Bone SPECT imaging of the painful back

Efficacy of SPECT over planar bone scan in the diagnosis of solitary vertebral lesions in patients with low back pain

Background:

The purpose of our study has been to evaluate the efficacy of single photon emission computed tomography (SPECT) over planar bone scan in identifying solitary vertebral lesions in patients with low backache and its ability to differentiate various pathologies according to the uptake pattern.

Materials and Methods:

The study included twenty patients out of whom six patients presented with known carcinoma and fourteen patients with low back pain. SPECT was done in all following planar skeletal survey. Benign and malignant lesions were identified according to the uptake pattern in vertebral elements, based on Gary F. Gates observations. Final diagnosis was obtained by means of biopsy or correlation with radiograph or computed tomography (CT) or magnetic resonance imaging (MRI), and / or follow up.

Results:

SPECT detected additional 30% of solitary vertebral lesions that were obscured on planar scan. Seven out of twenty were localized in anterior vertebral body and were diagnosed as benign ostophytes in six and osteoma in one substantiating the previous observations. Out of six cases of known carcinoma, three were having solitary metastases and showed posterior vertebral body uptake with pedicle involvement. SPECT could localize specific lesions as source of pain in eleven patients with low back pain (78%) and identified various etiologies including benign tumors (osteoid osteoma and osteoma), facet arthritis, discitis, transverse process fractures and spondylolysis.

Conclusion:

Our study highlighted the higher diagnostic value of SPECT over planar skeletal scintigraphy in localizing solitary vertebral lesions in low backache patients. Based on SPECT pattern, malignant and benign lesions could be differentiated in the given clinical context.

Increased Uptake in a Vertebral Bone Island Seen Only on SPECT

Skeletal scintigraphy may be performed to evaluate a suspected bone island. In general, a bone island does not demonstrate increased uptake on bone scan. A case of increased uptake in a lumbar vertebral body bone island seen on SPECT, but not conventional planar imaging, is presented.

Fractured osteophyte demonstrated on SPECT and computed tomography

ABSTRACT We present an interesting case of a fractured osteophyte causing back pain that was demonstrated both on bone single photon emission computed tomography (SPECT) and computed tomography (CT). The magnetic resonance images, thoracic anterior spine plain radiograph, whole-body bone scan passes, and thoracic spot view were not impressive. Bone SPECT was the impetus for getting the CT scan. The CT scan not only demonstrated the osteophyte but a pseudarthrosis that was probably causing the pain. If it were not for the positive SPECT bone scan, the CT scan would not have been ordered after unimpressive magnetic resonance imaging.

Importance of positioning and technical factors in anatomic localization of sporting injuries in scintigraphic imaging

Sports medicine is becoming increasingly important as more people take up exercise for health and well-being. It is adding to the spectrum of acute and chronic injuries that have traditionally been seen in elite or professional athletes. Because of its high sensitivity and lesion contrast, bone scintigraphy has traditionally played a key role in the detection of such injuries. This role has been reduced in recent times by the increased use of magnetic resonance imaging (MRI), which has functional capability, high-contrast resolution, and high-spatial resolution. Bone scintigraphy has the capability of detecting early cortical ligament avulsion and enthesopathic disease before the onset of edema or changes in bone marrow that are detected by MRI. If this capability is added to more precise anatomic localization of lesions, we may see a resurgence in its use in sports medicine. A number of techniques are presented in this article, encompassing positioning, special views, and tomographic reconstructions, that can significantly improve the accuracy of localization of scintigraphic abnormalities with reference to anatomic models or sources of cross-sectional anatomy.

The use of SPECT bone scans to evaluate patients with idiopathic jaw pain

OBJECTIVE

The purpose of this study was to investigate the potential usefulness of single photon emission computed tomography (SPECT) bone scanning with technetium-99m methylene diphosphonate (Tc-99m MDP) in the diagnosis of idiopathic jaw pain. Unlike planar bone scanning, SPECT uses tomographic technology to provide 3-dimensional images, which are more useful in localizing small lesions.

STUDY DESIGN

Twenty patients, each with a diagnosis of chronic idiopathic jaw pain, were compared after SPECT bone scanning with 20 age-matched and gender-matched normal controls. Uptake was identified and compared in sites with previously detected jaw pathoses and jaw pain.

RESULTS

Nineteen of 20 patients with jaw pain evaluated with SPECT had positive scans, in contrast with 12 of 20 control subjects (P <.04). Positive scans were correlated with painful sites in 15 of 20 patients, with the remaining 5 patients demonstrating no uptake in painful locations. Patients with jaw pain demonstrated 37 of 80 mouth quadrants with positive scans, in contrast with 21 of 80 mouth quadrants in the controls (P <.01). Nineteen of 24 painful mouth quadrants had uptake in the pain group. Of the 21 quadrants positive in the controls, 17 were correlated with previously detected jaw pathoses. The sensitivity and specificity for detecting painful sites were 0.79 and 0.68, respectively. The sensitivity and specificity for detecting previously identified pathoses in the jaws of normal controls were 0. 80 and 0.93, respectively.

