RESUMEN

BACKGROUND: Lumbar disc herniation is often associated with an inflammatory process. In this context, inflammation has been considered a key factor in the modulation of pain. Here, we present a case of inflammatory activity directly documented in a patient with a lumbar disc herniation. CASE DESCRIPTION: A 49-year-old male presented with progressive low back pain and left-sided S1 radiculopathy, without a focal neurological deficit. The lumbar MR revealed a prominent herniated disc at the L5-S1 level, with compression of the left S1 root. The patient underwent a L5-S1 discectomy using a standard interlaminar approach. Although initially he was pain free, he required three additional operations to address recurrent pain complaints. As research indicates that local inflammation contributes to neuropathic pain, we had the patient undergoes single-photon emission computed tomography (SPECT) imaging using technetium-99m-labeled-infliximab (an anti-tumor necrosis factor [TNF]-alpha monoclonal antibody) before a proposed fourth operation. The SPECT study documented a strong signal at the site of the herniated disc, thus confirming the diagnosis of a pro-inflammatory process involving the S1 nerve root. Nine months after the fourth operation, the patient was pain free. Of interest, the second SPECT study in the now asymptomatic patient demonstrated no detectable/ residual signal at the operative/disc site. CONCLUSION: Absence of a SPECT TNF-alpha signal in a pain-free patient following a lumbar discectomy correlates with the reduction/resolution of the local preoperative inflammatory response.

RESUMEN

Madelung's disease is characterized by the manifestation of multiple ectopic lipomas, usually found in the cervical-thoracic region, however, clinical manifestation may vary among patients. It has been postulated that lipomas associated with Madelung's disease are linked to brown adipose tissue (BAT) due to the presence of uncoupling protein 1 (UCP1). Therefore, we here investigated whether BAT activity is present in a patient with Madelung's disease. 18 F-fluorodeoxyglucose (18 F-FDG) uptake using PET/CT after a cooling procedure was measured together with body temperature and energy expenditure. Finally, adipose tissue biopsies were taken from the lipomas for gene expression analysis and histology. 18 F-FDG uptake was not detected after the cooling procedure in the lipomas. Furthermore, adipose tissue biopsies derived from the lipomas did not express UCP1. We thus conclude that cold-stimulated BAT activity was not detected in lipomas associated with Madelung's disease. Additional research in other patients is needed to unravel the role of dysfunctional BAT in Madelung's disease.

Asunto(s)

RESUMEN

In patients with neurofibromatosis type 1, transformation of neurofibromas into a malignant peripheral nerve sheath tumor (MPNST) is a severe complication of the disease. Fluorine-18-fluorodeoxyglucose PET/computed tomography (PET/CT) is a viable option for detecting malignant tumors in neurofibromatosis type 1 patients. The aim of this review was to assess the diagnostic performance of the most frequently used parameters of PET/CT in detecting MPNST. An extensive computer search was performed using the Cochrane Library, Pubmed, and Medline/Embase databases. Two reviewers independently extracted data of relevant studies and assessed the methodological quality (QUADAS-2). The diagnostic performance of PET/CT parameters in individual studies was determined by calculating a diagnostic odds ratio (DOR) using the absolute numbers of true-positive, true-negative, false-positive, and false-negative test results. A total of eight studies were included, of which three evaluated the standardized uptake value as a diagnostic parameter, two assessed the tumor-to-liver (T/L) ratio, and three articles described both parameters. The cut-off values for maximum standardized uptake value (SUVmax) ranged from 3.2 to 4.5; for the T/L ratio, the cut-off values were between 1.0 and 4.3. The sensitivity and specificity ranged from 90 to 100% and from 80 to 100%, respectively (SUVmax). T/L ratios were associated with 92-100% sensitivity and 72-94% specificity. The corresponding DORs ranged from 57 to 145 (SUVmax) and 35 to 655 (T/L ratio). Both the SUV and the T/L ratio are associated with high sensitivity combined with acceptable specificity in detecting MPNST. There is a tendency toward higher DORs using the T/L ratio, but the number of studies is limited.

