Age- and sex-specific changes in visceral fat mass throughout the life-span.

OBJECTIVE: Visceral fat mass (VFM) is a risk factor for cardiovascular diseases, type 2 diabetes mellitus, and malignancy; however, normative data are limited. The aim of this study was to provide reference data for VFM from a large, apparently healthy Caucasian adult population. METHODS: Volunteers aged 20 to 93 years from the Copenhagen City Heart Study had a standardized whole-body dual-energy x-ray absorptiometry scan performed using the iDXA (GE Lunar). Total and regional fat mass was measured. VFM was quantified using the CoreScan application. RESULTS: A total of 1277 participants were included (708 women, mean [SD], age: 56 [19] years, height: 1.66 [0.07] m, BMI: 24.64 [4.31] kg/m2 ; and 569 men, age: 57 [18] years, height: 1.80 [0.07] m, BMI: 25.99 [3.86] kg/m2 ). Increased VFM was positively correlated with age in both sexes. Men had significantly higher VFM in mass (g) after normalization to body size (m2 ) and total fat mass (p < 0.001). VFM increased more in women with high values of the android/gynoid ratio. CONCLUSIONS: Normative data of VFM from a large, healthy Danish cohort aged 20 to 93 years are presented. VFM increased with age in both sexes, but men had significantly higher VFM compared with women with the same BMI, body fat percentage, and fat mass index.

Comparison of temporal artery ultrasound versus biopsy in the diagnosis of giant cell arteritis.

BACKGROUND/OBJECTIVES: Giant cell arteritis (GCA) is a medical and ophthalmological emergency due to risk of stroke and sudden irreversible loss of vision. Fast and accurate diagnosis is important to prevent complications and long-term high dose glucocorticoids toxicity. Temporal artery biopsy is gold standard for diagnosing GCA. However, temporal artery ultrasound is a fast and non-invasive procedure which may provide a supplement or an alternative to biopsy. This study assesses the diagnostic performance of ultrasound and biopsy in the diagnosis of GCA. SUBJECTS/METHODS: Examination results of patients suspected of having GCA in the period from August 2018 to June 2019 were reviewed. Patients underwent clinical examination and blood tests. Within a few days of starting glucocorticoid treatment, temporal ultrasound and unilateral biopsy were performed. Experienced physicians established the final clinical diagnosis at 6-months follow-up. RESULTS: Seventy-eight patients underwent both ultrasound and biopsy. Thirty-five (45%) received the final clinical diagnosis of GCA. Compared with the final clinical diagnosis, biopsy had a sensitivity of 69% (51-83%) and a specificity of 100% (92-100%), and ultrasound a sensitivity of 63% (45-79%) and a specificity of 79% (64-94%). Area under the receiver operating characteristics curves were 0.84 and 0.71 for biopsy and ultrasound respectively (p = 0.048). False negative rate of ultrasound was 4 out of 78 (5%). CONCLUSION: Sensitivity of ultrasound is almost on par with that of biopsy although the overall diagnostic accuracy of ultrasound was slightly lower. We find that ultrasound is a reliable tool for first line diagnosis of GCA.

Multimodality Imaging in Cranial Giant Cell Arteritis: First Experience with High-Resolution T1-Weighted 3D Black Blood without Contrast Enhancement Magnetic Resonance Imaging.

In order to support or refute the clinical suspicion of cranial giant cell arteritis (GCA), a supplemental imaging modality is often required. High-resolution black blood Magnetic Resonance Imaging (BB MRI) techniques with contrast enhancement can visualize artery wall inflammation in GCA. We compared findings on BB MRI without contrast enhancement with findings on 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/low-dose computed tomography (2-[18F]FDG PET/CT) in ten patients suspected of having GCA and in five control subjects who had a 2-[18F]FDG PET/CT performed as a routine control for malignant melanoma. BB MRI was consistent with 2-[18F]FDG PET/CT in 10 out of 10 cases in the group with suspected GCA. In four out of five cases in the control group, the BB MRI was consistent with 2-[18F]FDG PET/CT. In this small population, BB MRI without contrast enhancement shows promising performance in the diagnosis of GCA, and might be an applicable imaging modality in patients.

