Publications by authors named "Abass Alavi"

700 Publications

Emerging role of 18F-FDG PET/CT in Castleman disease: a review.

Insights Imaging 2021 Mar 11;12(1):35. Epub 2021 Mar 11.

Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997.
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http://dx.doi.org/10.1186/s13244-021-00963-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7952491PMC
March 2021

An understanding of the atherosclerotic molecular calcific heterogeneity between coronary, upper limb, abdominal, and lower extremity arteries as assessed by NaF PET/CT.

Am J Nucl Med Mol Imaging 2021 15;11(1):40-45. Epub 2021 Feb 15.

Department of Radiology, University of Pennsylvania Philadelphia, United States.

We aimed to quantify the heterogeneity of atherosclerosis in upper and lower limb vessels using F-NaF-PET/CT and compare calcification in coronary arteries to peripheral arteries. 68 healthy controls (42±13.5 years, 35 females, 33 males) and 40 patients at-risk for cardiovascular disease (55±11.9 years, 22 females, 18 males) underwent PET/CT imaging 90 minutes after the injection of F-NaF (2.2 Mbq/Kg). The following arteries were examined: coronary artery (CA), ascending aorta (AS), arch of aorta (AR), descending aorta (DA), abdominal aorta (AA), common iliac artery (CIA), external iliac artery (EIA), femoral artery (FA), popliteal artery (PA). Average SUVmean (aSUVmean) was calculated for each arterial segment. A paired t-test compared the aSUVmean between CA vs. AS, AR, DA, AA, CIA, EIA, FA, and PA. CA aSUVmean in the at-risk group was higher than the healthy control group (0.74±0.04 vs. 0.67±0.04, P=0.03). Furthermore, the F-NaF uptake in the CA was lower than in AS, AR, DA, AA, CIA, EIA, FA, and PA in both healthy (all P≤0.0001) and at-risk (all P≤0.0001). Higher F-NaF uptake in non-cardiac arteries in both healthy controls and patients at-risk suggests CA calcification is a late manifestation of atherosclerosis. This differential expression of atherosclerosis is likely due to interaction of hemodynamic parameters specific to the vascular bed and systemic factors related to the development of atherosclerosis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7936246PMC
February 2021

F-FDG-PET/CT in the assessment of atherosclerosis in lung cancer.

Am J Nucl Med Mol Imaging 2021 15;11(1):1-9. Epub 2021 Feb 15.

Department of Radiology, University of Pennsylvania Philadelphia, PA, USA.

The aim of this study was to assess the risk of atherosclerosis in patients with lung cancer compared to patients with extrapulmonary malignancies using F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). We hypothesized that patients with lung cancer would demonstrate increased FDG uptake in the thoracic aorta compared to patients with extrapulmonary cancers. Thirty-four lung cancer patients (21 male, 13 female, 64.1 ± 12.9 yo) were retrospectively compared to seventy-eight patients with extrapulmonary malignancies (46 male, 32 female, 59.6 ± 12.8 yo). Average maximum standardized uptake value (avgSUVmax) and maximum target-to-blood pool ratio (TBRmax) were measured by mapping regions of interest of the ascending aorta, aortic arch, and descending aorta. Two-tailed Student's t-test was used to assess the differences in avgSUVmax and TBRmax between the two groups and between smokers and non-smokers. Age and gender distribution between the groups were not statistically different. AvgSUVmax and TBRmax were statistically significant increase in lung cancer patients compared to extrapulmonary cancer patients in the ascending aorta, aortic arch, and descending aorta, suggesting a lung cancer-associated increased risk of atherosclerosis development. AvgSUVmax was not significantly different between smokers and non-smokers in all sections of the thoracic aorta. Moving forward, large, prospective studies that directly compare PET data between different malignancies of different stages will help determine the role of FDG-PET/CT in assessing paraneoplastic vascular disease.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7936247PMC
February 2021

Alterations in cerebral glucose metabolism as measured by 18F-fluorodeoxyglucose-PET in patients with persistent postconcussion syndrome.

Nucl Med Commun 2021 Mar 3. Epub 2021 Mar 3.

Department of Integrative Medicine and Nutritional Sciences, Marcus Institute of Integrative Health, Thomas Jefferson University, Philadelphia, Pennsylvania Partners Neurology, Massachusetts General Hospital & Brigham and Women's Hospital, Harvard Medical School, Boston Department of Radiology, University of Pennsylvania Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.

Background: Many patients who have traumatic brain injury experience a wide range of psychiatric and neurological symptoms (including impairment in functional status, cognition, and mood), and if persistent are referred to as persistent postconcussion syndrome (PCS). To our knowledge, this is the first study to broadly evaluate metabolic dysregulation in a heterogenous patient population meeting the criteria for PCS.

