diagnosis of undifferentiated spondyloarthropathy is made in
patients with seronegative arthritis who do not meet the criteria for the
diagnosis of Reiter syndrome or psoriatic arthritis. Radiographic
findings include osteoporosis, soft-tissue swelling, bone erosion, and
periosteal reaction.

32. Polymyositis
• Myositis in patients with HIV infection and AIDS can be a result of host
response to the virus, secondary to zidovudine therapy, or caused by
opportunistic infections such as toxoplasmosis.
• MR imaging is the preferred modality. Polymyositis can be isointense
relative to muscle on T1-weighted images; thus, T2-weighted or STIR
images are necessary to establish the diagnosis.
• Unlike with pyomyositis, rim enhancement is not present in polymyositis.
AIDS-related peripheral neuropathy can have MR imaging features similar
to those of polymyositis.

33. 42 year old patient with polymyositis (PM),
one of the inflammatory myopathies.
The large proximal muscles are involved,
generally in a symmetric pattern.
MRI of thighs showing increased signal in
the quadriceps muscles bilaterally
consistent with polymyositis.

34. Neoplasms
• Non-Hodgkin lymphoma (NHL) and Kaposi sarcoma are the two most
common neoplasms observed in HIV-infected and AIDS patients and
account for the majority of neoplastic musculoskeletal involvement in this
population.
Non-Hodgkin Lymphoma
• NHL is the second most common type of tumor in patients with HIV
infection and AIDS after Kaposi sarcoma. NHL is seen 60 times more
frequently in AIDS patients than in the general population and is one of the
criteria for the diagnosis of AIDS in an HIV-infected person.
• Extranodal and widely disseminated disease, including muscle and bone
involvement, is also more frequently found in this population, particularly
in children.

35. Non-Hodgkin Lymphoma (contd.)
• Lymphomas affecting bone can produce lytic lesions, sclerotic lesions,
or “mixed” lesions with an indistinct zone of transition. HIV-associated
NHL bone lesions are usually lytic.
• Among the lytic changes, the most frequently seen is a permeative
pattern with cortical destruction, often associated with a soft-tissue
mass.
• Periosteal reaction is not commonly associated with NHL.
• The imaging features of musculoskeletal involvement by NHL are
similar to those of many bone tumors. However, bone lesions in AIDS-
related lymphoma tend to be more sharply marginated and to grow
more rapidly than those associated with Kaposi sarcoma.

36. NHL in a 40-year-old man. (a) Radiograph of the pelvis shows an ill-defined lytic
lesion in the right
iliac bone (arrows). (b) Axial contrast-enhanced CT scan helps confirm the lytic
lesion, demonstrating cortical disruption
of the iliac bone (solid arrows) with an associated enhancing soft-tissue mass
involving the right iliacus
muscle (open arrow).

37. Non-Hodgkin Lymphoma (contd.)
• CT is the primary staging modality for lymphomas because of its generally superior
spatial resolution. CT shows the bone changes with better conspicuity and can also
suggest the presence of an associated soft-tissue mass. High-speed CT is particularly
beneficial in the chest, where respiratory and cardiac motion tend to degrade MR
images.
• MR imaging is the method of choice for evaluating bone marrow changes and
characterizing adjacent soft-tissue involvement. Bone marrow changes are seen as
areas of hypointensity on T1-weighted images and as areas of hyperintensity on STIR
images or fat-saturated fast spin-echo T2-weighted images. The associated soft-tissue
mass appears hyperintense on T2- weighted images.

