0
selected
-
1.
Neuroimaging Applications in Restless Legs Syndrome.
Rizzo, G, Plazzi, G
International review of neurobiology. 2018;:31-64
Abstract
Neuroimaging studies provide information useful to understand the pathophysiology of restless legs syndrome. Molecular PET and SPECT imaging findings mainly supported dysfunction of dopaminergic pathways involving not only the nigrostriatal but also mesolimbic pathways. Magnetic resonance imaging (MRI) studies have used different techniques. Studies using iron-sensitive sequences supported the presence of a regionally variable low brain iron content, mainly at the level of substantia nigra and thalamus. The search for brain structural or microstructural abnormalities by voxel-based morphometry, diffusion tensor imaging or cortical thickness analysis has reported none or variable findings in restless legs syndrome patients, most of them in regions belonging to sensorimotor and limbic/nociceptive networks. Functional MRI studies have substantially demonstrated activation or connectivity changes in the same networks. Magnetic resonance spectroscopy studies showed metabolic changes in the thalamus, which is a hub of these networks. In summary, neuroimaging findings in restless legs syndrome support the presence of reduction of brain iron content, of dysfunction of mesolimbic and nigrostriatal dopaminergic pathways, and of abnormalities at level of limbic/nociceptive and sensorimotor networks.
-
2.
Clinical imaging in dementia with Lewy bodies.
Surendranathan, A, O'Brien, JT
Evidence-based mental health. 2018;(2):61-65
-
-
Free full text
-
Abstract
Dementia with Lewy bodies (DLB) is a common neurodegenerative dementia in older people; however, the clinical features, particularly cognitive fluctuations and rapid eye movement sleep disorder, are often hard to elicit, leading to difficulty in making the diagnosis clinically. Here we examine the literature for the evidence behind imaging modalities that could assist in making the diagnosis. Dopamine transporter (DAT) imaging remains the best modality for differentiation from dementia of Alzheimer's type with high sensitivity and specificity reported based on pathological diagnoses. 123Iodine-metaiodobenzylguanidine myocardial scintigraphy (MIBG) however is rapidly becoming an alternative imaging modality for the diagnosis of DLB, though studies assessing its accuracy with postmortem verification are still awaited. However, there are suggestions that MIBG may be better in the differentiation of vascular parkinsonism from DLB than DAT scans but may have lower sensitivity for detecting DLB compared with the 80% sensitivity seen in DAT imaging. Structural MRI scans have long been used for the diagnosis of dementia; however, their utility in DLB is limited to revealing the presence of coexisting Alzheimer's disease. Fluorodeoxyglucose (FDG) PET is an alternative biomarker that can also differentiate Alzheimer's disease and DLB but lacks the evidence base of both DAT and MIBG scans.
-
3.
123I-ioflupane SPET and 123I-MIBG in the diagnosis of Parkinson's disease and parkinsonian disorders and in the differential diagnosis between Alzheimer's and Lewy's bodies dementias.
Nuvoli, S, Palumbo, B, Malaspina, S, Madeddu, G, Spanu, A
Hellenic journal of nuclear medicine. 2018;(1):60-68
Abstract
Nuclear medicine procedures are widely used as "in vivo" biomarkers in a large number of brain diseases, especially in the diagnosis of Parkinson's disease (PD) and of parkinsonian disorders (pD). Furthermore, nuclear medicine is used in the differential diagnosis of dementias especially Alzheimer's disease (AD) and dementia with Lewy's bodies (LBD) which share many clinical symptoms and often LBD is misdiagnosed as AD. The differential diagnosis between these clinical entities is crucial for treatment since LBD also shares some clinical symptoms with parkinsonian disorders. We reviewed the most relevant papers that study the usefulness of both iodine-123-ioflupane studied by single photon emission tomography (123I-ioflupane SPET) and of 123I-metaiodobenzylguanidine (123I-MIBG) cardiac scintigraphy in the diagnosis of PD and pD and in the differential diagnosis between AD and LBD in order to contribute to the clinical practice of the diseases.
-
4.
Hybrid SPECT/CT Imaging in the Management of Differentiated Thyroid Carcinoma.
