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R Lagalla

Publications and source records attributed to R Lagalla.

At least 73 records · Page 4Linked to original sources
PubMed1996

[An experimental in-vitro evaluation of membrane antigen expression and of interleukin production by monocytes exposed to magnetic resonance].

The interactions of magnetic fields and radiofrequency with biological systems have been described by several authors. However, no definitive conclusions have been drawn yet as to the safety of the magnetic fields and radiofrequencies used in clinical examinations. The immune system is one of the most complex biological systems, in which a network of intracellular signals regulates the immune response. Interleukins are released by an activation process which involves, at least in part, intra- and/or extracellular calcium mobilization. The latter step can be influenced by the in vitro effect of this type of nonionizing radiations produced by an MR system on peripheral blood mononuclear cells. Our results show that the 2-hour exposure to magnetic fields (0.5 T) and radiofrequency caused an increase in the spontaneous release of IL2, IL4, IL10, TNF alpha and INF gamma, while the amount of the same cytokines induced by PHA stimulation was decreased. No differences were observed in the spontaneous or PHA-induced release of IL6 by exposure to magnetic fields (MRI). Furthermore, the expression of the CD 11b molecule was increased at the same time. These results may be useful for us to understand the interactions between magnetic fields and radiofrequencies and the immune system.

Antigens, Surface↗
PubMed1996

[A quantitative in-vitro analysis of the effects of magnetic fields and radiofrequencies on amino acid metabolism].

The extensive use of magnetic resonance imaging in medical diagnosis needs experimental confirmation of the real biological harmlessness of magnetic fields and radiofrequencies in the imaging process. To date, no unquestionable conclusions have been drawn and experimental results differ in various literature reports. We investigated the effects of radiofrequencies and magnetic fields on the amino acid content of plasma samples from 10 healthy volunteers aged 25 to 30 years; the samples were exposed for 60 minutes to MR fields at 0.5 T with the sequences commonly used in clinical practice. After exposure to magnetic fields, the samples were analyzed with chromatography and the results compared with those of plasma samples not exposed to MR fields. Thirty-four different amino acids were investigated and no significant changes were observed in the total concentration of any of them. Our results show that, at least in a cell-free system, exposure to a magnetic field at 0.5 T causes no significant quantitative changes in amino acid composition, at least no changes demonstrable at chromatography. On the other hand, our preliminary observation does not exclude that exposure to nonionizing radiation may modify in vivo enzyme kinetics with transient qualitative, but not quantitative, changes.

Adult↗
PubMed1996

[Biomechanical correlations of lesions associated with traumatic diseases of the anterior cruciate ligament. Analysis with magnetic resonance].

To investigate the correlations between traumatic injuries of the anterior cruciate ligament and other ligamentous, meniscal and bone traumatic injuries, a series of 193 patients with anterior cruciate ligament injuries studied with MRI between January 1992 and December 1994, was retrospectively reviewed. MR results were compared with arthroscopic and/or surgical findings in most (181) patients; in the remaining 12 patients, clinical follow-up was performed. We used two 0.5 superconductive MR units, with dedicated coils and T1-weighted spin-echo and T2*-weighted gradient-echo sequences on the axial, sagittal and coronal planes. Anterior cruciate ligament injuries were associated with other ligamentous, meniscal and bone injuries in 78% of patients. The patients were classified in 5 groups depending on biomechanics and the association of injuries: -group I: isolated injury of the anterior cruciate ligament (41 patients), most frequently caused by forced extension stress associated with "kissing contusions" of the anterior portion of the lateral femoral condyle and of the lateral tibial plateau; this type of injury is less frequently caused by forced flexion stress associated with avulsion fracture of the tibial eminence; -group II: associated injury of the anterior cruciate ligament and medial compartment (62 patients), caused by forced flexion-external rotation stress (abduction, valgism and external rotation). The classic association of this mechanism was the injury of the anterior cruciate ligament, medial collateral ligament and medial meniscus (O'Donoghue triad) (9 patients). Valgus stress and the pivot-shift phenomenon can impact the tibial and femoral articular surfaces, with consequent osteochondral contusion; -group III: associated injury of the anterior cruciate ligament and lateral compartment (26 patients), caused by forced flexion-internal rotation stress (adduction, varism and internal rotation). This mechanism can cause, as a typical bone lesion, Segond fractures; -group IV: associated injury of the anterior cruciate ligament, lateral and medial compartments observed in 52 patients with different associations of varus-valgus and rotatory stress; -group V: in 5 patients, anterior cruciate ligament injury was associated with traumatic injury of the posterior cruciate ligament; in this case, posterior displacement of the tibia and knee hyperextension were the most common mechanisms of injury. In conclusion, our results demonstrate that anterior cruciate ligament injuries due to traumatic sprains of the knee are rarely isolated (21%). Thus, it is important to know the biomechanics of knee trauma to read MR images in order to detect possibly associated injuries. The final goal is to assess the actual extent of the traumatic damage for best subsequent clinical-therapeutic management.