Asunto(s)

RESUMEN

PURPOSE: To investigate thyroid gland characteristics on 18F-FDG positron emission tomography/computed tomography (PET/CT) imaging in patients with neurofibromatosis type 1 (NF1). SUBJECTS AND METHODS: Thyroid gland characteristics of patients with a clinical diagnosis of NF1 who underwent 18F-FDG PET/CT imaging for the first time to distinguish benign neurofibroma from malignant peripheral nerve sheath tumor (MPNST) at our institution (n = 69) were compared to PET/CT imaging of sarcoidosis (n = 25) and early stage lung cancer (T1N0M0 tumors, n = 15) patients. RESULTS: Two NF1 patients (3%) showed a diffuse 18F-FDG uptake in the thyroid gland, 2 patients (3%) had an irregular uptake, and 7 patients (10%) had a focal uptake. Among the sarcoidosis patients, 1 showed a diffuse uptake (4%) and 1 had an irregular uptake (4%). In the early stage lung cancer group, 1 patient showed a diffuse uptake (7%) and 1 had a focal uptake (7%). NF1 patients had larger mean thyroid volume and mean SUVmax compared to sarcoidosis patients but not compared to early stage lung cancer patients. Four NF1 patients were diagnosed with multinodular goiter, 2 patients were diagnosed with benign chronic lymphocytic thyroiditis, 1 patient had metastasis to the thyroid, and 1 patient had medullary thyroid cancer. CONCLUSION: Even though NF1 patients did not show an increased risk of thyroid incidentaloma on PET/CT compared to previous studies on non-thyroid cancer patients, the incidence shows that awareness of possible thyroid disease is important.

RESUMEN

Altered estrogen-induced neuroprotection has been implicated in the etiology of psychotic disorders. Using bone mineral density as a marker of lifetime estrogen exposure, a longitudinal family study was conducted to discriminate between etiological mechanisms and secondary effects of disease and treatment. Dual X-ray absorptiometry scans were acquired twice, with an interval of 3 years, in 30 patients with psychotic disorder (male (M)/female (F): 24/6, mean age of 32 years at second measurement), 44 non-psychotic siblings of patients with a psychotic disorder (M/F: 26/18, mean age 32) and 27 controls (M/F: 7/20, mean age 35). Total bone mineral density, Z-scores and T-scores were measured in the lumbar spine and proximal femur. Associations between group and bone mineral density changes were investigated with multilevel random regression analyses. The effect of prolactin-raising antipsychotic medication was evaluated. (Increased risk of) psychotic disorder was not associated with disproportionate bone mineral density loss over a three year period. Instead, femoral bone mineral density measures appeared to decrease less in the patient versus control comparison (total BMD: B = 0.026, 95% CI 0.002 to 0.050, p = 0.037; Z-score: B = 0.224, 95% CI 0.035 to 0.412, p = 0.020; and T-score: B = 0.193, 95% CI 0.003 to 0.382, p = 0.046). Current or past use of a prolactin-raising antipsychotic medication was not associated with bone mineral density changes. In this small longitudinal study, there was no evidence of ongoing estrogen deficiency in psychotic disorder as there was no excessive loss of bone mineral density over a 3-year period in patients using antipsychotic medication.

Asunto(s)

RESUMEN

PURPOSE: The objective of the study was to systematically assess aortic inflammation in patients with granulomatosis with polyangiitis (GPA) using (18)F-2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET)/CT. METHODS: Aortic inflammation was studied in PET/CT scans obtained from 21 patients with GPA; 14 patients with sarcoidosis were included as disease controls, 7 patients with stage I or II head and neck carcinoma ascertained during routine clinical practice were used as healthy controls (HC) and 5 patients with large vessel vasculitis (LVV) were used as positive controls. Aortic (18)F-FDG uptake was expressed as the blood-normalized maximum standardized uptake value (SUVmax), known as the target to background ratio (mean TBRmax). RESULTS: The mean TBRmax (interquartile range) of the aorta in patients with GPA, sarcoidosis, HC and LVV were 1.75 (1.32-2.05), 1.62 (1.54-1.74), 1.29 (1.22-1.52) and 2.03 (1.67-2.45), respectively. The mean TBRmax was significantly higher in patients suffering from GPA or LVV compared to HC (p < 0.05 and p < 0.005, respectively) and tended to be higher in patients suffering from sarcoidosis, but this did not reach statistical significance (p = 0.098). The mean TBRmax of the most diseased segment was significantly higher compared to HC [1.57 (1.39-1.81)] in LVV patients [2.55 (2.22-2.82), p < 0.005], GPA patients [2.17 (1.89-2.83), p < 0.005] and patients suffering from sarcoidosis [2.04 (1.88-2.20), p < 0.05]. In GPA patients, the mean TBRmax of the aorta was significantly higher in patients with previous renal involvement [2.01 (1.69-2.53)] compared to patients without renal involvement in the past [1.60 (1.51-1.80), p < 0.05]. Interrater reproducibility with a second reader was high (all intraclass correlation coefficients >0.9). CONCLUSION: Patients suffering from GPA show marked aortic FDG uptake.

