Use Of Single-photon Emission Computed Tomography Imaging Research Articles

Planar and single-photon emission computed tomography imaging in dogs with thyroid tumors: 68 cases.

BackgroundInformation on scintigraphy findings in dogs with thyroid neoplasia is scarce. The use of single‐photon emission computed tomography (SPECT) could improve detection of metastatic disease.Hypothesis/ObjectivesTo describe planar and SPECT imaging findings in dogs with thyroid tumors, and to compare SPECT and thoracic radiography for metastasis detection.AnimalsSixty‐eight dogs with thyroid neoplasia.MethodsRetrospective study, search of medical records for dogs with thyroid neoplasia (2008‐2018).ResultsThyroid scintigraphy was available from 68 dogs, of which 6 presented after surgical resection. Radionuclide uptake was increased in 56% of dogs, decreased in 24%, and comparable to that of the salivary glands in 13%. The remainder had multiple masses with variable uptake. A homogeneous uptake pattern was present in 16% and a heterogeneous uptake pattern in 73%. In 11% (all dogs with multiple masses), various uptake patterns were present. Thyroid tumors were well delineated in 55%. There was a significant association between hormone status and uptake pattern (P = .009), with a heterogeneous uptake pattern in the majority of euthyroid dogs, and hormone status and tumor circumscription (P = .003), with well‐circumscribed margins in the majority of hypothyroid and hyperthyroid dogs. Thoracic SPECT imaging was available in 39 dogs and identified metastatic lesions in 15 dogs. Thoracic radiographs were performed in 14 of these dogs, and detected metastases in 3 dogs.Conclusions and Clinical ImportanceSPECT imaging is a viable imaging technique to screen for thoracic metastasis and wider use of SPECT imaging is recommended in dogs with thyroid neoplasia.

ACCURACY OF FLUOROPROPYL‐2β‐CARBOMETHOXY‐3β‐(4‐ IODOPHENYL) NORTROPANE DATSCAN FOR THE DIAGNOSIS OF LEWY BODY DEMENTIA

To the Editor: Dementia with Lewy bodies (DLB), the second main cause of dementia after Alzheimer's disease, is responsible for 15% to 25% of neurodegenerative dementia. Diagnosis at an early stage is sometimes difficult. Diagnostic criteria have been established and reviewed to facilitate diagnosis.1 Evaluation of dopamine transporter with fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane (single photon emission computed tomography (SPECT)), referred to as DaTSCAN (General Electric Health Care, Chalfont St. Giles, UK), appears useful in differentiating Alzheimer's disease from DLB. An 84-year-old woman presented with a 2-year fluctuating cognitive decline associated with recurrent visual hallucinations. Her neurological examination was normal. Her past medical history included chronic atrial fibrillation and hypertension. The first suspected diagnosis was Alzheimer's disease because of the progressive evolution and the neuropsychological test showing altered episodic memory. Her Mini-Mental State Examination score was 25. Her brain computed tomography (CT) scan showed global atrophy. Treatment with a neuroleptic drug was started to reduce hallucinations but was stopped because of worsening cognitive decline. The patient was transferred to the Geriatrics Department at CHU La Miletrie, Poitiers, France. Clinical examination did not show any parkinsonism. Daily visual hallucinations continued. The patient exhibited a misidentification delusion (Capgras syndrome), because she believed she saw her son's double. Biological blood testing was normal. Electroencephalography was requested because of suspected temporal lobe epilepsy, but no evidence was found. Cerebral perfusion SPECT was performed that showed a distinct reduction of cortical perfusion with occipital affect, which is uncommon in Alzheimer's disease. The association between fluctuating cognitive decline and recurrent visual hallucinations suggested DLB, despite the absence of parkinsonian syndrome. DaTSCAN was performed and showed distinct dopamine transporter asymmetry at the expense of the right striatum (Figure 1), which strengthened the diagnostic hypothesis. Treatment with an acetylcholinesterase inhibitor resulted in rapid cognitive improvement and reduced hallucinations. After 36 months of follow-up, the patient was free of clinical parkinsonian syndrome. DaTSCAN shows distinct dopamine transporter asymmetry with lack of binding in the right putamen. This case report confirms the usefulness of SPECT imaging with DaTSCAN to facilitate the diagnosis of dementia. A European, multicenter, prospective, longitudinal study reported a mean sensitivity of 78% and specificity of 97% with the use of DaTSCAN to ascertain the diagnosis of Parkinson's disease.2 DaTSCAN is also helpful for patients with hallucinations.3 This case underscores the accuracy of DaTSCAN SPECT to optimize the diagnosis in patients with uncertain degenerative disease. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Odile Bouverie: study concept and design, acquisition of subjects and data, analysis and interpretation of data, and preparation of letter. Rémi Coudroy and François Salmon:and Roger Gil analysis and interpretation of data and preparation of manuscript. Isabelle Merlet-Chicoine and Roger Gil: analysis and interpretation of data. Marc Paccalin: study concept and design, analysis and interpretation of data, and preparation of manuscript. Sponsor's Role: No sponsor's role.

