Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT

2007 ◽  
Vol 46 (01) ◽  
pp. 38-42 ◽  
Author(s):  
V. Schulz ◽  
I. Nickel ◽  
A. Nömayr ◽  
A. H. Vija ◽  
C. Hocke ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
One Dimension ◽  
Patient Specific ◽  
Data Sets ◽  
Facet Joints ◽  
Lumbar Vertebral Body ◽  
Ct System ◽  
Ct Data ◽  
Attenuation Corrected

SummaryThe aim of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated. Methods: Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). Results: After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p <0.05). Conclusions: AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting leftto- right ratios. Therefore, at clinical evaluation of attenuation- corrected scans special attention should be given to possible misalignments between SPECT and CT.

Does Vertebral Body Tethering Cause Disc and Facet Joint Degeneration? A Preliminary MRI Study with Minimum 2-years Follow-up

2021 ◽  
Author(s):  
Altug Yucekul ◽  
Burcu Akpunarli ◽  
Atahan Durbas ◽  
Tais Zulemyan ◽  
Irem Havlucu ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
Joint Degeneration ◽  
Facet Joint Degeneration ◽  
Mri Study

CyberKnife rhizotomy for facetogenic back pain: a pilot study

2007 ◽  
Vol 23 (6) ◽  
pp. E1 ◽  
Author(s):  
Gordon Li ◽  
Chirag Patil ◽  
John R. Adler ◽  
Shivanand P. Lad ◽  
Scott G. Soltys ◽  
...  
Keyword(s):  
Back Pain ◽  
Radiofrequency Ablation ◽  
Facet Joint ◽  
Late Onset ◽  
Target Volume ◽  
Facet Joints ◽  
Positron Emission ◽  
Cyberknife Radiosurgery ◽  
Joint Injections

Object By targeting the medial branches of the dorsal rami, radiofrequency ablation and facet joint injections can provide temporary amelioration of facet joint–producing (or facetogenic) back pain. The authors used CyberKnife radiosurgery to denervate affected facet joints with the goal of obtaining a less invasive yet more thorough and durable antinociceptive rhizotomy. Methods Patients with refractory low-back pain, in whom symptoms are temporarily resolved by facet joint injections, were eligible. The patients were required to exhibit positron emission tomography–positive findings at the affected levels. Radiosurgical rhizotomy, targeting the facet joint, was performed in a single session with a marginal prescription dose of 40 Gy and a maximal dose of 60 Gy. Results Seven facet joints in 5 patients with presumptive facetogenic back pain underwent CyberKnife lesioning. The median follow-up was 9.8 months (range 3–16 months). The mean planning target volume was 1.7 cm3 (range 0.9–2.7 cm3). A dose of 40 Gy was prescribed to a mean isodose line of 79% (range 75–80%). Within 1 month of radiosurgery, improvement in pain was observed in 3 of the 5 patients with durable responses at 16, 12, and 6 months, respectively, of follow-up. Two patients, after 12 and 3 months of follow-up, have neither improved nor worsened. No patient has experienced acute or late-onset toxicity. Conclusions These preliminary results suggest that CyberKnife radiosurgery could be a safe, effective, and non-invasive alternative to radiofrequency ablation for managing facetogenic back pain. No patient suffered recurrent symptoms after radiosurgery. It is not yet known whether pain relief due to such lesions will be more durable than that produced by alternative procedures. A larger series of patients with long-term follow-up is ongoing.