Ahmed, N, Niyaz, K, Borakati, A, Marafi, F, Birk, R, Usmani, S
Asian Pacific journal of cancer prevention : APJCP. 2018;(2):303-308
Abstract
Differentiated thyroid cancer (DTC) has a good prognosis overall; however, lifelong follow-up is required for many cases. Radioiodine planar imaging with iodine-123 (I-123) or radioiodine-131 (I-131) remains the standard in the follow-up after initial surgery and ablation of residual thyroid tissue using I-131 therapy. Radioiodine imaging is also used in risk-stratifying and for staging of thyroid cancer, and in long-term follow-up. Unfortunately, the lack of anatomical detail on planar gamma camera imaging and superimposition of areas presenting with increased radioiodine uptake can make accurate diagnosis and localization of radioiodine-avid metastatic disease challenging, leading to false positive results and potentially to over-treatment of patients. Hybrid SPECT/CT allows precise anatomical localization and superior characterization of foci of increased tracer uptake when compared to planar imaging. This, in turn, allows the differentiation of pathological and physiological uptake, increasing the accuracy of image interpretation and ultimately improving the accuracy of DTC staging and subsequent patient management. In this review, we look at the unique and emerging role that SPECT/CT plays in the management of DTC, illustrated by examples from our own clinical practice.
-
5.
Low-dose dual-isotope procedure planed for myocardial perfusion CZT-SPECT and assessed through a head-to-head comparison with a conventional single-isotope protocol.
Imbert, L, Roch, V, Merlin, C, Djaballah, W, Cachin, F, Perrin, M, Claudin, M, Verger, A, Boutley, H, Karcher, G, et al
Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology. 2018;(6):2016-2023
Abstract
PURPOSE OF THE REPORT This study aimed at assessing an original low-dose dual-isotope procedure in which the abnormal stress Tc-99m Sestamibi SPECT is followed by rest Tl-201 SPECT, along with a head-to-head comparison with a single-isotope procedure. METHODS AND RESULTS One hundred two patients, referred for a low-dose stress-SPECT with Sestamibi (123 ± 20 MBq) on a CZT camera and for whom a rest Sestamibi SPECT was warranted, had an additional Tl-201 rest-SPECT (52 ± 5 MBq) between stress and rest Sestamibi SPECT recordings. Tl-201 images were processed for spill-over and scatter corrections, and uptake differences with stress Sestamibi SPECT were analyzed: (1) for rest acquisitions from Tl-201 (dual-isotope procedure) and from Sestamibi (single-isotope procedure) and (2) in segments for which a diagnosis of ischemia, infarct, or normal perfusion was achieved. Mean effective dose was 8.3 mSv for dual-isotope but would decrease to 5.7 mSv for an expected rate of 37% of patients for whom rest-SPECT is not warranted. After a further background correction of Tl-201 images, the rest-stress difference in myocardial uptake was equivalent between dual- and single-procedures for identifying ischemic segments (respective areas-under-curves: 0.83 ± 0.03 and 0.81 ± 0.03). CONCLUSION This original dual-isotope procedure provides acceptable radiation doses and consistent results, as compared with conventional single-isotope.
-
6.
Differential diagnosis of posterior fossa brain tumors: Multiple discriminant analysis of Tl-SPECT and FDG-PET.
Yamauchi, M, Okada, T, Okada, T, Yamamoto, A, Fushimi, Y, Arakawa, Y, Miyamoto, S, Togashi, K
Medicine. 2017;(33):e7767
-
-
Free full text
-
Abstract
This study investigated the combined capability of thallium-201 (Tl)-SPECT and fluorine-18-fluoro-deoxy-glucose (FDG)-PET for differential diagnosis of posterior fossa brain tumors using multiple discriminant analysis.This retrospective study was conducted under approval of the institutional review board. In the hospital information system, 27 patients with posterior fossa intra-axial tumor between January 2009 and June 2015 were enrolled and grouped as the following 7 entities: low grade glioma (LGG) 6, anaplastic astrocytoma (AA) 2, glioblastoma (GBM) 3, medulloblastoma (MB) 3, hemangioblastoma (HB) 6, metastatic tumor (Mets) 3, and malignant lymphoma (ML) 4. Tl and FDG uptakes were measured at the tumors and control areas, and several indexes were derived. Using indexes selected by the stepwise method, discriminant analysis was conducted with leave-one-out cross-validation.The predicted accuracy for tumor classification was 70.4% at initial analysis and 55.6% at cross-validation to differentiate 7 tumor entities. HB, LGG, and ML were well-discriminated, but AA was located next to LGG. GBM, MB, and Mets largely overlapped and could not be well distinguished even applying multiple discriminant analysis. Correct classification in the original and cross-validation analyses was 44.4% and 33.3% for Tl-SPECT and 55.6% and 48.1% for FDG-PET.
-
7.
Molecular imaging of advanced thyroid cancer: iodinated radiotracers and beyond.
