No abstract

The diagnostic gain associated with image subtractions was assessed regarding contrast-enhanced 3D magnetic resonance angiography (MRA) image sets of the pelvic and lower extremity arteries. The MRA strategy combined a dedicated vascular coil with a single injection, two-station protocol. Voxel-by-voxel signal intensity subtraction was performed on MRA image sets obtained before and during dynamic infusion of a para-magnetic contrast agent. Nonsubtracted and subtracted MRA image sets were assessed for the presence of occlusive (four grades) disease, using DSA as the standard of reference. In addition, SNR and CNR were recorded for each vascular segment on both the non-subtracted and subtracted images. Index terms: magnetic resonance angiography; peripheral vascular disease; image subtraction; contrast media; magnetic resonance imagery CONTRAST-ENHANCED 3D MRA combines fast 3D gradient echo imaging with the intravenous administration of a para-magnetic contrast agent. Collected during the intra-arterial phase of the intravenously administered para-magnetic contrast agent (1-3), the images provided by this technique display arteries containing the T1-shortening contrast agent, thereby eliminating saturation-and turbulence-induced artifacts which limit time-of-flight and phase-contrast MRA (4 -6). Contrast-enhanced 3D MRA has thus emerged throughout the world as the modality of choice for assessing the thoracic and abdominal aorta (1,(7)(8)(9)(10)(11)(12), and the renal, pelvic and carotid arteries (13-17).Contrast-dose limitations initially curtailed the technique to the display of the vascular territory contained within a single 40 cm-48 cm field of view. The development of "bolus chase" techniques has extended coverage to the entire run-off vasculature, encompassing the pelvic, femoral, popliteal and trifurcation arteries. Based on intermittent rapid table motion during a slow intravenous injection of a para-magnetic contrast agent, the technique allows for the acquisition of several slightly overlapping 3D data sets (18,19).To compensate for enhancement of surrounding tissues due to capillary leakage associated with the slow infusion of the extra-cellular agents, some investigators recommend the use of a subtraction technique (18 -22). Image subtraction, however, prolongs and complicates the MRA exam; the time for data acquisition and image reconstruction is doubled, due to collection and reconstruction of baseline images at identical locations prior to administration of the contrast agent. Furthermore, the actual subtraction process is time-consuming. To avoid partial volume effects related to the phase differences between the flowing and stationary magnetization within a voxel, complex subtractions have been proposed (23). In contrast to the more commonly employed magnitude subtractions, complex subtractions can be performed either by subtracting the raw or Fourier-transformed data, followed by magnitude image calculation or subtraction of phase-corrected, real-part images.The purpose of this study was to det...

No abstract

In the study presented, the long-term outcome and satisfaction of 34 patients who underwent simultaneous bilateral breast reconstruction with a free transverse rectus abdominis muscle (TRAM) flap between 1988 and 2001 were assessed. Flap complications affected 13 of 68 flaps (19.1%). Anastomosis revision was needed in 6 cases (8.8%), the salvage rate being 50%. The rates of total and partial flap loss were 4.4% and 1.5%, respectively. Bilateral flap loss did not occur. Four patients developed donor site complications (11.7%), with wound healing problems being the most common (5.8%). Most patients were satisfied with their decision to have had breast reconstruction with free TRAM, 91% would choose the same operation again, and 91% would recommend this procedure to other patients. Of the operated patients, 20.8% felt an improvement in their sexual life; more patients, however, reported an improvement concerning their social life (37.5%) and life in general (50%).

The low profile AO system appears effective in achieving bony union whilst minimising incidence of hardware irritation, at a follow up of 2 years.

Following surgical reduction of an irreducible hip in developmental dysplasia of the hip, imaging is required to ascertain successful reduction. Recent studies have compared MRI versus computed tomography (CT) in terms of cost, time, sensitivity and specificity. This is the first study to compare intraobserver and interobserver reliability for both modalities. Nineteen CT scans of 38 hips in 10 patients and nine MRI scans of 18 hips in six patients were reviewed on two separate occasions by three clinicians. Image clarity, confidence of diagnosis, time taken to perform the scan as well as radiation dose for CT were recorded. Intraobserver and interobserver reliability κ values were calculated. There were 14 female patients and one male patient. The mean age at the time of the scan was 12 months (range 3-25 months). Intraobserver reliability was greater than 0.8 (both CT and MRI). Interobserver reliability was greater than 0.8 (both CT and MRI). Image clarity was higher for CT for two out of the three clinicians (9.47 vs. 6.33 P<0.05; 9.89 vs. 8.11, P<0.05). All clinicians were equally confident in the diagnosis when using CT or MRI. The time taken to perform the investigation was not significantly different (3.32 vs. 4.88 min, P>0.05). The mean radiation dose for CT was 91.75 DLP (dose length product, mGy×cm) (95% confidence interval±26.95). Our results show that MRI is equal to CT as an imaging modality in the assessment of postreduction hips in developmental dysplasia of the hip. Intraobserver and interobserver reliability was excellent for both. The image clarity was higher for CT, but this method of imaging carries a significant risk of radiation exposure. We recommend that MRI should supersede CT as an imaging modality for this clinical situation.

No abstract

Although patients were more satisfied with the results of autologous breast reconstruction, procedure choice did not affect quality of life.