122. Does vertebral body tethering cause disc and facet joint degeneration? An MRI study with minimum two years of follow-up

2021 ◽  
Vol 21 (9) ◽  
pp. S60
Author(s):  
Altug Yucekul ◽  
Burcu Akpunarli ◽  
Atahan Durbas ◽  
Tais Zulemyan ◽  
Irem Havlucu ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
Joint Degeneration ◽  
Facet Joint Degeneration ◽  
Mri Study

Accuracy of Patient-Specific 3D Printed Drill Guides in the Placement of a Canine Coxofemoral Toggle Pin through a Minimally Invasive Approach

2020 ◽  
Author(s):  
Brett G. Darrow ◽  
Kyle A. Snowdon ◽  
Adrien Hespel
Keyword(s):  
Minimally Invasive ◽  
Three Dimensional ◽  
Bone Tunnel ◽  
Patient Specific ◽  
Exit Point ◽  
Minimally Invasive Approach ◽  
Invasive Approach ◽  
Post Procedure ◽  
Drill Guide ◽  
Ct Data

Abstract Objective The aim of this study was to evaluate the accuracy of patient-specific three-dimensional printed drill guides (3D-PDG) for the placement of a coxofemoral toggle via a minimally invasive approach. Materials and Methods Pre-procedure computed tomography (CT) data of 19 canine cadaveric hips were used to design a cadaver-specific 3D-PDG that conformed to the proximal femur. Femoral and acetabular bone tunnels were drilled through the 3D-PDG, and a coxofemoral toggle pin was placed. The accuracy of tunnel placement was evaluated with post-procedure CT and gross dissection. Results Coxofemoral toggle pins were successfully placed in all dogs. Mean exit point translation at the fovea capitis was 2.5 mm (0.2–7.5) when comparing pre- and post-procedure CT scans. Gross dissection revealed the bone tunnel exited the fovea capitis inside (3/19), partially inside (12/19) and outside of (4/19) the ligament of the head of the femur. Placement of the bone tunnel through the acetabulum was inside (16/19), partially inside (1/19) and outside (2/19) of the acetabular fossa. Small 1 to 2 mm articular cartilage fragments were noted in 10 of 19 specimens. Clinical Significance Three-dimensional printed drill guide designed for coxofemoral toggle pin application is feasible. Errors are attributed to surgical execution and identification of the borders of the fovea capitis on CT data. Future studies should investigate modifications to 3D-PDG design and methods. Three-dimensional printed drill guide for coxofemoral toggle pin placement warrants consideration for use in select clinical cases of traumatic coxofemoral luxation.

The profile of the spinal column in subjects with lumbar developmental spinal stenosis

2021 ◽  
Vol 103-B (4) ◽  
pp. 725-733
Author(s):  
Marcus Kin Long Lai ◽  
Prudence Wing Hang Cheung ◽  
Dino Samartzis ◽  
Jaro Karppinen ◽  
Kenneth M. C. Cheung ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Spinal Stenosis ◽  
Vertebral Body ◽  
Spinal Canal ◽  
Facet Joint ◽  
Spinal Column ◽  
Stepwise Logistic Regression ◽  
Diagnostic Study ◽  
Vertebral Canal ◽  
Dural Sac

Aims The aim of this study was to determine the differences in spinal imaging characteristics between subjects with or without lumbar developmental spinal stenosis (DSS) in a population-based cohort. Methods This was a radiological analysis of 2,387 participants who underwent L1-S1 MRI. Means and ranges were calculated for age, sex, BMI, and MRI measurements. Anteroposterior (AP) vertebral canal diameters were used to differentiate those with DSS from controls. Other imaging parameters included vertebral body dimensions, spinal canal dimensions, disc degeneration scores, and facet joint orientation. Mann-Whitney U and chi-squared tests were conducted to search for measurement differences between those with DSS and controls. In order to identify possible associations between DSS and MRI parameters, those who were statistically significant in the univariate binary logistic regression were included in a multivariate stepwise logistic regression after adjusting for demographics. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported where appropriate. Results Axial AP vertebral canal diameter (p < 0.001), interpedicular distance (p < 0.001), AP dural sac diameter (p < 0.001), lamina angle (p < 0.001), and sagittal mid-vertebral body height (p < 0.001) were significantly different between those identified as having DSS and controls. Narrower interpedicular distance (OR 0.745 (95% CI 0.618 to 0.900); p = 0.002) and AP dural sac diameter (OR 0.506 (95% CI 0.400 to 0.641); p < 0.001) were associated with DSS. Lamina angle (OR 1.127 (95% CI 1.045 to 1.214); p = 0.002) and right facet joint angulation (OR 0.022 (95% CI 0.002 to 0.247); p = 0.002) were also associated with DSS. No association was observed between disc parameters and DSS. Conclusion From this large-scale cohort, the canal size is found to be independent of body stature. Other than spinal canal dimensions, abnormal orientations of lamina angle and facet joint angulation may also be a result of developmental variations, leading to increased likelihood of DSS. Other skeletal parameters are spared. There was no relationship between DSS and soft tissue changes of the spinal column, which suggests that DSS is a unique result of bony maldevelopment. These findings require validation in other ethnicities and populations. Level of Evidence: I (diagnostic study) Cite this article: Bone Joint J 2021;103-B(4):725–733.

