TECHNIQUE: SPECT scan performed with imaging 3 hours after injection of 25 mci Technetium MDP

Transcription

1 Page 1 of 10 Medical Center of South Arkansas (MCSA) Patient Name: SPECT imaging Comparison to prior Recumbent MRI L-SPINE WITHOUT CONTRAST Referring: Dr. Radiologist: Dr. David Harshfield, Jr. M.D., M.S. Scan Date: (compared with prior L-Spine MRI) Date of Birth: Chart #: Previous Study: No previous comparison study available at the time of this dictation. Patient History: 53 year old female with low back pain and bilateral lower extremity symptoms. TECHNIQUE: SPECT scan performed with imaging 3 hours after injection of 25 mci Technetium MDP FINDINGS: Anterior T2W MRI Anterior SPECT image The SPECT scan reveals pars and facet uptake indicating active bone metabolism predominantly on the right at the L3-4 level, and involving the left pars and facet at the L4-5 level.

2 Page 2 of 10 ALIGNMENT: Adynamic/static configuration of the spinal axis as a manifestation of loss of the normal lordosis. PATHOANATOMY: Evidence of facet hypertrophy accompanied by developing collisional lesions of the pars interarticularis along the lower lumbar levels, most pronounced on the right at L3-4 and on the left at L4-5, with associated discopathy and canal stenosis. Multi-level degenerative changes, with preferential lateral canal narrowing and stress reaction along the concavities of the scoliotic curvatures, thus greater along the rightward L3-4 segment and leftward L4-5 segments, with level analysis provided in the body of this report. Single renal artery supply to each kidney, with normal appearance of the mesoaortic component of the left renal vein, with no evidence of left renal vein entrapment. Partial 'transitional anatomy' of the lumbosacral junction in which large transverse processes of L5 accompanied by substantive iliolumbar and lumbosacral ligaments results in relative protection of the caudal disc (in this case L5-S1). As load sharing is shifted away from the less mobile lumbosacral (in this case L5-S1) disc, there is accentuated degenerative stress placed on the adjacent cephalad disc (in this case L4-5), as well as the SI joints.

3 Page 3 of 10 T10-11, T12-L1 and L1-2: Normal intradiscal T2 signal, without compressive discopathy, central canal stenosis, foraminal stenosis or nerve root compression. T11-12: No increased tracer accumulation on the SPECT scan associated with the noncompressive degenerative changes, as this level serves as the transition zone between the relatively immobile upward 10 thoracic disc levels and more mobile thoracolumbar segments. Biomechanically, the thoracolumbar segments are considered a transition zone and as such are more susceptible to injury or premature degenerative change for a number of reasons. First, transition from the relatively rigid thoracic spine to the more mobile lumbar spine. Second, change in facet orientation from sagittal in the thoracic spine to coronal in the lumbar spine. Third, shift in spinal alignment from a kyphotic thoracic spine to a lordotic lumbar spine. And, fourth, loss of inherit stability in the thoracic spine provided by articulation to the rib cage and sternum. L2-3: No increased tracer accumulation associated with the decreased intradiscal T2 signal, without compressive discopathy, central canal stenosis, foraminal stenosis or nerve root compression.

4 Page 4 of 10 L3-4: Degenerative radial expansion of the disk and apposing vertebral endplates with leftward translation of L3 on L4 and preferential narrowing of the leftward disc space height. Increased tracer uptake on SPECT scan indicating active bone metabolism of the right L3-4 facet and L3 pars is contrasted with MRI evidence of generative radial expansion of the disk and apposing vertebral endplates with leftward translation of L3 on L4 and preferential narrowing of the leftward disc space height. Fibro-osseous stress reaction and sclerosis of the pars interarticularis bilaterally, consistent with developing collisional lesions of the pars interarticularis of L3, greater on the right. Progression of this process may result in narrowing of the superior recesses of the spinal neuroforamina due to anterior curve remodeling of the of the apices of the superior articular facet processes of the caudal L4 vertebra associated with collisional excavated erosion of the contact points with the undersurfaces of the cephalad L3 pars interarticularis. Right L3 pars interarticularis (Scotty dog neck) with fibro-osseous stress reaction. Left L3 pars interarticularis (Scotty dog neck) with fibro-osseous stress reaction.

