Computerized tomography of the glottis after intracordal autologous fat injection

According to the committee on speech, voice, and swallowing disorders of the American Academy of Otolaryngology-Head and Neck Surgery, various surgical methods such as laryngeal framework surgery, laryngeal re-innervation, and injection laryngoplasty might be used to palliate inferior laryngeal nerve paralysis. In the present case report we document the survival and exact location of the boluses of autologous fat in one patient in whom this material was used for injection laryngoplasty.

[What is bright on T1 MRI scans?]

The list of entities associated with a high signal intensity on T1-weighted images is extensive and classically includes fat, proteins, hemorrhage, melanin and gadolinium. However, additional entities may be responsible for abnormally high signal intensity on T1-weighted images. These include ion deposition in metabolic disorders, free radicals, increased proton density, flow phenomena, some artifacts, and new contrast agents. The aim of this article is to display both the common and uncommon causes for a high T1 signal intensity and to discuss the underlying mechanisms or attributable pathophysiology for this phenomenon.

[Radiological surveillance of operated ethmoidal cancers. Practical points]

Radiological follow-up of ethmoidal neoplasms is not clearly established in terms of imaging modalities (CT, MRI) or periodicity. This paper, based on 4 typical cases, tries to describe the main imaging features of this radiological follow-up. Initial CT 3 to 6 months after surgery is essential, being the reference examination. It can show postoperative bone changes. During follow-up, a CT scanner every 6 months seems sufficient. For the image interpretation, a comparison with the two previous CT is mandatory. Any bone destruction must be considered as suspicious, even if very small. MRI should be performed in case of sphenoidal opacity, in order to differentiate between tumor recurrence and retentional fluid. MRI is also necessary and useful when the tumor presents an intradural or intracranial extension.

The aryepiglottic fold as a rare location of adenoid cystic carcinoma

We report one case of a mass in the aryepiglottic fold seen on CT, which proved to be an adenoid cystic carcinoma. There was nothing specific about the imaging characteristics that would allow it to be confidentially differentiated from squamous cell carcinoma.

Complication of jet ventilation during microlaryngeal surgery

Complications during jet ventilation for microlaryngoscopy, which is usually a relatively safe procedure, are rare. Those described have included hypoventilation, pneumothorax, pneumomediastinum, subcutaneous emphysema, pneumoperitoneum, and gastric distention. We describe herein a case of a life-threatening complication during jet ventilation with a Carden's tube that ended in laparotomy.

[The value of magnetic resonance imaging in the diagnosis of spinal cord hemangioblastoma. Apropos of 12 cases]

This study concerned a series of 12 patients, 4 of whom had Von Hippel-Lindau disease. Six of these patients were explored by myelography, 6 by spinal cord angiography, 8 by CT scan with contrast injection and 12 by MRI, with gadolinium injection in 8. MRI proved to be the choice examination for the diagnosis of spinal cord tumor, but gadolinium injection was necessary since it made it possible to detect the tumoral bud and its intense enhancement. The absence of gadolinium injection led us to an erroneous initial diagnosis of syringomyelia in two patients and glioma in one. Sagittal sections made it easier to evaluate the tumoral extension in patients with evidence or suspicion of Von Hippel-Lindau disease. Arteriography was indicated, as it provided a preoperative map and diagnosed punctiform lesions.

MRI in chronic progressive radiation myelopathy

OBJECTIVE

Our goal was to assess medullary lesions in patients suffering from chronic progressive radiation myelopathy (CPRM) using MRI.

MATERIALS AND METHODS

In a group of 10 patients suffering from CPRM, MRI findings (11 examinations), radiation protocols, and patient prognoses were reviewed.

RESULTS

A cord enlargement was demonstrated in five cases, whereas four cases presented with medullary atrophy. As demonstrated by MRI, radiation-induced medullary lesions progressed toward cord atrophy in one patient. When MRI and/or comparison myelogram were performed within 8 months following the onset of the myelopathy, a cord enlargement was usually encountered. When the patient was evaluated > 8 months after the first neurological symptoms, a cord atrophy was always demonstrated. Medullary lesions extended beyond the boundaries of the radiation field in 67% of the cases. However, with the exception of one case, the main focus of the cord damage was included within an irradiated cord segment. An enlarged cord was often associated with a neurologic deterioration and a fatal outcome. In patients with cord atrophy, the neurologic deficit was often static and survival rates were better.

CONCLUSION

These results suggest a revision of classic criteria used for the diagnosis of CPRM. By demonstrating cord lesions, MRI helps to establish disease prognosis.

Internal architecture of the parotid gland at MR imaging: facial nerve or ductal system?

