Cone beam CT evaluation of skeletal and nasomaxillary complex volume changes after rapid maxillary expansion in OSA children.

OBJECTIVE: The first objective of this study was to evaluate skeletal changes and changes in dimensions and volume of the upper airways before and after rapid maxillary expansion (RME) therapy in children with obstructive sleep apnoea (OSA), by Cone Beam computed tomography (CBCT). The second objective was to evaluate if RME therapy could improve both the patency of the nasal airways and the Obstructive Sleep Apnoea Syndrome (OSAS). METHODS: 19 children with OSA and malocclusion took CBCT scans with a Dentascan and 3D reconstruction program before (T0) and 4 months after (T1) RME. Patients underwent an ENT visit with auditory and respiratory tests, including a daytime sleepiness questionnaire, a 19-channel polysomnography, and an orthognatodontic examination before orthodontic therapy (T0), after 2 months (T1) with the device still on, and 4 months after the end of the orthodontic treatment (T2). RESULTS: In all cases opening of the mid-palatal suture was demonstrated. Nasal osseous width, volume of the total upper airways, nasal cavity and nasopharynx and oropharynx increased significantly (P, .001). The increased W-ANS, W-mid and WPNS were closed linked to the enlarged midpalatal suture (P, .001). The increased WPNS were closed linked to the enlarged pterygoid processes (P, .001). The increased V-NC and V-NPA was closely linked to the enlarged W-PNS (P, .001) as well as VOPA and consequently to the enlarged midpalatal suture and pterygoid processes. CONCLUSION: RME treatment had a positive effect on children affected by chronic snoring and OSA, causing an increase in volume of the nasal cavity and nasopharynx, with expansion of the nasal osseous width and maxillary width. Enlarged nasal width at the PNS plane contributed to the increase in nasopharynx volume. Enlarged maxillary width showed a direct correlation to increased airways volume, bringing a functional improvement. The results show that the RME therapy can restore and improve a normal nasal airflow with disappearance of obstructive sleep breathing disorder.

Skeletal changes after rapid maxillary expansion in children with obstructive sleep apnea evaluated by low-dose multi-slice computed tomography.

OBJECTIVE: The objective of this study was to evaluate the skeletal effects of rapid maxillary expansion (RME) therapy performed using teeth as anchors, in obstructive sleep apnea (OSA) children, by low-dose computed tomography (CT) of the midpalatal suture opening, maxillary base width, nasal cavities width, first molar angulation and, unlike most studies in the literature, on the pterygoid processes distance. METHODS: Fourteen children (mean age 8.68 years) with OSA presenting a malocclusion characterized by upper-jaw contraction had 16-Multislice CT (MSCT) scans taken before (T0) and after (T1) RME. All exams were performed using a rigid protocol to ensure reproducibility of image collection over time, with a 16-row MSCT scanner equipped with a Dentascan reconstruction program. Scanning parameters were as follows: scout view in the anteroposterior (AP) and laterolateral (LL); 1.25-mm slice thickness with 0.6-mm collimation from the dentoalveolar and basal areas of the maxilla up to the nasal cavity, parallel to the palatal plane; 80 kV, 100 mA with an 11.25-mm table speed/rotation, rotation time 0.6 s. Matrix size was 512 × 512. RESULTS: Opening of the midpalatal suture was demonstrated in all cases. The results showed statistically significant T0 to T1 increments in all treated cases and clear imaging findings. CONCLUSION: Use of three-dimensional (3D)-CT for follow-up studies requires a very rigid protocol to maintain reproducible positions in the scanner over time. The images confirm the real remodeling of craniofacial structure. However, to be valid such an imaging approach needs great attention to reproducibility of anatomic images over time. The changes in volume of the UA, even with a rigid protocol, cannot be affirmed with 3D-CT. There is a need to improve the definition of markers using this imaging approach when performing longitudinal studies; currently this issue is unresolved.

Postarthroscopy Imaging in Femoroacetabular Impingement: Persistent Pain May Be Due to an Insufficient Correction of Preoperative Abnormalities.

