Comparison of pinhole and SPECT 99mTc-MIBI imaging in primary hyperparathyroidism.

OBJECTIVE: This study aims to compare dual tracer, dual phase pinhole technetium-99m labelled 2-methoxyisobutylisonitrile (Tc-MIBI) imaging (including oblique imaging), with single photon emission computed tomography (SPECT) and dual phase planar Tc-MIBI images, and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images for the localization of parathyroid adenomas in the neck in primary hyperparathyroidism. METHODS: Sixty-two patients underwent Tc-MIBI dual phase, anterior and anterior oblique pinhole images of the neck, anterior planar images of the neck and chest and early phase neck/chest SPECT followed by [Tc] pertechnetate anterior and anterior oblique pinhole thyroid images. Images were reviewed by consensus in three combinations - dual phase anterior and anterior oblique pinhole Tc-MIBI images and pinhole thyroid images; SPECT and dual phase planar Tc-MIBI images and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images. RESULTS: For 52 parathyroid adenomas in 50 patients, the sensitivity of dual phase anterior and anterior oblique pinhole Tc-images and pinhole thyroid images was 81%. Significantly lower sensitivities were observed with SPECT and dual phase planar Tc-MIBI images (54%, P=0.0005) and combined SPECT, dual phase planar Tc-MIBI images and anterior pinhole thyroid images (65%, P=0.0209). The positive predictive value for all imaging combinations was 88-92%. CONCLUSION: Dual phase anterior and anterior oblique pinhole Tc-MIBI images and pinhole thyroid images are significantly more sensitive than imaging combinations that included SPECT and remains the optimal imaging protocol for the localization of parathyroid adenomas in the neck in primary hyperparathyroidism.

Imaging in cutaneous melanoma.

Cutaneous melanoma (CM) is a common malignancy and imaging, particularly lymphoscintigraphy (LS), positron-emission tomography with 2-fluoro-2-deoxyglucose (FDG-PET), ultrasound, radiography computed tomography (CT) and magnetic resonance imaging have important roles in staging and restaging, surgical guidance, surveillance and assessment of recurrent disease. This review aims to summarize the available data regarding these and other imaging modalities in CM and provide the basis for subsequent formulation of guidelines regarding the use of imaging in CM. PubMed and Medline searches were performed and reference lists from publications were also searched. The published data were reviewed and tabulated. There is level I evidence supporting the use of LS and sentinel lymph node biopsy in nodal staging for CM. There is level III evidence demonstrating the superiority of ultrasound to palpation in the assessment of lymph nodes in CM. There is level IV evidence supporting FDG-PET in American Joint Committee on Cancer stage III/IV and recurrent CM and that FDG-PET/CT may be superior to FDG-PET. Level IV evidence also supports the use of CT in the same group of patients and the role of CT appears to be complementary to FDG-PET. Various imaging modalities, especially LS/sentinel lymph node biopsy and FDG-PET/CT, add incremental information in the management of CM and the various modalities have complementary roles depending on the clinical situation.

Guidelines for imaging in cutaneous melanoma.

The preceding article reviewed the available data on imaging modalities in cutaneous melanoma. Based on this review, this article aims to provide guidelines for the use of the various imaging modalities in cutaneous melanoma and to indicate the level of supporting evidence and strength of recommendation with associated explanatory notes.

SPECT/CT imaging using a spiral CT scanner for anatomical localization: Impact on diagnostic accuracy and reporter confidence in clinical practice.

PURPOSE: To evaluate the incremental benefit in routine clinical practice of computed tomography (CT) scans acquired for anatomical localization on an integrated SPECT/CT which incorporates a spiral CT scanner, in comparison with conventional planar and SPECT scanning. METHODS: The first 50 studies acquired on the integrated system were evaluated by two experienced nuclear medicine physicians who were aware of the patient's clinical history. These included bone scans, gallium scans, octreotide scans, sestamibi parathyroid scans and MIBG scans. For each patient study, abnormalities were assessed on planar and SPECT images for location and provisional diagnosis and a quantitative scale was used to assess reporter confidence. The fused SPECT/CT images were then reviewed and the location and provisional diagnosis noted and reporter confidence was assessed using the same quantitative scale. RESULTS: There were 129 abnormalities detected in 50 patient studies. For localization of abnormalities, the inclusion of the CT resulted in a minor change in 16% of cases and a significant change in 11% over planar/SPECT imaging alone. The confidence of localization was improved moderately in 19% and improved significantly in 6%. For diagnosis, SPECT/CT resulted in a minor change in 10% and a significant change in 9% over planar/SPECT imaging. The confidence of diagnosis was improved moderately in 10% and improved significantly in a further 10% of cases. For the final scan interpretation, there would have been no change in 44% patients, a minor change in 30% and a significant change in 26% with the use of SPECT/CT. CONCLUSION: Use of integrated SPECT/CT with a high spatial resolution, spiral CT used for anatomical localization improves accuracy and reporter confidence in clinical practice. As a result, final reports were different in 56% of the cases, including being significantly different in 26% patients compared to reporting with planar/SPECT alone.