Methods: A total of 64 PCS patients and 37 healthy controls underwent 18F-fluorodeoxyglucose-PET (18F-FDG-PET) scanning, and 70 brain structures (including left and right structures where appropriate) were analyzed in each subject.

Results: Compared to the brains of healthy controls, those of PCS patients demonstrated 15 hypermetabolic and 23 hypometabolic regions. Metabolic changes in the brains of PCS patients were subsequently correlated with various indices of symptom severity, mood, and physical/cognitive function. Among PCS patients, increased metabolism in the right cingulate gyrus correlated with the severity of postconcussion symptoms. Conversely, increased metabolism in the left temporal lobe was associated with both improved mood and measures of adaptability/rehabilitation. Furthermore, increased metabolism in the bilateral orbitofrontal regions correlated with improved working memory.

Conclusions: Overall, these findings suggest a complex pattern of cerebral metabolism in PCS patients, with a mixture of hypometabolic and hypermetabolic regions that correlate with various symptoms, highlighting both potential pathological and compensatory mechanisms in PCS. The findings also suggest that FDG PET is useful for providing neurophysiological information in the evaluation of patients with PCS and may help guide future targeted therapies.
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http://dx.doi.org/10.1097/MNM.0000000000001397DOI Listing
March 2021

PET-based Novel Imaging Techniques with Recently Introduced Radiotracers.

PET Clin 2021 Apr;16(2):xv-xvi

Division of Nuclear Medicine, Department of Radiology, University of Pennsylvania, School of Medicine, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Electronic address:

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http://dx.doi.org/10.1016/j.cpet.2021.01.001DOI Listing
April 2021

Tau Imaging in Head Injury.

PET Clin 2021 Apr;16(2):249-260

Division of Radiology and Nuclear Medicine, Oslo University Hospital, Sognsvannsveien 20, Oslo 0372, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Problemveien 7, Oslo 0315, Norway. Electronic address:

Tau proteins play a significant role in a variety of degenerative neurologic conditions. Postmortem neuropathology studies of victims of repeat and severe head trauma have defined a unique spatial expression of neurologic tauopathies in these individuals, known as chronic traumatic encephalopathy. Established and newly developed radiotracers are now being applied to head injury populations with the intent of diagnosis and disease monitoring. This review assesses the role of tau in head injury, the state of tau radiotracer development, and the potential clinical value of tau-PET as derived from head injury studies.
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http://dx.doi.org/10.1016/j.cpet.2020.12.009DOI Listing
April 2021

Novel Musculoskeletal and Orthopedic Applications of F-Sodium Fluoride PET.

PET Clin 2021 Apr 12;16(2):295-311. Epub 2021 Feb 12.

Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA; Division of Radiology and Nuclear Medicine, Oslo University Hospital, Sognsvannsveien 20, Oslo 0372, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Problemveien 7, Oslo 0315, Norway. Electronic address:

PET imaging with F-sodium fluoride (NaF), combined with computed tomography or magnetic resonance, is a sensitive method of assessing bone turnover. Although NaF-PET is gaining popularity in detecting prostate cancer metastases to bone marrow, osseous changes represent secondary effects of cancer cell growth. PET tracers more appropriate for assessing prostate cancer metastases directly portray malignant activity and include F-fluciclovine and prostatic specific membrane antigen ligands. Recent studies investigating NaF-PET suggest utility in the assessment of benign musculoskeletal disorders. Emerging applications in assessing traumatic injuries, joint disease, back pain, orthopedic complications, and metabolic bone disease are discussed.
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http://dx.doi.org/10.1016/j.cpet.2020.12.006DOI Listing
April 2021

Non-F-FDG/F-NaF Radiotracers Proposed for the Diagnosis and Management of Diseases of the Heart and Vasculature.

PET Clin 2021 Apr 12;16(2):273-284. Epub 2021 Feb 12.

Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Electronic address:

F-fluorodeoxyglucose (F-FDG) and F-sodium fluoride (F-NaF) are front-runners in PET. However, these tracers have limitations in the imaging of diseases in the heart. A multitude of other radiotracers have been identified as potentially useful PET agents in the identification of cardiovascular disease. This critical review examines recent studies with the use of non-F-FDG/F-NaF radiotracers in the identification and surveillance of cardiovascular diseases. We highlight the need for further investigation into alternative PET radiotracers to demonstrate their clinical value in the management of these pathologies.
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http://dx.doi.org/10.1016/j.cpet.2020.12.005DOI Listing
April 2021

A Critical Review of PET Tracers Used for Brain Tumor Imaging.

PET Clin 2021 Apr 13;16(2):219-231. Epub 2021 Feb 13.

Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Electronic address:

The brain is a common site for metastases as well as primary tumors. Although evaluation of these malignancies with contrast-enhanced MR imaging defines current clinical practice, F-fluorodeoxyglucose (FDG)-PET has shown considerable utility in this area. In addition, many other tracers targeting various aspects of tumor biology have been developed and tested. This article discusses recent developments in PET imaging and the anticipated role of FDG and other tracers in the assessment of brain tumors.
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http://dx.doi.org/10.1016/j.cpet.2020.12.004DOI Listing
April 2021

Achievements and beyond: Scientific trajectory of Professor Mohammad A. Rafi.

Bioimpacts 2021 7;11(1):1-4. Epub 2020 Dec 7.

Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.

This biography highlights the scientific trajectory of Professor Mohammad A. Rafi, Ph.D., who, in particular, has greatly advanced the field of neurodegenerative disorders during his long and successful tenure at Jefferson Medical College, Thomas Jefferson University. This Editorial recognizes, above all, Professor Rafi's significant contributions to the study of lysosomal storage disorders as they relate to Krabbe Disease.
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http://dx.doi.org/10.34172/bi.2021.01DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7803920PMC
December 2020

The critical role of FDG-PET/CT imaging in assessing systemic manifestations of COVID-19 infection.

Eur J Nucl Med Mol Imaging 2021 Apr;48(4):956-962

Keck School of Medicine, University of Southern California (USC), Los Angeles, CA, USA.

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http://dx.doi.org/10.1007/s00259-020-05148-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7791152PMC
April 2021

Assessment of atherosclerosis in multiple myeloma and smoldering myeloma patients using F- sodium fluoride PET/CT.

J Nucl Cardiol 2021 Jan 3. Epub 2021 Jan 3.

Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA.

Background: To compare the NaF uptake in the thoracic aorta and whole heart, as an early indicator of atherosclerosis, in multiple myeloma (MM) and smoldering multiple myeloma (SMM) patients with a healthy control (HC) group.

Methods: Forty-four untreated myeloma patients (35 MM and nine SMM) and twenty-six age and gender-matched HC subjects were collected. Each individual's NaF uptake in three parts of the aorta (AA: ascending aorta, AR: aortic arch, DA: descending aorta) and the whole heart was segmented. Average global standardized uptake value means were derived by sum of the product of each slice area divided by the sum of those slice areas. Results were reported as target to background ratio (TBR).

Results: There was a significant difference between the NaF uptake in the thoracic aorta of myeloma and HC groups [AA (myeloma = 1.82 ± 0.21, HC = 1.24 ± 0.02), AR (myeloma = 1.71 ± 0.19, HC = 1.28 ± 0.03) and DA (myeloma = 1.96 ± 0.28, HC = 1.38 ± 0.03); P-values < 0.001]. The difference in the whole heart NaF uptake between two groups was also significant (P < 0.001).

Conclusions: We observed a higher uptake of NaF in the thoracic aorta and whole heart of myeloma patients in comparison to the matched control group.
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http://dx.doi.org/10.1007/s12350-020-02446-0DOI Listing
January 2021

Association between atherosclerotic cardiovascular disease risk score estimated by pooled cohort equation and coronary plaque burden as assessed by NaF-PET/CT.

Am J Nucl Med Mol Imaging 2020 15;10(6):312-318. Epub 2020 Dec 15.

Department of Radiology, University of Pennsylvania Philadelphia, PA, USA.

Pooled Cohort Equations (PCE) combines metabolic and non-metabolic parameters to predict the 10-year risk of atherosclerotic cardiovascular disease (ASCVD). Therefore, we hypothesize that ASCVD risk score is correlated to global cardiac microcalcification, as assessed by F-sodium fluoride-positron emission tomography/computed tomography (NaF-PET/CT). Sixty-one individuals (53.4±8.9 years, 32 females, 100% Caucasian) without known ASCVD underwent NaF-PET/CT imaging. Global cardiac average SUVmean (aSUVmean), also known as the Alavi-Carlsen Calcification Score, was calculated across manually defined regions of interest on each axial slice for each individual. The 10-year ASCVD risk score was determined for each individual using the PCE as per ACC/AHA guidelines, and then individuals were categorized into low-, borderline-, intermediate-, and high-risk groups based on their score. Linear regression analysis was applied to compare each individual's ASCVD score and aSUVmean. Global cardiac aSUVmean stratified by groups estimated by 10-year ASCVD risk score were 0.67±0.09 for low risk (n=32), 0.70±0.11 for borderline risk (n=10), 0.72±0.10 for intermediate risk (n=17), and 0.78±0.10 for high risk (n=2). ASCVD risk score was significantly correlated to aSUVmean (r=0.27, P=0.03). This is among the first studies to compare ASCVD risk scores to cardiac plaque burden as assessed by NaF-PET/CT. Large, prospective studies are needed to further investigate the potential of NaF uptake in ASCVD.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724277PMC
December 2020

Utilization of NaF-PET/CT in assessing global cardiovascular calcification using CHADS and CHADS-VASc scoring systems in high risk individuals for cardiovascular disease.