Asunto(s)

RESUMEN

Tools for evaluation of disease activity in patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) include scoring clinical manifestations, determination of biochemical parameters of inflammation, and obtaining tissue biopsies. These tools, however, are sometimes inconclusive. 2-deoxy-2-[F]-fluoro-D-glucose (FDG) positron emission tomography (PET) scans are commonly used to detect inflammatory or malignant lesions. Our objective is to explore the ability of PET scanning to assess the extent of disease activity in patients with AAV.Consecutive PET scans made between December 2006 and March 2014 in Maastricht (MUMC) and between July 2008 and June 2013 in Brussels (EUH) to assess disease activity in patients with AAV were retrospectively included. Scans were re-examined and quantitatively scored using maximum standard uptake values (SUVmax). PET findings were compared with C-reactive protein (CRP) and ANCA positivity at the time of scanning.Forty-four scans were performed in 33 patients during a period of suspected active disease. All but 2 scans showed PET-positive sites, most commonly the nasopharynx (n = 22) and the lung (n = 22). Forty-one clinically occult lesions were found, including the thyroid gland (n = 4 patients), aorta (n = 8), and bone marrow (n = 7). The amount of hotspots, but not the highest observed SUVmax value, was higher if CRP levels were elevated. Seventeen follow-up scans were made in 13 patients and showed decreased SUVmax values.FDG PET scans in AAV patients with active disease show positive findings in multiple sites of the body even when biochemical parameters are inconclusive, including sites clinically unsuspected and difficult to assess otherwise.

Asunto(s)

RESUMEN

BACKGROUND: Fat tissue, and particularly visceral fat, is known to play a role in low grade systemic inflammation in COPD, and is likely to contribute to the excess cardiovascular comorbidity in COPD. Therefore, we aimed to study (18)FDG-PET-assessed inflammation of the aorta and the (visceral) fat, and evaluate its interrelations and differences in subjects with and without COPD. METHODS: We retrospectively identified 42 patients (71% male, 48% current smokers, mean age 66.6 ± 8.3 years, mean BMI 25.1 ± 4.3 kg/m(2)), who underwent (18)F-FDG-PET/CT for suspected early stage bronchus carcinoma. COPD-diagnosis was based on spirometry and defined as FEV1/FVC < lower limit of normal. Inflammatory status of aortic and fat regions was defined as the average of obtained maximum target-to-background ratios (meanTBRmax). The TBR is the standardized uptake value (SUV) normalized to (18)F-FDG blood pool activity. RESULTS: Compared to controls, patients with COPD (n = 19; 45%) had increased meanTBRmax of both the abdominal aorta (1.31 ± 0.14 vs. 1.49 ± 0.31; p = 0.02) and the abdominal visceral fat (0.28 ± 0.09 vs. 0.38 ± 0.18; p = 0.047), while inflammatory activity of the abdominal subcutaneous fat failed to show statistically significant differences (0.21 ± 0.09 vs. 0.24 ± 0.09; p = 0.345). In all patients, meanTBRmax of abdominal visceral fat was correlated with meanTBRmax of the abdominal aorta, independently of age and BMI (ß = 0.590, p = 0.002). CONCLUSION: Metabolic activity of the abdominal aorta and visceral fat is increased in COPD patients compared to peers. The degree of visceral fat metabolic activity is associated with aortic inflammation. More prospective research is warranted concerning the role of visceral fat in the development of vascular comorbidity in COPD.

