White Blood Cell Scintigraphy Research Articles

Tc-99m Labeled HMPAO white Blood Cell Scintigraphy in a patient with Hip Prosthesis

Background The ability to follow the distribution and migration of biologically active cells in human is essential for the development of cell-based therapies and diagnostics. Nuclear medicine imaging is widely applied in clinic as an attractive technique for in vivo WBC and stem cell tracking. The aim of this study was to evaluate prosthesis infection of a 51 years old man with previous history of hip prosthesis in the left side 17 years ago, and pain in the left femur since 7 months ago using 99mTc-HMPAO labeled WBC. Methods: After sterile isolation of patient's WBCs from RBC and Platelet, they were incubated with 30 mCi of 99mTc-HMPAO for 20 minutes. The labeled WBCs were isolated from 99mTc-HMPAO by centrifuge (450 g, 5 min) in sterile condition and reinjected to the patient. Planar Imaging was acquired (256 × 256 matrix, 5 min) two & four hours post injection. Results: Planar images showed no uptake on the left femur (suspicious to infection) which excludes the patient from surgery replacement of the prosthesis. Conclusion: Leukocyte scintigraphy with 99mTc-HMPAO has been a useful diagnostic method for three decades in the detection of bone infection, fever of unknown origin and suspicion of acute appendicitis. Key Words: Leukocyte labeling, Hip prosthesis, 99mTc-HMPAO, Scintigraphy.

Reply to comment by Koranda: 99mTc-HMPAO-labelled leucocytes in musculoskeletal infections—the choice of reference tissue for a semiquantitative analysis

Dear Sir, We thank Dr. Koranda for his comment and questions [1] regarding our article aimed at defining the best image acquisition protocols and interpretation criteria for white blood cell (WBC) scintigraphy with Tc-HMPAO-labelled leucocytes in musculoskeletal infections [2]. As a conclusion of our retrospective study, we recommend using a dual acquisition protocol with acquisition times of 3–4 h and 20–24 h after reinjection. Acquisition times for the scans have to be corrected for decay of the radionuclide and the images should be displayed with the number of counts and the same intensity scale, making comparisons between images possible without observer bias. Visual analysis, in the majority of cases, is sufficient for diagnosis. Increased uptake or enlargement of area of uptake over time is considered positive for an infection, whereas a decreased or stable uptake over time is considered negative for an infection. In all major subgroups of patients (suspected infected hip prosthesis, suspected infected knee prosthesis, suspected osteomyelitis, suspected infected osteosynthesis), visual analysis showed better sensitivity, specificity and diagnostic accuracy compared to semiquantitative analysis. However, in cases where visual analysis does not allow an easy interpretation and diagnosis, there is an added value of applying a semiquantitative analysis. Increase of a lesion to reference tissue (L/R) ratio over time is considered positive for an infection. Dr. Koranda questioned the reference sites that were used for the semiquantitative analysis. In our study we compared four different reference regions: contralateral tissue, ipsilateral bone marrow, contralateral bone marrow and the anterior superior iliac crest. However, calculation of background in all regions was not always possible. In some cases the anterior superior iliac crest was not in the field of view, and sometimes also bone marrow (ipsior contralateral) was not visible. We were able to calculate (in a total of 297 patients) L/R ratios in 285 patients for contralateral tissue, in 169 patients for ipsilateral bone marrow, in 177 patients for contralateral bone marrow and in 73 patients only for the anterior superior iliac crest. Overall, the diagnostic accuracy for the contralateral tissue was the best (84.2 %) as compared to 81.7 % for ipsilateral bone marrow, 76.8 % for contralateral bone marrow and 82.2 % for the anterior superior iliac crest. Dr. Koranda states that the diagnostic accuracy of the method using the anterior superior iliac crest as a reference region was determined in the subgroup of patients with infected hip prosthesis only and that the diagnostic accuracy of all other methods was calculated for larger groups of patients [1]. Indeed, in the infected hip prosthesis subgroup all four reference regions were calculated and, of course, in this group we were able to calculate a relatively high number of anterior superior iliac crests as reference tissue compared to the other groups, since this reference region was mostly included in the field of view. However, even in eight patients with a suspected infected hip prosthesis, the anterior superior iliac crest was not in the field of view or was only visible with superimposed bowel uptake. A. W. J. M. Glaudemans (*) : E. F. J. de Vries :R. H. J. A. Slart : R. A. J. O. Dierckx :A. Signore Department of Nuclear Medicine andMolecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands e-mail: a.w.j.m.glaudemans@umcg.nl