A radiologic-anatomic study was performed to determine the nature of the low-signal-intensity curvilinear structures currently seen in the normal parotid gland on axial T1-weighted magnetic resonance (MR) images. These structures are considered by some to represent the intraparotid facial nerve. After cannulation of the Stensen duct, the authors imaged the parotid gland of two cadavers in situ before and after intraductal injection of gadolinium tetrazacyclododecanetetraacetic acid. Retrograde filling was obtained in one gland. The same sections were used throughout a subsequent anatomic study, allowing correlation of the MR findings with the macroscopic and histologic appearance of the gland. Comparison of MR images and gross and histologic sections established that two intraparotid facial nerve segments, although identified from the histologic study, were not visible on corresponding MR images. Many areas of low signal intensity seen within the gland were found to represent the main duct and some afferent ductal branches.

[Ante- and posthypophyseal insufficiency with infundibulum abnormalities]

The hypopituitarism and the diabetes insipidus are often idiopathic. A retrospective study of 6 cases of diabetes insipidus and 8 cases of partial or total idiopathic antehypophyseal insufficiency has shown the value of MRI to demonstrate anomalies of the infundibulum or hypothalamic-hypophysis "stages". MRI allows to bring together some cases of idiopathic hypopituitarism in a new entity which is the hypopituitarism due to a newborn section of the infundibulum.

[The normal cranial nerves in MRI. Description and visualization frequency]

In order to assess the value of MR in the depiction of intracranial nerves, we retrospectively reviewed 60 patients investigated over a period of 2 years. The aim of this study was: 1) to assess the score of MR in the detection of cranial nerves III to XII; 2) to determine accurate landmarks allowing for easy detection of those cranial nerves. Cranial nerves III, V, VII, VIII are well seen (70 to 100%), very often in both axial, sagittal and coronal sections. Nerves IX to XII are correctly studied only on axial planes [81 and 83%), but it is difficult to distinguish between the vagal nerve and the glossopharyngeal and spinal nerves. Due to their oblique direction and small size, fourth and sixth nerves are rarely visualized. The more important landmarks are the chiasma, the colliculi, the Meckel's cave, the internal auditory canal, the jugular foramen, the hypoglossal canal and the different brainstem structures. We suggest the following scanning protocol: short spin echo sequences (TR = 600 ms, TE = 20 msec), 3 to 5 continuous sections, 16 to 20 cm field of vue with respectively 4 or 2 excitations, 256 x 256 matrix, with at least one acquisition plane (axial), but preferably two or three planes. Thus MR is sensitive exam in the recognition of cranial nerves, and it must be the first step exam in patients presenting with cranial nerve disease.

Ventriculus terminalis of the conus medullaris: MR imaging in four patients with congenital dilatation

MR findings in four patients with MR evidence of congenital cystic dilatation of the ventriculus terminalis were reviewed retrospectively. The ventriculus terminalis is a small cavity of the conus medullaris that forms during embryonic development as result of canalization and retrogressive differentiation. The dilated ventriculus terminalis appears on MR images as a small ovoid cavity with regular margination; intralesional fluid resembles cerebrospinal fluid on all MR sequences. After injection of contrast material, MR imaging shows no enhancement of the cyst or its wall, and thus differentiates congenital dilatation of the ventriculus terminalis from cystic tumors, which occur more frequently in this region.

[Physico-chemical properties of 4 endodontic sealing cements]

Four endodontic sealers were compared with two series of tests, in thin layer and in 10 mm long and 5 mm diameter rods. Under these conditions, the Pulp Canal Sealer showed the best ability to present a thin layer and the same flow than the Cortisomol. Its setting time was 15 minutes. Forty-eight hours later, the Sealite showed a very good tightness compared to the other sealers. At 30 days, the Pulp Canal Sealer and the OZn-Eugénol were the tightest ones. Less water was absorbed with the Cortisomal and the Sealite. Is there, for these sealers, any correlation between water-absorbtion and tightness?

[Computerized electroencephalographic monitoring in anesthesia]

The computerized electroencephalogram monitor provides a simple interpretation of the standard EEG trend. In the operating room, this compact EEG monitor is convenient and the trend is easy to read for a non-specialist user. EEG monitoring is especially indicated in carotid endarterectomy for the detection of ischemic event during surgery. The use of this monitor should be recommended for high risk patients (cardiac surgery, cerebral aneurysm surgery, controlled hypotension) to determine the adequate depth of anesthesia and to perform a stress-free anesthesia when the anesthetic drug is given by titration according to the decrease in the awakening electrical cerebral activity.