Am J Nucl Med Mol Imaging 2020 15;10(6):293-300. Epub 2020 Dec 15.

Department of Radiology, University of Pennsylvania Philadelphia, United States.

CHADS and CHADS-VASc scores are used to estimate the risk of strokes in patients with atrial fibrillation. We sought to determine the global quantification of cardiovascular molecular calcification in high risk individuals by NaF-PET/CT and compare it with CHADS and CHADS-VASc scores. We identified 40 high risk individuals for cardiovascular disease from the Cardiovascular Molecular Calcification Assessed by F-NaF PET CT (CAMONA) trial and calculated CHADS and CHADS-VASc scores for each. Ninety minutes after NaF injection (2.2 Mbq/kg), PET/CT imaging was performed. CT imaging was done for attenuation correction and anatomic correlation. The global cardiac uptake was calculated from regions of interest manually drawn on axial PET/CT images made in OsirixMD. Global cardiac average SUVmean (aSUVmean) values were calculated, and linear regression analysis was employed for statistical purposes. Subjects had mean age of 55 ± 11.9 SD years, (Range: 23-73 years), female 55%. The sample consisted of subjects with a mean aSUVmax of 2.9 ± 1.4, aSUVmean was 0.8 ± 0.2, CHADS 0.9 ± 0.6 (Range: 0-3), CHADS-VASc 1.8 ± 1.3 (Range: 0-5). Based on the linear regression models, we found a direct correlation between global cardiac aSUVmean and CHADS score (r=0.58, P≤0.0001) and also between global cardiac aSUVmean and CHADS-VASc (r=0.37, P=0.01). Based on the results of our study we conclude that patients with a higher CHADS and CHADS-VASc scores had a higher atherosclerotic burden and could be at greater risk of cardiovascular events. These scoring systems can help with risk stratification for predicting future adverse atherosclerotic events.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724281PMC
December 2020

Comparison of atherosclerotic burden in non-lower extremity arteries in patients with and without peripheral artery disease using F-NaF-PET/CT imaging.

Am J Nucl Med Mol Imaging 2020 15;10(6):272-278. Epub 2020 Dec 15.

Department of Radiology, University of Pennsylvania Philadelphia, United States.

Atherosclerosis is the most common cause of peripheral artery disease (PAD). We compared the atherosclerotic burden in non-lower extremity arteries in patients with and without PAD using F-sodium fluoride (NaF)-PET/CT. We identified five individuals (61.8±6.6 years, one male, four females) with PAD and matched to five individuals without PAD based on age and gender from the unfavorable cardiovascular risk profile group of the CAMONA trial (60±7.2 years, one male, four females). Individuals underwent PET/CT imaging 90 minutes after the injection of NaF (2.2 Mbq/Kg). CT imaging was conducted to account for attenuation correction and anatomic referencing. The NaF uptake was measured by manually defining regions of interest on each axial slice on the following arteries: coronary artery (CA), carotid artery (CR), ascending aorta (AS), arch of aorta (AR), descending aorta (DA), and abdominal aorta (AA). Average SUVmean (aSUVmean) was calculated for each segment. Wilcoxon's signed rank test was used for statistical analysis. The total aSUVmean was higher in the PAD group compared to the non-PAD group (6.54±0.9 vs. 5.03±0.45, P=0.043). Comparison revealed higher NaF uptake in CR, AS, AR, and DA in the PAD group compared to the non-PAD group (0.93±0.25 vs. 0.54±0.14, P=0.01; 1.28±0.20 vs. 0.86±1.19, P<0.01; 1.18±0.17 vs. 0.90±0.19, P=0.03; 1.32±0.24 vs. 0.91±0.15, P=0.01). The NaF uptake in CA and AA was similar between the two groups (0.77±0.04 vs. 0.71±0.05, P=0.11; 1.07±0.28 vs. 1.12±0.30, P=0.82). We found individuals with PAD had higher atherosclerotic burden in the carotid arteries and thoracic aorta compared to non-PAD subjects.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724274PMC
December 2020

Global brain glucose uptake on 18F-FDG-PET/CT is influenced by chronic cardiovascular risk.

Nucl Med Commun 2021 Apr;42(4):444-450

Department of Radiology, Hospital of the University of Pennsylvania.

Purpose: The goal of this study was to assess global cerebral glucose uptake in subjects with known cardiovascular risk factors by employing a quantitative 18F-fluorodeoxyglucose-PET/computed tomography (FDG-PET/CT) technique. We hypothesized that at-risk subjects would demonstrate decreased global brain glucose uptake compared to healthy controls.

