Quantitative bone single-photon emission computed tomography imaging for uninfected nonunion: comparison of hypertrophic nonunion and non-hypertrophic nonunion

Recently, a standardized uptake value (SUV) has been used to evaluate bone single-photon emission computed tomography (SPECT). The aim of this study was to investigate quantitative SPECT imaging of uninfected nonunion to compare hypertrophic nonunion and non-hypertrophic nonunion using volume-based parameters

Estrogen is involved in improvement of impaired cardiac glucose uptake in cancer patients

AbstractWe previously demonstrated that inflammatory stress impaired cardiac glucose uptake, using fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) by showing that a proportion of patients with subtle FDG signals was remarkably increased compared with that of normal subjects. The current study assessed the inhibitory effects of cancer-associated stress on cardiac glucose uptake in female cancer patients, and compared the results with those obtained for healthy female subjects. Cardiac glucose uptake was decreased in female cancer, as indicated by the significantly higher number of patients with poor FDG uptake and the lower number of patients with high FDG uptake, compared with the number of healthy subjects with poor and high FDG uptake, respectively. These results suggest that cancer-associated stress inhibited cardiac glucose utilization. From the 78 female cancer patients, 13 oophorectomized patients, who underwent repeated postoperative follow-up examinations by FDG-PET/CT before and after receiving hormone replacement therapy (HRT) with estrogen derivatives, were analyzed to determine the effects of estrogen on cardiac glucose uptake. HRT increased a proportion of patients with high FDG signals to comparable in healthy subjects with high FDG uptake, whereas that of patients with poor FDG uptake decreased. These results suggest that estrogen can improve cardiac glucose uptake in cancer-resected and oophorectomized patients.<Learning objective: This study presents us a new point of view, which should be taken into account on the pathophysiology in some cardiovascular diseases, the sex-differences of energy substrates for the heart, i.e., estrogen or its derivatives accelerates the preference of glucose by the heart. Unfortunately, a very few studies have studied on this issue, e.g., effects of sex-steroid on cardiac uptake of energy substrate, and therefore, this suggests that cardiologists do not focus on this issue.

Is contrast material needed after treatment of malignant lymphoma in positron emission tomography/computed tomography?

Positron emission tomography (PET)/computed tomography (CT) with (18)F-fluorodeoxyglucose is widely used for post-therapeutic surveillance of malignant lymphoma. Debate still exists as to whether intravenous contrast media during the CT stage of a PET/CT scan should be used. The purpose of this study was to investigate the clinical value of contrast agent in PET/CT in patients with lymphoma following treatment

Visualization of intensive atrial inflammation and fibrosis after cryoballoon ablation: PET/MRI and LGE-MRI analysis

Background: Atrial inflammation plays an important role in initiating atrial fibrosis, which could perpetuate atrial fibrillation (AF). However, the method of visualization of atrial inflammation has not been established. We sought to investigate whether the intensive atrial inflammation caused by cryoballoon ablation (CBA) could be detected by positron emission tomography/ magnetic resonance imaging (PET/MRI) and whether the atrial inflammation could be associated with consequent fibrosis. Methods: A total of 10 paroxysmal atrial fibrillation patients after CBA were enrolled. To detect and quantify intensive atrial inflammation, PET/MRI was performed to assess regional F-18-fluorodeoxyglucose (F-18-FDG) uptake one day after the CBA, and the standardized uptake values (SUV) max were compared between the pulmonary vein (PV) antrum where CBA could be applied and the healthy left atrial (LA) wall where CBA could not be applied. Furthermore, the atrial inflammation one day after the procedure and atrial fibrosis areas one month after the procedure were three-dimensionally quantified by PET/MRI and late-gadolinium enhancement magnetic resonance imaging (LGE-MRI), respectively. Results: The mean SUV max at the PV antrum was significantly higher than that on the healthy LA wall (2.12 ± 0.35 vs 1.73 ± 0.30, P = .00021). The volume of the atrial inflammation strongly correlated with that of the atrial fibrosis (r = .94 [.76-.99], P = .00006). Conclusions: The atrial inflammation after CBA could be detected by PET/MRI. CBA-induced atrial inflammation was strongly associated with consequent lesion maturation

Influence of Metal Implants on Quantitative Evaluation of Bone Single-Photon Emission Computed Tomography/Computed Tomography

When visualizing biological activity at nonunion sites by the radioisotopes, gamma rays are more attenuated if metal implants are placed in the bone. However, the effects of various implant types and their placement on gamma ray attenuation in quantitative evaluation remain unknown. To elucidate these effects, we created a phantom that simulated the nonunion of the femur in this study. The count of gamma rays was measured by single-photon emission computed tomography/computed tomography (SPECT/CT) while considering CT-based attenuation correction (CTAC), metal implant placement, type (intramedullary nail or plate), and position. The count differed significantly with and without CTAC and with and without implants (both types) under CTAC. Significantly different counts were observed between the intramedullary nail and plate placed contralaterally to the lesion (i.e., non-lesion side). No significant difference was observed between the intramedullary nail and plate on the lesion side or between plates on the non-lesion and lesion sides. The measured standardized uptake value (SUV) was closer to the true SUV with CTAC than without. Moreover, the count was higher with implants than without. However, even with implants, it was lower than the actual count, indicating the absence of overcorrection. Implant type and position do not seem to influence the count