Technical aspect of CT angiography of lower extremities.

Objective: To assess the less invasive technique of CT angiography for evaluation of lower extremity arteries with nonionic water soluble iodinated contrast medium. Methods: One hundred thirty patients underwent a CT angiography of lower extremity using smart prep technique above the iliac creast 1 inch. and the following parameters: Helical, Rotation time : 0.8 seconds, Rotation length : full, Detector configuration : 16X1.25 mm, Helical thickness : 1.25, Pitch : 1.375:1, Speed : 27.50 mm/rotation, Beam collimation : 20 mm, Image interval : 1.0 mm, Gantry tilt : 0.0, SFOV : large, X-ray energy 140 kV, 260 mA. Results: The data of CT Acquisition and Contrast Medium Parameters were Scanning coverage (mm): 1040 ฑ 88, Scanning duration (sec): 33+ 5, Number of transverse sections: 1063+ 348 iodine dose (g): 89.8+ 5.3, Concentration of contrast medium(mg/ml): 356.7+ 24.4, Volume of contrast medium (ml): 120+ 0, Contrast medium injector rate (ml/sec): 4+ 0, Injection duration (sec): 30+ 0, Scanning -to-injection duration ratio: 1.08+ 0.2, Delay between contrast medium initiation and scanning (sec): 26+ 5.3. Conclusion: The conventional study for lower extremity arteries is conventional angiography which is invasive method. This method required admission and absolute bed rest at least 8-12 hours after procedure. The CT angiography takes advantage over conventional angiography, including 3D volumetric analysis, minimally invasive vascular opacification and depiction of mural calcium. The fastest and more slices of current generation of 16 slices multidetector CT scanner is possible to study entire length of lower extremities.

A comparison of MR myelography of brachial plexus injury with CT myelography and conventional myelography.

The purpose of study is to assess the accuracy of magnetic resonance myelography (MRM) of the cervical spine in patients with preganglionic Brachial Plexus Injury (BPI) by using CT myelography as the gold standard and comparing this with routine conventional myelography. Patients with a clinically diagnosis of Brachial plexus Injury were studied (9 males, 1 female, aged 16 - 42 years old) [mean age = 25.4 years old]). All patients had undergone clinical evaluation by an orthopedic surgeon and five patients had had additional somatosensory evoked potentials (SEP) performed. All patients were investigated by conventional myelography, computed tomography myelography (CTM) and magnetic resonance myelography (MRM). We used CT myelography as the gold standard and the accuracy of MRM and myelography were assessed in relative to this. The sensitivity in detecting a pseudomeningocele by MRM is 100% and the sensitivity in detecting nerve root abnormality is 90% at the level of the C5, C6 roots and 100% for the C7, C8, T1 roots. MR Myelography had many advantages over conventional and CT myelography which include the absence of radiation and the lack of need for intrathecal injection of contrast medium.

Computed tomography of the pelvis: Utilizing the oil-filled method in evaluation of bladder neoplasm.

Five patients with oil-filled bladders were studied by computed tomography, which dramatically demonstrated the intravesical tumor component. Negative contrast bladder opacification technique is found to be accurate, reproducible and simple. Negative contrast avoids false evaluation near the bladder well from partial volume effect as occurs with positive contrast material. Thus, CT staging of bladder neoplasm may be considered a highly accurate procedure.