Methods: We compared 35 healthy male controls and 14 male subjects at increased risk for cardiovascular disease (CVD) as assessed by the systematic coronary risk evaluation (SCORE) tool. All subjects were grouped into two age-matched cohorts: younger (<50 years) and older (≥50 years). The global standardized uptake value mean (Avg SUVmean) was measured by mapping regions of interest of the entire brain across the supratentorial structures and cerebellum. Wilcoxon's rank-sum test was used to assess the differences in Avg SUVmean between controls and at-risk subjects.

Results: Younger subjects demonstrated higher brain Avg SUVmean than older subjects. In addition, in both age strata, the 10-year risk for fatal CVD according to the SCORE tool was significantly greater in the at-risk groups than in healthy controls (younger: P = 0.0304; older: P = 0.0436). In the younger cohort, at-risk subjects demonstrated significantly lower brain Avg SUVmean than healthy controls (P = 0.0355). In the older cohort, at-risk subjects similarly had lower Avg SUVmean than controls (P = 0.0343).

Conclusions: Global brain glucose uptake appears to be influenced by chronic cardiovascular risk factors. Therefore, FDG-PET/CT may play a role in determining the importance of CVD on brain function and has potential for monitoring the efficacy of various therapeutic interventions.
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http://dx.doi.org/10.1097/MNM.0000000000001349DOI Listing
April 2021

Magnetic resonance imaging-based partial volume-corrected 18F-sodium fluoride positron emission tomography in the femoral neck.

Nucl Med Commun 2021 Apr;42(4):416-420

Department of Radiology, Hospital of the University of Pennsylvania.

Objectives: 18F-sodium fluoride (NaF) is a radiotracer used in PET that reflects calcium metabolism and osteoblastic activity. In this study, we assessed the construct validity of a novel application of global assessment to measure NaF uptake in the femoral neck as a method of evaluating physiologic changes in osteoblastic metabolism with age.

Methods: Whole-body NaF-PET/computed tomography (CT) images and MRI of 24 male patients with a history of nonmetastatic prostate cancer between the ages of 36 and 82 years (67.8 ± 9.6) were analyzed. A region of interest delineated the entire femoral neck on the PET/CT image to determine the mean standardized uptake value (SUVmean). Correction for the partial volume effect was performed by measuring the volume of inert yellow bone marrow by MRI segmentation. Multiple linear regression was used to assess the relationship of uptake with age and body weight.

Results: The SUVmean with and without partial volume correction decreased with respect to age (P = 0.001 and P = 0.002, respectively). Body weight was not significantly related to any measured PET parameter.

Conclusion: Our results support the use of global NaF uptake with magnetic resonance-derived partial volume correction in the femoral neck. Because osteoblastic metabolism is known to decrease with normal aging, the observed decrease in NaF uptake constitutes evidence for convergent validity, indicating that the proposed methodology likely reflects systemic osteoblastic activity. Future studies of this methodology are warranted in other instances of varying osteoblastic activity such as in metabolic bone diseases and for the evaluation of therapy targeting osteoblastic metabolism.
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http://dx.doi.org/10.1097/MNM.0000000000001344DOI Listing
April 2021

Utility of FDG-PET/CT in clinical psoriasis grading: the PET-PASI scoring system.

Am J Nucl Med Mol Imaging 2020 15;10(5):265-271. Epub 2020 Oct 15.

Department of Radiology, Hospital of The University of Pennsylvania Philadelphia, PA, USA.

Psoriatic skin lesions are metabolically active, which makes them candidates for imaging with 18-F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). The aim of our study was to correlate FDG-PET findings with Psoriasis Area and Severity Index (PASI) scores, the most widely-used grading system for psoriasis. Thirty-three subjects and a total of 84 FDG-PET/CT scans from a prospective clinical trial [NCT01553058] with >2 months moderate-to-severe psoriasis were included. Subjects underwent whole-body FDG-PET/CT imaging 60 min after intravenous FDG administration, prior to the start of treatment. Scans were repeated 12 weeks and 52 weeks after baseline scans were conducted and after treatment or placebo administration was initiated. Each subject and scan was graded by our "PET-PASI" scoring system, a qualitative review of multi-plane reconstructions for both attenuation-corrected (AC) and non-attenuation-corrected (NAC) PET images. PASI and PET-PASI scores were correlated using Spearman's rho analysis. Our study demonstrated a significant positive correlation between each subject's corresponding PET-PASI and PASI scores before and during treatment or placebo administration (r=0.53, P<0.001). We also found positive correlations between PET-PASI and PASI scores across different regions of the body (head and neck: r=0.22, upper extremities: r=0.26, trunk: r=0.48, and lower extremities: r=0.58). In conclusion, AC and NAC FDG-PET/CT images may be utilized to evaluate lesions in subjects with moderate-to-severe psoriasis. Our methodology could have future implications in the diagnosis and therapeutic management of psoriasis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675113PMC
October 2020

Correlation of whole-bone marrow dual-time-point F-FDG, as measured by a CT-based method of PET/CT quantification, with response to treatment in newly diagnosed multiple myeloma patients.