5 Page 5 of 10 Atrophic changes of the erector spinae musculature involving primarily the spinotransversarius, multifidus, and quadratus lumborum groups. L4-5: Decreased intradiscal T2 signal with right paracentral disc protrusion with right lateral translation of L4 on L5 with preferential narrowing of the leftward disc space height. Increased tracer uptake on SPECT scan indicating active bone metabolism of the left L4-5 facet and L4 pars is contrasted with MRI evidence of right paracentral disc protrusion with right lateral translation of L4 on L5 with preferential narrowing of the leftward disc space height. Right L4 pars interarticularis (Scotty dog neck) with fibro-osseous stress reaction. Left L4 pars interarticularis (Scotty dog neck) with fibro-osseous stress reaction.

6 Page 6 of 10 Loss of leftward disk space height, with concomitant rostral caudal subluxation and hypertrophy of the facets, contribute to the degree of central canal and bi-foraminal narrowing, greater on the left. Fibro-osseous stress reaction and sclerosis of the pars interarticularis bilaterally, greater on the left, consistent with developing collisional lesions of the pars interarticularis of L4. Progression of this process may result in narrowing of the superior recesses of the spinal neuroforamina due to anterior curve remodeling of the of the apices of the superior articular facet processes of the caudal L5 vertebra associated with collisional excavated erosion of the contact points with the undersurfaces of the cephalad L4 pars interarticularis. Partial effacement of perineural fat planes surrounding the intracanalicular portions of the exiting L4 nerve rootlets, greater on the left, that if clinically consequential may present with diminished knee jerk (Westphal s sign) reflex, motor weakness of quadriceps femoris (knee extension), decreased sensation of the medial malleolus, pain distribution in the anterior thigh. Effacement of the perineural fat planes surrounding the extraforaminal portions of the traversing (descending) L5 nerve rootlets noted, greater on the right, that if clinically consequential may present with diminished medial hamstring reflex, motor weakness of the extensor hallucis longus and tibialis anterior (foot drop), decreased sensation of the great toe, or pain distribution in the posterior lower extremity. Atrophic changes of the erector spinae musculature involving primarily the spinotransversarius, multifidus, and quadratus lumborum groups. L5-S1: No increased tracer accumulation associated with the decreased intradiscal T2 signal with broad based rightward posterior disc displacement. Right L5 pars interarticularis (Scotty dog neck) Left L5 pars interarticularis (Scotty dog neck)

7 Page 7 of 10 Loss of rightward disk space height, with concomitant rostral caudal subluxation and hypertrophy of the facets, contribute to the degree of central canal and bi-foraminal narrowing, slightly greater on the right. Fibro-osseous stress reaction and sclerosis the of the pars interarticularis bilaterally, consistent with developing collisional lesions of the pars interarticularis of L5. Progression of this process may result in narrowing of the superior recesses of the spinal neuroforamina due to anterior curve remodeling of the of the apices of the superior articular facet processes of the caudal S1 vertebra associated with collisional excavated erosion of the contact points with the undersurfaces of the cephalad L5 pars interarticularis. Effacement of the perineural fat planes surrounding the intracanalicular portions of the exiting L5 nerve rootlets noted, that if clinically consequential may present with diminished medial hamstring reflex, motor weakness of the extensor hallucis longus and tibialis anterior (foot drop), decreased sensation of the great toe, or pain distribution in the posterior lower extremity. Effacement of the extra foraminal portions of the traversing S1 nerve rootlets noted, that if clinically consequential may present with diminished Achilles (ankle jerk) reflex, motor weakness of the gastrocnemius (plantar flexion), decreased sensation of the lateral foot, and/or posterior lower extremity pain often extending to the level of the ankle. Atrophic changes of the erector spinae musculature involving primarily the spinotransversarius, multifidus, and quadratus lumborum groups. SI Joints: Symmetric increased tracer accumulation accompanying the symmetric hypertrophy of the sacroiliac joints with accompanying fibro-osseous stress reaction within the sacrum ala, bilaterally. Incidental notation made of accessory superior bundles of the piriformis muscles bilaterally arising from the anterior inferolateral S2 segment (instead of the typical origin from the lower sacral segments), through which the exiting S2 nerve rootlets must pass, but without morphologic MRI evidence of piriformis syndrome. IMPRESSION: ALIGNMENT: Adynamic/static configuration of the spinal axis as a manifestation of loss of the normal lordosis with subtle scoliosis. PATHOANATOMY: 1. MRI evidence from revealed facet hypertrophy accompanied by developing collisional lesions of the pars interarticularis along the lower lumbar levels, now correlated with SPECT evidence of more pronounced tracer uptake indicating active bone metabolism on the right at L3-4 and on the left at L4-5, with associated discopathy and canal stenosis.