38. Multicentric B-cell NHL in a 44-year-old
man. (a) Anteroposterior chest
radiograph shows multiple ‹osteolytic
lesions (arrows) involving the right
humerus, the right and left scapulae, the
medial third of the right clavicle, and
multiple left ribs. (b) Follow-up chest
radiograph obtained 3 months later
demonstrates progression of the
disease, with diffuse lymphomatous
involvement of both lungs and more
prominent multiple osteolytic lesions
(arrows). (c) Sagittal T1-weighted brain
MR image shows a soft-tissue tumor
with both extradural involvement (solid
arrow) and subgaleal extension (open
arrow) within the medullary cavity of the
parietal bone. (d) On an axial T2-
weighted MR image, the soft-tissue mass
has intermediate signal intensity due to
bone involvement and extends to the
subgaleal space (solid arrow). Abnormal
signal intensity owing to tumor involvement
is also seen within the left parietal bone
(open arrow). (e) Anteroposterior
radiograph of the right knee shows a
destructive osteolytic lesion of the
proximal lateral tibial metaphysis (arrow).
(f ) Sagittal T1-weighted MR image
shows the infiltrative tumor that is
isointense relative to muscle and replaces
the bone marrow of the proximal tibia
(arrow). Flexion deformity of the knee
secondary to pain is also appreciated. (g)
Tc-99m bone scintigram (left) with
magnified view (right) show extensive
abnormal radiotracer uptake at the level of
the distal femur and proximal tibia (solid
arrows) and in the skull (open arrow).
There is also abnormal uptake in the
proximal femoral shaft (arrowheads).

39. Multicentric lymphoma with
involvement of the craniofacial
region in a 31-year-old patient. (a)
Axial CT scan obtained at the level
of the midface shows a prominent
soft-tissue mass that occupies the
left maxillary region and extends
into the soft tissues of the face.
Aggressive bone destruction of the
anterior and medial walls of the left
antrum is also seen (arrows). (b)
Axial CT scan of the superior
head shows multiple round,
hypoattenuating lytic lesions of
the calvaria (arrowheads). (c)
Sagittal T1-weighted MR image
demonstrates a prominent mass
that infiltrates the superficial and
deep structures of the face (arrow).
The multiple osteolytic lesions
within the marrow of the cranial
bones have moderate signal
intensity (arrowheads), in contrast
with the low signal intensity of the
normal bone. (d) Axial contrast-
enhanced T1-weighted MR image
shows multiple enhancing
hyperintense soft-tissue masses
within the medullary cavity of the
bones of the skull vault
(arrowheads). Some of the masses
extend into the epidural space.

40. Kaposi Sarcoma
• Kaposi sarcoma is the most common type of tumor in HIV-infected and
AIDS patients. It is a vascular neoplasm that generally has multifocal
lesions and can involve virtually any organ. Mucocutaneous tissues, lymph
nodes, and visceral organs are the most frequently affected tissues.
• It can either occur secondary to local extension or be present without
neighboring abnormalities; however, it is almost always seen in the setting
of multifocal disease.
• Radiography, CT, and MR imaging are complementary in the evaluation of
Kaposi sarcoma as the cause of focal pain in HIV-infected and AIDS
patients. Radiography shows cortical lesions ranging from bone erosion to
osseous destruction, as well as periosteal reaction.

41. Kaposi Sarcoma (contd.)
• CT gives a more detailed characterization of lytic bone changes. MR
imaging is outstanding in depicting bone marrow abnormalities, as seen in
lymphoma or infection, and can better help identify overlying soft-tissue
masses.
• Scintigraphy may be useful in further characterization, showing red blood
cell pooling, thallium-201 uptake, and no abnormalities at Ga-67
scintigraphy. Infection and tumors such as lymphoma typically show avidity
to gallium instead, making scintigraphy a potential tool for narrowing the
differential diagnosis.
• Nevertheless, biopsy is necessary for definitive diagnosis.

42. Kaposi Sarcoma with cutaneous, muscular and osseous involvement in 25
year old man. Axial contrast enhanced CT of the lower chest shows
multiple round, multiple, enhancing lesions in the muscles of the chest wall
(arrowheads). Bone involvement is seen in one of the posterior left ribs
(arrow)

43. Osteonecrosis
• There have been several reports of osteonecrosis in HIV-positive patients,
most often occurring in the femoral head.
• MR imaging is the most sensitive imaging modality for detecting early
AVN. In the reactive phase, a “double line” sign may be created on T2-
weighted images by the juxtaposition of low and high signal intensity
between infarct and normal bone marrow. This disease can also be seen in
bone marrow of long bones usually in the distal or proximal diaphysis,
where it can be either single or multifocal.