Am J Nucl Med Mol Imaging 2020 15;10(5):257-264. Epub 2020 Oct 15.

Department of Radiology, Hospital of The University of Pennsylvania PA, USA.

The practical application of dual-time-point-imaging (DTPI) technique still remains controversial. One of the issues is that current parameters of DTPI quantification suffer from some deficiencies, mainly limited sampling of the diseased sites by confining measurements to specific locations. We aimed to examine the correlation between the percent change from early to delayed scans in whole-bone marrow (WBM) F-FDG uptake, as measured by a CT-based method of PET/CT quantification, and response to treatment in multiple myeloma (MM) patients. Pre-treatment F-FDG-PET/CT scans of 36 newly diagnosed MM patients were collected in a prospective study at 1 h and 3 h post tracer injection (NCT02187731). A threshold algorithm based on bone Hounsfield units on CT was applied to segment and quantify WBM F-FDG uptake. Patients were separated into two treatment groups: high-dose therapy with autologous stem cell transplant (HDT) and non-high dose therapy (non-HDT). The International Response Criteria for MM patients was used to determine each patient's response to treatment. In the HDT group, WBM F-FDG uptake increased significantly in patients that had a poor response to treatment, from a median of 1.31 (IQR: 1.13-1.64) at 1 h to a median of 1.85 (1.45-2.10) at 3 h. The median percent change was 37.77% (IQR: 23.47-46.4), with a range of 6.10-50.73 ( = 0.003). However, no significant change in uptake was observed in patients with a complete response ( = 0.24). The same trend was observed for the non-HDT group. WBM uptake of F-FDG assessed with dual-time-point imaging may have a role in predicting treatment response in MM.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675111PMC
October 2020

Total-Body PET Imaging of Musculoskeletal Disorders.

PET Clin 2021 Jan;16(1):99-117

Department of Radiology, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.

Imaging of musculoskeletal disorders, including arthritis, infection, osteoporosis, sarcopenia, and malignancies, is often limited when using conventional modalities such as radiography, computed tomography (CT), and MR imaging. As a result of recent advances in Positron Emission Tomography (PET) instrumentation, total-body PET/CT offers a longer axial field-of-view, higher geometric sensitivity, and higher spatial resolution compared with standard PET systems. This article discusses the potential applications of total-body PET/CT imaging in the assessment of musculoskeletal disorders.
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http://dx.doi.org/10.1016/j.cpet.2020.09.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684980PMC
January 2021

Imaging Atherosclerosis by PET, With Emphasis on the Role of FDG and NaF as Potential Biomarkers for This Disorder.

Front Physiol 2020 22;11:511391. Epub 2020 Oct 22.

Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, United States.

Molecular imaging has emerged in the past few decades as a novel means to investigate atherosclerosis. From a pathophysiological perspective, atherosclerosis is characterized by microscopic inflammation and microcalcification that precede the characteristic plaque buildup in arterial walls detected by traditional assessment methods, including anatomic imaging modalities. These processes of inflammation and microcalcification are, therefore, prime targets for molecular detection of atherosclerotic disease burden. Imaging with positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose (FDG) and 18F-sodium fluoride (NaF) can non-invasively assess arterial inflammation and microcalcification, respectively. FDG uptake reflects glucose metabolism, which is particularly increased in atherosclerotic plaques retaining macrophages and undergoing hypoxic stress. By contrast, NaF uptake reflects the exchange of hydroxyl groups of hydroxyapatite crystals for fluoride producing fluorapatite, a key biochemical step in calcification of atherosclerotic plaque. Here we review the existing literature on FDG and NaF imaging and their respective values in investigating the progression of atherosclerotic disease. Based on the large volume of data that have been introduced to the literature and discussed in this review, it is clear that PET imaging will have a major role to play in assessing atherosclerosis in the major and coronary arteries. However, it is difficult to draw definitive conclusions on the potential role of FDG in investigating atherosclerosis given the vast number of studies with different designs, image acquisition methods, analyses, and interpretations. Our experience in this domain of research has suggested that NaF may be the tool of choice over FDG in assessing atherosclerosis, especially in the setting of coronary artery disease (CAD). Specifically, global NaF assessment appears to be superior in detecting plaques in tissues with high background FDG activity, such as the coronary arteries.
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http://dx.doi.org/10.3389/fphys.2020.511391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7642524PMC
October 2020

Amyloid Hypothesis: The Emperor's New Clothes?

J Alzheimers Dis 2020 ;78(4):1363-1366

Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.

