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Purpose To compare the reliability and accuracy of the pre-treatment dosimetry predictions using cone-beam computed tomography (CBCT) versus 99mTc-labeled macroaggregated albumin (MAA) SPECT/CT for perfused volume segmentation in patients with hepatocellular carcinoma treated by selective internal radiation therapy (SIRT) using 90Y-glass microspheres. Materials and methods Fifteen patients (8 men, 7 women) with a mean age of 68.3 ± 10.5 (SD) years (range: 47–82 years) who underwent a total of 17 SIRT procedures using 90Y-glass microspheres for unresectable hepatocellular carcinoma were retrospectively included. Pre-treatment dosimetry data were calculated from 99mTc-MAA SPECT/CT using either CBCT or 99mTc-MAA SPECT/CT to segment the perfused volumes. Post-treatment dosimetry data were calculated using 90Y imaging (SPECT/CT or PET/CT). The whole liver, non-tumoral liver, and tumor volumes were segmented on CT or MRI data. The mean absorbed doses of the tumor (DT), non-tumoral liver, perfused liver (DPL) and perfused non-tumoral liver were calculated. Intra- and interobserver reliabilities were investigated by calculating Lin's concordant correlation coefficients (ρc values). The differences (biases) between pre- and post-treatment dosimetry data were assessed using the modified Bland–Altman method (for non-normally distributed variables), and systematic bias was evaluated using Passing–Bablok regression. Results The intra- and interobserver reliabilities were good-to-excellent (ρc: 0.80–0.99) for all measures using both methods. Compared with 90Y imaging, the median differences were 5.8 Gy (IQR: −12.7; 16.1) and 5.6 Gy (IQR: −13.6; 10.2) for DPL-CBCT and DPL-99mTc-MAA SPECT/CT, respectively. The median differences were 1.6 Gy (IQR: −29; 7.53) and 9.8 Gy (IQR: −28.4; 19.9) for DT-CBCT and DT-99mTc-MAA SPECT/CT respectively. Passing–Bablok regression analysis showed that both CBCT and 99mTc-MAA SPECT/CT had proportional biases and thus tendencies to overestimate DT and DPL at higher post-treatment doses. Conclusion CBCT may be a reliable segmentation method, but it does not significantly increase the accuracy of dose prediction compared with that of 99mTc-MAA SPECT/CT. At higher doses both methods tend to overestimate the doses to tumors and perfused livers.

Nuclear medicine imaging is widely used in pain medicine. Low back pain is commonly encountered by physicians, with its prevalence from 49% to 70%. Computed tomography (CT) or magnetic resonance imaging (MRI) are usually used to evaluate the cause of low back pain, however, these findings from these scans could also be observed in asymptomatic patients. Bone scintigraphy has an additional value in patients with low back pain. Complex regional pain syndrome (CRPS) is defined as a painful disorder of the extremities, which is characterized by sensory, autonomic, vasomotor, and trophic disturbances. To assist the diagnosis of CRPS, three-phase bone scintigraphy is thought to be superior compared to other modalities, and could be used to rule out CRPS due to its high specificity. Studies regarding the effect of bone scintigraphy in patients with extremity pain have not been widely conducted. Ultrasound, CT and MRI are widely used imaging modalities for evaluating extremity pain. However, SPECT/CT has an additional role in assessing pain in the extremities.

Background Iterative computed tomography (CT) image reconstruction shows high potential for the preservation of image quality in diagnostic CT while reducing patients’ exposure; it has become available for low-dose CT (LD-CT) in high-end hybrid imaging systems (e.g. single-photon emission computed tomography [SPECT]-CT). Purpose To examine the effect of an iterative CT reconstruction algorithm on image quality, image noise, detectability, and the reader’s confidence for LD-CT data by a subjective assessment. Material and Methods The LD-CT data were validated for 40 patients examined by an abdominal hybrid SPECT-CT (U = 120 kV, I = 40 mA, pitch = 1.375). LD-CT was reconstructed using either filtered back projection (FBP) or an iterative image reconstruction algorithm (Adaptive Statistical Iterative Reconstruction [ASIR]®) with different parameters (ASIR levels 50% and 100%). The data were validated by two independent blinded readers using a scoring system for image quality, image noise, detectability, and reader confidence, for a predefined set of 16 anatomic substructures. Results The image quality was significantly improved by iterative reconstruction of the LD-CT data compared with FBP ( P ≤ 0.0001). While detectability increased in only 2/16 structures ( P ≤ 0.03), the reader’s confidence increased significantly due to iterative reconstruction ( P ≤ 0.002). Meanwhile, at the ASIR level of 100%, the detectability in bone structure was highly reduced ( P = 0.003). Conclusion An ASIR level of 50% represents a good compromise in abdominal LD-CT image reconstruction. The specific ASIR level improved image quality (reduced image noise) and reader confidence, while preserving detectability of bone structure.

Carcinoid tumors are relatively rare and can occur in the thorax, abdomen, or pelvis. Functional imaging in the form of Indium-111 pentetreotide scanning is widely used for identification of these tumors and it exploits the fact that the vast majority of these tumors express somatostatin receptors on their cell membrane. In this report, we present a case of a 76-year-old man who was diagnosed with peritoneal carcinomatosis. The findings of the initial imaging made by planar and single photon emission computed tomography were misleading and the actual diagnosis was only made by single photon emission computed tomography/computed tomography.

Objectives To study the vascularity and bone metabolism of the femoral head/neck following hip resurfacing arthroplasty, and to use these results to compare the posterior and the trochanteric-flip approaches. Methods In our previous work, we reported changes to intra-operative blood flow during hip resurfacing arthroplasty comparing two surgical approaches. In this study, we report the vascularity and the metabolic bone function in the proximal femur in these same patients at one year after the surgery. Vascularity and bone function was assessed using scintigraphic techniques. Of the 13 patients who agreed to take part, eight had their arthroplasty through a posterior approach and five through a trochanteric-flip approach. Results One year after surgery, we found no difference in the vascularity (vascular phase) and metabolic bone function (delayed phase) at the junction of the femoral head/neck between the two groups of patients. Higher radiopharmaceutical uptake was found in the region of the greater trochanter in the trochanteric-flip group, related to the healing osteotomy. Conclusions Our findings using scintigraphic techniques suggest that the greater intra-operative reduction in blood flow to the junction of the femoral head/neck, which is seen with the posterior approach compared with trochanteric flip, does not result in any difference in vascularity or metabolic bone function one year after surgery.