Santhanam, P, Solnes, LB, Rowe, SP
Medical oncology (Northwood, London, England). 2017;(12):189
Abstract
An important aspect of differentiated thyroid cancer (DTC) management is disease localization by imaging. Functional imaging of thyroid cancer with iodinated radiotracers has been employed for metastatic disease detection for long. More recently, 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT), a non-iodinated ubiquitous PET tracer, has been used to detect non-radioiodine (RAI) avid disease. Advances in molecular imaging have led to the development of newer tracers like 18F-TFB (18F-tetrafluoroborate) that are transported through the sodium-iodide symporter (NIS) as well as 68 Ga-DOTATATE that image the somatostatin receptors sub-type 2 expressed in medullary thyroid cancer and some DTC. In coming years, there will be focus on newer receptor targets like prostate-specific membrane antigen expression and endoradiotherapies and theranostics.
-
8.
New solid state cadmium-zinc-telluride technology for cardiac single photon emission computed tomographic myocardial perfusion imaging.
Alenazy, AB, Wells, RG, Ruddy, TD
Expert review of medical devices. 2017;(3):213-222
Abstract
Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is well established as diagnostic test for patients with suspected or known coronary artery disease. New camera systems have been developed with cadmium-zinc-telluride (CZT) detectors, novel collimator designs and reconstruction software. Areas covered: We review the current state of cardiac SPECT, advances in conventional camera technology and the development and clinical validation of solid-state CZT cameras. Expert commentary: The development of CZT systems is timely and addresses current issues for clinical SPECT imaging. These systems have a significant increase in photon sensitivity, permitting much lower radiation patient doses at a time when the lay and medical communities are very concerned about the radiation doses resulting from medical imaging. The increased count sensitivity permits shorter acquisition times and greater patient throughput which may address the ongoing and increasing issue of decreased funding for healthcare and, particularly, diagnostic imaging. The improved image resolution should improve diagnostic accuracy and increase the value of SPECT imaging for management of patients with CAD at a time of significant competition from other imaging modalities.
-
9.
MIBG in Neuroblastoma Diagnostic Imaging and Therapy.
Sharp, SE, Trout, AT, Weiss, BD, Gelfand, MJ
Radiographics : a review publication of the Radiological Society of North America, Inc. 2016;(1):258-78
Abstract
Neuroblastoma is a common malignancy observed in infants and young children. It has a varied prognosis, ranging from spontaneous regression to aggressive metastatic tumors with fatal outcomes despite multimodality therapy. Patients are divided into risk groups on the basis of age, stage, and biologic tumor factors. Multiple clinical and imaging tests are needed for accurate patient assessment. Iodine 123 ((123)I) metaiodobenzylguanidine (MIBG) is the first-line functional imaging agent used in neuroblastoma imaging. MIBG uptake is seen in 90% of neuroblastomas, identifying both the primary tumor and sites of metastatic disease. The addition of single photon emission computed tomography (SPECT) and SPECT/computed tomography to (123)I-MIBG planar images can improve identification and characterization of sites of uptake. During scan interpretation, use of MIBG semiquantitative scoring systems improves description of disease extent and distribution and may be helpful in defining prognosis. Therapeutic use of MIBG labeled with iodine 131 ((131)I) is being investigated as part of research trials, both as a single agent and in conjunction with other therapies. (131)I-MIBG therapy has been studied in patients with newly diagnosed neuroblastoma and those with relapsed disease. Development and implementation of an institutional (131)I-MIBG therapy research program requires extensive preparation with a focus on radiation protection.
-
10.
Radionuclide Imaging of Musculoskeletal Infection: A Review.
Palestro, CJ
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2016;(9):1406-12
Abstract
There are numerous imaging tests for diagnosing musculoskeletal infection. Radiographs are routinely performed, because even when not diagnostic, they provide an anatomic overview of the region of interest that could influence subsequent procedure selection and interpretation. MRI is sensitive and provides superb anatomic detail. Bone scintigraphy accurately diagnoses osteomyelitis in bones not affected by underlying conditions. (67)Ga is used primarily for spondylodiskitis. Although in vitro labeled leukocyte imaging is the radionuclide test of choice for complicating osteomyelitis such as diabetic pedal osteomyelitis and prosthetic joint infection, it is not useful for spondylodiskitis. Antigranulocyte antibodies and antibody fragments have limitations and are not widely available. (111)In-biotin is useful for spondylodiskitis. Radiolabeled synthetic fragments of the antimicrobial peptide ubiquicidin are promising infection-specific agents. (18)F-FDG is the radiopharmaceutical of choice for spondylodiskitis. Its role in diabetic pedal osteomyelitis and prosthetic joint infection is not established. Preliminary data suggest (68)Ga may be useful in musculoskeletal infection. (124)I-fialuridine initially showed promise as an infection-specific radiopharmaceutical, but subsequent investigations were disappointing. The development of PET/CT and SPECT/CT imaging systems, which combine anatomic and functional imaging, has revolutionized diagnostic imaging. These hybrid systems are redefining the diagnostic workup of patients with suspected or known infection and inflammation by improving diagnostic accuracy and influencing patient management.