Prediction of psychiatric response to donepezil in patients with mild to moderate Alzheimer's disease

Donepezil is a selective acetylcholinesterase inhibitor approved for the symptomatic treatment of mild to moderate Alzheimer's disease (AD). Since behavioral symptoms severely affect quality of life for AD patients and their caregivers, predicting behavioral responses to donepezil will be useful in managing patients with AD. In this study, we analyzed 70 consecutive cases with mild to moderate AD. Caregivers were interviewed with the Neuropsychiatric Inventory for behavioral assessment and 4-point improvement at week 12 was accepted as a treatment response. Twenty-one (30.0%) patients showed a behavioral response, while 42 (60.0%) showed no behavioral change and 7 (10.0%) worsened. Dysphoria, anxiety and apathy significantly improved after treatment among the responder group. The baseline profile including age, sex, Mini-Mental State Examination (MMSE), the Alzheimer's Disease Assessment Scale (ADAS-cog) and the Geriatric Depression Scale did not differ significantly among the three groups. Statistical Parametric Mapping analysis of single photon emission computed tomography (SPECT) images at baseline showed that cerebral blood flow in the premotor and parietotemporal cortices was significantly higher in the responder group than in the worse group. The present study suggested usefulness of SPECT imaging in the prediction of behavioral response to donepezil among AD patients even with similar psychiatric symptoms and cognitive functions.

Selective use of single-photon emission computed tomography myocardial perfusion imaging in a chest pain center

Emergency department chest pain centers (CPCs) vary in their approach to patients with chest pain and nonischemic electrocardiograms (ECG). Although single-photon emission computed tomography (SPECT) myocardial perfusion imaging has been evaluated in this setting, both acutely at rest and after stress, we questioned its application in all patients. We prospectively evaluated the utility of selective SPECT imaging in a CPC (i.e., rest SPECT for ongoing pain, stress SPECT if unable to undergo exercise electrocardiography) and its impact on the overall disposition of all emergency department chest pain patients. Over 3 years, 2,601 patients were evaluated in a CPC (2,211 [85%] were sent home, 390 [15%] were hospitalized). Of 390 CPC patients hospitalized, 182 (47%) were diagnosed with coronary artery disease at the time of hospital discharge. Only 28 patients (1.1%) had an acute myocardial infarction. After 3 years, the proportion of all chest pain patients hospitalized and those diagnosed as “rule-out myocardial infarction” decreased from 53% to 41% and 32% to 18% of all chest pain patients, respectively (both p <0.0001). Overall, 906 patients (35%) required SPECT imaging to complete the CPC evaluation. Had SPECT imaging not been performed selectively, and all 906 patients been admitted, 762 (29%) would have been hospitalized unnecessarily based on the final diagnoses. Alternatively, sending all these patients home would have resulted in 144 (6%) inappropriate discharges of patients with coronary artery disease. A CPC protocol using the selective use of SPECT imaging permits the complete evaluation of all patients in the CPC, significantly reduces hospitalizations for chest pain, and restricts hospital admission to more appropriate patients.

SPECT Imaging in the Diagnosis of Meniscal Tears

Sixty patients scheduled for arthroscopy of a knee because of suspected meniscal tears had preoperative planar and single photon emission computed tomography (SPECT) radionuclide scans. A crescentic pattern of uptake on the SPECT transaxial view was used as a criterion for diagnosing a tear of a meniscus. The sensitivity of the investigation was 77%, specificity 74%, negative predictive value (NPV) 65%, positive predictive value (PPV) 83%, and accuracy 76%. Tears of the posterior horn of the cartilage were also associated with intense focal uptake on the transaxial view as well as increased equilibrium activity in the adjacent femoral condyle. When these appearances were included as additional criteria the sensitivity rose to 90%, NPV 81%, and accuracy 84%. This study confirms the usefulness of SPECT imaging in identifying meniscal tears.