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Zeleznik, Michael P.ORCID iD iconorcid.org/0000-0002-0706-1805
Publications (5 of 5) Show all publications
Brodén, C., Olivecrona, H., Maguire Jr., G. Q., Noz, M. E., Zeleznik, M. P. & Sköldenberg, O. (2016). Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study. BioMed Research International, Article ID 5909741.
Open this publication in new window or tab >>Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study
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2016 (English)In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 5909741Article in journal (Refereed) Published
Abstract [en]

Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA). The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT) to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty.

Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated.

Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv.

Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2016
National Category
Orthopaedics Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-189725 (URN)10.1155/2016/5909741 (DOI)000380310600001 ()2-s2.0-84979782542 (Scopus ID)
Note

QC 20190207

Available from: 2016-07-11 Created: 2016-07-11 Last updated: 2019-10-03Bibliographically approved
Svedmark, P., Berg, S., Noz, M. E., Maguire Jr., G. Q., Zeleznik, M. P., Weidenhielm, L., . . . Olivecrona, H. (2015). A New CT Method for Assessing 3D Movements in Lumbar Facet Joints and Vertebrae in Patients before and after TDR. BioMed Research International, 2015, 1-9, Article ID 260703.
Open this publication in new window or tab >>A New CT Method for Assessing 3D Movements in Lumbar Facet Joints and Vertebrae in Patients before and after TDR
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2015 (English)In: BioMed Research International, ISSN 2314-6133, Vol. 2015, p. 1-9, article id 260703Article in journal (Refereed) Published
Abstract [en]

This study describes a 3D-CT method for analyzing facet joint motion and vertebral rotation in the lumbar spine after TDR. Ten patients were examined before and then three years after surgery, each time with two CT scans: provoked flexion and provoked extension. After 3D registration, the facet joint 3D translation and segmental vertebral 3D rotation were analyzed at the operated level (L5-S1) and adjacent level (L4-L5). Pain was evaluated using VAS. The median (±SD) 3D movement in the operated level for the left facet joint was 3.2 mm (±1.9 mm) before and 3.5 mm (±1.7 mm) after surgery and for the right facet joint was 3.0 mm (±1.0 mm) before and 3.6 mm (±1.4 mm) after surgery. The median vertebral rotation in the sagittal plane at the operated level was 5.4° (±2.3°) before surgery and 6.8° (±1.7°) after surgery and in the adjacent level was 7.7° (±4.0°) before and 9.2° (±2.7°) after surgery. The median VAS was reduced from 6 (range 5–8) to 3 (range 2–8) in extension and from 4 (range 2–6) to 2 (range 1–3) in flexion.

National Category
Orthopaedics Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-176268 (URN)10.1155/2015/260703 (DOI)000364668500001 ()2-s2.0-84947475183 (Scopus ID)
Note

QC 20151102

Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2019-09-20Bibliographically approved
Lundblad, H., Maguire Jr., G. Q., Karlsson-Thur, C., Jonsson, C., Noz, M. E., Zeleznik, M. P., . . . Weidenhielm, L. (2015). Using PET/CT Bone Scan Dynamic Data to Evaluate Tibia Remodeling When a Taylor Spatial Frame Is Used: Short and Longer Term Differences. BioMed Research International, 2015, 1-11, Article ID 574705.
Open this publication in new window or tab >>Using PET/CT Bone Scan Dynamic Data to Evaluate Tibia Remodeling When a Taylor Spatial Frame Is Used: Short and Longer Term Differences
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2015 (English)In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2015, p. 1-11, article id 574705Article in journal (Refereed) Published
Abstract [en]

Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consentto undergo Na18F− PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curveeliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions werecompared to this Patlak-like approach. Spherical volumes of interest (VOIs) were drawn to include broken bone, other (normal)bone, and muscle. The SUV𝑚(𝑡) (𝑚 = max, mean) and a series of slopes were computed as (SUV𝑚(𝑡𝑖) − SUV𝑚(𝑡𝑗))/(𝑡𝑖 − 𝑡𝑗), forpairs of time values 𝑡𝑖 and 𝑡𝑗. A Patlak-like analysis was performed for the same time values by computing ((VOI𝑝(𝑡𝑖)/VOI𝑒(𝑡𝑖)) −(VOI𝑝(𝑡𝑗)/VOI𝑒(𝑡𝑗)))/(𝑡𝑖−𝑡𝑗), where p = broken bone, other bone, andmuscle and e = expected activity in aVOI. Paired comparisonsbetween Patlak-like and SUV𝑚 slopes showed good agreement by both linear regression and correlation coefficient analysis(𝑟 = 84%, 𝑟𝑠 = 78%-SUVmax, 𝑟 = 92%, and 𝑟𝑠 = 91%-SUVmean), suggesting static scans could substitute for dynamic studies.Patlak-like slope differences of 0.1 min−1 or greater between examinations and SUVmax differences of ∼5 usually indicated goodremodeling progress, while negative Patlak-like slope differences of −0.06 min−1 usually indicated poor remodeling progress in thiscohort.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2015
National Category
Orthopaedics Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-173247 (URN)10.1155/2015/574705 (DOI)000361696200001 ()
Note