Asunto(s)

RESUMEN

BACKGROUND: Sarcoidosis is characterized by a wide range of disease manifestations. In the management and follow-up of sarcoidosis patients, knowledge of extent of disease, activity and severity is crucial. Objectives The aim of this study was to assess the extent, distribution and consistency of inflammatory organ involvement using 18F-FDG PET/CT (PET) in sarcoidosis patients with persistent disabling symptoms. METHODS: Retrospectively, sarcoidosis patients who underwent a PET between 2005 and 2011 (n=158) were included. Clinical data were gathered from medical records and PET scans were evaluated. Positive findings were classified as thoracic and/or extrathoracic. RESULTS :Of the studied PET positive sarcoidosis patients (n=118/158; 75%), 93% had intrathoracic activity (79% mediastinal and 64% pulmonary activity, respectively) and 75% displayed extrathoracic activity (mainly peripheral lymph nodes, bone/bone marrow, and spleen). Hepatic positivity was always accompanied by splenic activity, whereas the majority of patients with parotid gland, splenic or bone/bone marrow activity showed lymph node activity. A substantial number of patients with PET positive pulmonary findings (86%) had signs of respiratory functional impairment. No obvious association between hepatic, splenic or bone/bone marrow activity and their corresponding laboratory abnormalities suggestive of specific organ involvement, was found. CONCLUSIONS: The majority of studied patients appeared to have PET positive findings (75%), of which a high proportion (75%) displayed extrathoracic activity. Hence, PET can be especially useful in the assessment of extent, distribution and consistency of inflammatory activity in sarcoidosis to provide an explanation for persistent disabling symptoms and/or to provide a suitable location for biopsy.

Asunto(s)

RESUMEN

(99m)Tc-dimercaptosuccinic acid [DMSA(III)] and colloidal human serum albumin ((99m)Tc-nanocolloid) are widely used radiopharmaceuticals. Recently, in our institution we encountered image quality problems in DMSA scans after changing the brand of syringes we were using, which triggered us to look into the adsorption properties of syringes from different brands for (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid. We also describe a clinical case in which adsorption of (99m)Tc-DMSA(III) caused inferior imaging quality. DMSA and nanocolloid were labeled with (99m)Tc following manufacturer guidelines. After synthesis, syringes with (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid were stored for 15, 30, 60, and 120 min. We evaluated Luer Lock syringes manufactured by different brands such as Artsana, Henke-Sass-Wolf, B. Braun Medical N.V., CODAN Medizinische Geräte GmbH & Co KG, Becton Dickinson and Company, and Terumo Europe. Adsorption of (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid was acceptably low for all syringes (<13%), except for two brands with (99m)Tc-DMSA(III) adsorption rates of 36 and 30%, respectively, and for one brand with a (99m)Tc-nanocolloid adsorption rate of 27%. Adsorption of (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid reaches critical levels in syringes produced by two brands, potentially causing poor image quality--for example, in DMSA scans using pediatric radiopharmaceutical doses. It is advised to check the compatibility of any radiopharmaceutical with syringes as an integral part of the quality assurance program.

Asunto(s)

RESUMEN

BACKGROUND: Serotonin (5-HT) has long been implied in the pathophysiology of Parkinson's disease (PD). In addition, the 5-HT2A receptor is associated with the regulation of motor function and mood. OBJECTIVE: To assess regional 5-HT2A receptor expression in unmedicated patients with de novo PD. METHODS: Eight de novo, drug naïve patients with PD and eight healthy control subjects underwent a single photon emission computed tomography (SPECT) scan with the highly selective 5-HT2A radioligand 123I-5-I-R91150. RESULTS: In de novo PD patients 5-HT2A receptor binding was significantly reduced in the anterior striatum and the premotor cortex in PD patients compared to controls. In addition, occipital binding was elevated in PD patients. No changes in 5-HT2A receptor binding were found in the prefrontal and parietal cortex. CONCLUSION: In de novo PD patients, 5-HT2A receptor expression is changed in key areas of the basal ganglia-thalamocortical motor circuit and occipital cortex. This suggests altered 5-HT neurotransmission to contribute to development of PD motor and non-motor symptoms.