Native Aortic and Prosthetic Vascular Stent Infection on 99mTc-Labeled White Blood Cell Scintigraphy

The value of (99m)Tc-labeled white blood cell scintigraphy for endovascular prosthetic infections is well known. In the unique case reported here, infection of the native aorta was detected in addition to an infected vascular prosthesis. The case demonstrates that (99m)Tc-labeled white blood cell scintigraphy can identify not only the more usual prosthetic stent/graft infection but also infection of the native aorta. When scrutinizing studies for infection of prosthetic material, readers should also carefully examine the native aorta.

Image acquisition and interpretation criteria for 99mTc-HMPAO-labelled white blood cell scintigraphy: results of a multicentre study

There is no consensus yet on the best protocol for planar image acquisition and interpretation of radiolabelled white blood cell (WBC) scintigraphy. This may account for differences in reported diagnostic accuracy amongst different centres. This was a multicentre retrospective study analysing 235 WBC scans divided into two groups. The first group of scans (105 patients) were acquired with a fixed-time acquisition protocol and the second group (130 patients) were acquired with a decay time-corrected acquisition protocol. Planar images were interpreted both qualitatively and semiquantitatively. Three blinded readers analysed the images. The most accurate imaging acquisition protocol comprised image acquisition at 3 - 4 h and at 20 - 24 h in time mode with acquisition times corrected for isotope decay. Using this protocol, visual analysis had high sensitivity and specificity in the diagnosis of infection. Semiquantitative analysis could be used in doubtful cases, with no cut-off for the percentage increase in radiolabelled WBC over time, as a criterion to define a positive scan.

A large retrospective single-centre study to define the best image acquisition protocols and interpretation criteria for white blood cell scintigraphy with 99mTc-HMPAO-labelled leucocytes in musculoskeletal infections

The diagnosis of infection is often based on clinical, pathological and microbiological results. However, these investigations lack specificity. White blood cell (WBC) scintigraphy is considered the gold standard nuclear imaging technique for diagnosing infections in bone and soft tissues (except spondylodiscitis). However, image acquisition and interpretation criteria differ amongst centres throughout the world, leading to differences in reported results. The aim of this study was to identify the most accurate WBC scintigraphy acquisition and interpretation protocols for diagnosis of bone and soft tissue infections. Included in this retrospective study were 297 patients with suspected bone or soft tissue infection who underwent WBC scintigraphy with (99m)Tc-HMPAO-labelled leucocytes between 2009 and 2012. Sensitivity, specificity, accuracy, and positive and negative predictive values of WBC scintigraphy were determined for two different dual time point acquisition protocols (fixed-time acquisition and time decay-corrected acquisition) and five image interpretation methods (visual and semiquantitative with four different reference regions of interest). Final diagnosis was based on pathological and microbiological reports, and when these were not available, on clinical follow-up of at least 6 months. The best acquisition protocol was 4 h and 20 - 24 h dual time-point acquisition with time decay-corrected acquisition. When using this acquisition protocol, visual qualitative interpretation led to a sensitivity of 85.1 %, a specificity of 97.1 %, a diagnostic accuracy of 94.5 %, a positive predictive value of 88.8 % and a negative predictive value of 95.9 %. For semiquantitative analysis, the best results were found when lesion-to-reference ratios were calculated with the contralateral side as the reference tissue, except for osteomyelitis and infected osteosynthesis, for which the contralateral bone marrow was found to be the best reference tissue. Results of the semiquantitative analyses per se were not better than for visual analysis. In the optimal analysis protocol, scans are first visually evaluated, and if this gives equivocal results, semiquantitative analysis is performed. This strategy resulted in an improved sensitivity of 97.9 %, a specificity of 91.8 % and a diagnostic accuracy of 93.1 %. WBC scintigraphy for bone and soft-tissue infection is best performed using a dual acquisition protocol at 4 h and at 20-24 h after injection, in which the acquisition time of the scans is corrected for decay. In most patients, visual analysis is sufficient and leads to high diagnostic accuracy. When interpretation by visual analysis is inconclusive, semiquantitative analysis adds accuracy. Based on our results, we propose a flow chart for analysing WBC scintigraphy in musculoskeletal infections.

