Stability of standardized uptake values for quantitative bone SPECT for jawbone lesions: a single-center cross-sectional study.

BACKGROUND: The long time required for bone uptake of radiopharmaceutical material after injection for bone scintigraphy is a burden for patients with poor health. Thus, to assess whether the uptake time could be reduced for single-photon emission computed tomography (SPECT) of the jawbone, this study evaluated differences in maximum standardized uptake values (SUVmax) within patients using SPECT imaging at 2 and 3 hours after radiopharmaceutical injection. METHODS: A total of 33 patients undergoing treatment or in post-treatment follow-up for medication-related osteonecrosis of the jaw, who visited our hospital between July 2020 and August 2021 and could receive SPECT twice on the same day, were enrolled in the study. Patients were injected with technetium-99 m hydroxymethylene diphosphonate (Tc-99 m HMDP) intravenously. The SUVmax for healthy parietal bones and jawbone lesions were calculated from the SPECT images using quantitative analysis software, and the SUVmax were compared between 2- and 3-hour uptake times. RESULTS: After exclusion, 30 patients were included in the study. In the 2-hour and 3-hour images, the median SUVmax of the parietal bones were 1.90 and 1.81, respectively, and those of the jawbone lesions were 9.25 and 9.39, respectively. The limits of agreement (LOA) ranged from - 0.33 to 0.25 in the parietal bones, and the %LOA ranged from - 9.8 to 17.3% in the jawbone lesions, showing high equivalence between the two uptake durations. The SUVmax showed no clinical differences between the 2- and 3-hour uptake durations for Tc-99 m HMDP SPECT of the jawbone. CONCLUSIONS: The results of this study justify a 2-3-hour uptake window when performing quantitative SPECT of the jawbone. Therefore, the minimum uptake time can potentially be reduced to only 2 hours.

Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital-based Cancer Registry.

BACKGROUND: Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type. METHODS: From a Hospital-based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow-up periods of less than 1 month. SPSS 25 was used for statistical analysis. RESULTS: The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793-12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782-10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275-9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280-9.231). The 2-year survival rate after hepatic metastasis was 21.7%. CONCLUSIONS: The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow-up after treatment.

[Basic evaluation of the optimal flip angle for hepatocyte phase with gadolinium ethoxybenzyl diethylenetriamine pantaacetic acid: selection of the optimal flip angle by the imaging findings].

Gadolinium ethoxybenzyl diethylenetriamine pantaacetic acid (Gd-EOB-DTPA) is incorporated into liver cells, and liver parenchyma show hyperintensity due to the T1 shortening effect. The T1 value of liver parenchyma in the hepatocyte phase changes from the pre-contrast phase. However, in patients with liver dysfunction, the difference of T1 value is generally small. In examination of hepatic disease, the optimal flip angle should be selected according to the patient's state. The definition of hepatic dysfunction based on biochemical data is diverse. Therefore, if the image findings can estimate liver dysfunction, the operator will select the optimal flip angle. Hence, we defined the criteria of liver dysfunction based on the image data; one or more of the following abnormalities-irregular liver surface, splenomegaly, and expansion of portal trunk. In classification by imaging data, we compared the T1 value of liver parenchyma in the hepatocyte phase, and found that the T1 value was significantly different between normal and cirrhotic liver. Then, in a phantom study simulating normal and cirrhotic liver, we set the optimal flip angle (FA)-21 degrees for the normal liver state, and 18 degrees for the LC state. In Gd-EOB-DTPA-enhanced study, the operator can select the optimal FA for each patient according to the image findings.

Detection of amiodarone-induced pulmonary toxicity in supine and prone positions: high-resolution computed tomography study.

BACKGROUND: The aim of the present study was to describe the effectiveness and feasibility of high-resolution computed tomography (HRCT) in patients in supine and prone positions to detect amiodarone-induced pulmonary toxicity (APT). With regard to the possible differential diagnosis, our second goal was to emphasize the clinical value of HRCT with the patients in supine and prone positions compared with other paraclinical tests. METHODS AND RESULTS: Thoracic HRCT taken in both positions for 23 patients who were administrated amiodarone were prospectively evaluated in the current study. High-resolution computed tomography scans obtained with the patient in a prone position were helpful in differentiating dependent opacity from lung disease in 11 out of 23 patients. In another 4 patients, HRCT scans obtained with the patient in a prone position were useful in confirming the presence of subtle ground-glass opacities, considered as APT. Combination of HRCT in supine and prone positions provided a more reproducible method for evaluating the global extent of APT than other paraclinical tests. CONCLUSIONS: High-resolution computed tomography used in prone positions as well as a supine position could be an effective technique for reducing false-positive results in detection of APT and preventing the clinically serious pulmonary adverse effects by amiodanone.