Purpose The purpose of this study was to evaluate the effect of correction of abnormal radiographic parameters on postoperative pain in a group of patients treated arthroscopically for femoracetabular impingement (FAI). Methods A retrospective study was performed on 23 patients affected by mixed-type FAI and treated arthroscopically. There were 11 males and 12 females with a mean age of 46.5 (range: 28-67) years. Center-edge (CE) and α angles were measured on preoperative and postoperative radiographic and magnetic resonance imaging (MRI) studies and were correlated with persistent pain at follow-up. Results The mean preoperative CE and α angles were 38.6 ± 5.2 and 67.3 ± 7.2 degrees, respectively. At follow-up, in the 17 pain-free patients, the mean pre- and postoperative CE angle were 38.1 ± 5.6 and 32.6 ± 4.8 degrees, respectively, whereas the mean pre- and postoperative α angles at MRI were 66.3 ± 7.9 and 47.9 ± 8.9 degrees, respectively. In six patients with persistent hip pain, the mean pre- and postoperative CE angles were 39.8 ± 3.6 and 35.8 ± 3.1 degrees, respectively, whereas the mean pre- and postoperative α angles were 70.0 ± 3.9 and 58.8 ± 2.6 degrees, respectively. Mean values of all the analyzed radiological parameters, except CE angle in patients with pain, improved significantly after surgery. On comparing patient groups, significantly lower postoperative α angles and lower CE angle were observed in patients without pain. Conclusion In case of persistent pain after arthroscopic treatment of FAI, a new set of imaging studies must be performed because pain may be related to an insufficient correction of preoperative radiographic abnormalities. Level of Evidence Level IV, retrospective case series.

Efficacy of systemic thrombolysis within 4.5 h from stroke symptom onset: a single-centre clinical and diffusion-perfusion 3T MRI study.

PURPOSE: The efficacy of thrombolytic treatment with recombinant tissue plasminogen activator (rt-PA) within 3 h from stroke onset has been extensively supported by randomised placebo-controlled multicentre trials. In our single-centre study, we investigated the efficacy of intravenous (IV) administration of rt-PA within 4.5 h of stroke onset, in terms of clinical and radiological outcome, using a 3T magnetic resonance (MR) scanner in a cohort of patients similar to that of multicentre clinical trials. MATERIALS AND METHODS: Consecutive patients treated with IV rt-PA were compared with an historical cohort of untreated patients (controls). Inclusion criteria were: (1) infarction of the middle cerebral artery territory, (2) eligibility for IV rt-PA treatment, and (3) 3T perfusion- and diffusion-weighted MR imaging and MR angiography performed within 4.5 h and repeated after 5-7 days. Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS). Growth of the DWI lesion, saved hypoperfused tissue, and clinical outcome was assessed and compared in treated patients and controls. RESULTS: Forty-three patients treated with rt-PA and 69 controls were eligible for the analysis. Treated patients showed higher percentages of saved hypoperfused tissue (75 vs. 40 %; p = 0.009), vessel recanalisation (65 vs. 27.5%; p = 0.003), and haemorrhagic transformation (21 vs. 7%; p = 0.004), without any clinically significant haemorrhages. Furthermore, treated patients had a significant improvement of NIHSS at 24 h (p < 0.001), at discharge (p ≤ 0.001), and at the 3-month clinical evaluation (p < 0.001), while similar rates of both treated patients and controls achieved a 3-month modified Rankin scale ≤ 2 (62 and 65%; p = 0.7). CONCLUSION: Treatment with IV rt-PA within 4.5 h of stroke onset preserves a significant amount of brain tissue from final infarction, and increases the possibility of early and late clinical improvement.

Three-dimensional evaluation of masseter muscle in different vertical facial patterns: a cross-sectional study in growing children.

