PMR is a common inflammatory rheumatic disease. Although its clinical characteristics are fully recognized, no specific test for its diagnosis has been established to date. Several studies have ...described a wide variety of diseases that present with polymyalgic symptoms. A .sup.18 FDG-PET/CT scan could help to deal with these differential diagnoses. The goal of our study is to describe the findings of the .sup.18 FDG-PET/CT scan in a cohort of PMR patients and to detail how the .sup.18 FDG-PET/CT scan improves accuracy when diagnosing other underlying conditions. This cross-sectional study enrolled patients with a diagnosis of PMR who underwent to a .sup.18 FDG-PET/CT scan to rule out other diagnosis. The .sup.18 FDG-PET/CT scan was performed either following clinical criteria at the onset of clinical symptoms or when the patient became PMR steroid resistant. Patients' demographic, clinical and analytical data at the moment of the .sup.18 FDG-PET/CT scan were recorded. The final diagnosis was confirmed according to clinical judgement. A total of 103 patients with PMR were included. In 49.51% of patients, the .sup.18 FDG-PET/CT scan was ordered to study resistance to steroid therapy. The final diagnoses of patients were PMR in 70.9% patients, large vessel vasculitis in 15.5%, neoplasms 4.8% and another diagnosis in the rest. The .sup.18 FDG-PET/CT scan is a very useful technique for the study of Polymyalgia Rheumatica, not only to help in the diagnostic process, but also due to its role in the identification of a variety of PMR-like patrons.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective
To determine the cutoffs that optimized the agreement between 18F‐Florbetapir positron emission tomography (PET) and Aβ1‐42, Aβ1‐40, tTau, pTau and their ratios measured in cerebrospinal ...fluid (CSF) on the LUMIPULSE G600II instrument, we quantified the levels of these four biomarkers in 94 CSF samples from participants of the Sant Pau Initiative on Neurodegeneration (SPIN cohort) using the Lumipulse G System with available 18F‐Florbetapir imaging.
Methods
Participants had mild cognitive impairment (n = 35), AD dementia (n = 12), other dementias or neurodegenerative diseases (n = 41), or were cognitively normal controls (n = 6). Levels of Aβ1‐42 were standardized to certified reference material. Amyloid scans were assessed visually and through automated quantification. We determined the cutoffs of CSF biomarkers that optimized their agreement with 18F‐Florbetapir PET and evaluated concordance between markers of the amyloid category.
Results
Aβ1‐42, tTau and pTau (but not Aβ1‐40) and the ratios with Aβ1‐42 had good diagnostic agreement with 18F‐Florbetapir PET. As a marker of amyloid pathology, the Aβ1‐42/Aβ1‐40 ratio had higher agreement and better correlation with amyloid PET than Aβ1‐42 alone.
Interpretation
CSF biomarkers measured with the Lumipulse G System show good agreement with amyloid imaging in a clinical setting with heterogeneous presentations of neurological disorders. Combination of Aβ1‐42 with Aβ1‐40 increases the agreement between markers of amyloid pathology.
Objective
The purpose of this study was to compare image quality and lesion detection capability between a digital and an analog PET/CT system in oncological patients.
Materials and methods
One ...hundred oncological patients (62 men, 38 women; mean age of 65 ± 12 years) were prospectively included from January–June 2018. All patients, who accepted to be scanned by two systems, consecutively underwent a single day, dual imaging protocol (digital and analog PET/CT). Three nuclear medicine physicians evaluated image quality using a 4-point scale (−1, poor; 0, fair; 1, good; 2, excellent) and detection capability by counting the number of lesions with increased radiotracer uptake. Differences were considered significant for a
p
value <0.05.
Results
Improved image quality in the digital over the analog system was observed in 54% of the patients (
p
= 0.05, 95% CI, 44.2–63.5). The percentage of interrater concordance in lesion detection capability between the digital and analog systems was 97%, with an interrater measure agreement of κ = 0.901 (
p
< 0.0001). Although there was no significant difference in the total number of lesions detected by the two systems (digital: 5.03 ± 10.6 vs. analog: 4.53 ± 10.29;
p
= 0.7), the digital system detected more lesions in 22 of 83 of PET+ patients (26.5%) (
p
= 0.05, 95% CI, 17.9–36.7). In these 22 patients, all lesions detected by the digital PET/CT (and not by the analog PET/CT) were < 10 mm.
