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Publications (10 of 16) 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 ()
Note

QC 20190207

Available from: 2016-07-11 Created: 2016-07-11 Last updated: 2019-02-07Bibliographically approved
Kim, Y. S., Maguire Jr., G. Q. & Noz, M. E. (2016). Do Small-Mass Neutrinos Participate in Gauge Transformations?. Advances in High Energy Physics, 1-7, Article ID 1847620.
Open this publication in new window or tab >>Do Small-Mass Neutrinos Participate in Gauge Transformations?
2016 (English)In: Advances in High Energy Physics, ISSN 1687-7357, E-ISSN 1687-7365, p. 1-7, article id 1847620Article in journal (Refereed) Published
Abstract [en]

Neutrino oscillation experiments presently suggest that neutrinos have a small but finite mass. If neutrinos have mass, there should be a Lorentz frame in which they can be brought to rest. This paper discusses how Wigner’s little groups can be used to distinguish between massive and massless particles. We derive a representation of the SL(2,c) group which separates out the two sets of spinors: one set is gauge dependent and the other set is gauge invariant and represents polarized neutrinos. We show that a similar calculation can be done for the Dirac equation. In the large-momentum/zero-mass limit, the Dirac spinors can be separated into large and small components. The large components are gauge invariant, while the small components are not. These small components represent spin-1/2 non-zero-mass particles. If we renormalize the large components, these gauge invariant spinors represent the polarization of neutrinos. Massive neutrinos cannot be invariant under gauge transformations.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2016
National Category
Subatomic Physics
Identifiers
urn:nbn:se:kth:diva-189756 (URN)10.1155/2016/1847620 (DOI)2-s2.0-84979656442 (Scopus ID)
Note

QC 20160713

Available from: 2016-07-13 Created: 2016-07-13 Last updated: 2017-11-28Bibliographically 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)2-s2.0-84947475183 (Scopus ID)
Note

QC 20151102

Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2018-01-10Bibliographically approved
Lee, S., Noz, M. E. & Maguire Jr., G. Q. (2015). Dynamic PET visualization of bone remodeling using NaF-18. Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Dynamic PET visualization of bone remodeling using NaF-18
2015 (English)Report (Other academic)
Abstract [en]

Positron emission tomography (PET) studies acquired in list mode offer the opportunity to provide a cine loop showing the dynamics of 18F- PET uptake, giving a visualization of regional bone remodeling. The focus of this report is a group of patients treated with Taylor spatial frames (TSF). The studies were acquired for a period of 45 minutes and saved in list mode. The list was decoded and subsequently segmented into time intervals of one minute each. For each time interval a sinogram was generated from which volumes of one minute each were reconstructed. Slices projected from these volumes could then be displayed as a dynamic loop superimposed on the corresponding computed tomography (CT) slice in order to visualize the 18F- uptake insitu. It was indicated that this technique has the potential of becoming an additional technique to that of using static volumes and SUV values only.

As the list mode data was decoded it also offered a method to evaluate the potential decrease in injected activity by eliminating every Nth event from the list before reconstructing the 45 minute volume. This was done and the indication was that the injected activity and hence the effective dose to the patient can be decreased. However, in this work, this was not proven clinically.

The open source STIR software was used to reconstruct volumes from sinograms to enable an unlimited access to reconstructing volumes without disturbing the daily routine at the clinic. The data was acquired on a clinical Siemens Medical Solutions Biograph 64 TruePoint TrueV, PET/CT scanner situated at the Nuclear Medicine Department at the Karolinska University Hospital in Solna. This scanner was not supported by the STIR software, hence the data collected by the Siemens PET/CT scanner was translated so that 3D reconstructions could be computed using the STIR tools. The reconstructions made in STIR resulted in volumes of sufficient visual quality, but not as good as those reconstructed by the scanner itself. Further optimization in STIR was left for future work.

According to the physicians who treat these patients, dynamic visualization was of sufficient interest to continue to develop and optimize this method. The cine loops that were presented to the physicians were made from JPEG slices produced from the one minute volumes and put together as GIF files. It was also possible to vary the reconstruction time (from uniformly one minute) as well as the presentation rate in the cine loop, but this was left for future work. Ultimately, the cine loop will be implemented in the locally developed software tool.