44. AVN. Anteroposterior radiographs of the
ankles show intramedullary bone infarcts at the
distal tibial diaphyses as irregular calcifications
with the long axes parallel to the cortical bones
(arrow).
AVN in an HIV-positive patient. Anteroposterior
(left) and lateral (right) radiographs of the
right knee show multiple intramedullary bone
infarcts of the femur and tibia (arrows).

45. Osteoporosis
• A very high prevalence of low bone mineral density has been reported in
HIV-infected individuals.
• Study showed that the markers of bone turnover tended to be elevated in of
HIV-infected patients.
• HIV infected patients suffer from osteopenia or osteoporosis regardless of
type and duration of anti-retroviral therapy because of other associated
conditions.
• DEXA scan and bone densitometry remain the mainstay for evaluating this
condition.

46. Rhabdomyolysis
• The most common causes of rhabdomyolysis in HIV-positive patients are infection,
toxemia, alcohol abuse, and substance abuse, and even the virus has been postulated
as causing rhabdomyolysis.
• CT typically reveals calcification of muscles, particularly in the back, thighs, and
pelvis (ie, psoas muscle). Early in the disease process, nonspecific hypoattenuating
areas may be seen in the involved muscles of the pelvis and extremities; other CT
findings include renal enlargement, persistent nephrogram, and perinephric fluid.
• The sensitivity of MR imaging in the detection of abnormal muscles in patients with
rhabdomyolysis has been reported to be superior to that of CT or ultrasonography.
The affected muscle has variable signal intensity on T1-weighted MR images,
whereas it is invariably hyperintense on T2-weighted images, a finding that is
consistent with edematous changes in the muscle.

47. Rhabdomyolysis in a 44-year-old man with AIDS and renal failure. Axial unenhanced
CT scan of the abdomen demonstrates bilateral abnormal increased attenuation of the
psoas muscle (arrows) and, to a lesser extent, of the paraspinal and oblique
abdominal muscles (arrowheads) due to diffuse calcifications.

48. Hypertrophic Osteoarthropathy
• Hypertrophic osteoarthropathy is a systemic disorder that primarily affects
the bones, joints, and soft tissues. It is most frequently associated with
pulmonary neoplasm and has been observed in HIV-infected patients with
P carinii pneumonia.
• Radiographic findings include smooth periosteal reaction involving the
diaphysis of the long bones is noted. As the disease progresses, the
periosteal reaction becomes irregular and extends to involve the metaphysis
and epiphysis.

49. Hypertrophic
osteoarthropathy in a 35-
year-old man with AIDS and
P carinii pneumonia.
Anteroposterior (left) and
lateral (right) radiographs of
the right knee show
abnormal thickening of the
cortical bone with diffuse
periosteal bone formation at
the distal femur and
proximal tibia
(arrowheads).The
changes were seen
bilaterally.

50. Conclusion
• Although musculoskeletal complications are not as common as pulmonary
or CNS abnormalities in HIV-positive individuals, there is a high
prevalence of such complications in this population.
• HIV infection predisposes these individuals to a variety of complications
that can affect the musculoskeletal system, including various opportunistic
infections, immune-related neoplasms, myositis, osteoporosis, and several
rheumatologic syndromes.
• Radiography plays an important role in early diagnosis and treatment
planning in this population, in whom clinical and laboratory findings are
commonly equivocal and nonspecific.
• Although biopsy is often necessary for the final diagnosis, it is important for
the radiologist to be familiar with the different types of musculoskeletal
disease in HIV-infected and AIDS patients so that an appropriate
differential diagnosis can be established from the musculoskeletal images
obtained in these individuals.