Conclusion
Digital PET/CT offers improved image quality and lesion detection capability over the analog PET/CT in oncological patients, and even better for sub-centimeter lesions.
Purpose
The purpose of this study was to assess whether digital photon counting technology in digital PET/CT influences the quantification of SUVmax in target lesions and regions of reference ...compared to analog PET/CT before an interchangeable use of either system in follow up studies.
Methods
From January to June of 2018, 100 oncological patients underwent successive PET/CT imaging with digital and analog systems in the same day. Fifty-eight patients underwent analog imaging first and digital imaging thereafter, and 42 patients the other way round. SUVmax was measured in reference regions (liver and mediastinal blood pool) and in the most metabolically active target lesion in each patient. According to the sequence order of PET/CT acquisition, two groups of SUVmax values were obtained, i.e. group 1: analog PET/CT performed first; group 2: digital PET/CT performed first.
Results
Mean SUVmax in the total sample (regardless of the order of PET/CT acquisition) in the target lesions with the analog PET/CT was 8.14 ± 6.39 and the digital 9.97 ± 6.14 (
P
= 0.000). Total mean SUVmax in the liver with the analog was 4.39 ± 2.59 and the digital 4.46 ± 3.18 (
P
= 0.477). Total mean SUVmax in the mediastinal blood pool with the analog was 2.30 ± 0.67 and the digital 2.54 ± 0.74 (
P
= 0.000).
Group 1: mean SUVmax in the target lesions with the analog system was 6.64 ± 4.71 and the digital 9.48 ± 5.60 (
P
= 0.000). Mean liver SUVmax with the analog was 4.70 ± 2.90 and the digital 4.80 ± 3.72 (
P
= 0.088). Mediastinal blood pool SUVmax with the analog was 2.33 ± 0.66 and the digital 2.45 ± 0.73 (
P
= 0.041).
Group 2: mean SUVmax in target lesions with the digital system was 10.63 ± 6.88 and the analog 10.16 ± 7.76 (
P
= 0.046). Mean liver SUVmax with the digital was 3.99 ± 2.20 and the analog 3.96 ± 2.04 (
P
= 0.218). Mediastinal blood pool SUVmax with the digital was 2.66 ± 0.75 and the analog 2.27 ± 0.68 (
P
= 0.000).
No significant differences between both time delays were found.
Conclusions
Improved photon counting technology in the digital PET/CT, and the effect of delayed increased uptake and retention significantly increases SUVmax values. This has to be taken into account before interchangeable use of either system in follow up studies.
Purpose
To assess metabolic changes in cerebral
18
F-FDG PET/CT in premanifest and manifest Huntington’s disease (HD) subjects compared to a control group and to correlate
18
F-FDG uptake patterns ...with different disease stages.
Materials and methods
Thirty-three gene-expanded carriers (Eight males; mean age: 43 y/o; CAG > 39) were prospectively included. Based on the Unified Huntington’s Disease Rating Scale Total Motor Score and the Total Functional Capacity, subjects were classified as premanifest (preHD = 15) and manifest (mHD = 18). Estimated time disease-onset was calculated using the Langbehn formula, which allowed classifying preHD as far-to (preHD-A) and close-to (PreHD-B) disease-onset. Eighteen properly matched participants were included as a control group (CG). All subjects underwent brain
18
F-FDG PET/CT and MRI.
18
F-FDG PET/CT were initially assessed by two nuclear medicine physicians identifying qualitative metabolic changes in the striatum. Quantitative analysis was performed using SPM8 with gray matter atrophy correction using the BPM toolbox.
Results
Visual analysis showed a marked striatal hypometabolism in mHD. A normal striatal distribution of
18
F-FDG uptake was observed for most of the preHD subjects. Quantitative analysis showed a significant striatal hypometabolism in mHD subjects compared to CG (
p
< 0.001 uncorrected,
k
= 50 voxels). In both preHD groups we observed a significant striatal hypometabolism with respect to CG (
p
< 0.001 uncorrected,
k
= 50 voxels). In mHD subjects we observed a significant striatal hypometabolism with respect to both preHD groups (
p
< 0.001 uncorrected,
k
= 50 voxels).
Conclusion
18
F-FDG PET/CT might be a helpful tool to identify patterns of glucose metabolism in the striatum across the stages of HD and might be relevant in assessing the clinical status of gene-expanded HD carriers due to the fact that dysfunctional glucose metabolism begins at early preHD stages of the disease.