Abstract [sv]

Positronemissionstomografi (PET) studier som förvärvats i list mode erbjuder möjligheten att göra film slingor som visar dynamiken i 18F- PET upptag. Detta förväntas ge en dynamisk visualisering av var ben nybildas. Fokus i denna rapport är en grupp patienter som behandlats med Taylor spatial frames (TSF). Bilderna i studien förvärvades under en period av 45 minuter och sparades i list mode. List mode data avkodades och delades därefter upp i tidsintervaller på en minut vardera. För varje tidsintervall rekonstruerades ett sinogram för vilka bilder av volymen rekonstruerades. Skivor från dessa volymer kan sedan visas som en dynamisk slinga ovanpå motsvarande datortomografi (CT) skiva för att visualisera 18F- upptaget in situ. Denna teknik visade sig ha potential att bli en ytterligare teknik utöver de statiska volymer och SUV-värden som redan finns tillgängliga.

Eftersom listmode data avkodats erbjuds också en metod för att utvärdera en potentiell minskning av den injicerade aktivitet genom att eliminera varje N: te händelse från listan innan volymen på 45 minuter rekonstrueras. Detta utfördes och det visade sig att den injicerade aktiviteten och därmed den effektiva dosen till patienten potentiellt kan minskas men i detta arbete har detta inte bevisats kliniskt.

Mjukvaran STIR, som är tillgängligt för allmänheten, användes för att rekonstruera volymer från sinogram för att möjliggöra en obegränsad tillgång till att rekonstruera volymer utan att störa den dagliga rutinen på kliniken. Data förvärvades i en klinisk Siemens Medical Solutions Biograph 64 TruePoint TrueV, PET/CT-skanner som är placerad vid nuklearmedicinska avdelningen vid Karolinska Universitetssjukhuset i Solna. Skannern var inte kompatibel med STIR mjukvaran. Därför översattes det data som samlats in av Siemens PET/CT-skannern så att 3D-rekonstruktioner kan beräknas med hjälp av verktygen i STIR. De rekonstruktioner som gjorts i STIR gav upphov till volymer av tillräcklig visuell kvalitet för denna studie, men var inte lika bra som de som rekonstrueras genom själva skannern. Ytterligare optimering i STIR lämnades för framtida arbete.

Enligt de läkare som behandlar dessa patienter var en dynamisk visualisering av tillräckligt intresse att fortsätta utveckla och optimera den här metoden. Film slingor som presenterades för läkarna gjordes från JPEG bilder tagna från skivor av volymer på en minut vardera som producerats och sattes ihop som GIF-filer. Det var också möjligt att variera återuppbyggnadstiden (från jämnt en minut) samt presentationshastigheten i film slingan, men detta lämnades till framtida arbetet. I slutändan kommer film slingan implementeras i ett lokalt utvecklat verktyg.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. p. xvii,131
Series
TRITA-ICT ; 2015:24
Keywords
PET, Image Reconstruction, Dynamic Visualization, List Mode, STIR, PET, Bildrekonstruktion, Dynamisk visualisering, List mode, STIR
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-176272 (URN)
Note

QC 20151102

Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2015-11-17Bibliographically approved
Skeppholm, M., Svedmark, P., Noz, M. E., Maguire Jr., G. Q., Olivecrona, H. & Olerud, C. (2015). Evaluation of mobility and stability in the Discover artificial disc: an in vivo motion study using high-accuracy 3D CT data. Journal of Eurosurgery : Spine, 23(3), 383-389
Open this publication in new window or tab >>Evaluation of mobility and stability in the Discover artificial disc: an in vivo motion study using high-accuracy 3D CT data
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2015 (English)In: Journal of Eurosurgery : Spine, ISSN 1547-5654, E-ISSN 1547-5646, Vol. 23, no 3, p. 383-389Article in journal (Refereed) Published
Abstract [en]