Adolescent↗
PubMed1996

[Stener lesions: ultrasonography assessment in 12 cases].

We investigated the ultrasonographic (US) features of Stener injury and thus the role of US in the diagnosis of this condition. Stener injuries are characterized by the tear of the cubital ligament system of the first metacarpophalangeal joint during hyperabduction. This condition may be associated with the displacement of the ligament proximal stump above the thumb adductor muscle. We examined 12 patients (9 men and 3 women) with a clinical diagnosis of joint instability due to hyperabduction of the first metacarpophalangeal joint. All the US exams were performed with a linear probe (7.5-10 MHz); a 13-MHz probe was also used in 7 patients. All the patients were submitted to radiography in the standard projections, to detect associated bone injuries. US allowed the identification of a round lesion surrounded by a hypoechoic halo, between the distal edge of the dorsal interosseous muscle of the first finger and the first metacarpal bone (the proper Stener injury) in 4/12 patients. In contrast, no typical sign was shown in the other 8 patients. US results were then compared with surgical findings. The diagnosis of proper Stener injury was surgically confirmed in 4 patients. Only 2 patients with clinical signs of thumb instability, who were negative for Stener injuries at US, were submitted to surgery which demonstrated the ligament tear responsible for joint instability, but ruled out the displacement. To conclude, US must be integrated with clinical signs because this imaging method accurately shows complete tears with displaced proximal stump of the cubital ligament.

Adult↗
PubMed1996

[Introduction to the study of the Willis circle with transcranial color Doppler: methodological notes and preliminary experience].

To date, adult intracranial circulation has been studied only with pulsed-wave Doppler US, which is a useful diagnostic tool even though several technical and practical limitations are related to the difficult location of intracranial vessels. Recently, dedicated color-Doppler transducers have been proposed, which can pass through the skull which makes a physiologic barrier for the US beam: this technique has been called transcranial color-Doppler (TCD). We report on our personal experience with TCD in 30 healthy volunteers (12 men and 18 women, age range: 17-75 years) submitted to TCD for Willis circle imaging. We used an ATL Ultramark 9HDI unit with a phased array transducer (3.5 MHz) and 2 MHz Doppler frequency; the PRF was 3000 Hz, with 80% color gain. 100 Hz wall filters were used. The middle cerebral artery was always shown correctly in all subjects, while the posterior one was depicted only in 7 cases (23.3%); in contrast, the anterior cerebral artery was demonstrated in 3 cases only (10%). Nowadays, TCD is mostly applied to normal intracranial circle studies, to assess normal blood speed values more accurately. To this purpose, both the direct visualization of blood vessels and the flowmetric values obtained measuring the incidence angle are useful pieces of information. TCD permits a more accurate study of intracranial local blood flow in the Willis circle and of its changes in pathologic conditions. In contrast, TCD yield is poor in characterizing intracranial tumor tissue.

Adult↗
PubMed1995

Idiopathic intracranial hypertension: orbital MRI.

The case is reported of a patient with idiopathic intracranial hypertension examined with magnetic resonance imaging. Marked enhancement of the optic nerve heads was found, which might be related to blood-retinal barrier breakdown related to a sudden rise in intracranial cerebrospinal fluid pressure.

Adult↗
PubMed1995

Bell's palsy and visualization of the facial nerve by MRI.

A group of patients complaining of facial nerve palsy (Bell's palsy) were evaluated with MRI using a 0.5 unit and high resolution T1-weighted images, in order to evaluate the efficacy of Gd-DTPA enhancement in depicting the degree of nerve damage: MRI examination was performed within 24 hours to two weeks after the onset of palsy. The authors describe the results obtained from the analysis of 11 cases of Bell's palsy, discussing the prognostic and clinical significance.

Adolescent↗
PubMed1995

[Neoadjuvant intralesional chemotherapy for breast neoplasm in advanced stage. Assessment of its efficacy with Doppler color].