Recent applications of nuclear medicine in diagnostics: II part

Introduction: Positron-emission tomography (PET) and single photon emission computed tomography (SPECT) are effective diagnostic imaging tools in several clinical settings. The aim of this article (the second of a 2-part series) is to examine some of the more recent applications of nuclear medicine imaging techniques, particularly in the fields of neurology, cardiology, and infection/inflammation. Discussion: A review of the literature reveals that in the field of neurology nuclear medicine techniques are most widely used to investigate cognitive deficits and dementia (particularly those associated with Alzheimer disease), epilepsy, and movement disorders. In cardiology, SPECT and PET also play important roles in the work-up of patients with coronary artery disease, providing accurate information on the state of the myocardium (perfusion, metabolism, and innervation). White blood cell scintigraphy and FDG-PET are widely used to investigate many infectious/inflammatory processes. In each of these areas, the review discusses the use of recently developed radiopharmaceuticals, the growth of tomographic nuclear medicine techniques, and the ways in which these advances are improving molecular imaging of biologic processes at the cellular level.

Radiolabelled white blood cell scintigraphy in the work-up of dermal filler complications

Scintigraphy with radiolabelled autologous white blood cells (WBC) is a widely used method for the detection of sites of infection. In this study we evaluated the role of WBC scintigraphy in the diagnosis and follow-up of patients with suspected soft tissue infection caused by dermal fillers in the face. We compared several qualitative and quantitative interpretation criteria and the results obtained with MRI and high-frequency US (HFUS). Between 2007 and 2011, ten consecutive patients (all women) aged between 25 and 65years showing a reaction to dermal fillers were enrolled in the study. In five of these patients WBC scintigraphy was repeated at the end of therapy. Scintigraphy with (99m)Tc-HMPAO-labelled WBC was performed in each patient acquiring planar and SPECT images at 3h and 20h as well as HFUS with Doppler analysis and MRI with Gd-DTPA. The final diagnosis was determined by fine-needle aspiration and microbiological analysis of lesions in eight patients (before therapy in six and after therapy in two) and by clinical data and follow-up (at least 1year) in seven patients (before therapy in four and after therapy in three). Two patients were treated with steroids, and the others were treated with antibiotics for 3weeks. Several qualitative and semiquantitative interpretation criteria were applied to define the best strategy for accurate diagnosis of infections, implemented by SPECT images in patients with doubtful planar scans. The WBC scintigraphy results were also compared with the MRI and HFUS results. Sensitivity, specificity and accuracy were respectively 90%, 100% and 93.3% for WBC scintigraphy with qualitative and semiquantitative interpretation of planar images and 100%, 100% and 100% with qualitative analysis of SPECT images. Sensitivity, specificity and accuracy for HFUS were 44%, 66% and 50%, and for MRI were 50%, 100% and 67.6%, respectively. Scans performed after therapy in five patients were negative in three and still positive in two (all true results). In conclusion, scintigraphy with radiolabelled WBC was found to be the most accurate method for diagnosing infection in patients with long-term dermal filler complications, particularly using qualitative analysis of SPECT images. No differences were observed with planar images using either qualitative or semiquantitative analysis. HFUS and MRI may provide additional important information for defining the nature of the filler and for surgery, but are not accurate enough for diagnosing infection.