Occult cerebrovascular malformations: follow-up with MR imaging

The clinical and magnetic resonance (MR) imaging findings in 20 patients with MR evidence of occult cerebrovascular malformations (OCVMs) were retrospectively analyzed. Of 27 lesions followed up throughout a mean period of 18 months, eight showed obvious evolution on MR images (four cases of regression and four cases of new bleeding). Three new independent lesions were disclosed. Clinical evolution was discordant with MR findings in five patients. In the other patients, topography of the lesion, mass effect, and location of the hemorrhage could explain clinical data. The dynamic nature of OCVMs must be considered in decisions on therapeutic management.

Value and limits of arthrography in the study of pathological mediopatellar plicae of the knee; a comparison with arthroscopy

The results from arthroscopy and arthrography were compared in a prospective study of the mediopatellar plicae in 100 knees with internal disorders. With reference to arthroscopy, the sensitivity and specificity of arthrography for the detection of mediopatellar plicae were, respectively, 83.6 and 88.8%. The arthrographic signs of pathological plicae were: a thick plica, thicker than the internal condylar cartilage (sensitivity: 72%; specificity: 84%) and an interposed plica (sensitivity: 85%; specificity: 81.8%). Statistically the arthrographic signs agreed with the arthroscopic signs. The two methods did not differ significantly in their contribution to the diagnosis of pathological plicae.

Cystic schwannoma mimicking a brain stem tumor: MR features

A case of cystic schwannoma that presented as an intraaxial lesion on CT is reported. Magnetic resonance was able to detect the extraaxial origin of the tumor.

Estimating anesthetic depth by electroencephalography during anesthetic induction and intubation in patients undergoing cardiac surgery

Intravenous (IV) anesthesia titrated to continuous computer-processed electroencephalograms (EEGs) was studied in 32 consecutive patients undergoing cardiac surgery. Anesthesia was induced with fentanyl 50 micrograms/kg with no EEG monitoring (n = 16) or 25 to 50 micrograms depending on changes in EEG (n = 16). EEG, oxygen saturation by pulse oximeter, intra-arterial blood pressure (BP), central venous pressure (CVP), and pulmonary artery pressure (PAP) (n = 18) were monitored continuously. Cardiac output (CO), CVP, PAP, spectral-edge frequency for each hemisphere, and BP were recorded before induction, immediately before intubation, and 1 and 5 minutes after intubation. With EEG monitoring, intubation was performed when spectral-edge frequency decreased to 10 Hz or less. Recall and pain were investigated 2 to 12 weeks postoperatively. With EEG, the amount of fentanyl used before intubation was significantly lower (39.7 +/- 2 micrograms/kg; p less than 0.005) than without EEG (50 micrograms/kg). The decrease in BP (% change) was less with than without EEG; mean changes in BP between preinduction and preintubation were -7.4% +/- 3.8% and -16.5% +/- 3.1% and between preinduction and 1 minute after intubation 0.3% +/- 3.4% and -12.5% +/- 3.5%, respectively. Percent changes in mean BP between intubation and 1 minute after were 9.6% +/- 4.0% with EEG and 5.2% +/- 3.0% without EEG. No patient in either group had recall. The authors conclude that using EEG monitoring to estimate depth of anesthesia during induction and laryngoscopy may increase safety in high-risk patients undergoing cardiac surgery.

Magnetic resonance investigations of non-acoustic petrous lesions

Twenty cases of intrapetrous lesions were studied by a 1.5 T magnetic resonance (MR) unit. In all cases, comparisons were made between MR, CT and clinical findings. Our present material included 9 cholesteatomas, 1 cholesterol cyst, 3 primary epidermoid carcinomas, 2 metastatic neoplasms, 1 glomus jugulare tumor and 4 facial neurinomas. Gadolinium was injected in 7 cases and seemed to be the best method for studying the intrapetrous tumors. MR permitted accurate topographic study and assessment of tumoral extension, as well as a ready demonstration of tumor vascularity. The present findings also showed that MR is not capable of defining small bony detail or calcifications.

[Diagnosis of diseases of the spinal cord and the vertebral column]

Magnetic resonance imaging (MRI) nowadays plays a predominant role in the diagnosis and evaluation of spinal canal pathologies and has reduced the other exploratory methods, including computerized tomography (CT) and myelography, to an ancillary role. These pathologies are divided into three groups: those where MRI is the only imaging method (syringomyelia, tumours in the spinal canal, phakomatoses, external pachymeningitis, spinal cord injuries, myelitis); those where MRI is the initial method and is completed by other examinations (vascular malformations, dysraphism, myelopathies due to cervical osteoarthritis) and those where MRI still play a lesser role than CT (degenerative lesions of the lumbar column).