The aim of the present study was to analyze the anatomical three-dimensional (3D) characteristics of masseter muscle in growing subjects with different vertical patterns by using an ultrasound (US) method. The sample comprised 60 prepuberal subjects (33 males, 27 females) with a mean age of 11.5 ± 1.6 years with late mixed or permanent dentition and Class I molar and skeletal relationship. For each subject, a lateral cephalogram was required, and according to the mandibular plane angle (Frankfort horizontal plane/mandibular plane angle [FMA]), the subjects were divided into three groups of different underlying vertical facial patterns: brachyfacial: FMA < 22°, mesofacial: 22° ≤ FMA ≤ 28°, and dolichofacial: FMA > 28°. For each subject, an US scan was carried out to analyze the width, the thickness, the cross-sectional area, and the volume of the masseter muscle. Mean differences in measurements between vertical facial subgroups were contrasted by means of analysis of variance (ANOVA) with Tukey's post hoc tests (p < 0.05). Measurements of the whole masseter in dolichofacial patients were significantly smaller when compared with brachyfacial and mesofacial individuals during relaxation and contraction. The volume of the masseter decreased significantly by 10% going from the brachyfacial group to the mesofacial group and from the mesofacial group to the dolichofacial group with no difference between the left and the right sides. A significant negative correlation was found between the US measurements and the divergency (FMA°). Ultrasound is a technique indicated in children for evaluating muscles of mastication in vivo. Growing patients with a dolichofacial vertical pattern present with a reduced dimension of the masseter when compared with brachyfacial and mesofacial subjects.

Diffusion tensor imaging and magnetic resonance spectroscopy assessment of cancellous bone quality in femoral neck of healthy, osteopenic and osteoporotic subjects at 3T: Preliminary experience.

UNLABELLED: We assessed the potential of diffusion tensor imaging (DTI) in combination with proton magnetic resonance spectroscopy (1H-MRS), in cancellous bone quality evaluation of the femoral neck in postmenopausal women. INTRODUCTION: DTI allows for non-invasive microarchitectural characterization of heterogeneous tissue. In this work we hypothesized that DTI parameters mean diffusivity (MD) and fractional anisotropy (FA) of bone marrow water, can provide information about microstructural changes that occur with the development of osteoporosis disease. Because osteoporosis is associated with increased bone marrow fat content, which in principal can alter DTI parameters, the goal of this study was to examine the potential of MD and FA, in combination with bone marrow fat fraction (FF), to discriminate between healthy, osteopenic and osteoporotic subjects, classified according to DXA criteria. MATERIALS AND METHODS: Forty postmenopausal women (mean age, 68.7 years; range 52-81 years), underwent a Dual-energy X-ray absorptiometry (DXA) examination in femoral neck, to be classified as healthy (n=12), osteopenic (n=14) and osteoporotic (n=14) subjects. 1H-MRS and DTI (with b value=2500 s/mm2) of femoral neck were obtained in each subject at 3T. The study protocol was approved by local Ethics Committee. MD, FA, FF and MD/FF, FA/FF were obtained and compared among the three bone-density groups. One-way ANOVA with multiple comparisons Bonferroni test and Pearson correlation analysis were applied. Receiver operating characteristic (ROC) curve analysis was also performed. RESULTS: Reproducibility of DTI measures was satisfactory. CV was approximately 2%-3% for MD and 4%-5% for FA measurements. Moreover, no significant difference was found in both MD and FA measurements between two separate sessions (median 34 days apart) comprised of six healthy volunteers. FF was able to discriminate between healthy and osteoporotic subjects only. Conversely MD and FA were able to discriminate healthy from osteopenic and healthy from osteoporotic subjects, but they were not able to discriminate between osteopenic and osteoporotic patients. A significant correlation between MD and FF was observed in healthy group only. A moderate correlation was found between MD and T-score when all groups together are considered. No significant correlation was found between MD and T-score within groups. A significant positive correlation between FA and FF was found in both osteopenic and osteoporotic groups. Vice-versa no correlation between FA and FF was observed in healthy group. A high significant positive correlation was found between FA and T-score in all groups together, in healthy and in osteoporotic groups. MD/FF and FA/FF are characterized by a higher sensitivity and specificity compared to MD and FA in the discrimination between healthy, and osteoporotic subjects. MD/FF vs. FA/FF graph extracted from femoral neck, identify all healthy individuals according to DXA results. CONCLUSION: DTI-(1)H-MRS protocol performed in femoral neck seems to be highly sensitive and specific in identifying healthy subjects. A MR exam is more expensive when compared to a DXA investigation. However, even though DXA BMD evaluation has been the accepted standard for osteoporosis diagnosis, DXA result has a low predictive value on patients' risk for future fractures. Thus, new approaches for examining patients at risk for developing osteoporosis would be desirable. Preliminary results showed here suggest that future studies on a larger population based on DTI assessment in the femoral neck, in combination with 1H-MRS investigations, might allow screening of high-risk populations and the establishment of cut-off values of normality, with potential application of the method to single subjects.