Prosthetic vascular graft infection imaging

PurposeWe are reporting our experience with imaging of vascular graft infections using computed tomography angiography (CTA), white blood cell (WBC) scintigraphy and software-based fusion imaging. Material and methodsInstitutional review board approval was obtained. We performed a retrospective review of patients who had clinical signs and symptoms of vascular graft infection in whom both WBC single photon emission computed tomography (SPECT) and CTA was performed between 2005 and 2010. We performed fusion imaging with available data using software coregistration technique and analyzed outcome of the patients. ResultsWe had 20 patients; 11 had grafts of the aorta, five had peripheral vascular grafts, three had aortic and peripheral vascular grafts, and one had a thoracic aortic graft. WBC imaging was positive in 10 patients, negative in six patients and indeterminate in 4 patients. CTA was positive in six patients, negative in four patients and indeterminate in 10 patients. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value (NPV) for WBC, CTA and WBC SPECT/CTA fusion were 75/100/80/100/50%, 88/50/80/88/50% and 94/50/85/88/67% respectively. ConclusionThe use of CTA, WBC scintigraphy, and image co-registration influenced the diagnostic confidence of graft infection and the outcome of the patients. Software-based fusion imaging of both modalities resulted in improved sensitivity, accuracy, and NPV.

Imaging orthopedic implant infections

The diagnosis of infections associated with orthopedic implants is based on a combination of clinical signs, laboratory findings and imaging studies. There is no gold standard imaging technique: conventional radiography is indispensable, although 50% of the time the radiograph is normal. Computed tomography (CT), magnetic resonance imaging (MRI) and ultrasonography are valuable to detect soft tissue abnormalities. Bone scintigraphy (BS) rules out active infection. For infections involving the peripheral skeleton, labeled white blood cell (WBC) scintigraphy coupled with colloid scintigraphy is the reference technique, whereas a gallium scan is always necessary for imaging the spine or pelvis. To confirm or rule out infection, needle aspiration with analysis of aspirated fluid is the cornerstone of the diagnostic algorithm.

Tc-99m Labeled HMPAO white Blood Cell Scintigraphy in Pediatric Patients

Objective: 99mTc labeled hexamethylpropylene amine oxime (HMPAO) white blood cell (WBC) scintigraphy is a frequently used option for acute infection, particularly in pediatric patients. This scintigraphy is applied to detect sites of infection/inflammation in patients with fever of unknown origin, to find and follow up osteomyelitis, and to detect suspicion of acute appendicitis. The aim of this retrospective study was to evaluate the value of 99mTc-HMPAO labeled WBC scintigraphy in pediatric patients.Material and Methods: The study was conducted between January 2006 and December 2008 and included 13 patients (5 boys, 8 girls; mean age 6.9±6.2 years). Those patients who had suspicion of bone infection (n=7), fever of unknown origin (n=3), and suspicion of acute appendicitis (n=3) were evaluated retrospectively. 99mTc-HMPAO labeled WBC scintigraphy imaging was performed to all patients. Diagnosis was done according to operation and pathological results or clinical follow-up.Results: 99mTc-HMPAO labeled WBC scintigraphy has been found to be true positive in 6 cases, true negative in 6 cases, and false negative in one patient who had fewer unknown origin. The false negative case has been found to have encephalitis with MRI. Conclusion: Leukocyte scintigraphy has been described as a useful diagnostic tool in the diagnosis of suspicion of bone infection, fever of unknown origin and suspicion of acute appendicitis. 99mTc-HMPAO labeled WBC scintigraphy is a rapid and very accurate method for detecting those pathologies. Our results showed that WBC scintigraphy might be reliably used for diagnosis of suspected bone infection and acute appendicitis, fever of unknown origin, and acute appendicitis, in pediatric patient population.Conflict of interest:None declared.

