Papers by Henrik Lundblad
European Journal of Orthopaedic Surgery & Traumatology
Purpose To demonstrate the usefulness of positron emission tomography (PET)/computed tomography (... more Purpose To demonstrate the usefulness of positron emission tomography (PET)/computed tomography (CT) bone scans for gaining insight into healing bone status earlier than CT or X-ray alone. Methods Forty-one prospective patients being treated with a Taylor Spatial Frame were recruited. We registered data obtained from successive static CT scans for each patient, to align the broken bone. Radionuclide uptake was calculated over a spherical volume of interest (VOI). For all voxels in the VOI, histograms and cumulative distribution functions of the CT and PET data were used to assess the type and progress of new bone growth and radionuclide uptake. The radionuclide uptake difference per day between the PET/CT scans was displayed in a scatter plot. Superimposing CT and PET slice data and observing the spatiotemporal uptake of 18F− in the region of healing bone by a time-sequenced movie allowed qualitative evaluation. Results Numerical evaluation, particularly the shape and distribution o...
Clinical orthopaedics and related research, 2017
When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bon... more When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride ((18)F(-)) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons. Absorbed on the bone surface from blood flow, (18)F(-) attaches to the osteoblasts in cancellous bone and acts as a pharmacokinetic agent, which reflects the local physiologic activity of bone. This is important because it shows bone formation indicating that the bone is healing or no bone formation indicating no healing. As (18)F(-) is extracted from blood in proportion to blood flow and bone formation, it thus enables determination of bone healing progress. The primary objective of this study was to determine whether videos showing the spatiotemporal uptake of (18)F(-) via PET bone scans could show problematic bone healing in patien...
BioMed Research International, 2015
Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, ... more Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consent to undergo Na(18)F(-) PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curve eliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions were compared to this Patlak-like approach. Spherical volumes of interest (VOIs) were drawn to include broken bone, other (normal) bone, and muscle. The SUV m (t) (m = max, mean) and a series of slopes were computed as (SUV m (t i ) - SUV m (t j ))/(t i - t j ), for pairs of time values t i and t j . A Patlak-like analysis was performed for the same time values by computing ((VOI p (t i )/VOI e (t i ))-(VOI p (t j )/VOI e (t j )))/(t i - t j ), where p = broken bone, other bone, and muscle and e = expected activity in a VOI. Paired comparisons between Patlak-like and SUV m slopes showed good agreement by both linear regression and correlation coefficient analysis (r = 84%, r s = 78%-SUVmax, r = 92%, and r s = 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 good remodeling progress, while negative Patlak-like slope differences of -0.06 min(-1) usually indicated poor remodeling progress in this cohort.
European journal of nuclear medicine and molecular imaging, Jan 23, 2016
The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteot... more The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring. Hence, an imaging technique capable of quantifying bone healing progression would be advantageous. A cohort of 24 patients with different orthopedic conditions, pseudarthrosis (n = 10), deformities subjected to correction osteotomy (n = 9), and fracture (n = 5) underwent dynamic [(18)F]-fluoride (Na(18)F) PET/CT at 8 weeks and 4 months, respectively, after application of a TSF. Parametric images, corresponding to the net transport rate of [(18)F]-fluoride from plasma to bone, K i were calculated. The ratio of the maximum K i at PET scan 2 and 1 ([Formula: see text]) as well as the ratio of the maximum Standard Uptake Value at PET scan 2 and 1 ([Formula: see text]) were calculated...
Lakartidningen, Nov 27, 2003
BioMed Research International, 2015
Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, ... more Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consent to undergo Na(18)F(-) PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curve eliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions were compared to this Patlak-like approach. Spherical volumes of interest (VOIs) were drawn to include broken bone, other (normal) bone, and muscle. The SUV m (t) (m = max, mean) and a series of slopes were computed as (SUV m (t i ) - SUV m (t j ))/(t i - t j ), for pairs of time values t i and t j . A Patlak-like analysis was performed for the same time values by computing ((VOI p (t i )/VOI e (t i ))-(VOI p (t j )/VOI e (t j )))/(t i - t j ), where p = broken bone, other bone, and muscle and e = expected activity in a VOI. Paired comparisons between Patlak-like and SUV m slopes showed good agreement by both linear regression and correlation coefficient analysis (r = 84%, r s = 78%-SUVmax, r = 92%, and r s = 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 good remodeling progress, while negative Patlak-like slope differences of -0.06 min(-1) usually indicated poor remodeling progress in this cohort.
Läkartidningen, Jan 27, 2003
Knee Surgery, Sports Traumatology, Arthroscopy, 2012
Many attempts with contradictory results have been made to correlate different features of OA wit... more Many attempts with contradictory results have been made to correlate different features of OA with pain. One reason may be that pain at rest and pain with movement are seldom considered separately although the mechanisms may be quite different. Furthermore, pain ratings are subject to individual interpretation making an inter-individual comparison questionable. By instead calculating the absolute and relative changes in pain on an intra-individual level after total knee arthroplasty (TKA), we aimed at exploring a relationship between pain and radiological and histological changes. In 69 patients undergoing TKA, preoperative radiographs and perioperative histological samples of the synovial membrane were graded for severity of osteoarthritic and inflammatory changes. The findings were related to the intensity of pain at rest and with movement both preoperatively and 18 months postoperatively according to the visual analogue scale (VAS). The radiographic and histological findings showed no significant correlation with the mean pre- or postoperative pain scores. Instead, change in pain with movement from pre- to postoperative was significantly related to the grade of radiographic osteoarthritis. Best pain relief by TKA was achieved in patients with severe radiographic changes. This, however, only applied to pain with movement. Pain at rest and pain with movement may have different mechanisms. We believe that assessing the intensity of pain at rest and pain with movement separately and considering changes in pain on an individual level will be helpful strategies in future follow-up studies and efforts aimed at explaining the mechanisms of pain in OA.
Journal of Nuclear Medicine Technology, 2014
Diagnosis of new bone growth in patients with compound tibia fractures or deformities treated usi... more 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. 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. 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. 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.
The Journal of Bone and Joint Surgery, 1998
W e studied the presence of sensory nerves by immunohistochemistry in the interface membranes of ... more W e studied the presence of sensory nerves by immunohistochemistry in the interface membranes of hip prostheses after aseptic loosening. Substance P (SP), neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) were analysed as was protein gene product (PGP) 9.5, a general marker for nerve fibres.
Acta Anaesthesiologica Scandinavica, 2007
Scientific World Journal, 2014
Monitoring and quantifying bone remodeling are of interest, for example, in correction osteotomie... more 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 Na 18 F 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 SUV max 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 SUV max 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 Na 18 F PET measurements to clinical and radiological findings.
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Papers by Henrik Lundblad