Twenty women with breast cancer confirmed at cyto-histology, 4 of them with axillary lymph node metastases, were submitted to neo-adjuvant chemotherapy with the conventional systemic treatment combined with intralesion drug administration and monitored by means of color-Doppler ultrasonography (CDU). Before treatment, CDU demonstrated marked color signal increase in 18 cases. After treatment, tumor vascularity clearly decreased and response was more apparent since treatment had been local rather than systemic. In this paper, the consistent semiology of breast cancer is discussed together with the progressive changes in CDU color signal, the latter a valuable parameter for surgical timing. Histology, performed during treatment and on the surgical specimen, allowed treatment results to be monitored, showing a rich proliferation of connective tissue and the persistence of rare neoplastic nests. In 2/4 patients with lymph node metastases, the latter lesions reduced in size. The postoperative follow-up of these patients, which was the object of our study, currently ranges 4 to 36 months, in which period of time no relapses have been observed. The results obtained so far suggest the effectiveness of combined parenteral and local drug administration in the preoperative treatment of breast cancer. Moreover, this approach makes surgery feasible even in the most advanced forms (T3-T4). CDU is the most accurate method to monitor neo-adjuvant treatment effectiveness.

Aged↗
PubMed1995

[Magnetic resonance in the evaluation of lesions of the posterior tibial tendons].

Posterior tibial tendon (PTT) tears are the most common cause of unilateral flatfoot in adults. It is a chronic pathologic condition with a degenerative inflammatory character which usually affects middle-aged or elderly women, with no history of trauma. PTT tears occur more rarely in young patients, after an acute traumatic event. Clinically, PTT tears present with pain along the tendon, increased by weight bearing, swelling and functional limitation. PTT tears are surgically classified in three types: with tendon hypertrophy, with tendon atrophy and with complete tendon tear. The three different anatomicosurgical patterns require different therapeutic approaches. This work was aimed at investigating MR capabilities in recognizing the direct and indirect signs of PTT tears, assessing MR sensitivity in different types of tears. Fourteen patients with clinically suspected PTT tears and 10 control patients underwent MRI of the ankle (0.5 T, GE Vectra) following a study protocol including SE T1-weighted and FSE T2-weighted scans acquired on the axial and sagittal planes. In all patients, the transverse diameter, the shape and the section surface of the lesions were calculated on the axial planes at different levels; all these parameters were compared with those of the adjacent tendons, i.e., flexor longus ditae and flexor hallucis. Moreover, the probable presence was investigated of intratendineous signal intensity changes, of peritendineous synovial fluid and of indirect signs of PTT tear, i.e., the lack of longitudinal talonavicular alignment and the bulging of the medial navicular tubercle. According to MR results, the 14 patients were subdivided into 8 patients with type-I tears, 2 with type-II tears and 4 patients with type-III tears. The measures of healthy and injured tendons were in substantial agreement: in fewer cases, agreement was found also between symptomatic and control patients with intratendineous signal changes. Thus, the specificity of the two parameters was reduced. Finally, such indirect signs of PTT tear as a hypertrophic navicular tubercle and the lack of longitudinal talonavicular alignment exhibited good specificity, but sensitivity was barely sufficient. MR diagnoses were confirmed at surgery in 6 patients with type-II and type-III tears. In conclusion, MRI appears to be a suitable modality for recognizing and classifying PTT tears and a useful tool for the treatment and follow-up of these patients.

Adolescent↗
PubMed1995

[Biomechanics and semeiotics of traumatic lesions of the posterior cruciate ligament using magnetic resonance].

The authors reviewed 458 MR examinations of the knee to assess the potentials of this technique in the study of traumatic injuries of the posterior cruciate ligament (PCL) and to investigate the frequency of their association with injuries of other knee joints. MR images were acquired with an 0.5-T super-conductive unit with an extremity coil. T1-weighted spin-echo (SE) and T2*-weighted gradient-echo (GE) sequences were used on sagittal, coronal and, in some cases, axial planes, with 3-mm slice thickness and 0-1 mm slice gap. The following parameters were studied to diagnose partial or complete PCL tears: PCL thickness and outline, disruption of ligamentous fasci and signal intensity features. The injuries were classified as proximal, intermediate and distal according to their site. Thirteen PCL tears were detected, 5 of them complete and 8 partial. Complete tears were found in 4/5 patients in the middle third and one patient had a distal intersection tear with tibial bone avulsion. Partial tears were found in the distal tract in 5/8 patients, in the proximal tract in one patient and in the middle third in 2 patients. In 12/13 patients capsuloligamentous knee tears were associated. Overall MR rate of PCL tears was 2.8%; of them, 92.3% were associated with other capsuloligamentous injuries. MR diagnosis was confirmed at arthroscopy in 12/13 patients. The sagittal plane was best in optimally demonstrating the whole PCL and its injuries. GE T2* sagittal sequences demonstrated the site of PCL tears better than SE sagittal ones. Relative to other authors, we found MRI an extremely reliable method to distinguish partial from complete PCL tears. This was probably due to the thinner slices (3 mm) we used. MRI can accurately assess the extent of traumatic injuries of the PCL and of other capsuloligamentous parts of the knee, which is relevant from the clinical point of view. Indeed, MRI allows useless diagnostic arthroscopy to be avoided and yields major indications to choose the correct treatment.