Tc99m-HMPAO white blood cell scintigraphy: added value of SPECT/CT for infection diagnosis in cardiothoracic surgery

We report a case of a woman who came to our attention because of fever and a sternal fistula draining purulent fluid. Four years before, she had undergone cardiothoracic surgery to place a patch because of a myocardial rupture. Under suspicion of a deep mediastinal infection, a Tc99m-HMPAO white blood cell (WBC) scintigraphy was performed. The use of planar imaging and single photon emission computed tomography (SPECT/CT) imaging allowed the identification of a sternal infection, which involved the anterior mediastinum up to pericardium and diaphgram. SPECT/CT led to a precise diagnosis of a thoracic infection, providing the location and extent of the disease. This turned out useful to improve therapeutic strategies.

Tc99m-HMPAO white blood cell scintigraphy: added value of SPECT/CT for infection diagnosis in cardiothoracic surgery

We report a case of a woman who came to our attention because of fever and a sternal fistula draining purulent fluid. Four years before, she had undergone cardiothoracic surgery to place a patch because of a myocardial rupture. Under suspicion of a deep mediastinal infection, a Tc99m-HMPAO white blood cell (WBC) scintigraphy was performed. The use of planar imaging and single photon emission computed tomography (SPECT/CT) imaging allowed the identification of a sternal infection, which involved the anterior mediastinum up to pericardium and diaphgram. SPECT/CT led to a precise diagnosis of a thoracic infection, providing the location and extent of the disease. This turned out useful to improve therapeutic strategies.

99mTc-HMPAO labelled white blood cell scintigraphy in the diagnosis and monitoring of response of the therapy in patients with active bronchiectasis

AimThe aim of this study was to assess the role of labelled leukocyte scintigraphy in the diagnosis and monitorization of response to therapy of patients with active bronchiectasis. Material and methodsTwenty patients underwent 99mTechnetium hexamethylpropyleneamine oxime (99mTc-HMPAO) labelled white blood cell (WBC) scintigraphy. A second scintigraphy was performed in 13 patients at 10 day of the treatment. Regional 99mTc-HMPAO WBC uptake and radiologic imaging findings (high resolution computed tomography or Chest X-Ray) in the lungs were classified into 3 categories in 6 lung areas. scintigraphic, radiological and clinical disease scores were calculated for all patients. ResultsAn abnormal accumulation was visually observed in 19 of 20 patients on the pre-treatment scans, the scintigraphy showing 95% sensitivity. A significant difference was found between early and late ratios (P=0.001) in the pre-treatment scans. The infected areas revealed a significant decrease in uptake ratios on the post-treatment scans compared to the pre-treatment scans (P=0.001). However, no significant correlation was determined between clinical and radiological scores, clinical and scintigraphic scores and also between scintigraphic and radiological scores (P≥0.05). Conclusions99mTc-HMPAO WBC scintigraphy may be a useful tool to evaluate response to therapy in patients with active bronchiectasis.

99mTc-HMPAO labelled white blood cell scintigraphy in the diagnosis and monitoring of response of the therapy in patients with active bronchiectasis

AimThe aim of this study was to assess the role of labelled leukocyte scintigraphy in the diagnosis and monitorization of response to therapy of patients with active bronchiectasis. Material and methodsTwenty patients underwent 99mTechnetium hexamethylpropyleneamine oxime (99mTc-HMPAO) labelled white blood cell (WBC) scintigraphy. A second scintigraphy was performed in 13 patients at 10 day of the treatment. Regional 99mTc-HMPAO WBC uptake and radiologic imaging findings (high resolution computed tomography or Chest X-Ray) in the lungs were classified into 3 categories in 6 lung areas. scintigraphic, radiological and clinical disease scores were calculated for all patients. ResultsAn abnormal accumulation was visually observed in 19 of 20 patients on the pre-treatment scans, the scintigraphy showing 95% sensitivity. A significant difference was found between early and late ratios (P=0.001) in the pre-treatment scans. The infected areas revealed a significant decrease in uptake ratios on the post-treatment scans compared to the pre-treatment scans (P=0.001). However, no significant correlation was determined between clinical and radiological scores, clinical and scintigraphic scores and also between scintigraphic and radiological scores (P≥0.05). Conclusions99mTc-HMPAO WBC scintigraphy may be a useful tool to evaluate response to therapy in patients with active bronchiectasis.

