How to perform 3D reconstruction of skull base tumours

The surgical management of skull base lesions is difficult due to the complex anatomy of the region and the intimate relations between the lesion and adjacent nerves and vessels. Minimally invasive approaches are increasingly used in skull base surgery to ensure an optimal functional prognosis. Three-dimensional (3D) computed tomography (CT) reconstruction facilitates surgical planning by visualizing the anatomical relations of the lesions in all planes (arteries, veins, nerves, inner ear) and simulation of the surgical approach in the operating position. Helical CT angiography is performed with optimal timing of the injection in terms of tumour and vessel contrast enhancement. 3D definition of each structure is based on colour coding by automatic thresholding (bone, vessels) or manual segmentation on each slice (tumour, nerves, inner ear). Imaging is generally presented in 3 dimensions (superior, coronal, sagittal) with simulation of the surgical procedure (5 to 6 reconstructions in the operating position at different depths).

Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part I: Locoregional extension assessment: 2012 SFORL guidelines

OBJECTIVES

To set out good practice guidelines for locoregional extension assessment of squamous cell carcinoma of the head and neck (excluding nasopharynx, nasal cavities and sinuses).

MATERIALS AND METHODS

A critical multidisciplinary review of the literature on locoregional extension assessment of squamous cell carcinoma of the head and neck was conducted, applying levels of evidence in line with the French health authority's (HAS) literature analysis guide of January 2000.

CONCLUSION

Based on the levels of evidence of the selected articles and on work-group consensus, graded guidelines are set out for clinical, endoscopic and imaging locoregional extension assessment of head and neck cancer.

[Two particular cases of superior semicircular canal dehiscence related to a procidence of the superior petrous sinus]

We report two cases of superior semicircular canal dehiscence related to a dehiscence of the superior petrous sinus that creates a localized notch of the most superior part of the superior semicircular canal. This vascular dehiscence was suspected at CT and was confirmed by MR imaging with identification of the superior petrous sinus in touch with the intralabyrinthine fluid at this level. This not well-known etiology of the superior semicircular canal dehiscence syndrome has to be searched and described by radiologists, allowing an optimal surgical approach.

Extension patterns of nasopharyngeal carcinoma

The nasopharynx represents an intersection between the nasal choanae, the oropharynx, the deep facial spaces, the skull base and the intracranial cavity. Most nasopharyngeal neoplasms are malignant tumors showing aggressive local infiltration along well-defined routes. The primary role of imaging is accurate tumor mapping and detection of possible tumor extension, especially to the skull base and the deep facial spaces. The aim of this paper is to illustrate these extension patterns of nasopharyngeal carcinomas on imaging and to show the particular implication of imaging in the correct staging of the lesion.

[Paranasal sinuses: postoperative imaging]

Radiologic assessment after sinus surgery requires not only a good knowledge of the primary disease, but also a mandatory understanding of every surgical technique and approach. After having described these techniques, we will illustrate immediate, possible but rare, post-operative complications. The various pathologies responsible for a delayed recurrence will also be illustrated. A chapter will be dedicated to paranasal sinuses malignant tumors follow up after surgery.

[Clinical implications of acoustic neuromas growth rate in volumetric study]

OBJECTIVE

The pattern of neuroma growth is of great importance in choosing the appropriate management. This paper tests the clinical impact of tumor growth rate assessed by volumetry. There is a conviction that some slowly growing tumors could be observed for many years.

METHOD AND PATIENTS

Volume measurements were performed on T1- weighted MR images (spin echo sequences) after injection of gadolinium using a special dedicated software. The studied group included 17 patients in whom at least two MRI examinations were carried out and tumor growth was confirmed. The intervals between initial and the first follow-up examination were 14.2 months on the average. In 7 cases tumor evolution was observed in 2 periods (3 MRI studies) and in 4 cases in 3 periods (4 MRI studies).

RESULTS

The growth rate depended on tumors volume and clinical stage (P<0.01). Small tumors can be observed more safely than advanced tumors because their increase in mass is lower.