Customised hybrid CT-MRI 3D-printed model for grade V spondylolisthesis in an adolescent

2021 ◽  
Vol 14 (3) ◽  
pp. e239192
Author(s):  
Jayanthi Parthasarathy ◽  
Eric A Sribnick ◽  
Mai-Lan Ho ◽  
Allan Beebe
Keyword(s):  
Potential Benefit ◽  
High Spatial Resolution ◽  
Composite Model ◽  
Added Value ◽  
Patient Specific ◽  
Team Approach ◽  
Multidisciplinary Team Approach ◽  
3D Printed ◽  
Ct Data ◽  
Ct And Mri

3D-printed patient-specific models provide added value for initial clinical diagnosis, preoperative surgical and implant planning and patient and trainee education. 3D spine models are usually designed using CT data, due to the ability to rapidly image osseous structures with high spatial resolution. Combining CT and MRI to derive a composite model of bony and neurological anatomy can potentially provide even more useful information for complex cases. We describe such a case involving an adolescent with a grade V spondylolisthesis in which a composite model was manufactured for preoperative and intraoperative evaluation and guidance. We provide a detailed workflow for creating such models and outline their potential benefit in guiding a multidisciplinary team approach.

Computer-assisted Diagnosis for Early Stage Pleural Mesothelioma

2007 ◽  
Vol 46 (03) ◽  
pp. 324-331 ◽  
Author(s):  
P. Jäger ◽  
S. Vogel ◽  
A. Knepper ◽  
T. Kraus ◽  
T. Aach ◽  
...  
Keyword(s):  
Early Stage ◽  
Computation Time ◽  
Hounsfield Unit ◽  
Computer Assisted ◽  
Clinical Test ◽  
Pleural Mesothelioma ◽  
Data Sets ◽  
Data Set ◽  
Average Computation Time ◽  
Ct Data

Summary Objectives: Pleural thickenings as biomarker of exposure to asbestos may evolve into malignant pleural mesothelioma. Foritsearly stage, pleurectomy with perioperative treatment can reduce morbidity and mortality. The diagnosis is based on a visual investigation of CT images, which is a time-consuming and subjective procedure. Our aim is to develop an automatic image processing approach to detect and quantitatively assess pleural thickenings. Methods: We first segment the lung areas, and identify the pleural contours. A convexity model is then used together with a Hounsfield unit threshold to detect pleural thickenings. The assessment of the detected pleural thickenings is based on a spline-based model of the healthy pleura. Results: Tests were carried out on 14 data sets from three patients. In all cases, pleural contours were reliably identified, and pleural thickenings detected. PC-based Computation times were 85 min for a data set of 716 slices, 35 min for 401 slices, and 4 min for 75 slices, resulting in an average computation time of about 5.2 s per slice. Visualizations of pleurae and detected thickeningswere provided. Conclusion: Results obtained so far indicate that our approach is able to assist physicians in the tedious task of finding and quantifying pleural thickenings in CT data. In the next step, our system will undergo an evaluation in a clinical test setting using routine CT data to quantifyits performance.