CONCLUSION

Patients with idiopathic jaw pain had a significantly greater frequency of positive SPECT bone scans when compared with normal controls. However, the sensitivity and specificity of SPECT bone scans in detecting painful sites were low. These findings suggest that SPECT bone scanning with Tc-99m MDP is not indicated as a routine imaging procedure for the detection of jaw pathoses, but may be considered as a potential research tool in the future study of chronic idiopathic jaw pain.

[Scintigraphic pattern in a case of Tarlov cyst]

We report the case of a 40-year-old man remitted to our department with a history of lower back pain and sciatica with no history of trauma. The laboratory analyses showed normal values whereas plain radiographs showed a sacrum rarefaction area. A 99mTc-MDP bone scintigraphy was performed to evaluate the lumbosacral area. Planar images did not show any abnormality. SPECT images revealed photopenic abnormality in the second sacral vertebral right hemibody, with no peripherally increased radiotracer accumulation. Subsequent MRI and CT myelography demonstrated the nature of the photopenic area as secondary to vertebral erosion by sacral perineurial cyst (Tarlov cyst).

Evaluation of lower back pain with bone scintigraphy and SPECT

Bone scintigraphy and single photon emission computed tomography (SPECT) may be performed for evaluation of lower back pain, especially when a bone abnormality is suspected. Various patterns of tracer activity based on precise identification of the anatomic location of increased uptake may be observed and used to evaluate bones and joints. Lesions centered about the disk space and vertebral body include spondylodiskitis, metastatic disease, vertebral body fracture, and degenerative disease (disk disease, spondylosis deformans). In diskitis, tracer uptake has a vertical orientation. Metastatic involvement should be suspected in solitary lesions evaluated with SPECT when the area of increased uptake extends from the vertebral body into the pedicle. Fractures are seen on planar and SPECT images as a linear, horizontally oriented area of increased uptake centered in the vertebral body. In degenerative disease, increased uptake is centered about the disk space and may be seen in and project beyond the surface of the vertebral body. Lesions of the posterior arch (comprising the pedicle, lamina, and facet joints) include spondylolysis, pedicle lesions, osteoarthritis of the facet joints, and fracture of the transverse process. Scintigraphy may help differentiate long-standing asymptomatic spondylolysis from ongoing disease. In osteoarthritis of the facet joints, SPECT may be used to select patients to be treated with therapeutic injections. Increased uptake in the transverse process most often indicates a fracture, although tumors may also occur in this location. These findings at planar bone scintigraphy and SPECT allow differentiation of common pathologic conditions and can lead to a specific diagnosis.

SPECT bone scanning of the spine

Radionuclide bone scanning is a well accepted method for uncovering a variety of bony lesions including abnormalities of vertebral bodies that may be causing spinal pain. Single photon emission computed tomography (SPECT) is especially useful in such an evaluation because it allows for precise localization of a lesion to the vertebral body, disc space, or vertebral arch. This anatomic distinction is necessary in order to accurately diagnose the underlying condition detected by the bone scan. Most bony abnormalities result in focal areas of abnormal tracer activity but do not affect all components of a vertebra with equal frequency nor have a random pattern of involvement. Vertebral diseases tend to conform to predictable patterns that can be more readily identified by SPECT than planar imaging. Metastatic tumors commonly involve the posterior portion of the vertebral body, often in combination with a pedicle. Extensive abnormalities involving the vertebral body and vertebral arch, but sparing the pedicles, are usually benign as are lesions isolated to articular facets and lamina or disc space. Postoperative patients have additional potential problems including pseudarthrosis and complications following use of internal fixation devices including pedicle screws. Nuclear medicine physicians must speak the language of their referring physicians who are anatomically oriented and used to the exquisite morphologic detail of computed tomography (CT) and magnetic resonance imaging (MRI). SPECT allows for greater anatomic information compared with planar imaging as well as straightforward comparison with other tomographic-based studies such as CT and MRI.

Technical considerations for optimal orthopedic imaging

Over the past 25 years bone scintigraphy has played an essential role in most Nuclear Medicine departments, accounting for 25% to 60% of the patient volumes. No longer is every bone scan ordered as part of a metastatic workup. Today radionuclide bone imaging (RNBI) is included in most orthopedic diagnostic pathways. It is necessary to optimize the bone scan procedure to be sensitive, to carefully localize abnormal uptake for diagnosis, to correlate the bone scans, plain radiographs, computed tomographic (CT) scans, and magnetic resonance (MR) scans that accompany the patient, and to be precise in reporting a final impression. This can be done through meticulous attention to the image acquisition so that it encompasses not only equipment specifications and acquisition parameters, but also patient history, preparation, imaging protocols, positioning, and image correlation. The importance of these considerations, the rationale to explain them, and suggested guidelines for their implementation will be discussed in this article.

The retroisthmic cleft. Scintigraphic appearance and clinical relevance in patients with low back pain

This article describes the scintigraphic appearance of both a symptomatic and asymptomatic retroisthmic cleft in two athletes with low back pain. This lesion, which involves the lamina, is the least common of the neural arch defects of which spondylolysis is the most common. The anatomy of the lesion is discussed and illustrated. The literature about the possible cause of these lesions is reviewed. The report emphasizes the valuable role of radionuclide bone imaging in patients who have pain of potentially osseous origin, and who have a lesion of uncertain physiologic significance seen on an anatomic study such as a plain x-ray, CT scan, or MRI.