CONCLUSION

The observation with the tumoral volume measurements appears to be a useful and accurate tool to estimate the tumor growth rate. The growth rate is a major factor for choosing the appropriate management.

Lymph node metastases from head and neck squamous cell carcinoma: MR imaging with ultrasmall superparamagnetic iron oxide particles (Sinerem MR) -- results of a phase-III multicenter clinical trial

The aim of this study was to compare the clinical usefulness of ultrasmall superparamagnetic iron oxide (USPIO) MR contrast media (Sinerem, Guerbet Laboratories, Aulnay-sous-Bois, France) with precontrast MRI in the diagnosis of metastatic lymph nodes in patients with head and neck squamous cell carcinoma, using histology as gold standard. Eighty-one previously untreated patients were enrolled in a multicenter phase-III clinical trial. All patients had a noncontrast MR, a Sinerem MR, and surgery within a period of 15 days. The MR exams were analyzed both on site and by two independent radiologists (centralized readers). Correlation between histology and imaging was done per lymph node groups, and per individual lymph nodes when the short axis was > or = 10 mm. For individual lymph nodes, Sinerem MR showed a high sensitivity (> or = 88%) and specificity (> or = 77%). For lymph node groups, the sensitivity was > or = 59% and specificity > or = 81%. False-positive results were partially due to inflammatory nodes; false-negative results from the presence of undetected micrometastases. Errors of interpretation were also related to motion and/or susceptibility artifacts and problems of zone assignment. Sinerem MR had a negative predictive value (NPV) > or = 90% and a positive predictive value (PPV) > or = 51%. The specificity and PPV of Sinerem MR were better than those of precontrast MR. Precontrast MR showed an unexpectedly high sensitivity and NPV which were not increased with Sinerem MR. The potential contribution of Sinerem MR still remains limited by technical problems regarding motion and susceptibility artifacts and spatial resolution. It is also noteworthy that logistical problems, which could reduce the practical value of Sinerem MR, will be minimized in the future since Sinerem MR alone performed as good as the combination of precontrast and Sinerem MR.

[Cricoid chondronecrosis after prolonged endotracheal intubation]

Subglottic area injuries after prolonged endotracheal intubation are relatively frequent but cricoid cartilage necrosis is rare, with uncertain prognosis. Endoscopic findings are evocative even when clinical signs are not. When suspected, CT scan is required. The CT appearance is not specific, but the diagnosis can be strongly suggested in cases of fragmentation and collapse of the cricoid cartilage. We report two cases of cricoid chondronecrosis.

[Pendred's syndrome. Current features]

Introduction Pendred's syndrome is a recessive autosomal disease, traditionally defined as the association of deaf-mutism, goiter and dysfunctional iodide organization revealed by the perchlorate discharge test. It represents 4 to 10% of the causes of congenital hypoacusis. Although described more than a 100 years ago, the association of thyroid and cochleo-vestibular damage remained unclear for many years. Genetic abnormalities Progress in molecular biology has revealed that the disease is related to alterations in the PDS gene situated on chromosome 7. The PDS gene is responsible for the production of pendrine, protein involved in anion (l-, Cl-) transportation, notably in the apical pole of the thyreocyte and the cochlear duct, where the endolympha is produced. Practical implications The truncation of pendrine related to the genetic alterations be responsible for the morpho-functional alterations in the cochlear apparatus and the thyroid. In this perspective, Pendred's syndrome would appear as a genetic disorder in anion transportation.

Correlation between Ki-67 index and some clinical aspects of acoustic neuromas (vestibular schwannomas)