8 Page 8 of MRI over view of the adynamic spine curvature correlated with the multi-level degenerative changes reveals preferential lateral canal narrowing and stress reaction corresponding to the greater degree of stress along the concavities of the scoliotic curvatures, thus greater along the rightward L3-4 segment and leftward L4-5 segment, with level analysis provided in the body of this report. 3. L3-4: Increased tracer uptake on SPECT scan indicating active bone metabolism of the right L3-4 facet and L3 pars is contrasted with MRI evidence of generative radial expansion of the disk and apposing vertebral endplates with leftward translation of L3 on L4 and preferential narrowing of the leftward disc space height. 4. L4-5: Increased tracer uptake on SPECT scan indicating active bone metabolism of the left L4-5 facet and L4 pars is contrasted with MRI evidence of right paracentral disc protrusion with right lateral translation of L4 on L5 with preferential narrowing of the leftward disc space height. 5. L5-S1: Decreased intradiscal T2 signal with broad based rightward posterior disc displacement with no increased tracer uptake on SPECT scan thus no evidence of active bone metabolism 6. Partial 'transitional anatomy' of the lumbosacral junction in which large transverse processes of L5 accompanied by substantive iliolumbar and lumbosacral ligaments results in relative protection of the caudal disc (in this case L5-S1). As load sharing is shifted away from the less mobile lumbosacral (in this case L5-S1) disc, there is accentuated degenerative stress placed on the adjacent cephalad disc (in this case L4-5), as well as the SI joints. Please see above report for additional and pertinent negative findings, as well as level by level analysis. Dr. David L. Harshfield, Jr. M.D., M.S. Board Certified Radiologist with multispecialty training in MSK, Ultrasound, Interventional Radiology and Cellular Medicine Comment: Presented here is a typical middle aged patient, with previous static recumbent MRI evidence of multilevel spondyloarthropathy manifested as varying severity lumbar disc protrusions and facet joint osteoarthrosis. Initially, the patient presented with low back pain extending into both lower extremities, rather non localizing clinical symptoms, but supportive of pathology in this region. The current SPECT findings reveal active bone metabolism localized to the rightward L3-4 and leftward L4-5 discovertebral segments. Facet arthropathy is a commonly accepted causative or contributing agent to low back pain syndromes. The ability of integrated SPECT correlated with other cross-sectional imaging modalities to precisely localize metabolically active facet joints is providing direction of treatment to manual therapies focused on improving spinal function The concept of lumbar facet joints causing or contributing to mechanical low back pain syndromes has been debated in the health care literature for decades. Practitioners of various specialties commonly treat patients presenting with low back pain but are faced with the diagnostic challenge of trying to identify a specific tissue source of low back pain. While this clinical conundrum may be the result of any of a number of pathologies, the vast majority of low back pain falls under the diagnostic umbrella of mechanical low back pain.