Posterior Epidural Migration of Sequestrated Lumbar Disc Fragments Into the Bilateral Facet Joints

Neurosurgery ◽  
2011 ◽  
Vol 69 (5) ◽  
pp. E1148-E1151 ◽  
Author(s):  
Tzuu-Yuan Huang ◽  
Kung-Shing Lee ◽  
Tai-Hsin Tsai ◽  
Yu-Feng Su ◽  
Shiuh-Lin Hwang
Keyword(s):  
Differential Diagnosis ◽  
Facet Joint ◽  
Lumbar Disc ◽  
Synovial Cyst ◽  
Leg Pain ◽  
Hybrid Technique ◽  
Facet Joints ◽  
Disc Disease ◽  
First Case ◽  
Rod System

Abstract BACKGROUND AND IMPORTANCE Symptomatic lumbar disc herniation is common. Migration of a free disc fragment is usually found in rostral, caudal, or lateral directions. Posterior epidural migration is very rare. We report the first case with posterior epidural migration and sequestration into bilateral facet joints of a free disc fragment. CLINICAL PRESENTATION A 78-year-old female presented with low back pain and right leg pain. Plain radiographs showed lumbar spondylolisthesis. Magnetic resonance imaging revealed a posterior epidural mass and intrafacet mass, which was hypointense on T1-weighted images and hyperintense on T2-weighted images. The lesion in the left L3-4 facet joint had rim enhancement, whereas the right one was not contrasted after gadolinium injection. Preoperative differential diagnosis included abscess, tumor, hematoma, or synovial cyst. An interbody cage fusion at L3-4 and L4-5 for spondylolisthesis was performed, and a hybrid technique was applied with the Dynesys flexible rod system at L3-S1 for multisegment degenerative disc disease. The lesion proved to be an epidural disc fragment with sequestration into bilateral facet joints. CONCLUSION A free disc fragment should be considered in the differential diagnosis of posterior epidural lesions, and even in the facet joint.

scholarly journals The problem of mismatches between CT scan and DXA results

2019 ◽  
pp. 12-17
Author(s):  
A. E. Bokov ◽  
S. G. Mlyavykh ◽  
A. A. Bulkin ◽  
A. Y. Aleynik ◽  
M. V. Rasteryeva
Keyword(s):  
Lumbar Spine ◽  
Cancellous Bone ◽  
Cross Sectional Study ◽  
Facet Joints ◽  
Mineral Density ◽  
Cross Sectional ◽  
Property Assessment ◽  
Ct Data ◽  
The Right ◽  
Vertebra Body

Background. It is reported that radiodensity measured in Hounsfield units becomes more and more popular in bone property assessment, however also mismatch with DXA results is observed.Purpose. The aim of this study is to evaluate the relationships between the results of DXA and CT with a focus on explanations for observed discrepancies.Material and methods. This is a cross-sectional study; forty patients were enrolled, all patients underwent DXA and CT. A bone mineral density BMD (g/cm2 ) was calculated for each vertebra of a lumbar spine (L1-L4 inclusive), neck, upper neck, shaft, Wards triangle and trochanter of hip. Bone radiodensity in HU was taken from each vertebral body in the sagittal, axial and coronal planes. A total vertebra body radiodensity including cortical bone and radiodensity of only cancellous bone were calculated. To assess a potential impact on DXA and CT data agreement a mean radiodensity and square of the right and left vertebral pedicles and facet joints were measured for each vertebra.Results. A strong correlation between BMD measured using DXA and CT data was estimated with a multiply r accounting for 0,84169, p<0,0001, however the most contributing parameters were those calculated for facet joints. It has been detected that both radiodensity of only a cancellous bone and total have a weak correlation with matching BMD measurements of a proximal femur.Conclusion. The results of DXA could be strongly influenced by hypertrophic changes of facet joints. Both CT and DXA measurements taken from a lumbar spine may have a mismatch with figures taken from hip. 

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