Bilateral Vertebral Artery Vasculitis-A Rare Manifestation of Giant Cell Arteritis and a Difficult Diagnosis Made Possible by 2-[18F]FDG PET/CT.

Giant cell arteritis (GCA) is the most common form of large vessel vasculitis. GCA is a medical and ophthalmological emergency, and rapid diagnosis and treatment with high-dose corticosteroids is critical in order to reduce the risk of stroke and sudden irreversible loss of vision. GCA can be difficult to diagnose due to insidious and unspecific symptoms-especially if typical superficial extracranial arteries are not affected. In these cases, verification of clinical diagnosis using temporal artery biopsy is not possible. This example illustrates the diagnostic value of hybrid imaging with 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (2-[18F]FDG PET/CT), and the limitations of the temporal artery biopsy in bilateral vertebral GCA, causing transient ischemic attack in the visual cortex. In addition it indicates that inflammation in the artery wall can be visualized on 2-[18F]FDG PET/CT despite long term and ongoing high dose glucocorticoid treatment.

[Positron emission tomography/computed tomography in follow-up programmes for patients with colorectal cancer].

The current follow-up programmes for patients with colorectal cancer (CRC) after curative surgery do not include 18F-fluorodeoxyglucose-positron emission tomography (PET). Several small studies on selected patient populations indicate a high sensitivity of PET/computed tomography (CT) on visualizing relapse in patients with CRC after curative surgery. Therefore, PET/CT could probably be valuable in patients with unexplained increase in carcinoembryonic antigen level or a clinical suspicion of relapse, but PET/CT is not recommended as a standard in follow-up after CRC.

Higher vascular endothelial growth factor-C concentration in plasma is associated with increased forearm capillary filtration capacity in breast cancer-related lymphedema.

Breast cancer-related lymphedema (BCRL) is a frequent, chronic and debilitating swelling that mainly affects the ipsilateral arm and develops as a complication to breast cancer treatment. The pathophysiology is elusive opposing development of means for prediction and treatment. We have earlier shown that the forearm capillary filtration coefficient (CFC) is increased bilaterally in BCRL. In this study, we aimed to elucidate if increased CFC is associated with low-grade inflammation and/or vascular endothelial growth factor-c (VEGF-C) signaling. Fourteen patients with unilateral BCRL and nine matched breast cancer controls without BCRL participated. Forearm CFC was measured by venous congestion strain gauge plethysmography, and suction blisters were induced medially on the upper arms. Concentrations of 17 selected cytokines, VEGF-C, and total protein were measured in blister fluid and in plasma. Forearm CFC was higher bilaterally in BCRL subjects (P ≤ 0.036). No differences between forearms were found in either group. Plasma VEGF-C concentrations were significantly higher in the BCRL subjects (P < 0.001). In BCRL subjects, monocyte chemotactic protein 1 (MCP-1) (P = 0.009) and total protein (P = 0.035) concentrations were higher in blister fluid from edematous arms compared with nonedematous arms. No differences were found in interstitial cytokine or total protein concentrations between arms in control subjects. Higher plasma concentration of VEGF-C is a possible cause of bilaterally increased forearm CFC in BCRL subjects. Interstitially increased MCP-1 levels may augment local microvascular protein permeability in BCRL.

Foot skin depots of 18F-fluorodeoxyglucose do not enable PET/CT lymphography of the lower extremity lymphatic system in man.

BACKGROUND: In mice, 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT) lymphography enables detailed imaging of the lymphatic system and quantification of lymph node function. If this applies to humans, it may improve staging of several malignancies. The aim of this study was to elucidate whether foot skin depots of 18F-FDG make PET/CT imaging of the lower extremity lymphatic system possible in man. FINDINGS: In four healthy volunteers, 18F-FDG depots (5 MBq in 0.1-mL isotonic saline) were injected intradermally in one foot and subcutaneously in the other. Activity was measured in blood samples drawn simultaneously from the great saphenous veins about 5 cm proximal to the ankle joints and a medial cubital vein before and every minute for 15 min after depot injection. Immediately thereafter, a low-dose CT was performed from the ankles to the pelvis followed by two consecutive PET scans of the same region.Blood activity increased faster and to a greater extent in the great saphenous veins compared to the medial cubital vein. PET/CT images showed activity in the superficial and deep veins of the lower extremities. No lymphatic collectors or nodes were visualized. CONCLUSION: Neither subcutaneous nor intradermal injection of 18F-FDG allows imaging of the lower extremity lymphatic system in man.