The lengthy debate on the validity of the amyloid hypothesis and the usefulness of amyloid imaging and anti-amyloid therapeutic interventions in dementia continues unabated, even though none of them have been able to convince the medical world of their correctness and clinical value. There are huge financial interests associated with promoting both, but in spite of the large sums of money in their support, no effective anti-amyloid treatments or diagnostic use of amyloid imaging have emerged. There are solid scientific reasons that explain these negative results, and it is time to move forward to other promising options for the benefit of the patients.
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http://dx.doi.org/10.3233/JAD-200990DOI Listing
January 2020

Assessment of Total-Body Atherosclerosis by PET/Computed Tomography.

PET Clin 2021 Jan 5;16(1):119-128. Epub 2020 Nov 5.

Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce Street, PA 19104, USA.

Atherosclerotic burden has become the focus of cardiovascular risk assessment. PET/computed tomography (CT) imaging with the tracers 18F-fluorodeoxyglucose and 18F-sodium fluoride shows arterial wall inflammation and microcalcification, respectively. Arterial uptake of both tracers is modestly age dependent. 18F-sodium fluoride uptake is consistently associated with risk factors and more easily measured in the heart. Because of extremely high sensitivity, ultrashort acquisition, and minimal radiation to the patient, total-body PET/CT provides unique opportunities for atherosclerosis imaging: disease screening and delayed and repeat imaging with global disease scoring and parametric imaging to better characterize the atherosclerosis of individual patients.
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http://dx.doi.org/10.1016/j.cpet.2020.09.013DOI Listing
January 2021

Emerging Standards and the Hybrid Model for Organizing Scientific Events During and After The COVID-19 Pandemic.

Disaster Med Public Health Prep 2020 Oct 26:1-17. Epub 2020 Oct 26.

Universal Scientific Education and Research Network (USERN), the World.

Since the beginning of 2020, the COVID-19 pandemic has dramatically influenced almost every aspect of human life. Activities requiring human gatherings have either been postponed, cancelled, or held completely virtually. To supplement lack of in-person contact, people have increasingly turned to virtual settings on-line, advantages of which include increased inclusivity and accessibility and reduction of carbon footprint. However, emerging online technologies cannot fully replace, in-person scientific events. In-person meetings are not susceptible to poor internet connectivity problems, and they provide novel opportunities for socialization, creating new collaborations, and sharing ideas. To continue such activities, a hybrid model for scientific events could be a solution offering both in-person and virtual components. While participants can freely choose the mode of their participation, virtual meetings would most benefit those who cannot attend in-person due to the limitations. In-person portions of meetings should be organized with full consideration of prevention and safety strategies including risk assessment and mitigation, venue and environmental sanitation, participant protection and disease prevention, and promoting the hybrid model. This new way of interaction between scholars can be considered as a part of a resilience system which was neglected previously and should become a part of routine practice in scientific community.
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http://dx.doi.org/10.1017/dmp.2020.406DOI Listing
October 2020

Atherosclerosis Imaging with F-Sodium Fluoride PET.

Diagnostics (Basel) 2020 Oct 20;10(10). Epub 2020 Oct 20.

Department of Nuclear Medicine, Odense University Hospital, 5000 Odense, Denmark.

The evidence on atherosclerosis imaging with F-sodium-fluoride (NaF) positron emission tomography (PET) is hotly debated because of the different patient characteristics, methodology, vascular beds, etc. in reported studies. This review is a continuation of a previous review on this topic, which covered the period 2010-2018. The purpose was to examine whether some of the most important questions that the previous review had left open had been elucidated by the most recent literature. Using principles of a systematic review, we ended analyzing 25 articles dealing with the carotids, coronary arteries, aorta, femoral, intracranial, renal, and penile arteries. The knowledge thus far can be summarized as follows: by targeting active arterial microcalcification, NaF uptake is considered a marker of early stage atherosclerosis, is age-dependent, and consistently associated with cardiovascular risk. Longitudinal studies on NaF uptake, conducted in the abdominal aorta only, showed unchanged uptake in postmenopausal women for nearly four years and varying uptake in prostate cancer patients over 1.5 years, despite constant or increasing calcium volume detected by computed tomography (CT). Thus, uncertainty remains about the transition from active arterial wall calcification marked by increased NaF uptake to less active or consolidated calcification detected by CT. The question of whether early-phase atherosclerosis and calcification can be modified remains also unanswered due to lack of intervention studies.
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http://dx.doi.org/10.3390/diagnostics10100852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7590213PMC
October 2020

Prognostic significance of F-sodium fluoride in newly diagnosed multiple myeloma patients.

Am J Nucl Med Mol Imaging 2020 25;10(4):151-160. Epub 2020 Aug 25.

Department of Radiology, Hospital of The University of Pennsylvania PA, USA.

