Spectrum of Combined Tc99m-HDP SPECT/CT Findings in Benign...
Transcript of Spectrum of Combined Tc99m-HDP SPECT/CT Findings in Benign...
Spectrum of Combined Tc99m-HDP SPECT/CT Findings in Benign and Malignant
Bone Conditions: Additional or Redundant Information? Fabio Paes MD, Dimitrios Kalkanis MD, Osama Gomaa MD and Aldo Serafini MD
Department of Radiology, Division of Nuclear Medicine, University of Miami, Miami, Florida
All patients received 99mTc-diphosphonate IV. The examination
was performed as three phase scintigraphy of the affected part or a
single delayed phase. A series of 60 images were acquired
immediately, within the first minute after radiotracer injection.
Static images of radiotracer distribution in the blood pool, each of
30 seconds duration, were acquired until 6 minutes after injection.
Three to four hours after radiotracer injection, planar whole-body
scintigraphy and spot planar scintigraphy of the region of interest
were performed. A SPECT/CT, a hybrid camera (Symbia, Siemens)
consisting of a dual-head gamma camera and a helical MDCT
scanner was used. Counts from the 15% energy windows at 140 keV
were acquired into a 128 × 128 matrix (pixel size, 4.6 × 4.6 mm). CT
was always performed as low-dose CT: 130 kV; 20 mAs; rotation
time, 0.8 seconds; collimation, 2 × 1 mm. SPECT/CT images of the
area of interested, identified or not in the whole bode scan, were
obtained after the planar imaging acquisition.
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2. Pagenstert GI, Barg A, Leumann AG, et al. SPECT-CT imaging in degenerative joint
disease of the foot and ankle. J Bone Joint Surg Br. 2009 Sep;91(9):1191-6
3. Scharf S. SPECT/CT imaging in general orthopedic practice. Semin Nucl Med. 2009
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4. Ndlovu X, George R, Ellmann A, et al. Should SPECT-CT replace SPECT for the
evaluation of equivocal bone scan lesions in patients with underlying malignancies?
Nucl Med Commun. 2010 Apr 15.
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AJR Am
Bone scintigraphy is frequently used for the diagnostic evaluation of
orthopedic disorders because altered bone metabolism can be
detected before morphologic changes are detected with planar
radiography. Furthermore, whole-body scintigraphy can be used to
assess the integrity of the entire
skeleton. It is also well known, however, that bone scintigraphy has
low specificity because of its comparatively poor depiction of
morphologic features. Therefore, in cases of focally enhanced bone
metabolism, information from other imaging procedures is
necessary to establish a diagnosis. Although, the scintigraphic
images are usually compared to planar radiographs, these
frequently may not completely show pathologic changes due to the
presence of overlying bone or artifacts.
New hybrid SPECT/CT systems are capable of overcoming these
difficulties providing both metabolic and discrete anatomic
information. Recent data have shown that SPECT/CT imaging
increases the diagnostic accuracy and reader confidence of benign
and malignant focal bone conditions. Also, a single SPECT/CT
study can obviate additional imaging in a great number of patients.
We present here examples of benign and malignant bone pathology
in which SPECT/CT imaging provided additional diagnostic and
management value over planar scintigraphy.
Introduction
Technique
Bibliography
Possible Applications Abstract Whole body Bone Scintigraphy has been an established sensitive
method for evaluation of bone pathology. However, it lacks
specificity and adequate anatomical correlation, even when SPECT
technique is used. Bone Scintigraphy SPECT/CT has emerged as an
important modality in the diagnosis of benign and malignant
osseous conditions. When combined SPECT/CT is used, the benefit
of precise anatomic localization of the radiotracer uptake and the
corresponding CT appearance may help clarify the nature of an
abnormality. Despite the increasing clinical usage and experience
during the last few years, the SPECT/CT features of many osseous
conditions have not been fully described and many nuclear
medicine physicians, radiologists and other physicians (like
orthopedic surgeons) are slowly becoming familiar with the
combined Bone Scintigraphy SPECT/CT patterns.
Our goal is to demonstrate different examples of benign and
malignant conditions on Tc99m-HDP SPECT/CT, focusing on the
additive value of this method and its correlation with clinical
information and other imaging modalities. We will use a variety of
cases collected in our institution, including, among others:
osteoarthritis, undifferentiated connective tissue disease, stress
fracture, temporo-mandibular joint disease, heterotopic ossification,
osteosarcoma, and spine hemangioma.
Case 3 – Facet Joint Disease
Case 1 – Osteoarthritis
Area of abnormal
osteoblastic activity.
Possible additional value of SPECT/CT
imaging:
Spine - posterior elements Differentiate among pars fracture, tumor, facet joint
arthritis, metastasis and osteophytes.
Spine – vertebral body Localize underlying bone abnormality: tumor,
compression fracture, discitis/osteomyelitis, etc.
