Giulio Sodani

The latest innovation in MR imaging is SENSE (SENSitivity Encoding), a technology providing an important solution for the time necessary for signal encoding. In the SENSitivity Encoding (SENSE) approach, an array of multiple, simultaneously operated receiver coils is used for signal acquisition. In particular, the efficacy of SENSE technology is able to reduce the number of phase encodings by a factor (named R factor or Reduction factor) and to evaluate the same k space with fewer readout lines obtaining higher spatial and temporal resolution. An heterogeneous group of 30 patients with a variety of clinically proven diagnoses underwent Cardiac MR with SENSE technology to evaluate the technique's diagnostic efficacy. The sequences used were "Balanced" Ultrafast Gradient Echo (B-FFE) characterised by a hyper-intense blood signal with multislice multiphase and single slice multiphase acquisitions. In addition to reducing scan times, SENSE technology improved spatial and temporal resolution (40 frames/cardiac cycle) providing optimal dynamic evaluation of valve structures and wall kinesis. Furthermore, the use of the SENSE technique with B-FFE sequences (sB-FFE) enabled the qualitative evaluation of abnormal blood movements and transvalvular flows. The considerable time savings allowed by SENSE technology and the clear improvement in image quality constitute a step forward in cardiac MR imaging. The possibility of executing morphologic, dynamic, perfusional and spectroscopic studies in the same MR examination session with short acquisition times and good image quality are becoming more feasible.

Our aim was to prospectively evaluate a semi-quantitative pulmonary perfusion MR technique using a breath-hold 2D dynamic sequence in patients with severe pulmonary emphysema. Thirty patients with severe emphysema were studied with pulmonary perfusion MRI. Results were compared with those obtained through lung scintigraphy, considered as the gold standard technique. We used Fast Field Echo (FFE) pulse sequences in the coronal and sagittal planes, with paramagnetic contrast agent administration. Ten healthy volunteers were studied as the control group. Three thoracic radiologists independently reviewed all the subjects, evaluating the site and entity of perfusional defects. Peak intensity and apparent mean transit time were calculated. MRI showed high sensitivity (86.7%) and good specifity (80.0%) in detecting perfusional defects. We observed lower peak signal intensities in emphysematous regions. Lung perfusion MR is a potential alternative to Nuclear Medicine in the evaluation of severe pulmonary emphysema.

The aim of our study was to evaluate the diagnostic capabilities of computed tomography (CT) and magnetic resonance (MR) imaging in pyriformis syndrome (PS) and the long-term outcomes of CT-guided percutaneous treatment with botulinum. PS is a cause of sciatica and disability. The pain is usually increased by muscular contraction, palpation or prolonged sitting. Thirty-four patients suffering from PS, suspected on the basis of clinical and electrophysiological criteria and after imaging examinations had excluded other causes of sciatic pain, had positive lidocaine tests and were treated by intramuscular injection of botulinum toxin type A (BTX-A) under CT guidance. MR sequences was performed in nine patients before treatment and after three months to evaluate the extent of muscle denervation. In 30 cases relief of symptoms was obtained after 5-7 days. In four patients insufficient pain relief warranted a second percutaneous treatment which proved clinically successful. No complications or side effects were recorded after BTX-A injection. The MR examination demonstrated a change in signal intensity of the muscle in seven patients due to denervation, whereas in the remaining two cases only atrophy was detected. Larger series are necessary to confirm these preliminary results. CT-guided BTX-A injection in the pyriformis muscle is an emergent and feasible technique that appears to yield excellent local therapeutic effects without the risk of imprecise injection.

This study attempted to assess the feasibility and the accuracy of lung contrast enhanced magnetic resonance (MR) perfusion imaging in the evaluation of 20 healthy volunteers and to correlate the intensity/time (I/T) curves with the pulmonary physiological criteria. After an informed consensus, twenty no-smoker subjects, without any present or past pulmonary pathologies, were studied by means of an ultra-fast gradient echo sequence after a Gd-DTPA intravenous administration. The acquisitions were performed in coronal and sagittal planes, in supine and prone position, in breath holding. An ulterior acquisition was performed in only five cases immediately after 2-3 minutes of physical exercise. All the examinations, reviewed according to a visual score by three independent observers, resulted fairly interpretable. The I/T curves, obtained in post-processing evaluation, have the same trend in all cases and are correlated to the lung physiological criteria: the position changes of the examined subjects confirm the gravity dependence of perfusion; the study performed immediately after physical exercise showed a reduction of perfusion in the whole lung due to a transitory massive shift of blood mass from visceral to muscular districts. The extremely short acquisition and post-processing time coupled with a simple feasibility, the ability to detect physiological perfusional changes, the minimal invasivity indicate a potential clinical use of MR in the pulmonary perfusion defects evaluation.

Piriformis muscle syndrome (PMS) is a cause of sciatica, leg or buttock pain and disability. The pain is usually increased by muscular contraction, palpation or prolonged sitting. The aim of our paper was to evaluate the feasibility of CT-guided percutaneous botulinic toxin (BTX) injection for the purpose of PMS treatment. Thirty patients suffering from PMS, suspected with clinical and electrophysiological criteria, after imaging examinations excluding other causes of sciatic pain, resulted positive at the lidocaine test and were treated by intramuscular injection of BTX type A under CT guidance. The follow-up (12 months) was performed with clinical examination in all cases and with MR 3 months after the procedure in 9 patients to evaluate the denervative process entity of the treated muscle. In 26 cases relief of symptoms was obtained after 5–7 days. In 4 patients an insufficient relief of pain justified a second percutaneous treatment which was clinically successful. No complications or side effects were recorded after BTX injection. The MR examination showed a signal intensity change of the treated muscle in 7 patients due to the denervative process of PM, whereas in the remaining 2 cases only an atrophy of the treated muscle was detected. Larger series are necessary to confirm these MRI preliminary results. The CT-guided BTX injection in the PMS is an emergent and feasible technique that obtains an excellent local therapeutic effect without risk of imprecise inoculation.