Molecular imaging in a (pre-) clinical context

Molecular imaging can be defined as imaging of biological processes in a living organism at the molecular and/or cellular level. To achieve this goal, genetic information and new chemistries have to be combined into new imaging probes detectable by sophisticated imaging techniques. In contradistinction to conventional imaging, which mostly detects architectural, or morphological distortions (a late event), molecular imaging should be able to detect molecular changes that are at the basis of diseases. The detection of subtle pathologic changes in early, asymptomatic disease should have a tremendous impact on healthcare as a whole

Diagnosis of urothelial tumors with a dedicated dual-source dual-energy MDCT protocol: preliminary results

The purpose of this study was to evaluate the diagnostic performance of a dedicated dual-source dual-energy MDCT (DECT) protocol for the detection of urothelial tumors

A new MDCT technique for the detection and anatomical exploration of urogenital fistulas

OBJECTIVE: We tested a new MDCT technical protocol, combining i.v. and intravesical positive contrast agent and intravaginal neutral contrast agent, that optimizes exploration of urogenital fistulas. We examined three patients (four CT examinations in total) with this technique and proved that a preexisting subtle ureterovaginal fistula that was under treatment was still present, though clinically silent. CONCLUSION: The proposed MDCT examination protocol provides important information to help detect subtle urogenital fistulas

Orthodontically induced cervical root resorption in humans is associated with the amount of tooth movement

Introduction: The aim of this study was to investigate the variation in the amount of the orthodontically induced cervical root resorption and the association with several factors, such as the amount of tooth displacement, location of tooth in the maxilla or mandible, and presence of an interference that may influence the amount of root resorption. Subjects and methods: This study included 30 subjects (20 females, 10 males) with an age range of 11.3 to 43.0 years. Using a standardized experimental orthodontic tooth movement, 59 premolars were moved buccaly during 8 weeks with application of 1 N force. Fifty-eight contralateral premolars not subjected to orthodontic tooth movement served as controls. At the end of the experimental period the teeth were carefully extracted, scanned in a micro-computed tomography scanner with a resolution of 9 microm, and the reconstructed images were processed for volumetric evaluation of resorption craters at the cervical part of the root surface. Data were analyzed using unpaired t-test and the Pearson's correlation. Results: Higher amount of cervical root resorption was detected in the orthodontically moved teeth (0.00055 mm3) compared to controls (0.00003 mm3; P < 0.001). Moderate correlation was found between root resorption in the two experimental teeth within the same individual (R = 0.421, P = 0.023). Teeth located in the mandible presented more resorption than those in the maxilla (P = 0.046). The amount of root resorption was correlated to the amount of tooth movement (R = 0.318, P = 0.016). Conclusion: Application of a 1 N force over a 2-month period provokes severe root resorption at the compression cervical sites. Resorption is correlated with the amount of tooth movement and the location of the teeth

Diagnostic accuracy of digitized periapical radiographs validated against micro-computed tomography scanning in evaluating orthodontically induced apical root resorption

The aim of this study was to validate the use of digitized periapical radiographs in evaluating orthodontically induced apical root resorption against micro-computed tomography (micro-CT) scanning as a criterion standard test. In a standardized experimental protocol, 29 premolars in 16 subjects were tipped buccally for 8 wk. Nineteen contralateral premolars not subjected to orthodontic movement served as controls. Standardized periapical radiographs were taken before and after the experimental period (Rx method). These teeth were extracted and scanned using a micro-CT technique with a 9 mum resolution. Two calibrated examiners assessed blindly the presence or absence of apical root resorption on digitized radiographs and three-dimensional reconstructions of the scans. Significant differences were detected between the orthodontically moved teeth and controls: 86% of the orthodontically moved teeth and 21% of the control teeth showed apical root resorption when using micro-CT as a validation method. A total of 55% of the experimental teeth and 5% of the control teeth showed resorption when assessed using Rx method. The Rx method showed a specificity of 78% and a sensitivity of 44%, which means that less than half of the cases with root resorption identified using a CT scanner were identified by radiography. Nearly all the orthodontically moved teeth showed apical root resorption. Apical root resorption may be underestimated when evaluated using digitized periapical radiographs

Urinary stone detection and characterisation with dual-energy CT urography after furosemide intravenous injection: preliminary results

To investigate the added advantage of IV furosemide injection and the subsequent urine dilution in the detection of urinary calculi in the excretory phase of dual-source dual-energy (DE) computed tomography (CT) urography, and to investigate the feasibility of characterising the calculi through diluted urine

Standardized fluoroscopy-based technique to measure intraoperative cup anteversion

Direct anterior approach (DAA) with the patient lying supine has facilitated the use of intraoperative fluoroscopy and allows for standardized positioning of the patient. The current study presents a new technique to measure acetabular component anteversion using intraoperative fluoroscopy. The current paper describes a mathematical formula to calculate true acetabular component anteversion based on the acetabular component abduction angle and the c-arm tilt angle (CaT). The CaT is determined by tilting the c-arm until an external pelvic oblique radiograph with the equatorial plane of the acetabular component perpendicular to the fluoroscopy receptor is obtained. CaT is determined by direct reading on the C-arm device. The technique was validated using a radiopaque synbone model comparing the described technique to computed tomography anteversion measurement. The experiment was repeated 25 times. The difference in anteversion between the two measuring techniques was on average 0.2° (range -3.0-3.1). The linear regression coefficients evaluating the agreement between the experimental and control methods were 0.99 (95%CI 0.88-1.10, p < 0.001) and 0.33 (95%CI -1.53-2.20, p = 0.713) for the slope and intercept, respectively. The current study confirms that the described three-step c-arm acetabular cup measuring technique can reproducibly and reliably assess acetabular component anteversion in the supine position, as compared to CT-imaging. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res

Surgical management of adrenal metastases

This paper aims to review controversies in the management of adrenal gland metastasis and to reach an evidence-based consensus

Rencontre du "GPS" et du poumon: navigation électromagnétique pour le diagnostic des lésions pulmonaires

Among recent technological progress, electromagnetic navigational bronchoscopy (ENB), based on the principle of "GPS", allows the bronchoscopist to reach parenchymal lesions situated beyond the field of regular bronchoscopy. Compared to CT-scan guided transthoracic needle aspiration, the yield is lower (65%). However, the rate of complication (pneumothorax, hemorrhage) is significantly lower and the patient is not irradiated. Moreover, the yield remains stable also for cases associated to a lower yield of the transthoracic approach (small and/or deep and/or benign lesion). Beyond the diagnosis of peripheral lung nodules, ENB (alone or in combination with endobronchial ultrasound) is also an efficient and safe tool for disease staging by simultaneous (during the same procedure) sampling of associated hypermetabolic lymph nodes