Asunto(s)

RESUMEN

PURPOSE OF REVIEW: It is important to gain knowledge and understanding about the appropriate use of PET scan in the management of sarcoidosis patients. This means that, in view of the radiation dose and costs, defining appropriate indications for PET scanning in sarcoidosis patients is vital. RECENT FINDINGS: PET has been shown to be a very sensitive technique for the assessment of inflammatory activity in sarcoidosis by detecting and quantifying the degree of inflammatory and granulomatous reactions that occur in the lungs and elsewhere in the body. SUMMARY: PET is not indicated in the standard workup, but can be of great value to complement more routinely used techniques. On the basis of the current findings, PET offers added value in sarcoidosis patients with unexplained persistent disabling symptoms. PET appears especially helpful in those persistently symptomatic patients without serological signs of inflammatory activity, in patients with radiologic signs of fibrosis and in the detection of active cardiac sarcoidosis. The use of PET to assess the extent of disease can uncover a suitable location for biopsy to obtain histological evidence for the diagnosis or to explain the (mainly extrathoracic) symptoms. Furthermore, the detection of unexpected organ involvement may offer prognostic value.

Asunto(s)

RESUMEN

Cannabis use is associated with psychosis, particularly in those with expression of, or vulnerability for, psychotic illness. The biological underpinnings of these differential associations, however, remain largely unknown. We used Positron Emission Tomography and (18)F-fallypride to test the hypothesis that genetic risk for psychosis is expressed by differential induction of dopamine release by Δ(9)-THC (delta-9-tetrahydrocannabinol, the main psychoactive ingredient of cannabis). In a single dynamic PET scanning session, striatal dopamine release after pulmonary administration of Δ(9)-THC was measured in 9 healthy cannabis users (average risk psychotic disorder), 8 patients with psychotic disorder (high risk psychotic disorder) and 7 un-related first-degree relatives (intermediate risk psychotic disorder). PET data were analyzed applying the linear extension of the simplified reference region model (LSRRM), which accounts for time-dependent changes in (18)F-fallypride displacement. Voxel-based statistical maps, representing specific D2/3 binding changes, were computed to localize areas with increased ligand displacement after Δ(9)-THC administration, reflecting dopamine release. While Δ(9)-THC was not associated with dopamine release in the control group, significant ligand displacement induced by Δ(9)-THC in striatal subregions, indicative of dopamine release, was detected in both patients and relatives. This was most pronounced in caudate nucleus. This is the first study to demonstrate differential sensitivity to Δ(9)-THC in terms of increased endogenous dopamine release in individuals at risk for psychosis.

Asunto(s)

RESUMEN

The increased knowledge of molecular changes associated with different neurological disorders calls for the development of novel radioligands. Tiagabine (Gabitril) is an anticonvulsive drug that binds selectively to GABA transporter-1 and thereby inhibits GABA uptake. As radioligands for in-vivo imaging of the GABA transporter are not yet available, we radiolabelled tiagabine and assessed its efficacy for in-vivo imaging of these transporters. Tiagabine was first brominated at its vinylic part, which was then exchanged with I. Next, anaesthetized rats received a bolus injection of [I]iodotiagabine in their tail vein, which was immediately followed by acquisition of planar and high-resolution micro-single-photon emission computed tomography (SPECT) images of the total body with special focus on the brain. Uptake in anatomical regions was assessed by coregistration of micro-SPECT with micro-CT images. Tiagabine labelling with I resulted in 50% yield and 99.7% radiochemical purity. Within 3 h after injection, SPECT demonstrated an increased signal-to-background ratio in the nasal mucosa and/or the Harderian glands but not in the brain. In addition we observed an increased signal-to-background ratio in organs such as the thyroid, heart, liver, kidney and bladder. More than 99% pure I-labelled tiagabine can be obtained and applied in animal micro-SPECT studies. However, this new radioligand is not taken up sufficiently by the brain and therefore cannot be used to successfully detect cerebral GABA transporters.