Skull
Localize underlying bone abnormality: TMJ disease,
skull base fracture, otitis/mastoiditis, tumor, Paget’s
disease, etc.
Extremities
Delineate area of abnormal activity. Help to
differentiate trauma, tumor, DJD, arthritis, infection
or congenital abnormality.
Foot and Ankle
Identify stress fractures of the mid foot, DJD in the
mid foot and hind foot, tarsal coalition and
osteochondritis dissecans (OCD).
Soft tissues - Heterotopic
Ossification
Identify the soft tissue involved: e.g. areas of
heterotopic ossification. Plan surgical resection
when activity has resolved.
Orthopedic hardware
Identify failure of the surgical hardware: fracture of
the bone graft, formation of a pseudarthrosis,
hardware loosening; facet joint arthritis or disk
space degenerative disease at adjacent levels, or
findings, such as sacroiliitis, infection or pathology
associated with bone graft donor sites in the pelvis.
Key Points
•Bone Scintigraphy SPECT/CT has an additive value over whole
body scintigraphy and SPECT.
•SPECT/CT findings can help differentiate among bone pathologies
in several clinical scenarios, obviating extra imaging.
•Clinical information is key to interpret Bone SPECT/CT
scintigraphic findings correctly.
•Case: 73y/o male with severe neck pain, primary right sided and
worse with hyperextension.
•Findings: Severe osteoarthritis of the cervical spine, particularly C1-
C2 level. No osteoblastic involvement of the occiput-C1 joint.
•Additional value of SPECT/CT: Able to localize the areas of active
osteoarthritis and help in the surgical planning.
•Management: Patient underwent C1-T1 fusion.
Case 2 - Hemangioma
•Case: 79y/o female with a history of cauda equina paraganglioma,
post resection and L3-L5 laminectomy.
•Findings: Lytic lesion in the superior end-plate of L3 with intense
focal osteoblastic activity. Facet degenerative disease in the distal
lumbar spine.
•Additional value of SPECT/CT: Able to morphologic characterize
the area of abnormal activity. Exclude the possibility of osteophyte
or post surgical changes.
•Management: Biopsy proven Hemangioma. No evidence of
paraganglioma.
•Case: 57y/o female with osteoporosis and severe back pain. No history of trauma.
•Findings: Osteoarthritis of the L5-S1 facet joints, no fracture. Anterior beaking
osteophytes of L1-L2.
•Additional value of SPECT/CT: Able to exclude pathologic fracture of the
vertebral body and spondylolysis.
•Management: Patient underwent L5-S1 facet joint steroid injections with good
clinical response.
Case 4 – Heterotopic Ossification
•Case: 38y/o athlete male with history of trauma developed incapacitating leg and
hip pain.
•Findings: Severe osteoblastic activity in areas of heterotopic ossification involving
the left gluteus muscles and medial aspect of the left knee.
•Additional value of SPECT/CT: Localize the areas of active heterotopic ossification
and help in the surgical planning.
•Management: Initially treated with NSAIDS and then, surgery after improvement
of abnormal activity.
Case 5 – L3 Spondylolysis
•Case: 16y/o female with severe back pain, primary right sided and worse with
hyperextension.
•Findings: Levoscoliosis of the lumbar spine with focal activity in unilateral right
L3 spondylolysis.
•Additional value of SPECT/CT: Correctly diagnose the fracture and exclude
other causes of unilateral posterior elements activity.
•Management: Patient was placed on NSAIDS, physical rest and back brace.
Case 6 – Osteosarcoma
•Case: 50y/o female with osteosarcoma of the C2 vertebrae, post laminectomy,
posterior fusion and radiation.
•Findings: Persistent osteoblastic activity in an aggressive destructive lesion of
the C2 arch and odontoid. Linear activity along the posterior pedicle screws.
•Additional value of SPECT/CT: Localize recurrence and evaluate base of skull
extension.
•Management: Patient was started on chemotherapy, but developed lung
metastasis afterwards.
Case 7 – Fibrous Dysplasia
•Case: 45y/o female with dizziness and headache.
•Findings: Sclerotic ground glass osteoblastic active lesion in the clivus.
•Additional value of SPECT/CT: Localize the lesion and exclude other pathology.
•Management: Follow up imaging showed stable findings suggestive of Fibrous
Dysplasia.
Case 8 – TMJ disease
•Case: 58y/o female with neck pain and headache.
•Findings: Intense ostoblastic activity in the left temporal mandibular joint (TMJ)
with sclerosis of mandibular condyle and temporal fossa. Mild DJD of the upper
cervical spine (not shown).
•Additional value of SPECT/CT: Identify extra focus of abnormal osteoblastic
activity, in this case the TMJ.
•Management: Patient was treated with NSAIDS and night occlusal splints with
improvement of the pain.
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