OBJECT Artificial disc replacement (ADR) devices are unlike implants used in cervical fusion in that they are continuously exposed to stress not only within the implant site but also at their site of attachment to the adjacent vertebra. An imaging technique with higher accuracy than plain radiography and with the possibility of 3D visualization would provide more detailed information about the motion quality and stability of the implant in relation to the vertebrae. Such high-accuracy studies have previously been conducted with radiostereometric analysis (RSA), which requires implantation of tantalum markers in the adjacent vertebrae. The aim of this study was to evaluate in vivo motion and stability of implanted artificial discs. A noninvasive analysis was performed with CT, with an accuracy higher than that of plain radiographs and almost as high as RSA in cervical spine. METHODS Twenty-eight patients with ADR were included from a larger cohort of a randomized controlled trial comparing treatment of cervical radiculopathy with ADR or anterior cervical decompression and fusion. Surgical levels included C4-7; 18 patients had 1-level surgery and 10 patients had 2-level surgery. Follow-up time ranged from 19 to 50 months, with an average of 40 months. Two CT volumes of the cervical spine, 1 in flexion and 1 in extension, were obtained in each patient and then spatially registered using a customized imaging tool, previously used and validated for the cervical spine. Motion between the components in the artificial disc, as well as motion between the components and adjacent vertebrae, were calculated in 3 planes. Intraclass correlation (ICC) between independent observers and repeatability of the method were also calculated. RESULTS Intrinsic motion, expressed as degrees in rotation and millimeters in translation, was detectable in a majority of the ADRs. In the sagittal plane, in which the flexion/extension was performed, sagittal rotation ranged between 0.2 and 15.8 and translation between 0.0 and 5.5 mm. Eight percent of the ADRs were classified as unstable, as motion between at least 1 of the components and the adjacent vertebra was detected. Five percent were classified as ankylotic, with no detectable motion, and another 8% showed very limited motion due to heterotopic ossification. Repeatability for the motion in the sagittal plane was calculated to be 1.300 for rotation and 1.29 mm for translation (95% confidence level), ICC 0.99 and 0.84, respectively. All 3 patients with unstable devices had undergone 1-level ADRs at C5-6. They all underwent revision surgery due to increased neck pain, and instability was established during the surgery. CONCLUSIONS The majority of the artificial discs in this study showed intrinsic mobility several years after implantation and were also shown to be properly attached. Implant instability was detected in 8% of patients and, as all of these patients underwent revision surgery due to increasing neck pain, this might be a more serious problem than heterotopic bone formation.

Place, publisher, year, edition, pages
AMER ASSOC NEUROLOGICAL SURGEONS, 2015
Keywords
artificial disc replacement, mobility, computed tomography, instability, revision surgery
National Category
Neurology Surgery
Identifiers
urn:nbn:se:kth:diva-173426 (URN)10.3171/2014.12.SPINE14813 (DOI)000360027300018 ()2-s2.0-84947447284 (Scopus ID)
Note

QC 20150915. QC 20160222

Available from: 2015-09-15 Created: 2015-09-11 Last updated: 2017-12-04Bibliographically 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
Maguire Jr., G. Q., Noz, M. E., Olivecrona, H., Zeleznik, M. P. & Weidenhielm, L. (2014). A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis. Scientific World Journal, 2014, 528407
Open this publication in new window or tab >>A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis
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2014 (English)In: Scientific World Journal, ISSN 1537-744X, E-ISSN 1537-744X, Vol. 2014, p. 528407-Article in journal (Refereed) Published
Abstract [en]

As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (+/- SD) for the diameter of the acetabular cup of 54.21 (+/- 0.011) mm and for the femoral component head of 22.09 (+/- 0.02) mm. The wear error was +/- 0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction.

Keywords
Total Hip-Arthroplasty, Acetabular Component Migration, Cross-Linked Polyethylene, Semiautomated Program, Computed-Tomography, Femoral-Head, Prostheses, Radiostereometry, Penetration, Osteolysis
National Category
Orthopaedics Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-140524 (URN)10.1155/2014/528407 (DOI)000330650200001 ()2-s2.0-84893834636 (Scopus ID)
Note

QC 20140227

Available from: 2014-01-24 Created: 2014-01-24 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
Goldvasser, D., Hansen, V. J., Noz, M. E., Maguire Jr., G. Q., Zeleznik, M. P., Olivecrona, H., . . . Malchau, H. (2014). In vivo and ex vivo measurement of polyethylene wear in total hip arthroplasty. Acta Orthopaedica, 85(3), 271-275
Open this publication in new window or tab >>In vivo and ex vivo measurement of polyethylene wear in total hip arthroplasty
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2014 (English)In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 85, no 3, p. 271-275Article in journal (Refereed) Published
Abstract [en]