Adult↗
PubMed1994

Color Doppler ultrasonography in pediatric intussusception.

CDU was used in 11 children with intussusception. Demonstration of vascular images within the "pseudokidney" mass was possible in none of 11 cases. Of them, eight could be treated by hydrostatic reduction. In the remaining case, marked edema of the bowel wall did not allow reduction, and surgery had to be performed: no necrosis was observed in the surgical specimen. Both patients in whom CDU failed to demonstrate vascular signals had necrosis at surgery, and bowel resection was performed. Because of the limited number of patients examined at this time, no firm conclusions can be drawn from our experience. However, CDU seems a promising technique in detecting vascular changes occurring in intussusception, with a possible role as a predictive tool of bowel necrosis.

Child, Preschool↗
PubMed1994

[Angiogenetic capacity of breast neoplasms and correlation with color-Doppler semiology].

The authors correlated the presence/absence of color signal-as shown by color-Doppler ultrasonography (CDUS) in 22 cases of breast carcinoma-with lesion angiogenesis potentials, as evaluated in the histologic sections with the determination of the microscopic angiogenesis grading system (MAGS) index. In all 4 cases in which CDUS showed no color signal, MAGS index value exceeded 30, which is suggestive of high neoplastic neoangiogenesis potentials. In contrast, in 17 of 18 cases positive to CDUS, MAGS index value remained below 30 and the microscopic analysis showed the presence of many fresh vessels more than 1 mm in caliber. Consequently, the presence of color signals at CDUS exams may be related to the features of tumor feeding vessels and therefore a negative CDUS exam cannot be considered as a reliable sign to exclude a malignant lesion.

Breast Neoplasms↗
PubMed1994

[Comparison of echography and magnetic resonance in sprains of the external compartment of the ankle].

In most cases ankle sprains involve external compartment ligaments. In particular, the anterior talofibular ligament is involved alone in 70% of cases and together with calcaneofibular and posterior talofibular ligaments in the remaining 30% of cases. To investigate the potentials and the possible limitations of high-frequency US (7.5-13 MHz) for the preliminary assessment of the extent of damage of the capsulo-ligamentous lesions of the external ankle compartment, 25 athletes with clinical diagnosis of sprain trauma were examined with conventional radiology. Morphology and structure were studied from the semiologic point of view. US findings were compared with MR results. In all patients, US showed anterior talofibular ligament lesions alone in 13 patients and associated with calcaneofibular ligament lesions in 12 patients. The posterior talofibular and the interosseous talocalcaneal ligaments were never demonstrated by US. In 4/13 patients diagnosed by US as having isolated anterior talofibular lesions, MRI demonstrated a coexisting calcaneofibular lesion (4/13) and, in one of them, a posterior talofibular and interosseous talocalcaneal ligaments lesion. The comparison of US and MR findings in the patients US had diagnosed as having associated anterior talofibular and calcaneofibular ligaments lesions, showed 100% agreement; MRI allowed the demonstration of the lesions in the posterior talofibular and interosseous talocalcaneal ligaments in 2/12 patients. Considering the statistical prevalence of the anterior peroneal-astragalic lesions caused by ankle sprains, the use of high-frequency US as the first diagnostic approach seems justified. Nevertheless, MRI is a fundamental complement for accurately assessing damage extent.

Adolescent↗
PubMed1993

[Multimedia and didactics++. Application to the normal echographic anatomy of the female reproductive system].

It is widely known that US results strictly depends on operators and that each operator follows individual pathways. Therefore the authors have tried to develop high-interactivity tools, allowing the "customization" of learning to the user's demands. Progress linked to microprocessors' technology allowed a wide spread of cost-effective electronic processors with high graphic performances, capable of supporting sophisticated softwares which are useful to develop multimedial programs. Our experiment is aimed at integrating a multimedial management system for US studies, with the training activity of the medical staff US-expert. The system is structured on a hardware platform based on the Motorola microprocessor, class 68040, an application software developed by Apple. The environment for multimedial applications development uses the "Hypercard" interface of graphic presentation, by Apple. The software allows the realization of a multimedial environment of learning, where US images are associated with graphics, drawing and text references. The application allows a multimedial environment of learning for normal eidodiagnostic anatomy of the female reproductive system, where different courses can be followed autonomously. On the basis of a check performed on a group of students, although in a preliminary stage, the combination of conventional didactic material with either a paper or television support, with devices allowing the connection of texts, graphics and images in a dynamic way, proved to be very useful and to allow personal courses of learning, which can be always modified in an interactive way.

Audiovisual Aids↗