Our aim was to compare contrast-enhanced MR angiography (CE-MRA) and 3D time-of-flight (TOF) MRA at 3T for follow-up of coiled cerebral aneurysms.
Fifty-two patients treated with Guglielmi detachable ...coils for 54 cerebral aneurysms were evaluated at 3T MRA. 3D TOF MRA (TR/TE = 23/3.5; SENSE factor = 2.5) and CE-MRA by using a 3D ultrafast gradient-echo sequence (TR/TE = 5.9/1.8; SENSE factor = 3) enhanced with 0.1-mmol/kg gadobenate dimeglumine were performed in the same session. Source images, 3D maximum intensity projection, 3D shaded surface display, and/or 3D volume-rendered reconstructions were evaluated in terms of aneurysm occlusion/patency and artifact presence.
In terms of clinical classification, the 2 MRA sequences were equivalent for 53 of the 54 treated aneurysms: 21 were considered fully occluded, whereas 16 were considered to have a residual neck and 16 were considered residually patent at follow-up MRA. The remaining aneurysm appeared fully occluded at TOF MRA but had a residual patent neck at CE-MRA. Visualization of residual aneurysm patency was significantly (P = .001) better with CE-MRA compared with TOF MRA for 10 (31.3%) of the 32 treated aneurysms considered residually patent with both sequences. Coil artifacts were present in 5 cases at TOF MRA but in none at CE-MRA. No relationship was apparent between the visualization of patency and either the size of the aneurysm or the interval between embolization and follow-up.
At follow-up MRA at 3T, unenhanced TOF and CE-MRA sequences are similarly effective at classifying coiled aneurysms as occluded or residually patent. However, CE-MRA is superior to TOF MRA for visualization of residual patency and is associated with fewer artifacts.
New Findings
What is the central question of this study?
Do obesity‐specific factors affect skeletal muscle performance in older individuals?
What is the main finding and its importance?
Older obese ...women have a larger quadriceps femoris size but develop lower tension per unit of skeletal muscle than their normal‐weight counterparts.
Muscle impairment and excess body mass are very common among older people. Given that the effect of obesity on strength production has scarcely been studied in older individuals, we analysed functional and structural characteristics of quadriceps femoris (QF) in obese (OB) and normal‐weight (NW) older women with comparable habitual physical activity. In five OB (body mass index 36.8 ± 1.9 kg m−2, age 72.4 ± 2.3 years) and six NW well‐functioning older women (body mass index 24.3 ± 1.8 kg m−2, age 72.7 ± 1.9 years), peak knee‐extension torque (KET) was measured in isometric (90 deg knee flexion) and isokinetic conditions (240, 180, 120 and 60 deg s−1). Mid‐thigh QF cross‐sectional area (CSA) and muscle tissue fat content (MF%) were determined with magnetic resonance imaging (Dixon sequence). Muscle fascicle length and pennation angle (PA) were assessed with ultrasonography for each muscle belly of the QF (vastus lateralis, vastus intermedius, rectus femoris and vastus intermedius). Despite similar values of KET, CSA was 17.0% larger in OB than in NW women (P < 0.05), so that KET/CSA was significantly lower (P < 0.05) in OB women. Compared with NW women, OB women had 28.7% higher MF% (P < 0.05) and 24.9% higher average PA (P < 0.05), while fascicle length was similar. Overall, isometric KET/CSA was negatively affected by both MF% (P < 0.05) and PA (P < 0.05), while isokinetic KET/CSA was negatively affected only by MF% (P < 0.01). Muscle composition and architecture seem to be important determinants of KET/CSA in elderly women. In fact, owing to the effect of obesity overload, OB women have a larger QF size than NW women, but unfavourable muscle composition and architecture. The higher MF% and steeper PA observed in OB women are associated with reduced levels of muscle specific strength.