Background - Determination of the amount of wear in a polyethylene liner following total hip arthroplasty (THA) is important for both the clinical care of individual patients and the development of new types of liners. Patients and methods - We measured in vivo wear of the polyethylene liner using computed tomography (CT) (obtained in the course of regular clinical care) and compared it to coordinate-measuring machine (CMM) readings. Also, changes in liner thickness of the same retrieved polyethylene liner were measured using a micrometer, and were compared to CT and CMM measurements. The distance between the centers of the acetabular cup and femoral head component was measured in 3D CT, using a semi-automatic analysis method. CMM readings were performed on each acetabular liner and data were analyzed using 3D computer-aided design software. Micrometer readings compared the thickest and thinnest regions of the liner. We analyzed 10 THA CTs and retrievals that met minimal requirements for CT slice thickness and explanted cup condition. Results - For the 10 cups, the mean difference between the CT readings and the CMM readings was -0.09 (-0.38 to 0.20) mm. This difference was not statistically significant (p = 0.6). Between CT and micrometer, the mean difference was 0.11 (-0.33 to 0.55) mm. This difference was not statistically significant (p = 0.6). Interpretation - Our results show that CT imaging is ready to be used as a tool in clinical wear measurement of polyethylene liners used in THA.

Keywords
Cross-Linked Polyethylene, Computed-Tomography, CT, Trial
National Category
Orthopaedics
Identifiers
urn:nbn:se:kth:diva-147985 (URN)10.3109/17453674.2014.913225 (DOI)000337845000011 ()24758322 (PubMedID)2-s2.0-84902653490 (Scopus ID)
Note

QC 20140807

Available from: 2014-07-10 Created: 2014-07-10 Last updated: 2018-01-11Bibliographically approved
Hatherly, R., Brolin, F., Oldner, A., Sundin, A., Lundblad, H., Maguire Jr., G. Q., . . . Noz, M. E. (2014). Technical Requirements for Na18F PET Bone Imaging of Patients Being Treated Using a Taylor Spatial Frame.. Journal of nuclear medicine technology
Open this publication in new window or tab >>Technical Requirements for Na18F PET Bone Imaging of Patients Being Treated Using a Taylor Spatial Frame.
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2014 (English)In: Journal of nuclear medicine technology, ISSN 1535-5675Article in journal (Refereed) Published
Abstract [en]

Diagnosis of new bone growth in patients with compound tibia fractures or deformities treated using a Taylor spatial frame is difficult with conventional radiography because the frame obstructs the images and creates artifacts. The use of Na(18)F PET studies may help to eliminate this difficulty.

METHODS: Patients were positioned on the pallet of a clinical PET/CT scanner and made as comfortable as possible with their legs immobilized. One bed position covering the site of the fracture, including the Taylor spatial frame, was chosen for the study. A topogram was performed, as well as diagnostic and attenuation correction CT. The patients were given 2 MBq of Na(18)F per kilogram of body weight. A 45-min list-mode acquisition was performed starting at the time of injection, followed by a 5-min static acquisition 60 min after injection. The patients were examined 6 wk after the Taylor spatial frame had been applied and again at 3 mo to assess new bone growth.

RESULTS: A list-mode reconstruction sequence of 1 × 1,800 and 1 × 2,700 s, as well as the 5-min static scan, allowed visualization of regional bone turnover.

CONCLUSION: With Na(18)F PET/CT, it was possible to confirm regional bone turnover as a means of visualizing bone remodeling without the interference of artifacts from the Taylor spatial frame. Furthermore, dynamic list-mode acquisition allowed different sequences to be performed, enabling, for example, visualization of tracer transport from blood to the fracture site.

Keywords
Na18F, PET/CT, Taylor spatial frame, bone imaging
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-140510 (URN)10.2967/jnmt.113.133082 (DOI)24436472 (PubMedID)2-s2.0-84897483981 (Scopus ID)
Note

QC 20150629

Available from: 2014-01-24 Created: 2014-01-24 Last updated: 2015-06-29Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2442-1622

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