Asunto(s)

RESUMEN

BACKGROUND: Assessing inflammatory activity is useful in the management of persistent symptomatic sarcoidosis patients. (18)F-FDG PET (PET) has been shown to be a sensitive technique to assess inflammatory activity in sarcoidosis. The aim of this study was to evaluate whether the severity of pulmonary involvement is associated with PET activity in persistent symptomatic sarcoidosis patients. METHODS: Over a 5-year period, relevant clinical data including laboratory and lung function test results were gathered from the medical records of 95 sarcoidosis patients with persistent disabling symptoms who underwent both a PET and HRCT. HRCT scans were classified using a semiquantitative scoring system and PET findings as positive or negative, respectively. RESULTS: PET was positive in 77/95 patients, of whom 56 demonstrated pulmonary PET-positivity. HRCT scores were high (7.1 ± 3.6) in patients with positive pulmonary PET findings (n = 56) compared to patients with negative pulmonary PET findings (n = 39; 3.0 ± 2.9; p < 0.001). DLCO (65 ± 20% predicted) and FVC (85 ± 24% predicted) were low in patients with pulmonary PET-positivity versus those with negative pulmonary PET findings (79 ± 16% predicted; p = 0.001 and 96 ± 22% predicted; p = 0.044, respectively). Interestingly, out of the 26 patients with fibrotic changes, 22 (85%) had positive pulmonary PET findings, of whom 18/22 (82%) showed extrathoracic PET-positive lesions and 16/22 (73%) showed signs of serological inflammation. CONCLUSIONS: The severity of the pulmonary involvement, assessed by HRCT features and lung function parameters, appeared to be associated with PET activity in sarcoidosis. The majority of patients with fibrotic changes demonstrated inflammatory activity at pulmonary and extrathoracic sites.

Asunto(s)

RESUMEN

BACKGROUND: (18)F-FDG PET/CT (PET) is useful in assessing inflammatory activity in sarcoidosis. However, no appropriate indications are available. The aim of this study was to develop a prediction rule that can be used to identify symptomatic sarcoidosis patients who have a high probability of PET-positivity. METHODS: We retrospectively analyzed a cohort of sarcoidosis patients with non organ specific persistent disabling symptoms (n = 95). Results of soluble interleukin-2 receptor (sIL-2R) assessment and high-resolution computed tomography (HRCT) were included in the predefined model. HRCT scans were classified using a semi-quantitative scoring system and PET findings as positive or negative, respectively. A prediction model was derived based on logistic regression analysis. We quantified the model's performance using measures of discrimination and calibration. Finally, we constructed a prediction rule that should be easily applicable in clinical practice. RESULTS: The prediction rule showed good calibration and good overall performance (goodness-of-fit test, p = 0.78, Brier score 20.1%) and discriminated between patients with positive and negative PET findings (area under the receiver-operating characteristic curve, 0.83). If a positive predictive value for the presence of inflammatory activity of ≥90% is considered acceptable for clinical decision-making without referral to PET, PET would be indicated in only 29.5% of the patients. Using a positive predictive value of 98%, about half of the patients (46.3%) would require referral to PET. CONCLUSIONS: The derived and internally validated clinical prediction rule, based on sIL-2R levels and HRCT scoring results, appeared to be useful to identify sarcoidosis patients with a high probability of inflammatory activity. Using this rule may enable a more effective use of PET scan for assessment of inflammatory activity in sarcoidosis.

Asunto(s)

