Effects of age and gender on neuroanatomical volumes

Purpose:

To investigate age‐related differences, gender differences, and age‐by‐gender interactions on the volumes of 18 neuroanatomical structures, with a large sample at a single institution.

Materials and Methods:

A total of 861 normal subjects (mean age = 56.1 ± 9.8 years, age range = 24.0–84.8 years) were included in this study. All subjects were scanned at 3.0 T. Measurement of the 18 neuroanatomical volumes was performed with FreeSurfer v. 4.5. Differences in volumes of neuroanatomical structures were tested using analysis of covariance with intracranial volume‐normalized volume as the dependent variable, and independent variables of age, sex, age × sex, age × age, age × age × sex, and scanner. Nonsignificant higher‐order terms were removed sequentially from the model. A P value of < 0.0028 (=0.5/18) was considered to indicate a statistically significant difference.

Results:

All neuroanatomical volumes, except for the caudate nucleus, pallidum, and 4th ventricle, were significantly related to age (linearly or quadratically). Significant gender differences were found in all neuroanatomical volumes, except for cerebral white matter, cerebellar cortex, caudate nucleus, and amygdala. No neuroanatomical volume showed a significant interaction between age (age × age) and gender.

Conclusion:

Our results showed age and gender effects on neuroanatomical volumes, and indicate no gender difference in the aging process of neuroanatomical volumes. J. Magn. Reson. Imaging 2013;37:1072–1076. © 2012 Wiley Periodicals, Inc.     

Early Pregnancy Blood Lead and Spontaneous Abortion

Although evidence tends to suggest that high levels of lead exposure increase the risk of spontaneous abortion, we do not yet know whether moderate- to low-level exposure elevates risk. Among 351 women (aged 16 to 35 years, with single pregnancies) who were registered for a longitudinal study, 15 (4.3%) women experienced spontaneous abortion after the 12th week of gestation and before the 20th week. We collected participants' blood samples during the first trimester of pregnancy (8–12 weeks) for lead measurement by inductively coupled plasma-mass spectrometry. Mean ± standard deviation of blood lead was 3.8 ± 2.0 μg/dl (range 1.0–20.5 μg/dl) with a geometric mean of 3.5 μg/dl. Mean blood lead concentrations did not differ significantly between spontaneous abortion cases and ongoing pregnancies (3.51 ± 1.42 and 3.83 ± 1.99 μg/dl, respectively). The findings suggest that in apparently healthy women, low blood lead levels (mean <5 μg/dl) measured in early pregnancy may not be a risk factor for spontaneous abortion.     

Delayed sodium 18F-fluoride PET/CT imaging does not improve quantification of vascular calcification metabolism: Results from the CAMONA study

Background

This study aimed to determine if delayed sodium ¹⁸F-fluoride (Na¹⁸F) PET/CT imaging improves quantification of vascular calcification metabolism. Blood-pool activity can disturb the arterial Na¹⁸F signal. With time, blood-pool activity declines. Therefore, delayed imaging can potentially improve quantification of vascular calcification metabolism.

Methods and Results

Twenty healthy volunteers and 18 patients with chest pain were prospectively assessed by triple time-point PET/CT imaging at approximately 45, 90, and 180 minutes after Na¹⁸F administration. For each time point, global uptake of Na¹⁸F was determined in the coronary arteries and thoracic aorta by calculating the blood-pool-corrected maximum standardized uptake value (cSUV_MAX). A target-to-background ratio (TBR) was calculated to determine the contrast resolution at 45, 90, and 180 minutes. Furthermore, we assessed whether the acquisition time-point affected the relation between cSUV_MAX and the estimated 10-year risk for fatal cardiovascular disease (SCORE %). Coronary cSUV_MAX (P = .533) and aortic cSUV_MAX (P = .654) remained similar with time, whereas the coronary TBR (P < .0001) and aortic TBR (P < .0001) significantly increased with time. Even though the contrast resolution improved with time, positive correlations between SCORE % and coronary cSUV_MAX (P < .020) and aortic cSUV_MAX (P < .005) were observed at all investigated time points.

Conclusions

Delayed Na¹⁸F PET/CT imaging does not improve quantification of vascular calcification metabolism. Although contrast resolution improves with time, arterial Na¹⁸F avidity is invariant to the time between Na¹⁸F administration and PET/CT acquisition. Therefore, the optimal PET/CT acquisition time-point to quantify vascular calcification metabolism is achieved as early as 45 minutes after Na¹⁸F administration.     

Percutaneous thermal ablation of medium and large hepatocellular carcinoma

BACKGROUND:

Radiofrequency ablation (RFA) and microwave ablation (MWA) were found to be effective in treating hepatocellular carcinoma (HCC) smaller than 3 cm; however, to the authors' knowledge, the usefulness of thermal ablation in treating larger HCC, especially those >5 cm, has not been well documented. The present study evaluated the therapeutic efficacy of percutaneous thermal ablation with curative intention for HCC measuring between 3.0 cm and 7.0 cm.

METHODS:

Percutaneous RFA or MWA were used to treat 109 HCC patients with at least 1 tumor measuring between 3.0 cm and 7.0 cm. Fifty?eight patients received thermal ablation as the first treatment, and the remaining 51 were treated for posthepatectomy recurrent HCC. A total of 89 patients had a main tumor measuring 3.0 cm to 5.0 cm, and 20 patients had main tumors measuring 5.0 cm to 7.0 cm. Local therapeutic efficacy, long‐term outcome, and prognostic factors were analyzed.

RESULTS:

There were no treatment‐related deaths, and the major complication rate was 9.2%. Complete ablation rate was 92.6%. Local recurrence (LR) occurred in 22% patients, with a median time to LR of 4.6 months. Distant recurrences developed in 53.2% patients. The 1‐year, 3‐year, and 5‐year survival rates were 75.8%, 30.9%, and 15.4%, respectively. Univariate analysis indicated that incomplete tumor ablation, posthepatectomy recurrence, and preablation α‐fetoprotein (AFP) ≥200 ng/mL were 3 unfavorable prognostic factors for long‐term survival (P = .000, .015, and .008, respectively). Cox regression analysis confirmed that incomplete tumor ablation, recurrent tumors, and preablation AFP ≥200 ng/mL were independent unfavorable prognostic factors, with an exp(B) of 4.158 (P = .001), 1.568 (P = .082), and 1.593 (P = .082), respectively.

CONCLUSIONS:

Percutaneous thermal ablation was effective and safe in treating HCC between 3 cm and 7 cm, with acceptable local tumor control and long‐term outcomes. Completeness of ablation, previous history of treatment, and preablation AFP level were significant prognostic factors. Cancer 2009. © 2009 American Cancer Society.