A preclinical insert for small animal simultaneous SPECT and MR imaging, in particular for imaging mouse brains, is presented. It consists of ten static magnetic resonance imaging (MRI)-compatible ...gamma cameras based on tiles of silicon photomultipliers readout by a multichannel ASIC and coupled to 5 cm × 5 cm CsI(Tl) scintillators and to an MRI-compatible multipinhole collimator. Calibration and image reconstruction algorithm are illustrated. Mutual compatibility is demonstrated along with imaging performance that is comparable with other non-MR micro-SPECT systems: 0.9 mm tomographic spatial resolution across a transverse field of view of 15.6 mm, 12% energy resolution (at 140 keV), and 1105 cps/MBq sensitivity. Experimental results with phantoms (glass capillaries of 290 μm diameter and a mini Derenzo) are presented.
Purpose
Histology is the gold standard by which to diagnose and score hepatic fibrosis. Recently, it has been proposed that hepatic magnetic resonance spectroscopy (MRS) could provide an accurate ...representation of the disease process. The aim of this study was to correlate the in vivo high-field (3-Tesla)
1
H MRS features of noncirrhotic chronic hepatitis C patients stratified according to the histopathological stages of fibrosis.
Materials and method
Six healthy controls and 23 patients with biopsy-proven precirrhotic hepatitic C virus (HCV)-related liver disease were included. The subdivision of patients into the histopathological stages of fibrosis was based on the Ishak fibrosis (F) scoring system: mild hepatitis (0≤F≤1), moderate (2≤F≤3) and severe hepatitis (4≤F≤5). For correlation analysis, the Spearman nonparametric test was used. Differences between groups were calculated with the nonparametric Mann-Whitney
U
test. A
p
value <0.05 was considered significant. The particular metabolite content was evaluated in relative units (RU), according to the pattern metabolite/H
2
O=area of the metabolite ×1,000/area of nonsuppressed water.
Result
A significant statistical difference was observed between control vs. mild and moderate vs. severe disease severity in choline-containing compounds (CCC)/H
2
O ratios (
p
=0.0379 and
p
=0.0003) and in glutamine/glutamate (Glx)/H
2
O ratios (
p
=0.004 and
p
<0.0001), whereas a statistically significant difference in the lipid/H
2
O ratios was achieved only between control vs. moderate and between moderate vs. severe stages of disease (
p
=0.011 and
p
=0.0030).
Conclusion
High-field
1
H MRS successfully differentiates between mild/moderate vs. severe stages of chronic hepatitis and can be considered a complement to most standard imaging protocols in the liver.
Total sleep deprivation combined with light therapy causes rapid amelioration of bipolar depression. A polymorphism in the promoter for the serotonin transporter influences both antidepressant ...response and the structure and function of specific brain areas.
To determine whether antidepressant therapy or the genotype of the serotonin transporter influence the pattern of neural response to a task targeting the depressive biases in information processing (moral valence decision).
Before-and-after trial studying the biologic correlates of response to treatment.
University hospital. Patients Twenty inpatients with bipolar depression. Intervention Repeated total sleep deprivation combined with light therapy for 1 week.
Brain blood oxygen level-dependent functional magnetic resonance imaging using a 3.0-T scanner before and after treatment. Self-ratings and observer ratings of mood (visual analog scale 3 times daily and Hamilton Depression Rating Scale) before and after treatment.
We found significant interactions of treatment (before and after), response to treatment (Hamilton Depression Rating Scale score <8), and moral valence of the stimuli (positive or negative) in the anterior cingulate cortex, dorsolateral prefrontal cortex, insula, and parietal cortex. In these areas, responders changed their blood oxygen level-dependent responses to emotional stimuli in a pattern opposite of that in nonresponders. Genotype of the promoter for the serotonin transporter predicted response to treatment and influenced baseline neural responses in the anterior cingulate cortex and the dorsolateral prefrontal cortex.
Multiple factors that affect or are affected at the individual level by major depressive episodes in the course of bipolar disorder significantly interact in influencing brain cortical activity in specific areas.
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