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphedema.

Breast cancer-related lymphedema (BCRL) is a frequent and debilitating complication of breast cancer treatment. The pathophysiology is complex and remains poorly understood; however, data suggest that changes in the peripheral circulation may contribute to edema formation. In 13 volunteers with unilateral BCRL, the following aspects of upper extremity peripheral circulation were examined: muscle relative microvascular volume; capillary filtration coefficient; central and local sympathetic vascular reflexes; skin blood flow; and forearm blood flow. These were studied via real-time, contrast-enhanced ultrasound; venous occlusion strain-gauge plethysmography; lower-body negative pressure; noninvasive blood pressure measurements; and skin (99m)Tc-pertechnetate clearance technique. Measurements were performed bilaterally and simultaneously in the forearms, enabling use of the nonedematous forearm as a control. Capillary filtration coefficients were additionally measured in healthy, age-matched controls. The capillary filtration coefficient was 7.98 ± 2.52 µl·100 ml(-1)·mmHg(-1)·min(-1) (mean ± SD) in edematous forearms and 6.09 ± 1.83 µl·100ml·(-1)·mmHg(-1)·min(-1) in nonedematous forearms in the patient group (P < 0.001). The capillary filtration coefficient was 3.32 ± 1.17 µl·100ml(-1)·mmHg(-1)·min(-1) in the forearms of healthy controls; significantly less than the both the edematous and nonedematous forearms of the patient group (P < 0.001). No significant differences were found in muscle relative microvascular volume, forearm blood flow, skin blood flow, or central or local sympathetic vascular reflexes. Forearm microvascular filtration is increased in patients with BCRL, and more so in the edematous arm. The vascular sympathetic control mechanisms seem to be preserved. We propose that the increased capillary permeability may be due to low-grade inflammation promoted by reduced clearance of inflammatory mediators.

(18)F-FDG PET/CT in a rare case of Stewart-Treves syndrome: future implications and diagnostic considerations.

BACKGROUND: The aim of this article is to illustrate the possible applications of (18)F-fluorodeoxyglucose positron emission tomography/computer tomography ((18)F-FDG PET/CT) in chronic extremity lymphedema and its complications. METHODS AND RESULTS: (18)F-FDG PET/CT findings in a rare case of Stewart-Treves Syndrome (STS), angiosarcoma secondary to chronic extremity lymphedema, are presented. Lymphedema of the extremities is a debilitating disease characterized by chronic swelling due to interstitial edema caused by insufficient lymphatic drainage capacity. Progression with skin thickening, subcutaneous fibrosis, and increased adipose tissue volume is common. Chronic inflammation has been suggested as a key pathophysiologic component. STS is a rare complication with a very poor prognosis; however, early diagnosis and radical treatment is associated with increased survival. Thus, accurate pretreatment staging is paramount. (18)F-FDG PET/CT is highly sensitive in detecting increased glucose metabolism as seen in many types of cancer and inflammation. The role of (18)F-FDG PET/CT in the management of lymphedema and its complications has to our knowledge yet to be described. This case documents high (18)F-FDG uptake in STS, but is at the same time an example of the low specificity of this imaging modality. CONCLUSIONS: We suggest that (18)F-FDG PET/CT has the potential to become an important tool in the staging and treatment planning of Stewart-Treves syndrome. Furthermore, (18)F-FDG-accumulation may be a sensitive tool in detecting low grade inflammation in the skin and subcutis, which has been suggested to cause tissue remodeling in lymphedema progression. However, further studies are needed to elucidate this theory.