Can Sequential18F-FDG PET/CT Replace WBC Imaging in the Diabetic Foot?

White blood cell (WBC) scintigraphy is considered the nuclear medicine imaging gold standard for diagnosing osteomyelitis in the diabetic foot. Recent papers have suggested that the use of (18)F-FDG PET/CT produces similar diagnostic accuracy, but clear interpretation criteria have not yet been established. Our aim was to evaluate the role of sequential (18)F-FDG PET/CT in patients with a high suspicion of osteomyelitis to define objective interpretation criteria to be compared with WBC scintigraphy. Thirteen patients whom clinicians considered positive for osteomyelitis (7 with ulcers, 6 with exposed bone) were enrolled. The patients underwent (99m)Tc-exametazime WBC scintigraphy with acquisition times of 30 min, 3 h, and 20 h and sequential (18)F-FDG PET/CT with acquisition times of 10 min, 1 h, and 2 h. A biopsy or tissue culture was performed for final diagnosis. Several interpretation criteria (qualitative and quantitative) were tested. At final biopsy, 7 patients had osteomyelitis, 2 had soft-tissue infection without osteomyelitis, and 4 had no infection. The best interpretation criterion for osteomyelitis with WBC scintigraphy was a target-to-background (T/B) ratio greater than 2.0 at 20 h and increasing with time. A T/B ratio greater than 2.0 at 20 h but stable or decreasing with time was suggestive of soft-tissue infection. A T/B ratio of no more than 2.0 at 20 h excluded an infection. Thus, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for osteomyelitis were 86%, 100%, 100%, 86%, and 92%, respectively. For (18)F-FDG PET/CT, the best interpretation criterion for osteomyelitis was a maximal standardized uptake value (SUVmax) greater than 2.0 at 1 and 2 h and increasing with time. A SUVmax greater than 2.0 after 1 and 2 h but stable or decreasing with time was suggestive of a soft-tissue infection. An SUVmax less than 2.0 excluded an infection. (18)F-FDG PET at 10 min was not useful. Using these criteria, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for osteomyelitis were 43%, 67%, 60%, 50%, and 54%, respectively. Combining visual assessment of PET at 1 h and CT was best for differentiating between osteomyelitis and soft-tissue infection, with a diagnostic accuracy of 62%. (18)F-FDG PET/CT, even with sequential imaging, has a low diagnostic accuracy for osteomyelitis and cannot replace WBC scintigraphy in patients with diabetic foot.

Bone Scintigraphy and Radiolabeled White Blood Cell Scintigraphy for the Diagnosis of Mandibular Osteomyelitis

The aim of this study was to evaluate the diagnostic efficacy of bone scintigraphy (BS) and radiolabeled white blood cell scintigraphy (WBCS) in detecting septic activity in the flat bones of the jaw. A retrospective analysis was conducted using 38 studies of combined BS plus WBCS: 33 of them 3-phase BS and 36 of them 2-phase WBCS. These studies were performed on 34 patients, 19 women and 15 men with a mean age of 56 years (22-79), who presented with suspected mandibular osteomyelitis, either acute or chronic exacerbation. The results were compared with histologic findings (55%) or with a minimum clinical/radiologic follow-up of 6 months (average, 21 months), when biopsy results were not available. BS showed a sensitivity of 100%, a specificity of 6.7%, a positive predictive value of 62%, and a negative predictive value of 100%. For WBCS, the corresponding values were as follows: 73.7%, 78.6%, 82%, and 69%. Accuracy was 63.2% for BS and 94.7% for WBCS. WBCS has proven to be a useful test for detecting septic activity in the jaw bone, being more effective than BS alone, which under certain circumstances, can return a very high false-positive rate.

