The scope of this study was to evaluate the effects on radiation output and image noise varying the acquisition parameters with an automatic tube current modulation (ATCM) system in computed tomography (CT). Chest CT examinations of an anthropomorphic phantom were acquired using a GE LightSpeed VCT 64-slice tomograph. Acquisitions were performed using different pitch, slice thickness and noise index (NI) values and varying the orientation of the scanned projection radiograph (SPR). The radiation output was determined by the CT dose index (CTDIvol). Image noise was evaluated measuring the standard deviation of CT numbers in several regions of interest. The radiation output was lower if the SPR was acquired in the anterior-posterior projection. The radiation dose with the posterior-anterior SPR was higher, because the divergence of the X-ray beam magnifies the anatomical structures closest to the tube, especially the spinal column, and this leads the ATCM system to estimate higher patient attenuation values and, therefore, to select higher tube current values. The NI was inversely proportional to the square root of the CTDIvol and, with fixed NI, the CTDIvol increased as the slice thickness decreased. This study suggests some important issues to use the GE ATCM system efficiently.

The aim of this study was to investigate the neurophysiological bases of Active Music Therapy (AMT) and its effects on the normal brain. Twelve right-handed, healthy, non-musician volunteers were recruited. The subjects underwent 2 AMT sessions based on the free sonorous-music improvisation using rhythmic and melodic instruments. After these sessions, each subject underwent 2 fMRI scan acquisitions while listening to a Syntonic (SP) and an A-Syntonic (AP) Production from the AMT sessions. A 3 T Discovery MR750 scanner with a 16-channel phased array head coil was used, and the image analysis was performed with Brain Voyager QX 2.8. The listening to SP vs AP excerpts mainly activated: (1) the right middle temporal gyrus and right superior temporal sulcus, (2) the right middle frontal gyrus and in particular the right precentral gyrus, (3) the bilateral precuneus, (4) the left superior temporal sulcus and (5) the left middle temporal gyrus. These results are consistent with the psychological bases of the AMT approach and with the activation of brain areas involved in memory and autobiographical processes, and also in personal or interpersonal significant experiences. Further studies are required to confirm these findings and to explain possible effects of AMT in clinical settings.

The scope of this study was to quantify patient radiation exposure during two different techniques of kyphoplasty (KP), which differ by a cement delivery method, in order to assess whether or not one of the two used methods can reduce the patient dose. Twenty patients were examined for this investigation. One X-ray fluoroscopy unit was used for localization, navigation and monitoring of cement delivery. The patient biometric data, the setting of the fluoroscope, the exposure time and the kerma-area product (KAP) were monitored in all the procedures for anteroposterior (AP) and lateral (LL) fluoroscopic projections in order to assess the range of radiation doses imparted to the patient. Theoretical entrance skin dose (ESD) and effective dose (E) were calculated from intraoperatively measured KAP. An average ET per procedure was 1.5±0.5 min for the manual injection technique (study A) and 1.4±0.4 min for the distance delivery technique (study B) in the AP plane, while 3.2±0.7 and 5.1±0.6 min in the lateral plane, respectively. ESD was estimated as an average of 0.10±0.06 Gy for study A and 0.13±0.13 Gy for study B in the AP or/and 0.59±0.46 and 1.05±0.36 Gy in the lateral view, respectively. The cumulative mean E was 1.9±1.0 mSv procedure(-1) for study A and 3.6±0.9 mSv procedure(-1) for study B. Patient radiation exposure and associated effective dose from KP may be considerable. The technique of distance cement delivery appears to be slower than the manual injection technique and it requires a more protracted fluoroscopic control in the lateral projection, so that this system entails a higher amount of dose to the patient.

With the defined radiological procedure, the obtained KAP values are lower than recorded doses in interventional radiology, and the corresponding values of entrance skin dose are lower than the threshold dose for deterministic effects. Considering the effective dose at the median KAP value, the probability for stochastic effects is shown to be low, at approximately 1 in 39,000.

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