QC 20150910

Available from: 2015-09-08 Created: 2015-09-08 Last updated: 2018-01-11Bibliographically approved
Lundblad, H., Maguire Jr., G. Q., Olivecrona, H., Jonsson, C., Jacobsson, H., Noz, M. E., . . . Sundin, A. (2014). Can Na18F PET/CT Be Used to Study Bone Remodeling in the Tibia When Patients Are Being Treated with a Taylor Spatial Frame?. Scientific World Journal, 2014, 1-9
Open this publication in new window or tab >>Can Na18F PET/CT Be Used to Study Bone Remodeling in the Tibia When Patients Are Being Treated with a Taylor Spatial Frame?
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2014 (English)In: Scientific World Journal, ISSN 1537-744X, E-ISSN 1537-744X, Vol. 2014, p. 1-9Article in journal (Refereed) Published
Abstract [en]

Monitoring and quantifying bone remodeling are of interest, for example, in correction osteotomies, delayed fracture healing pseudarthrosis, bone lengthening, and other instances. Seven patients who had operations to attach an Ilizarov-derived Taylor Spatial Frame to the tibia gave informed consent. Each patient was examined by (NaF)-F-18 PET/CT twice, at approximately six weeks and three months after the operation. A validated software tool was used for the following processing steps. The first and second CT volumes were aligned in 3D and the respective PET volumes were aligned accordingly. In the first PET volume spherical volumes of interest (VOIs) were delineated for the crural fracture and normal bone and transferred to the second PET volume for SUVmax evaluation. This method potentially provides clinical insight into questions such as, when has the bone remodeling progressed well enough to safely remove the TSF? and when is intervention required, in a timelier manner than current methods? For example, in two patients who completed treatment, the SUVmax between the first and second PET/CT examination decreased by 42% and 13%, respectively. Further studies in a larger patient population are needed to verify these preliminary results by correlating regional (NaF)-F-18 PET measurements to clinical and radiological findings.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2014
Keywords
Na18F, PET/CT, Bone Remodeling, Taylor Spatial Frame
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-143408 (URN)10.1155/2014/249326 (DOI)000333602000001 ()2-s2.0-84897484026 (Scopus ID)
Note

QC 20140505. QC 20160222

Available from: 2014-03-20 Created: 2014-03-20 Last updated: 2017-12-05Bibliographically approved
Svedmark, P., Lundh, F., Nemeth, G., Noz, M. E., Maguire, G. Q. ., Zeleznik, M. P. & Olivecrona, H. (2011). Motion analysis of total cervical disc replacements using computed tomography: Preliminary experience with nine patients and a model. Acta Radiologica, 52(10), 1128-1137
Open this publication in new window or tab >>Motion analysis of total cervical disc replacements using computed tomography: Preliminary experience with nine patients and a model
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2011 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 52, no 10, p. 1128-1137Article in journal (Refereed) Published
Abstract [en]

Background: Cervical total disc replacement (CTDR) is an alternative to anterior fusion. Therefore, it is desirable to have an accurate in vivo measurement of prosthetic kinematics and assessment of implant stability relative to the adjacent vertebrae. Purpose: To devise an in vivo CT-based method to analyze the kinematics of cervical total disc replacements (CTDR), specifically of two prosthetic components between two CT scans obtained under different conditions. Material and Methods: Nine patients with CTDR were scanned in flexion and extension of the cervical spine using a clinical CT scanner with a routine low-dose protocol. The flexion and extension CT volume data were spatially registered, and the prosthetic kinematics of two prosthetic components, an upper and a lower, was calculated and expressed in Euler angles and orthogonal linear translations relative to the upper component. For accuracy analysis, a cervical spine model incorporating the same disc replacement as used in the patients was also scanned and processed in the same manner. Results: Analysis of both the model and patients showed good repeatability, i.e. within 2 standard deviations of the mean using the 95% limits of agreement with no overlapping confidence intervals. The accuracy analysis showed that the median error was close to zero. Conclusion: The mobility of the cervical spine after total disc replacement can be effectively measured in vivo using CT. This method requires an appropriate patient positioning and scan parameters to achieve suitable image quality.

Place, publisher, year, edition, pages
Sage Publications, 2011
Keywords
Adults, CT, CT high resolution, prostheses, cervical spine
National Category
Clinical Medicine Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-83801 (URN)10.1258/ar.2011.110230 (DOI)000299149300013 ()2-s2.0-83155193038 (Scopus ID)
Note

QC 20120214. QC 20160214

Available from: 2012-02-14 Created: 2012-02-13 Last updated: 2017-12-07Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0706-1805

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