FDG Uptake in Brown Adipose Tissue Activated by a ß3-Adrenergic Receptor Agonist Prescribed for Overactive Bladder.

Brown adipose tissue (BAT), which produces energy and is known to play a role as a hibernating gland, is sometimes visualized on F-FDG PET in children or in slender young adults in a cold environment. Because BAT is activated by catecholamines, FDG uptake in BAT is also observed in patients with pheochromocytoma or paraganglioma. We present the case of an elderly woman with remarkable FDG uptake in BAT. Activation of BAT by a ß3-adrenergic receptor agonist (mirabegron) prescribed for overactive bladder was suspected as the cause of the marked visualization of BAT in this patient.

Postoperative gluteal skin damage associated with latent development of gluteal muscle damage.

Preceding this study, we observed two cases of concurrent postoperative gluteal skin and muscle damage with extremely high serum creatine kinase (CK) levels, both of which were unrelated to pressure-induced tissue injury. However, postoperative gluteal skin damage accompanied by gluteal muscle damage has not been previously reported and the association between gluteal skin damage, gluteal muscle damage and pressure-induced tissue injury has not previously been investigated. Therefore, we conducted this study to determine the postoperative incidence of gluteal skin damage associated with gluteal muscle damage and assess associations with postoperative serum CK levels and pressure-induced tissue injury. We prospectively evaluated postoperative incidence of gluteal skin damage and measured serum CK levels in 929 consecutive patients who underwent abdominal, urological or gynecological surgery at our hospital. Magnetic resonance imaging (MRI) of the pelvis was performed in 67 patients who consented. As a result, two of 929 patients developed postoperative gluteal skin damage accompanied by gluteal muscle damage. Gluteal muscle damage without gluteal skin damage was observed in 23 of the 67 patients who underwent MRI, and volumes of damaged gluteal muscle and postoperative serum CK levels were positively correlated. Both gluteal skin and muscle damage were distinguishable from pressure-induced tissue injury. Based on the results of this study, we could confirm the occurrence of postoperative gluteal skin damage, distinct from pressure sores, accompanied by gluteal muscle damage. We also revealed latent development of postoperative gluteal muscle damage, distinguishable from compression-induced tissue injury, without accompanying gluteal skin damage.

"Early esophageal rim enhancement": a new sign of esophageal cancer on dynamic CT.

OBJECTIVE: To retrospectively assess a new CT finding of esophageal cancer, "early esophageal rim enhancement". MATERIALS AND METHODS: Sixty-two patients with pathological proven esophageal squamous cell carcinoma who underwent dual phase CT imaging (arterial and venous phases) were enrolled. Two blinded observes independently evaluated presence of partial or circumferential enhancement of the esophageal periphery on arterial (early esophageal rim enhancement) and venous phase CT images. The radiological assessment was compared with the pathological T-stages. Agreement between the observers was also evaluated with a Cohen' kappa value. RESULTS: Pathologic results found 19, 12, 30 and 1 lesions, respectively for T1, T2, T3 and T4 stages. Agreement between two readers was substantial (κ=0.71). Esophageal rim enhancement was observed in 0, 4, 24 and 1 lesions respectively for T1, T2, T3 and T4 stages at the arterial phase, whereas no esophageal rim enhancement could be detected at the venous phase. Early esophageal rim enhancement was more frequently observed in T3/T4 lesions than T1/T2 lesions with statistical significance (p<0.0001). The sensitivity, specificity and accuracy for the diagnosis of T3 or T4 lesion were 80.6%, 87.1% and 83.9%, respectively. CONCLUSION: Early esophageal rim enhancement may be helpful for assessing invasion into the adventitia.

CT and MR features of struma ovarii.

OBJECTIVE: The purpose of this study is to investigate radiologic findings of struma ovarii, and to correlate both CT and MR findings. MATERIALS AND METHODS: MR images of 26 cases were retrospectively reviewed. Post-contrast enhanced T1-weighted images were available in 17 patients. CT images, including seven non-contrast and eleven post-contrast studies, were available for review in 13 cases. RESULTS: All 26 tumors appeared as well-defined cystic tumors with solid components, which were multilobulated surfaces in 19 and smooth surfaces in seven. Twenty-four was multicystic, whereas two were unilocular. The solid components were recognized as thickened septi or walls in 23 and a mass in three tumors. On T2-weighted images, loculi of prominent low intensity were recognized in 16 tumors. On T1-weighted images, the punctuate foci of high intensity were recognized in 24 tumors in or adjacent to the solid components. Ascites was present in only one lesion. In six of seven cases with non-contrast CT images, high attenuation areas were recognized. In five of these six tumors, high attenuation areas corresponded to the areas of prominent low intensity and the solid components on T2-weighted images. In seven cases with CT, curvilinear calcifications were recognized in the solid components. CONCLUSION: Struma ovarii typically presents as a lobulated multicystic lesion with solid components. The tumors frequently include loculi of low intensity on T2-weighted images and punctuate foci of high intensity on T1-weighted images. On CT, high attenuation areas and calcifications in the solid components are common findings.

Effect of hyoscine butylbromide (HBB) on the uterine corpus: quantitative assessment with T2-weighted (T2W) MRI in healthy volunteers.

PURPOSE: To investigate effects of hyoscine butylbromide (HBB) on the appearance of three zonal anatomy of the uterine corpus on T2-weighted images (T2WI). MATERIALS AND METHODS: Sagittal T2WI of the pelvis were acquired before and after intramuscular administration of HBB with interval of 10 minutes in 22 healthy volunteers. By drawing polygonal regions of interest (ROIs), the uterine corpus was delineated into outer myometrium (OM), junctional zone (JZ), and endometrium (EM) in 20 subjects. Areas (mm(2)) and relative signal intensity (rSI) of each layer were compared between pre-HBB and post-HBB administration images by using paired t-tests. Histogram analysis was conducted for the uterine layers and changes were visualized. RESULTS: Areas of OM were significantly increased (P = 0.014) and mean rSI of JZ and OM were significantly increased (P = 0.007 and 0.001, respectively) after administration of HBB. Histogram showed an increase in the number of pixels with higher rSI in the OM, which was considered to be caused by an increase in interstitial fluid and vascular dilatation. EM did not show significant changes. CONCLUSION: Layer-wise ROI analyses demonstrated changes in the area and rSI in T2WI of the uterus after HBB administration. Histogram analysis contributed to the investigation of signal changes.