Lumbar spine MRI in upright position for diagnosing acute and chronic low back pain: statistical analysis of morphological changes.

BACKGROUND: Patients with low back pain frequently demonstrate recumbent magnetic resonance imaging (MRI) alterations not always related to homogeneous clinical symptoms. The purpose of this study was to evaluate and quantify the statistical significance of variations of some anatomical parameters of the lumbosacral spine and reveal occult disc pathologies from recumbent to upright position in patients with acute and chronic low back pain. MATERIALS AND METHODS: Fifty-seven patients complaining of low back pain (27 women, 30 men) underwent dynamic lumbosacral MRI with a 0.25-T tilting system (G-scan Esaote). We settled five parameters for which variations have been evaluated: lumbosacral angle, lordosis angle, L3-L4 intersomatic disc height, L3-L4 interspinous processes distance, and widest anteroposterior dural sac diameter. Images were obtained in both recumbent and upright positions. RESULTS: Statistically significant differences [one-way analysis of variance (ANOVA), p = 0.0043] were found between each pair of values of parameters sampled in recumbent and upright positions. In 70 % of patients, on visual qualitative analysis only, an increment of disc protrusions and/or spondylolisthesis was found in the upright position; in three cases, in the upright position only, an interarticular pseudocyst was found. CONCLUSIONS: Dynamic MRI with an open-configuration, low-field tilting MRI system is a feasible and promising tool to study degenerative pathology of the spine. Moreover, in cases of low back pain with negative MRI in the recumbent position or in patients with pain in the upright position only, tilting MRI permits visualization of occult spine and disc pathologies in patients with acute or chronic low back pain.

Orthodontics and obstructive sleep apnea in children.

Children who suffer from respiratory problems and obstructive sleep apnea (OSA) commonly exhibit disturbances of craniofacial morphology. A significant number have nasal obstruction associated with a narrow maxilla; maxillary constriction may increase nasal resistance and alter the tongue posture, leading to narrowing of the retroglossal airway and OSA. Sixty children with a case history of oral breathing, snoring, and night time apneas were studied. An orthognathodontic investigation was performed using radiographs that included not only the usual examinations (posteroanterior cephalographs and intraoral radiographs) but also computed tomographic scans. This article discusses the materials and methods and the results of this study.

Modifications of midpalatal sutural density induced by rapid maxillary expansion: A low-dose computed-tomography evaluation.

INTRODUCTION: The aim of this study was to evaluate the density of the midpalatal suture as assessed by low-dose computed tomography (CT) before rapid maxillary expansion (RME) (T0), at the end of active expansion (T1), and after a retention period of 6 months (T2). METHODS: The study sample comprised 17 prepubertal subjects (mean age, 11.2 years) with constricted maxillary arches and unilateral or bilateral posterior crossbite. The total amount of expansion was 7 mm in all subjects. Multi-slice low-dose CT scans were taken at T0, T1, and T2. On axial CT scanned images, 4 regions of interest (ROIs) were placed along the midpalatal suture (anterior [AS ROI] and posterior [PS ROI]) and in 2 regions of palatal bone (anterior and posterior). Density was measured in Hounsfield units. The Mann-Whitney U test and Friedman analysis of variance (ANOVA) with post-hoc test were used (P <0.05). RESULTS: The densities in the AS and PS ROIs were significantly smaller than the reference bone densities before RME therapy. Both AS and PS ROIs showed significant decreases in density from T0 to T1, significant increases from T1 to T2, and no significant differences from T0 to T2. CONCLUSIONS: The effective opening of the midpalatal suture by RME in prepubertal subjects was associated with a significant decrease in sutural density. The sutural density after 6 months of retention post-RME indicated reorganization of the midpalatal suture, since it showed values similar to the pretreatment ones.

