Single photon emission computed tomography (SPECT) and computed tomography (CT) integrated in one system (SPECT/CT) is an effective co-registration technique that helps to localize and characterize ...lesions in the hand and wrist. However, patient motion may cause misalignment between the two modalities leading to potential misdiagnosis. The aim of the present study was to evaluate the hardware-based registration accuracy of multislice SPECT/CT of the hand and wrist and to determine the effect of misalignment errors on diagnostic accuracy. A total of 55 patients who had multislice SPECT/CT of the hand and wrist between July 2008 and January 2010 were included. Two reviewers independently evaluated the fused images for any misalignments with six degrees of freedom: Translation and rotation in the X, Y and Z directions. The results were tested against an automated fusion tool (Syntegra). More than half of the patients had moved during SPECT scanning (Reviewer 1: 29 patients; Reviewer 2: 30 patients) and they all originated in the Y-direction translation (vertical hand motion). Five fused images had significant misalignment errors that could have led to misdiagnosis. The Wilcoxon test indicated statistically non-significant difference (P > 0.05) between reviewers and statistically non-significant difference between the reviewers and software registration. The study also showed high inter-reviewer agreement (κ = 0.87). Hand movement during the SPECT scan was common, but significant misalignments and subsequent misdiagnosis were infrequent. Future studies should investigate the use of hand and wrist immobilization devices and reductions of scan time to minimize patient motion.
To assess the prevalence and pathological nature of incidental focal thyroid uptake on (18)F-FDG (2-(18)F-fluoro-2-deoxy-D-glucose) PET (positron emission tomography) and examine the role of the ...maximum standardised uptake value (SUVmax) to differentiate benign from malignant thyroid pathology.
(18)F-FDG PET reports were retrospectively reviewed. Incidental focal tracer uptake in the thyroid was noted in 147 patients (0.5%). Patients with known primary thyroid malignancy were excluded. The final diagnosis was made following ultrasonography of the neck, fine-needle aspiration cytology (FNAC) or histopathology of the surgically resected specimen where surgery was indicated. A Mann-Whitney U test was used to compare the SUVmax of benign and malignant thyroid pathology. Receiver operating characteristic (ROC) analysis was performed to identify an SUVmax cutoff in differentiating benign from malignant pathology.
A final diagnosis was achieved in 47/147 (32%) of the patients. The diagnoses included benign lesions in 36 patients and malignancy in 9 patients. In 2 patients, FNAC demonstrated indeterminate follicular lesions; however, surgical excision was not performed. There was a highly significant difference in the mean SUVmax of malignant focal thyroid uptake (15.7 ± 5.9) compared to that of benign lesions (7.1 ± 6.8) with a p value of 0.000123. An SUVmax of 9.1 achieved a sensitivity of 81.6%, specificity of 100% and area under the curve of 0.915 in the ROC analysis differentiating benign from malignant disease.
The malignancy potential of incidental focal thyroid uptake remains high and warrants prompt and appropriate follow-up by the clinician. The SUVmax may aid in further characterisation of the lesion and its management.
Objective: To assess the prevalence and pathological nature of incidental focal thyroid uptake on 18F-FDG (2-18F-fluoro-2-deoxy-D-glucose) PET (positron emission tomography) and examine the role of ...the maximum standardised uptake value (SUVmax) to differentiate benign from malignant thyroid pathology. Material and Methods:18F-FDG PET reports were retrospectively reviewed. Incidental focal tracer uptake in the thyroid was noted in 147 patients (0.5%). Patients with known primary thyroid malignancy were excluded. The final diagnosis was made following ultrasonography of the neck, fine-needle aspiration cytology (FNAC) or histopathology of the surgically resected specimen where surgery was indicated. A Mann-Whitney U test was used to compare the SUVmax of benign and malignant thyroid pathology. Receiver operating characteristic (ROC) analysis was performed to identify an SUVmax cutoff in differentiating benign from malignant pathology. Results: A final diagnosis was achieved in 47/147 (32%) of the patients. The diagnoses included benign lesions in 36 patients and malignancy in 9 patients. In 2 patients, FNAC demonstrated indeterminate follicular lesions; however, surgical excision was not performed. There was a highly significant difference in the mean SUVmax of malignant focal thyroid uptake (15.7 ± 5.9) compared to that of benign lesions (7.1 ± 6.8) with a p value of 0.000123. An SUVmax of 9.1 achieved a sensitivity of 81.6%, specificity of 100% and area under the curve of 0.915 in the ROC analysis differentiating benign from malignant disease. Conclusion: The malignancy potential of incidental focal thyroid uptake remains high and warrants prompt and appropriate follow-up by the clinician. The SUVmax may aid in further characterisation of the lesion and its management.
Abstract Metaplastic carcinomas of the breast are a rare but recognised entity. They constitute a heterogeneous group of tumours that may contain cells of epithelial and/or mesenchymal origin. The ...type in which osseous metaplasia predominates is much more uncommon. We present a case of osteosarcomatous metaplasia within a primary breast carcinoma with associated axillary lymph node involvement also showing similar metaplastic changes; the latter is an extremely rare finding. The imaging findings including appearances on mammography, ultrasound, MRI, CT and bone scan are described for metaplastic carcinoma of the breast along with a review of the literature.
Summary
Left ventricular ejection fraction (LVEF) and wall thickening are fundamental aspects of cardiac function. Recently, gated single photon emission computerised tomography (GSPECT) and ...anatomical M‐mode echocardiography are new techniques, which have been introduced for the evaluation of left ventricular wall thickening and ejection fraction. These, however, have not been evaluated against established techniques, including equilibrium radionuclide ventriculography (ERNV), which remains the current gold standard for the evaluation of LVEF.
We examined the concordance between LVEF, wall motion and wall thickening scores derived from GSPECT, echocardiography and ERNV, in a group of 16 patients with suspected ischaemic heart disease.
Estimated ejection fraction correlated better between ERNV and gated SPECT (R2 = 0.93) than between echocardiography and either gated SPECT (R2 = 0.62) or ERNV (R2 = 0.71). There was poor correlation between gated SPECT and anatomical M‐mode echocardiography in the assessment of wall thickening (83/150, 56%; kappa = 0.31, p < 0.05) and similar correlation (100/150, 66%; kappa = 0.29, p < 0.01) for wall motion analysis.
In conclusion, estimations of ejection fraction by all the three studied modalities agreed to a degree sufficient for routine clinical practice. However, estimates of wall thickening from echocardiography cannot be used interchangeably with those derived from gated myocardial perfusion SPECT.
Management of chronic ankle and foot pain remains a challenge given the complex anatomy and function of the foot. Imaging plays a crucial role in the management of these, and the American College of ...Radiology has published the appropriateness criteria for the use of the available investigating modalities in the management of foot and ankle pathologies. These are broadly classified into anatomical and functional imaging modalities. Recent introduction of SPECT/CT scanners which are capable of combining functional and anatomical images promises an exciting and important development, and this chapter describes our clinical experience with SPECT/CT and discusses its potential applications in the imaging of complex foot and ankle pathologies.
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