Importance of radiological detection of early pulmonary acute complications of liver transplantation: analysis of 259 cases.

PURPOSE: Pulmonary complications are common causes of morbidity and mortality after orthotopic liver transplantation (OLT) and consist of atelectasis, pleural effusion, pulmonary oedema, adult respiratory distress syndrome (ARDS) and pneumonia. The aim of this paper is to describe the incidence of pulmonary complications after OLT during the first postoperative week and to evaluate the informative value of the chest X-ray (CXR) in clinical practice. MATERIALS AND METHODS: Patients who underwent OLT at the Ancona Transplant Centre between August 2005 and August 2012 were included in this retrospective study. The CXR and, if performed, the thoracic computed tomography (TCT) scans performed during the first 7 postoperative days were reviewed, and the radiological findings for atelectasis, pleural effusion, pulmonary oedema, ARDS and pneumonia were independently assessed and quantified by two radiologists according to the Fleischner Society criteria. Cases of pneumothorax after thoracentesis were assessed. Development of pneumonia was defined as the simultaneous presence of positive CXR or TCT and positive serological or fluid samples and clinical symptoms; the prevalence of infectious agents was assessed. The radiological reports produced in the clinical setting were compared with the findings. RESULTS: Among 259 patients included, atelectasis was observed in 227 patients (87.6 %); pleural effusion in 250 (96.5 %); pulmonary oedema in 204 (78 %); ARDS in seven patients (2.6 %); and pneumothorax in 37 patients (14 %). Pneumonia occurred in 32 cases (12.3 %). Pulmonary oedema was underestimated in the radiological reports in 104 cases (40 %). CONCLUSIONS: Knowledge about postoperative pulmonary complications and collaboration between the radiologist and clinician are essential for improving the management of OLT recipients.

Magnetic resonance imaging (MRI) artefacts in hip prostheses: a comparison of different prosthetic compositions.

PURPOSE: The purpose of the study was to compare the artefacts produced by different hip prostheses on magnetic resonance imaging (MRI). MATERIALS AND METHODS: An identical MRI protocol was used to perform a quali-quantitative in vitro evaluation of artefacts caused by different hip prosthetic materials at different field strengths: prosthesis number 1, composed of cobalt-chrome-molybdenum (head and stem); prosthesis number 2, composed of ceramic (head) and titanium (stem); prosthesis number 3, composed of cobalt-chrome (head) and titanium (stem). All prostheses were imaged with both a clinical 1 Tesla (T) (Signa Horizon, General Electrics) and 1.5 T (Achieva, Philips) MRI system, using spin echo (SE) and gradient echo (GRE) sequences: sagittal T1 SE, coronal T2 fast SE (FSE), axial T1 SE, axial T2 FSE, sagittal T2 GRE, axial T2* GRE, coronal T1 GRE, axial T1 GRE. The artefacts produced by each prosthesis were assessed in each sequence at the different field strengths, by measuring the two longest diameters of the artefact in each section and sequence and comparing them to the actual diameters so as to obtain a ratio expressing the effective degree of artefact. RESULTS: Cobalt-chrome produced the largest artefacts both in SE (1.73 at 1 T and 2.37 at 1.5 T) and GRE sequences (2.8 at 1 T and 3.06 at 1.5 T) followed by titanium (SE, 1.6 at 1 T, 2.13 at 1.5 T; GRE, 2 at 1 T, 2.94 at 1.5 T) and cobalt-chrome-molybdenum (SE, 1.51 at 1 T, 1.67 at 1.5 T; GRE, 2.13 at 1 T and 2.48 at 1.5 T); ceramic produced the smallest artefacts in all sequences (SE, 1.0 at 1 T and 1.18 at 1.5 T; GRE, 1.3 at 1 T and 1.22 at 1.5T). Increasing the magnetic field strength, titanium showed the greatest variations in artefact size, and ceramic the smallest ones. CONCLUSIONS: The composition of prosthetic implants is decisive in determining the quality of MR imaging.