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Biomedical subjects

G Jenner

Publications and source records attributed to G Jenner.

8 recordsLinked to original sources
PubMed1996

MR imaging of skeletal muscle hemangiomas. A report of 16 cases.

PURPOSE: Our purpose was to evaluate how MR imaging depicts the vascular fibrofatty structure of hemangiomas. MATERIAL AND METHODS: MR images of 16 histologically proven skeletal muscle hemangiomas were reviewed retrospectively in a nonblinded manner. One patient was examined at 0.5 T, 9 at 1.0 T, and 6 at 1.5 T, and the imaging protocols varied. RESULTS: All lesions were lobulated/tubular. Signal characteristics of fat were seen in 13 lesions as lace-like thin septa within or around the tumor. All 16 studies exhibited a hyperintense signal on T2-weighted spin-echo (SE) (n=15) or T1-weighted fast fat suppressed inversion recovery SE images (n=1). Postcontrast images showed marked signal enhancement in parts of the areas, both of high and low T2-weighted signal. Surgical staging based on MR images was correct in all lesions. CONCLUSION: MR images display the characteristic vascular fibrofatty structure of hemangiomas and may allow correct diagnosis.

Adolescent↗
PubMed1994

Changes in magnetic resonance images of muscle depend on exercise intensity and duration, not work.

Echo-planar magnetic resonance imaging was used to study the effect of exercise rate and duration on magnetic resonance imaging signal intensity (SI) of anterior tibialis muscle in normal human subjects (mean age 35 yr, n = 6). Axial midcalf echo-planar images (repetition time/echo time = 6,000/45, acquisition time = 80 ms) were acquired every 6 s for 1 min before and during 15 min of dynamic ankle dorsiflexion exercise (peak force 36% of 1 repetition maximum) at 10, 20, and 30 contractions/min. At each rate, muscle SI rose along an approximately exponential time course (mean time constant 1.8 min) toward a plateau that was linearly dependent on force times contraction rate (r = 0.64, P < 0.01) but varied significantly among subjects. The results confirm previous reports that changes in muscle SI correlate with exercise intensity, but not with total work performed, over a submaximal range of exercise intensities.

Adult↗
PubMed1989

Zinc in the elderly.

Zinc levels in plasma and leucocytes of elderly patients with and without cutaneous ulcers and in hospital were compared with those of a group of healthy elderly living at home and of a younger group. The groups in hospital had lower levels of plasma and leucocyte zinc than the control groups, but these were not associated with cutaneous ulcers. The zinc intake of the patients in hospital was well below the recommended daily allowance. Tissue zinc levels were found to be low in elderly patients in hospital, probably due to poor intake, but their contribution to the formation of skin ulcers was unproven.

Aged↗
PubMedDate not supplied

Rapid MR imaging of the liver: comparison of twelve techniques for single breath-hold whole volume acquisition.

Twelve magnetic resonance imaging pulse sequences for single breath-hold whole volume acquisition of the liver were evaluated on volunteers. Liver and spleen contrast to noise ratio (C/N), overall image quality, and grade of artifacts were compared. The 12 sequences included T2-weighted fast spin echo (FSE) with or without fat suppression (FS), fast multiplanar spoiled gradient recalled imaging (FMPSPGR), fast gradient recalled imaging without preparation pulses (FGR), FGR with inversion recovery preparation pulse nulling the liver or fat (IR-FGR-L and IR-FGR-F), FGR with driven equilibrium preparation pulse (DE-FGR), single shot moderately or heavily T2-weighted spin echo echo planar imaging (SE-EPI-mT2 and SE-EPI-hT2), multi-shot moderately T2-weighted spin echo echo planar imaging (multi-shot SE-EPI-mT2), inversion recovery EPI, and gradient echo EPI. In the quantitative analysis, FSE + FS showed a significantly higher C/N ratio than the others (p < 0.05). In the qualitative evaluation, DE-prepFGR, and single and multi-shot SE-EPI-mT2 had good results, as did FSE and FSE + FS. Further studies should be conducted to determine whether or not these breath-hold sequences can obviate current conventional non-breath-hold sequences.

Adipose Tissue↗
PubMedDate not supplied

Flow velocity and volume measurement of superior and inferior mesenteric artery with cine phase contrast magnetic resonance imaging.

The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3 +/- 46.8 ml/min (mean +/- standard error) during the fasting state, and 714.7 +/- 207.7 ml/min, 339.2 +/- 85.7 ml/min, and 263.8 +/- 21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p < 0.05). The corresponding flow measurements in the IMA were 63.1 +/- 11.2 ml/min, 67.6 +/- 11.2 ml/min, 57.9 +/- 8.6 ml/min, and 53.2 +/- 6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia.

Adult↗