RESUMEN

BACKGROUND: The prevalence of bone involvement in sarcoidosis has been estimated to be 3% to 5%, mostly affecting the phalanges. The aim of this study was to assess the prevalence and distribution pattern of bone and bone marrow involvement as detected by positron emission tomography/computed tomography (PET/CT) in sarcoidosis patients. METHODS: Between June 2006 and September 2010, 122 patients suffering from severe sarcoidosis who underwent a PET/CT and met the inclusion criteria were studied. In 94 (77%) patients, the PET/CT demonstrated positive findings associated with sarcoidosis. The 94 PET/CTs were screened for the presence of bone/bone marrow localizations. Additionally, low-dose CT scans were screened for other causes of increased bone uptake. Relevant clinical data were gathered retrospectively. RESULTS: Evidence for bone/bone marrow localizations was found in 34% of the 94 patients with PET/CT-positive findings. Of these patients, 60% showed obvious focal bone lesions at various localizations: axial skeleton (47%), pelvis (40%), extremities (34%), and skull (2%). In 40% of patients, diffuse increased uptake in both axial and peripheral bone marrow, without focal lesions, was found. Both diffuse and focal uptake were seen in 34%, whereas only focal lesions were observed in 25%. In all but 2 (6%) patients, no bone abnormalities on low-dose CT were found. CONCLUSIONS: More than one-third of PET/CT-positive sarcoidosis patients had osseous abnormalities on PET/CT. The majority of these lesions (94%) could not be detected on low-dose CT. No single localization of preference was found. These preliminary results stress the value of PET/CT imaging in the assessment of bone/bone marrow involvement in sarcoidosis patients.

Asunto(s)

Asunto(s)

RESUMEN

PURPOSE: because of the increasing prevalence of diabetes, complications of diabetes will also become more prevalent. The pathophysiology of Charcot neuro-osteoarthropathy (Charcot disease) as a complication of diabetes is still enigmatic. As a consequence, the optimal diagnostic, follow-up, and therapeutic strategies are unclear. To obtain more insight into the relation between bony abnormalities and the (concurrent) inflammatory response in acute Charcot disease, thereby creating more insight into the pathophysiology of this disease, we performed F-18 FDG PET/CT scanning. RESEARCH DESIGN AND METHODS: We performed F-18 FDG PET/CT and Tc-99m bone scintigraphy in 10 patients with Charcot disease. Bony abnormalities on CT-scan and areas of increased uptake on F-18 FDG PET and Tc-99m bone scintigraphy were assessed independently. Subsequently, fused PET/CT images were evaluated for number and location of PET lesions. RESULTS: nine patients had increased uptake of F-18 FDG, indicating inflammation, in 25 areas of soft tissue and/or bone without concurrent bony abnormalities on CT. CONCLUSIONS: presented F-18 FDG PET/CT data may indicate an inflammatory origin of Charcot disease, with secondary bone resorption, possibly due to decreased inhibitory neurogenic inflammatory responses as a result of small fiber neuropathy. If these findings can be confirmed in future studies, F-18 FDG PET/CT scanning may be added to the diagnostic arsenal in Charcot disease, and anti-inflammatory drugs may be added to the therapeutic arsenal.

Asunto(s)

RESUMEN

PURPOSE OF REVIEW: Nuclear medicine techniques have the capacity to investigate neuronal dysfunction at the synapse level. For instance, metaiodobenzylguanidine (MIBG) shows a similar uptake, storage and release as norepinephrine. Intravenously injected radiolabeled MIBG is able to reflect neuronal damage induced by inflammation and tumors. The purpose of this review is to evaluate the results and the limitation of these neuronal imaging techniques in patients with pulmonary and cardiac diseases and to give an opinion about the clinical value of these new diagnostic tools. RECENT FINDINGS: MIBG neuronal images of the lungs and heart can show heterogeneous distribution patterns with either diminished or increased MIBG uptake and/or washout. These changes reflect changes in endothelial integrity, neuronal innervations and clearance of norepinephrine. Interest in the role of neurotransmitter involvement and the relation between endothelial cell integrity and vascularization is growing and of utmost importance to understand the effect on pathophysiology of diseases. SUMMARY: At this moment, there is no added clinical value to routinely use MIBG scanning of the lungs and the heart. This is partly due to the many unresolved questions such as what actually happens and which factors influence MIBG uptake and washout under normal physiological circumstances. But the technique, if standardized and when dynamic time acquisition is performed with the latest equipment, such as PET and single photon emission computed tomography-computed tomography (SPECT-CT), has a tremendous potential. It can unravel upto now unknown relationships between innervation, vascularization and endothelial integrity. Other diagnostic tools such as MRI and CT do not have this capacity, so the future looks bright for these new neuronal imaging techniques.

Asunto(s)