The Additional Value of Tc 99m HMPAO White Blood Cell SPECT in the Evaluation of Bone and Soft Tissue Infections

Objective: The aim of this prospective study was to evaluate the additional value of Tc 99m HMPAO white blood cell (WBC) SPECT for bone and soft tissue infections.Materials and Methods: Thirty-eight patients with suspected bone and joint infection were included in the study. Patients were assigned into 2 groups according to the presence of orthopedic implants. All patients had multiphase bone scan (BS) with Tc 99m methylene diphosphonate and WBC scintigraphy. The planar images of BS and WBC images were evaluated together. SPECT WBC images were evaluated separately.Results: Group 1 had 30 patients including 12 patients with diabetic foot, 17 patients with suspected relapse of chronic osteomyelitis and 1 with septic arthritis. In 19 of 30 patients, BS and planar WBC images were similar with SPECT images in terms of final diagnosis. In the remaining 11 patients, planar BS+planar WBC images and SPECT WBC images were discordant. Group 2 included 8 patients with suspected infection of orthopedic implants. There was no difference between planar BS+planar WBC images and SPECT WBC in 6 of 8 patients. SPECT WBC images changed the diagnosis of 13 (34.2%) patients in the whole group. SPECT WBC images did not have any contribution in the evaluation of the 6 patients who had reactive changes. Conclusion: SPECT images made significant contribution in discriminating soft tissue infection from osteomyelitis and improved diagnosis in terms of localization and the extent of disease.Conflict of interest:None declared.

Nuove applicazioni della medicina nucleare in ambito diagnostico: II parte

Summary Introduction Positron-emission tomography (PET) and single photon emission computed tomography (SPECT) are effective diagnostic imaging tools in several clinical settings. The aim of this article (the second of a 2-part series) is to examine some of the more recent applications of nuclear medicine imaging techniques, particularly in the fields of neurology, cardiology, and infection/inflammation. Discussion A review of the literature reveals that in the field of neurology nuclear medicine techniques are most widely used to investigate cognitive deficits and dementia (particularly those associated with Alzheimer disease), epilepsy, and movement disorders. In cardiology, SPECT and PET also play important roles in the work-up of patients with coronary artery disease, providing accurate information on the state of the myocardium (perfusion, metabolism, and innervation). White blood cell scintigraphy and FDG-PET are widely used to investigate many infectious/inflammatory processes. In each of these areas, the review discusses the use of recently developed radiopharmaceuticals, the growth of tomographic nuclear medicine techniques, and the ways in which these advances are improving molecular imaging of biologic processes at the cellular level.

(i) Radionuclide imaging of joint prostheses: established & emerging applications

Bone and radiolabelled white blood cell scintigraphy are widely used in the evaluation of symptomatic joint prostheses. Emerging techniques including dual tracer scintigraphy, positron emission tomography - computed tomography (PET-CT) and immunoscintigraphy show promise as more specific tools for use in the assessment of prosthetic joint complications. This article will review the current and future role of radionuclide imaging in establishing the presence, and determining the cause of prosthetic joint complications.

Algodystrophie versus infection postopératoire : intérêt de la scintigraphie aux polynucléaires marqués à propos d’un cas clinique à la main

The differential diagnosis between complex regional pain syndrome (CRPS) and postoperative infection is sometimes difficult. We discuss such a case following surgical release of a trigger finger. Because of lack of an accurate diagnosis, the patient was subjected to more and more costly investigations and was operated one more (and unnecessary) time. As white blood cell scintigraphy ((99m)technetium hexamethylpropyleneamineoxime leukocyte [(99m)Tc HMPAO leu]) proved negative, it allowed us to identify with high specificity, a non infectious cause for the problem, and to stop over-investigation and inflation of the costs of treatment. However, the use of white blood cell scintigraphy should remain exceptional, because of its complexity and expense.