Sacroplasty: a treatment for sacral insufficiency fractures.

Sacral insufficiency fracture is a debilitating injury for which no active treatment is currently available. We present three consecutive cases of elderly patients with sacral insufficiency fractures whose symptoms were relieved immediately by treatment of the fractures by polymethylmethacrylate injections, a so-called sacroplasty.

Congenital absence of the internal carotid artery: case reports and review of the collateral circulation.

Absence of the internal carotid artery (ICA) is a rare congenital anomaly. The embryology of the ICA and the common collateral pathways associated with its congenital absence are reviewed, with four new cases provided for illustration. While collateral blood flow may allow these patients to remain asymptomatic, two of our patients presented with transient ischemic attacks.

Photosensitive epilepsy studied by functional magnetic resonance imaging and magnetic resonance spectroscopy.

Purpose: To study metabolic and hemodynamic correlates of photic stimulation-triggered discharges.

Methods: Simultaneous EEG, functional MRI (tMRI) and magnetic resonance spectroscopy (MRS) were performed in nine patients with photosensitive epilepsy and in 12 normal subjects.

Results: Prominent visual cortex activation was seen in all normal subjects and patients, and no tMRI-registered hemodynamic abnormalities were correlated with the brief photoparoxysmal spike-wave activity evoked in the photosensitive patients.

Hemodynamic and metabolic aspects of photosensitive epilepsy revealed by functional magnetic resonance imaging and magnetic resonance spectroscopy.

Purpose: To study in humans the hemodynamic and metabolic consequences of both photic stimulation-triggered and spontaneous generalized epileptiform discharges.

Methods: Simultaneous EEG, functional magnetic resonance imaging (fMRI) and MR spectroscopy were performed in a 1.5-T scanner in 16 patients with generalized epilepsy, including nine with photosensitive epilepsy, and 12 normal subjects.

Assessment of cerebral perfusion and arterial anatomy in hyperacute stroke with three-dimensional functional CT: early clinical results.

Purpose: Our purpose was to determine the clinical feasibility of quantitative three-dimensional functional CT in patients with hyperacute stroke.

Methods: Twenty-two patients who underwent clinically indicated CT angiography were studied: nine patients had no stroke, eight had mature stroke, and five had hyperacute stroke (less than 3 hours since ictus). Maps were obtained of perfused cerebral blood volume (PBV), and CT angiograms were generated by using standard techniques.

Hyperacute stroke: evaluation with combined multisection diffusion-weighted and hemodynamically weighted echo-planar MR imaging.

Purpose: To evaluate acute stroke with conventional, multisection diffusion-weighted (DW), and hemodynamically weighted (HW) magnetic resonance (MR) imaging.

Materials And Methods: The three MR imaging techniques were performed in 11 patients within 10 hours of the onset of acute hemiparesis. The volume of DW and HW abnormalities were compared with infarct volumes depicted at initial and/or follow-up MR or computed tomography (CT).

Quantitative in vivo tissue sodium concentration maps: the effects of biexponential relaxation.

The biexponential relaxation behavior of the sodium nucleus affects the accuracy of quantitative measurement of in vivo tissue sodium concentration (TSC). Theoretical analysis and in vivo experimental results are used to demonstrate the extent of the large bias in the measured TSC that arises when the relaxation behavior in vivo differs significantly from that of the calibration standards which is when a significant fraction of the total sodium signal decays with a relaxation time much shorter than the echo time (TE) used for imaging. This bias can be as large as 20% for measurements of TSC in a normal rat brain with TE = 2 ms.