OBJECTIVE: A marked impact on the splanchnic circulation is seen in liver cirrhosis. Doppler ultrasonography (DUS) was performed in a group of patients with end-stage liver cirrhosis before, during and after orthotopic liver transplantation (OLT) in order to investigate the hemodynamic changes in portal vein flow velocity. MATERIALS AND METHODS: Fifty-four patients submitted to OLT and intraoperative DUS were prospectively studied from January 2002 to July 2003. Seventeen patients were excluded because of missing data due to either technical difficulties to obtain the measurements or early patient death. All 37 patients included in the analysis had liver cirrhosis mainly associated with hepatitis C virus infection and alcoholic disease. Patients were submitted to DUS just before OLT, intraoperatively after graft reperfusion, and in the postoperative period (1st and 7th postoperative days). Mean flow velocity was measured at main, right and left portal veins. Statistical analysis was performed using paired t test. Differences were significant when p < 0.05. RESULTS: The mean pre-OLT velocity in the portal vein was 16.0 cm/s. Intraoperative measurements obtained few minutes after graft reperfusion showed an increase in portal vein velocity to 84.09 cm/s. Portal flow velocity was 71.0 cm/s and 58.5 cm/s in the 1st and 7th postoperative days, respectively. Intraoperative and postoperative mean flow velocity in the portal vein was significantly higher than in pre-OLT period (p < 0.001). On the 7th postoperative day, the mean flow velocity in the portal vein decreased significantly compared to intraoperative values (p < 0.05). CONCLUSION: In liver transplantation, there is a significantly increase in mean flow velocity in the portal vein immediately after graft reperfusion when compared to pre-OLT data. Likewise, after this initial peak flow there is a significant and progressive decrease in mean flow velocity in the portal vein, which tends to normalize on the 7th postoperative day.

Keywords: Portal vein, Mean velocity, Transplantation, Hemodynamics

The aim of this study is to compare helical computed tomography with imaging studies currently used to evaluate patients with acute low back pain. In addition, we briefly review the pathophysiology of urolithiasis. The literature published in the last 30 years was reviewed, and the following methods were discussed: plain abdominal radiographs, intravenous pielography, ultrasound of the urinary tract, and helical computed tomography. Helical computed tomography showed high sensitivity and specificity for detecting urolithiasis, virtually showing all stones, except in patients receiving indinavir. The accuracy of plain abdominal radiographs associated with ultrasound was similar to helical computed tomography, although the latter showed superiority as an isolated method. Data from literature suggest that whenever helical computed tomography is available, it is helpful in the evaluation of low back pain and also allows differential diagnosis between conditions that mimic the symptoms of urolithiasis.

Keywords: Plain abdominal radiographs, Helical computed tomography, Intravenous pielography, Low back pain, Ultrasound of the urinary tract, Urolithiasis

Knee pain is the most frequent symptom in osteoarthritis, a condition that is the leading cause of chronic disability in the elderly and one of the main sources of morbidity attributable to osteoarthritis in general. The causes of knee pain in individuals with osteoarthritis cannot be easily understood, and the knowledge of such causes is critical for determining future specific interventions. Bone attrition represents remodelling of the subchondral bone envelope in osteoarthritis, leading to a consequential change in bone shape and/or bone loss. However, bone attrition is not a feature that can be easily read, since it is hardly detected in the absence of clear defects of cortical bone integrity and because of overlap of bone structures at radiography. Bone attrition is associated not only with knee pain, but also with stiffness and disability. If attrition occurs prior to advanced osteoarthritis, this would suggest that changes in subchondral bone occur concurrently with cartilage loss and that treatments targeting cartilage loss alone are unlikely to be effective. Association with edemalike bone marrow lesions may be observed and constitute predictive factors for subchondral bone attrition. The present study was aimed at reviewing the literature, demonstrating the relevance of bone attrition and explaining how to diagnose this entity on imaging studies.

Keywords: Magnetic resonance imaging; Osteoarthritis; Knee pain; Bone attrition; Subchondral bone; Diagnosis.

In recent decades, there has been a significant increase in the number of imaging examinations performed on pregnant patients. That increase has occurred across the various modalities, including ultrasound, computed tomography, and magnetic resonance imaging. However, little is known about the risks that these examinations generate for the mother and fetus, related to the use of ionizing radiation or the use of contrast media. When pregnant patients are submitted to imaging studies, the principles of protection established by the International Commission on Radiological Protection should always be respected, to avoid injury to the pregnant woman and the fetus. The potential deleterious effects on the fetus must be weighed against the damage caused by not performing an examination that is clearly indicated, given that a delayed or missed diagnosis can be even more harmful to the health of the mother and of the fetus itself. The purpose of this review article is to address concerns regarding the safety of imaging methods used during pregnancy, as well as to identify typical clinical situations that require decisions to be made about the indication and optimal planning of imaging examinations.

Keywords: Pregnancy/radiation effects; Fetus/radiation effects; Emergencies; Radiography/adverse effects; Tomography, X-ray computed/adverse effects; Radiation protection.