Immediate and post-retention effects of rapid maxillary expansion investigated by computed tomography in growing patients.

OBJECTIVE: To determine by low-dose computed tomography (CT) protocol the dental and periodontal effects of rapid maxillary expansion (RME). MATERIALS AND METHODS: The sample comprised 17 subjects (7 males and 10 females), with a mean age at first observation of 11.2 years. Each patient underwent expansion of 7 mm. Multislice CT scans were taken before rapid palatal expansion (T0), at the end of the active expansion phase (T1), and after a retention period of 6 months (T2). On scanned images, measurements were performed at the dental and periodontal levels. Mean differences between measurements at T0, T1, and T2 were examined through analysis of variance (ANOVA) for repeated measures with post-hoc tests. RESULTS: All interdental transverse measurements were significantly increased at both T1 and T2 with respect to T0. In the evaluation of T0-T1 changes, periodontal measurements were significant on the buccal aspect of banded teeth with a reduction in alveolar bone thickness corresponding to the mesial (-0.5 mm; P < .05) and distal (-0.4 mm; P < .05) roots of the right first molar and to the mesial root of the left first molar (-0.3 mm; P < .05). In the evaluation of overall T0-T2 changes, the lingual bone plate thickness of both first molars was found to be significantly increased (+0.6 mm; P < .05). CONCLUSIONS: RME therapy induces a significant increase in the transverse dimension of the maxillary arch in growing subjects without causing permanent injury to the periodontal bony support of anchoring teeth discernible on CT imaging.

Role of computed tomography in the evaluation of orthodontic treatment in adult patients with obstructive sleep apnea syndrome (OSA).

OBJECTIVE: The aim of this study was to investigate pharyngeal size differences between pre- and posttrials of a Mandibular Advancement Device (MAD), using a computed tomography (CT),in the treatment of Obstructive Sleep Apnea (OSA) adult patients. MATERIALS AND METHODS: Eighteen patients with mild to moderate OSA (mean Apnea/Hypopnea Index, AHI, of 16.7) were treated with a MAD to wear at night only. After 3 months of treatment, three-dimensional changes in pharyngeal dimensions were measured on CT images performed with a sixteen detector-row CT scanner (Light Speed Plus; GE Medical Systems). Two consecutive axial sections from the hard palate to the epiglottis were obtained with and without the appliance. Measurements were made of the following airway areas (mm2) and lengths (mm): RF (nasopharynx); ROF (naso-oropharynx); OF (oropharynx); IPF (hypopharynx); SPL (soft palate length); SPT (soft palate thickness); Rgn (retrognation)-hyoid bone; hyoid bone-C2; Rgn-C2; PhL (oropharynx length); pharynx posterior wall thickness at three level. The angle between the hard and the soft palate (APDM) was also calculated. RESULTS: AHI improved significantly (from 16.7 to 11.2) when the appliance was used. Measurements from CT scans showed statistically significant expansion in the naso-oropharynx area (RF p<.014; ROF p<.050), in the Rgn-C2 length (p<.005) and in the angle between the hard and the soft palate (APDM p<.001). CONCLUSIONS: Our findings confirm the effectiveness of MAD in the treatment of patients with mild to moderate OSA. The use of MAD significantly expands the areas of the upper airway lumen most involved in the collapse.

Whole body 16-row multislice CT in emergency room: effects of different protocols on scanning time, image quality and radiation exposure.