Focal bone lesions and fractures due to weakened bone are associated with higher morbidity and mortality of multiple myeloma (MM) patients. F-sodium fluoride (F-NaF) is a sensitive PET radiotracer for detection of abnormal bone metabolism and, therefore, is particularly suited to assess the degree of bone involvement in MM patients. We aimed to investigate the prognostic significance of metabolic active volume (MAV) of F-NaF-avid lesions in MM patients. In addition to MAV, conventional methods of PET quantification, namely SUVmean and SUVmax, were measured in each patient for the purpose of comparison. Thirty-seven newly diagnosed MM patients were included. PET imaging was performed after intravenous administration of 200 MBq NaF. Active bone lesions and fractures on whole-body F-NaF-PET/CT scans were identified. An adaptive thresholding algorithm automatically calculated the total MAV, SUVmean and SUVmax for each patient (ROVER, ABX, Radeberg, Germany). The patients were followed for a median of 39.8 months after treatment (range: 17.8-55.4). The overall survival (OS) of patients with F-NaF-MAV value > 38.65 (36.36% [N of Events/Total N: 4/11]) was significantly shorter than that of patients with F-NaF-MAV value < 38.65 (3.85% [1/26]; = 0.002). In multivariate forward stepwise (conditional LR) Cox regression analysis of prognostic factors of OS (including F-NaF-MAV (> 38.65 or < 38.65), age, gender, beta-2 microglobulin, and revised international staging system), F-NaF-MAV remained the only significant factor (HR: 14.39, = 0.02). The results for PFS were not significant. Moreover, Kaplan-Meier analyses of conventional methods of PET quantification did not reveal any statistically significant log-rank -values. MM patients with high F-NaF-MAV had shorter overall survival, compared to those with low F-NaF-MAV levels (NCT02187731).
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486550PMC
August 2020

Association of triglyceride to high density lipoprotein ratio with global cardiac microcalcification to evaluate subclinical coronary atherosclerosis in non-diabetic individuals.

Am J Cardiovasc Dis 2020 15;10(3):241-246. Epub 2020 Aug 15.

Department of Radiology, University of Pennsylvania Philadelphia, United States.

Objective: Triglycerides (TG) to high density lipoprotein (HDL) ratio has been proposed as a marker of insulin resistance and atherosclerosis. We hypothesize that TG/HDL ratio correlates positively with global cardiac microcalcification as assessed by NaF-PET/CT as a surrogate marker for coronary atherosclerosis in healthy non-diabetic individuals.

Method: We identified 68 healthy, non-diabetic individuals (age 41.7 ± 13.5 years; 35/33 female/male) from the CAMONA trial. All underwent PET/CT imaging 90 minutes after NaF injection (2.2 Mbq/Kg). Global cardiac average SUVmean (aSUVmean) was calculated by a trained physician for each individual. Fasting plasma lipid profile (total cholesterol (TC), low-density lipoprotein (LDL), HDL, and TG) and fasting plasma glucose were recorded. TG/HDL ratio was calculated for every individual. Univariate and multivariate linear regression models were used to assess the association between TG/HDL ratio and global cardiac aSUVmean.

Result: On univariate analysis, there was a positive linear association of TG/HDL ratio and global cardiac aSUVmean (r=0.244, B=0.047, P=0.045). On multivariate analysis adjusted for age, gender, systolic blood pressure, diastolic blood pressure, smoking status, total cholesterol, low-density lipoprotein, and fasting plasma glucose, TG/HDL ratio was found to be independently associated with global cardiac aSUVmean (B=0.060, 95% CI: 0.007-0.114, P=0.027).

Conclusion: There was a positive correlation between TG/HDL ratio with global cardiac microcalcification assessed by NaF-PET/CT imaging.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486520PMC
August 2020

Recent Advances in Imaging with PET, Computed Tomography, and MR Techniques.

PET Clin 2020 Oct;15(4):xv-xvi

Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address:

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http://dx.doi.org/10.1016/j.cpet.2020.08.002DOI Listing
October 2020

Applications of Hybrid PET/Magnetic Resonance Imaging in Central Nervous System Disorders.

PET Clin 2020 Oct 21;15(4):497-508. Epub 2020 Jul 21.

Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Electronic address:

PET with 18F-fluorodeoxyglucose (FDG) is used to assess a wide array of inflammatory and neoplastic disorders. FDG-PET has shown particular utility in the evaluation of disorders of the central nervous system (CNS). Although fused PET/computed tomography (CT) is frequently used across the globe for these diseases, recent evidence has pointed to PET/magnetic resonance (MR) imaging as a more sensitive and specific molecular imaging modality. This article reviews the literature regarding the advantages of PET/MR imaging compared with PET/CT imaging, especially in CNS disease. It also introduces a new concept for PET-based evaluation of patients with neurodegenerative disorders: global disease assessment.
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http://dx.doi.org/10.1016/j.cpet.2020.06.004DOI Listing
October 2020