Reduction of sound levels with antinoise in MR imaging

A combination of active and passive techniques was used to reduce the sound levels in magnetic resonance imagers. These techniques were integrated into an existing audio system. Measurements of sound reduction varied with the protocol being used and averaged 9.9 dB with coaxial cabling and 14.2 dB with fiberoptic conduction of the feedback signal to a controller. Patient comfort and communication were improved.     

Detection of the sentinal node in squamous-cell carcinoma of the oral cavity and oropharynx. Preliminary study

INTRODUCTION: The sentinel lymph node is defined as the first relay of the lymphatic drainage of the tumor. Isotopic detection of the sentinel lymph node and absence of its metastatic invasion should theoretically be predictive of total drainage of the tumor. The goal of this study was to evaluate sentinel lymph node detectability by lymphoscintigraphy in N0 and/or N1 squamous-cell carcinoma of oral cavity and oropharynx and to determine its negative predictive value. MATERIAL AND METHOD: Lymphoscintigraphy was used for sentinel lymph node detection. The procedure required peritumoral injection of technicium-labeled colloids to enable anatomical and cutaneous location of the sentinel lymph node. A one-way Tyco-Mallinckrodt probe was used for intraoperative detection of the sentinel lymph node. This prospective study included 21 patients with N0 or N1 squamous-cell carcinoma of the oral cavity and the oropharynx. The surgical attitude based on T and N was not modified in this prospective study without direct individual benefit for the patient. Neck dissection was achieved without difficulty. RESULTS: The sentinel lymph node was identified in 20 out of 21 subjects. The sentinel lymph node was not identified in one patient with recurrence T2N0M0 squamous-cell carcinoma of the oropharynx radiated 3 years earlier. The percentage of false-negatives was 12.5% (1 false-negative out of 8 positive patients), giving a sensibility of the detection method of 87.5% (IC (95%)=[47.35-99.68]). This false-negative patient had a T3N0M0 squamous-cell carcinoma of the oropharynx with a sentinel lymph node removed in territory III. Neck dissection revealed 1 N + R- in the sub-mandibular territory associated with 27 N-R-. The probability of not finding a metastatic node at neck dissection when the sentinel lymph node is not metastatic (negative predictive value) was 92.3% (12/13) (IC (95)=[63.97-99.81]). The specificity of the method was 100%, as was the positive predictive value, because no sentinel node was diagnosed positive wrongly on frozen sections among patients without true histological node metastasis. DISCUSSION: For routine care of patients with squamous-cell carcinoma of the oral cavity and the oropharynx detection of the sentinel lymph node is proposed primarily for patients with T1T2N0 staging. Larger tumors can modify the architecture and flow within the lymphatic ducts, and consequently even the concept of a sentinel lymph node. Systematic neck dissection is required or T3T4, even when N0. Our series of T1T2N0 tumors is too small to enable statistically significant conclusions. A low level of false-negative in a larger series would be necessary to propose this technique instead of convention neck dissection for T1T2 tumors of the oral cavity and oropharynx.     

In vivo action of a new octadecaneuropeptide antagonist on neuropeptide Y and corticotropin-releasing hormone mRNA levels in rat

It has been reported that several of the effects induced by an octadecaneuropeptide (ODN), derived from an 86-amino-acid polypeptide termed diazepam-binding inhibitor, could be mediated by activation of a metabotropic receptor. In order to investigate the role and mechanism of action of ODN in the regulation of corticotropin-releasing factor (CRH) and neuropeptide Y (NPY) expression in the paraventricular nucleus and arcuate nucleus, respectively, we studied the effects of the acute intracerebroventricular administration of ODN (2 microg/rat) and the ODN antagonist to metabotropic receptor, cyclo(1-8)[Dleu5]OP (20 microg/rat), on the gene expression of the two neuropeptides in castrated male rat. ODN administration resulted in a 45% increase in CRH mRNA expression, an effect which was reversed by cyclo(1-8)[Dleu5]OP. When cyclo(1-8)[Dleu5]OP was administered alone, it induced a 19% decrease in CRH mRNA levels. ODN administration induced a 17% decrease in NPY mRNA expression while cyclo(1-8)[Dleu5]OP increased by 21% the hybridization signal. The administration of both ODN and ODN antagonist completely abolished the depressing effect of ODN on NPY mRNA. These data suggest that the effects of ODN on CRH and NPY mRNA might be mediated by interaction with metabotropic receptors. Moreover, since cyclo(1-8)[Dleu5]OP can by itself influence the expression of two peptide mRNAs, it might be suggested that ODN is exerting a tonic influence on NPY and CRH neurons.     

Late metastasis after a testicular Sertoli cell tumour

The diagnosis of Sertoli cell tumors is sometimes difficult and can be improved using anti inhibin immunohistochemistry. It is also difficult to establish the prognostic of Sertoli cell tumors. In our observation a high Mib 1 rate (20%) could have be taken in account to decide a better survey or/and a lymphadenectomy, which could have avoided lymph node metastasis in our patient, which was discovered ten years after orchidectomy.     

Cysts from the first branchial cleft. Apropos of a case

We describe a case of branchial cyst from the first branchial cleft in an 8-year-old patient, emphasizing the diagnostic difficulties of this type of lesion and the clinical aspects as well as the details of surgical treatment. The embryogenic origin and the anatomic relation with the facial nerve is recalled. Surgical treatment is indicated.     

Contribution of the semi-free radial forearm flap for head and neck reconstruction

Flap failure is mostly caused by venous thrombosis of the anastomosis. The failure rate is higher in post-irradiated neck. To reduce the risk of venous thrombosis, the authors propose to harvest the radial forearm flap using the cephalic vein as the drainage vein and as a pedicle. Only a single arterial anastomosis is carried out. This technique has been described already in patients who underwent head and neck ablative surgery with radical neck dissection. The authors report 2 cases in patients with post-irradiated neck. The flap transfers were successful in the 2 cases. The operative time of harvesting this hybrid version is the same with the conventional free flap technique. This version of the radial forearm flap can be a method of choice for some complex microvascular reconstruction in the head and neck region.     

The three-dimensional spiral scanner and volume rendering technique: importance in craniofacial traumatology and reconstructive surgery

There are two reconstruction methods for 3D imaging with a helical scanner: a surface rendering process providing a 3D-SSD (Surface Shaded Display) image that looks like a plaster cast skull and 3D-VRD (Volume Rendering Technique) which is more precise and gives 3D images similar to radiographs. We review briefly the techniques used to acquire these images and present 3D volume-rendering scanners, pointing out its usefulness in craniomaxillofacial traumatology and reconstructive surgery.