The objective of this study was to compare two different scanning protocols in patients suspected to have multiple trauma using multidetector 16-row computed tomography (CT) to better define scanning time, imaging quality and radiation exposure. Forty-six patients, between March 2004 and March 2005, with suspected multiple trauma (cerebral, spine, chest, abdominal and pelvis) were evaluated with two different protocols: Protocol "A" 26 patients; Protocol "B" 20 patients. Protocol A consists of a single-pass continuous whole-body acquisition (from vertex to pubic symphysis), whereas Protocol B of conventional segmented acquisition with scanning of body segments individually. Both protocols were performed using a multidetector 16-rows CT (Light-Speed 16, General Electric Medical System, Milwaukee, WI, USA) with the same technical factors. Radiation dose was evaluated in two ways: computer tomography dose index (CTDI) = dose measured in central and peripheral region of the subjects as a direct result of a CT section acquisition of T millimeters thick (independent from the two protocols) and dose length product (DLP) = total dose deposited over the length of the acquisition (dependent from the two protocols). Image quality was rated according to the following scores: 1, excellent; 2, good; 3, satisfactory; 4, moderate and 5, poor. The results were compared using Wilcoxon's test to identify significant difference in terms of image quality, scanning time, radiation exposure and presence of artifacts, assuming significance at a p value of <0.05. In the single-pass scanning, DLP was 2.671 mGy x cm and a total scan time of 35 s. In whole-body protocols, we have seen artifacts due to arm adduction in thorax and less image quality in brain. In the conventional segmented study, DLP was 3.217 mGy x cm and a total scan time of 65 s; this protocol offered less extraction capabilities of off-axial on focused images of the entire spine, aorta, facial bones or hip without rescanning. Protocol A revealed a significant decrease in scan time (35 vs 65 min, p < 0.05), time in the CT examination room (21.7 vs 31.6 min.; p < 0.05), and final image analysis (83.7 vs 102.9 min; p < 0.05) and radiation dose compared to protocol B (p < 0.05). No significant difference was found for patient transport time, image reconstruction time and imaging quality. Reconstruction and isotropic reformation of axial image acquired by whole-body, single-pass protocols due to entire spine evaluation, aortic and splanchnic CT angiography eliminate additional studies. The whole-body, single-pass protocols, compared with segmented acquisitions protocols, resulted in a reduced total radiation dose without relevant loss of diagnostic image information.

Virtual endoscopy in odontogenic sinus disease. Study technique and main pathological findings.

The use of CT scans in dental pathology is an established technique. The potential applications of Dentascan are further enhanced by the use of virtual navigation software, resulting in endoscopy-like imaging of the maxillary sinus, thus optimising both the diagnostic and therapeutic approach to sinus pathology of dental origin. The aim of this paper is to illustrate the technical-methodological aspects of maxillary sinus virtual endoscopy with Dentascan software and to document the most important and frequent diseases.

Treatment of intermetatarsal Morton's neuroma with alcohol injection under US guide: 10-month follow-up.

Morton's neuroma (MN) is a frequent cause of metatarsalgia. The aim of our study was to evaluate the efficacy of neuroma alcohol-sclerosing therapy (NAST) under US guide in MN after a 10-month follow-up. Forty intermetatarsal neuromas underwent alcohol-sclerosing therapy after sonographic evaluation of their dimensions and echotexture. After subcutaneous anesthesia, a sclerosing solution composed of anesthetic (carbocaine-adrenaline 70%) and ethylic alcohol (30%) was injected inside the mass under US guidance. The procedure was repeated at intervals of 15 days until the resolution of the symptoms. A total or partial symptomatic relief was obtained in 36 cases (90%). No procedure-related complications were observed. Transitory plantar pain, due to the flogistic reaction induced by the sclerosing solution, occurred in 6 cases (15%). The 10-month follow-up revealed a 20-30% mass volume reduction and an adiposus-like change in echotexture. In the 4 cases (10%) of therapeutic failure, the preliminary sonography demonstrated a hypoechoic echotexture with a strong US beam attenuation corresponding to a highly fibrous neuroma after surgical resection. The NAST is a feasible and cost-efficient procedure with high rates of therapeutic success.

Vascular involvement in pancreatic neoplasm: a comparison between spiral CT and DSA.