Computed tomography and magnetic resonance imaging of the pericardium: anatomy and pathology.

The purpose of this article is to review the characteristics of computed tomography (CT) and magnetic resonance imaging (MRI) of the pericardium and pericardial diseases. Because patients with pericardial diseases usually present with nonspecific symptoms, these diseases may not be detected until they have reached an advanced stage. It is therefore important to distinguish between normal pericardial structure and disease. Multiplanar reconstruction images of CT and MRI are useful for evaluating faint changes of the pericardium. The specific pericardial diseases described in this article include pericardial cyst, constrictive pericarditis, pericarditis with radiation pericarditis, postoperative pericardial hematoma, and cardiac tamponade due to a paracardiac mass (lymphoma).

Alveolar echinococcosis: MR findings in the liver.

PURPOSE: To clarify the magnetic resonance (MR) imaging findings of alveolar echinococcosis in the liver. MATERIALS AND METHODS: Thirty-five patients with 50 lesions histologically proven to be alveolar echinococcosis were evaluated with MR imaging. Lesions were assessed with regard to the distribution pattern of solid and cystic components and pattern of contrast material enhancement. RESULTS: Cystic components exhibited two patterns at T2-weighted MR imaging: small round cysts and large and/or irregular cysts. Forty-eight lesions (96%) contained small round cysts. Twenty-six lesions (52%) had large and/or irregular cysts. Forty-five lesions (90%) were associated with a solid component. MR imaging characteristics were categorized into five types: multiple small round cysts without a solid component (two lesions [4%], type 1), multiple small round cysts with a solid component (20 lesions [40%], type 2), a solid component surrounding large and/or irregular cysts with multiple small rounds cysts (23 lesions [46%], type 3), a solid component without cysts (two lesions [4%], type 4), and a large cyst without a solid component (three lesions [6%], type 5). In most cases (97%), contrast enhancement was weak. CONCLUSION: The MR findings of alveolar echinococcosis in the liver are multiple small round cysts with a weakly enhanced solid component. The cystic component can be a large and/or irregular lesion, and such lesions are depicted clearly at T2-weighted MR imaging.

Clinical role of (18)F-FDG PET for initial staging of patients with extrahepatic bile duct cancer.

In extrahepatic bile duct cancer, preoperative evaluation is important because only surgical excision of all detectable tumours is associated with improvement in 5-year survival. However, morphological imaging techniques, including computed tomography (CT), are still insufficient for accurate staging. The purpose of this study was to assess the additional value, in relation to CT, of 2-[(18)F]fluoro-2-deoxy- D-glucose positron emission tomography ((18)F-FDG PET) for the evaluation of extrahepatic bile duct cancer. Thirty patients with extrahepatic bile duct cancer underwent both (18)F-FDG PET and CT for initial staging. The results of the two modalities for evaluation of primary tumours and regional lymph nodes were compared with the final diagnoses based on pathological or clinical findings. The primary tumours were interpreted as malignant on the basis of CT in 24 (80%) of the patients, while (18)F-FDG PET revealed increased (18)F-FDG uptake in 18 (60%) of them. On the other hand, (18)F-FDG PET showed focal accumulation of (18)F-FDG in the bile duct in three of the six patients with equivocal findings on CT. The sensitivity, specificity and accuracy of CT for regional lymph node metastases were 54%, 59% and 57%, while those of (18)F-FDG PET were 38%, 100% and 73%, respectively. The specificity of (18)F-FDG PET for regional lymph node metastases was significantly higher than that of CT ( P<0.01). Of 14 patients with N1 or N2 disease diagnosed by CT, only seven (50%) had a final diagnosis of regional lymph node metastasis. In these 14 patients, (18)F-FDG PET accurately evaluated the N component of the disease in 12 patients (86%). In conclusion, in the initial staging of patients with extrahepatic bile duct cancer, (18)F-FDG PET offers additional value in relation to CT in evaluating both the primary tumour and regional lymph nodes.