9 Page 9 of 10 As a category, mechanical low back pain accounts for up to 97% of low back pain diagnoses. A diagnosis of mechanical low back pain implies that there are no vascular, infectious, inflammatory or neoplastic etiologies underlying the patient s complaints but does little to clinically isolate a specific source of pain or identify a definitive avenue of treatment. This diagnosis encompasses a broad subset of possible tissue pathologies, many of which cannot be accurately diagnosed by physical examination. This may limit the ability to specifically prescribe a treatment regimen or accurately predict a response to treatment. Radiologists (and other imagers ) may misread scans or fail to use the latest tests or technology. Physicians may simply get stuck on the idea of one diagnosis and ignore or overlook evidence it might be something else. Significance is a misleading word when dictated into an imaging report, as it is a slippery slope to attempt to ascribe significance to imaging findings, a task best left to the referring clinician. Lumbar facet joint capsules are richly innervated with nociceptive and autonomic nerve fibers and, as such, are a potential source of low back pain. Despite a broad range of reported prevalence, this position is generally accepted and is supported by investigations that have injected facet joints with corticosteroids, anesthetic agents and cellular medicine solutions and demonstrated success in relieving low back pain. Conventional imaging methods including X-ray, computed tomography and magnetic resonance imaging show the structure of the bone, but the source of the pain is often not directly related to obvious structural changes. Imaging evaluation must begin to correlate the Static-structural findings with Kinematic-functional assessment if we are ever to truly begin to understand osteoarthritis MRI, CT, SPECT, conventional radiography, ultrasound and DMX (digital motion X-ray) are the key imaging modalities for spinal osteoarthritis research today. Conventional Radiography (6 view C-spine series with flexion and extension) still has a role in clinical trials in light of regulatory requirements, but investigators need to be aware of the inherent limitations of static imaging. DMX can identify the two key imaging findings for the diagnosis of spine pathology; instability and rigidity MRI offers semi quantitative, quantitative and compositional assessment and can be utilized to visualize multiple individual tissue pathologies relating to pain and also to predict clinical outcome. Positional Upright MRI is the best modality for comprehensive imaging of spinal osteoarthritis: its strengths and unique advantages include ability to reveal segmental mobility dysfunction, as well as corroborative static anatomy. Fast approaching is a major paradigm shift with regards to the relevance of static imaging in patients with spinal axis pain. Pathoanatomy: The literature is beginning to reveal the vague to poor correlation with regards to spinal axis pain and the pathoanatomy demonstrated on current recumbent/static imaging systems. Pathokinesiology: What does appear to correlate, however, is the pathokinesiology that can be demonstrated only by the emerging technology known as upright functional/positional imaging. Within-subjects approach: And further, comparing the motion of the neighboring segments within an individual patient (the so-called within-subjects approach) is more accurate than by comparing the motion value recorded at each segment to an arbitrary cutoff value for that segmental level (the so-called betweensubjects approach). The addition of molecular imaging provided by single photon emission computed tomography combined with cross sectional imaging with CT or MRI is able to go beyond structure to pinpoint the subtle physiological processes causing the pain inflammation, for example. With more clinical certainty, interventionalists can offer a range of treatments to relieve their patients suffering. This case highlights several interesting findings for the clinical setting of low back pain and raises a number of potential research opportunities. Perhaps the most impressive finding is the demonstration of asymmetrically metabolically active bone involving facet joints demonstrating bilaterally symmetric degenerative changes that might not have been identified as pathological on MRI. While it is well documented that clinical symptoms do not correlate well with radiographic, multidetector CT or MRI findings, the increased radiotracer uptake found

10 Page 10 of 10 on the SPECT may help identify the specific source of pain (in this case due to painful facet arthropathy, ongoing degenerative changes or the chronic sequela of adverse mechanical loading). This case also demonstrates that facet hypertrophy found on MRI that does not correlate with SPECT positivity suggests that facet hypertrophy has either a latent period or represents an end-point as part of the degenerative process. It is possible that by the time facet hypertrophy is notable on anatomic imaging, the metabolic activity of the bone is normalizing, as demonstrated by the absence of tracer uptake at the right L5/S1 facet joint and both L3-4 facet joints (despite MRI appearance of stress reaction). Rehabilitative treatment directed at SPECT positivity may also allow potentially corrective conservative intervention before advanced degenerative changes occur, theoretically reducing the likelihood of disability due to profound alteration of joint mechanics. Whole-body bone scan is a very sensitive but poorly specific study for the detection of metabolic bone abnormalities. The accurate localization of metabolically active bone disease is often difficult in 2D imaging, but single photon emission computed tomography (SPECT) correlated with CT and/or MRI allows accurate diagnosis and anatomic localization. A molecular imaging scan such as SPECT can provide the necessary information about the physiological health of the spine to select the most appropriate pain treatment protocol. Incorporation of SPECT in work-ups of confusing or recalcitrant low backache patients could lead to more widespread use of this nuclear medicine procedure in the future by increasing the confidence level of paintreating physicians prior to interventions, thus improving their outcome.