The principal criterion for resectability of pancreatic carcinoma is the assessment of vascular involvement. In a prospective evaluation the ability of Spiral CT Angiography (CTA) to detect vascular involvement in 50 patients with pancreatic carcinoma, was proved; DSA was performed later in all patients. In 20 patients, without vascular involvement, a complete concordance was obtained. Of 30 patients with vascular involvement, there was complete concordance between CTA and angiography in 22 patients and discordance in 8 patients. CTA was superior in 2 cases with periadventitial infiltration and in 5 patients with splenoportal confluence thrombosis. DSA was superior in 1 case with infiltration of the superior mesenteric vein. After surgical evaluation, sensitivity of CTA and DSA was 97% and 77%, respectively, and the negative predictive values were 95% and 74%. As compared to DSA, CTA is more rapid and less invasive and can be considered the modality of choice for preoperative work-up of pancreatic neoplasm.

Pyriformis muscle syndrome: CT/MR findings in the percutaneous therapy with botulinic toxin.

PURPOSE: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Cineradiographic study of spine during cycling: effects of changing the pedal unit position on the dorso-lumbar spine angle.

PURPOSE: Low back pain is a frequent pathology among bicyclists, probably due to unappropriate saddle position. This radiographic study was conducted to evaluate dorso-lumbar angular values in two different pedal unit positions; the first one in a bicycle frame type with pedals in front of the saddle axis and the second one with the pedals behind the saddle axis, in order to define the most physiological sitting position. MATERIALS AND METHODS: Ten voluntary healthy adults, ranging in age between 21 to 45 years, were randomly choosen among a group of cyclist not involved in competition and underwent serial fluoroscopic studies while cyclists sit on two different saddles of a prototype cyclette; dorso-lumbar angles at both different sitting positions were measured on film according to modified Lippmann-Cobb method using as reference the upper somatic limitant of the eleventh or twelth dorsal vertebra and the lower somatic limitant of the third lumbar vertebra. RESULTS: Statistical analysis of the measured angles demonstrates that the differences between the dorso-lumbar spine angle in the different saddle positions are statistically significative with a coefficient correlation equals to 0.64015 and p>0.01; angular values are more physiological in the second position with pedal unit behind the saddle axis. CONCLUSIONS: The incidence and importance of low back pain in cyclists can be reduced with appropriate pedal unit position; the position with pedals behind the saddle axis permits more physiological spine angles in comparison with the classic one having the pedals in front of the saddle axis; this fact is due to a different pelvic position which coincides with lumbar angles.

A comparison between two different concentration of contrast media with multidetector CT for the study of abdominal vascular system.

PURPOSE: To evaluate two different concentrations of contrast medium (CM) and two different acquisition techniques to obtain vascular images with multislice spiral CT (msCT). MATERIALS AND METHODS: Thirty patients referred for msCT examinations of the kidney or upper abdomen underwent evaluation of the abdominal aorta during the arterial phase, after giving their consent (GE Light Speed Plus). In the first part of the study (20 patients) the enhancement values measured at six different levels of the aortoiliac axis (celiac trunk, suprarenal aorta, subrenal aorta, aortal bifurcation, right iliac and left iliac) were compared after administering two different concentrations of iodinated contrast medium (300 and 370 mgI/ml) with two different acquisition techniques (HQ and HS). The flow rate was 3 ml/sec. In the second part of the study 10 patients were examined by changing the flow rate (2 and 4 ml/sec). Both quantity and quality assessments were conducted on axial images and on vascular reconstructions. RESULTS: In the first part of the study the best results were obtained with the 370 mgI/ml concentration and with the HQ acquisition technique (pitch 3, table feed 7.5 mm/rotation, gantry rotation speed 0.5 s). The quality of reconstructions gradually improved before reaching 240 HU, above which image quality remained constant. The patients examined with a flow rate of 2 ml/sec showed a poor image quality, unlike those examined with a flow rate of 4 ml/sec where we observed the maximum threshold values and constant optimal vascular opacification, with no significant differences from the patients studied at 3 ml/sec. CONCLUSIONS: Our results indicate that, albeit on a limited number of patients, a higher concentration of CM and the use of an HQ technique allow a high quality examination to be obtained. The HS technique yields results comparable to those obtained with higher concentrations.