18
F-FDG PET/CT appears as a promising method to monitor the response to disease-modifying therapies even if applied in premanifest subjects.
Positron emission tomography (PET) is a functional imaging technique introduced in 1970s. Over the years, PET was used alone but is in 2000 when the first hybrid PET/CT device was clinically ...introduced. Since then, PET has continuously been marked by technological developments, being the most recent one the introduction of silicon photomultipliers (SiPMs) as an alternative to standard photomultiplier tubes used in analog PET/CT systems. SiPMs, the basis for the so called digital PET/CT systems, are smaller than standard photomultiplier tubes (enabling higher spatial resolution) and provide up to 100% coverage of the crystal area, as well as high sensitivity, low noise, and fast timing resolution. SiPMs in combination with optimized acquisition and reconstruction parameters improve the localization of the annihilation events, provide high definition PET images, and offer higher sensitivity and higher diagnostic performance. This article summarizes the evidence about the superior performance of the state of the art digital PET and highlights its potential clinical implications. Digital PET opens new perspectives in the quantification and characterization of small lesions, which are mostly undetectable using analog PET systems, potentially changing patient management and improving outcomes in oncological and non-oncological diseases. Moreover, digital PET offers the possibility to reduce radiation dose and scan times which may facilitate the implementation of PET to address unmet clinical needs.
ABSTRACTDementia with Lewy bodies (DLB) is the most common cause of dementia after Alzheimer disease. It is often underdiagnosed because of the overlapping with Alzheimer disease symptoms. We report ...the F-FDG and F-florbetapir dynamic PET images (early and delay phases) of an 83-year-old woman with cognitive impairment associated with visual hallucinations and parkinsonism due to probable DLB. This image highlights that the early phases of F-florbetapir may reflect regional cerebral perfusion with a pattern very similar to that of regional glucose metabolism in DLB.
Regression of Cardiac Lymphoma With Chemotherapy Fernández-Martínez, Juan; Descalzo-Buey, Martín; Menduiña-Gallego, Irene ...
JACC. Case reports,
01/2024, Letnik:
29, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A patient was admitted for chest pain with electrocardiographic changes, and cardiac magnetic resonance showed focal myocardial hypertrophy secondary to edema. Combined positron emission tomography ...and computed tomography corroborated foci of myocardial hypermetabolism, as well as multiple adenopathies consistent with lymphoma in the biopsy. Hypertrophy and edema regressed with chemotherapy.
Objective
To compare detectability of hyperfunctioning parathyroid tissue (HPT) by digital and analog 18F-fluorocholine PET/CT in patients with primary hyperparathyroidism and negative/inconclusive ...99mTc-MIBI scintigraphy-SPECT/CT.
Materials and methods
Thirty-three patients with primary hyperparathyroidism and negative/inconclusive 99mTc-MIBI scintigraphy-SPECT/CT were prospectively included. All patients accepted to be scanned by digital and analog PET/CT in the same imaging session after a single injection of 18F-fluorocholine. Three nuclear medicine physicians evaluated the digital and analog PET/CT datasets to assess the detection rate of HPT. Maximum standard uptake values (SUVmax) of HPT and locoregional lymph nodes were measured in both systems.
Results
HPT was detected in 30/33 patients by the digital system, whereas it was detected in 22/33 patients by the analog system (
p
< 0.01). Moreover, in 21 of these 33 patients, both systems detected one focal 18F-fluorocholine uptake, and in one patient the digital system detected two foci. Histopathology demonstrated HPT in 32 patients and it was inconclusive in one patient. The digital PET/CT detected HPT in 29 of the 32 patients, and the analog system in 22 of the 32 (
p
< 0.01). All HPT suspected lesions resected and detected only by the digital system (
n
= 8) were < 10 mm (7.5 ± 1.3 mm), while those detected by both systems (
n
= 22) were > 10 mm (13 ± 3.8 mm). SUVmax of HPT lesions was significantly higher than SUVmax of locoregional lymph node independently of the PET/CT system used (4.5 ± 1.9 vs. 2.9 ± 1.3,
p
< 0.0001).
Conclusions
Digital PET/CT offers superior performance over analog system in patients with suspected HPT and previous negative/inconclusive imaging examinations, particularly in sub-centimeter lesions. SUVmax can help in the differentiation between HTP and locoregional lymph nodes.
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