Evaluation of the proliferation activity of neuromas has a practical meaning when there are doubts about the complete resection of the tumor. Evaluation of the clinical aspects connected with increased proliferation activity may have a much broader application. The aim of this study was to correlate selected clinical and radiologic aspects of vestibular schwannomas with the results of the Ki-67 index. The studied group included 23 males and 20 females. Unilateral neuromas were stated in 38 cases (mean age, 52.2 years) and bilateral tumors in 5 cases (mean age, 44.2 years). The immunohistochemical tests (Ki-67) were performed on the specimens preserved in formalin and stored in paraffin. The Ki-67 index was estimated in a semiquantitative study. The mean value of Ki-67 index was 1.86%. In case of unilateral neuromas (n = 38), the average Ki-67 index was 1.74%. In 5 cases of bilateral tumors, the index amounted to 2.79% (P = 0.278). No significant correlation was found by comparing the value of the Ki-67 index with the age of patients (P = 0.410: r = 0.128). Significant differences in the value of the Ki-67 index were noted in the sub-groups of tumors that were evaluated radiologically as growing and stable. The mean value of Ki-67 index was 3.17% in the first subgroup; in stable neuromas, it was significantly lower, amounting to 1.11% (P = 0.020). Such results may confirm that the growth rate of vestibular schwannomas varies and may explain the difficulties in estimating the growth of neuromas on the basis of clinical aspects only.

Cochlear fossa enhancement at MR evaluation of vestibular Schwannoma: correlation with success at hearing-preservation surgery

PURPOSE

To describe a sign in magnetic resonance (MR) imaging that could reflect the state of the cochlear nerve before hearing-preservation surgery in small vestibular schwannomas.

MATERIALS AND METHODS

Thirty-one patients with serviceable hearing underwent 1.5-T MR imaging before hearing-preservation surgery. The presence of cochlear fossa enhancement on T1-weighted spin-echo images obtained after the administration of contrast material was compared with the results of hearing-preservation surgery.

RESULTS

Cochlear fossa enhancement was present in 13 patients, and all of them had total hearing loss after surgery. There was no cochlear fossa enhancement in 18 patients; 15 maintained serviceable hearing after surgery, and three had postoperative hearing loss with no serviceable hearing (sensitivity, 81%; specificity, 100%).

CONCLUSION

Cochlear fossa enhancement on T1-weighted spin-echo images seems to be a reliable sign for analyzing the state of the cochlear nerve. The absence of cochlear fossa enhancement could become an additional criterion for selecting the surgical approach in vestibular schwannomas.

Percutaneous nephrostomy: placement under laser guidance and real-time CT fluoroscopy

The purpose of this paper is to present our experience with real-time computed tomography (CT) fluoroscopy guided percutaneous nephrostomy (PNT) and to describe this technique involving puncture under laser guidance. We attempted 30 placements in 25 patients: puncture was directed by laser guidance and placement of the tube was made under real time CT fluoroscopy. 25 procedures were performed in prone position and 5 procedures in the supine position. The time necessary for the procedure ranged from 10 to 45 min (mean 25 min). The average duration of CT fluoroscopy per placement was 49 seconds (range 7-110 s). The PNT placement was successful as a sole procedure including puncture and catheter placement in 24 of 30 cases; in the remainder of cases, puncture was performed under CT guidance but the catheter was definitively positioned in conventional fluoroscopy. The CT fluoroscopy technique allows routine, efficient and safe PNT placement, especially when encountering difficult access to the pelvicaliceal system.

Feasibility of a pumpless extracorporeal respiratory assist device

BACKGROUND

Our study evaluated the efficacy and feasibility of a pumpless respiratory assist device and determined its capacity for carbon dioxide removal.

METHODS

In five adult pigs the left femoral vein and artery were cannulated with a 20F cannula and connected to a low-pressure hollow-fiber artificial lung. After we had obtained baseline values of mean arterial pressure, cardiac output, and blood flow across the artificial lung, the mean arterial pressure was reduced 20% and 40% relative to baseline; in a second phase, it was raised 20% and 40. Cardiac output and artificial lung flow were simultaneously recorded. We determined the carbon dioxide removal capacity of the artificial lung by gradually increasing the arterial partial carbon dioxide tension of the animal.

RESULTS

An increase of 10 mm Hg in mean arterial pressure resulted in an increase of flow of 0.14 L/min. The mean pressure drop across the artificial lung was measured at 17 +/- 9 mm Hg. The shunt flow over the artificial lung varied between 14 and 25% of the cardiac output of the animal. Depending on inlet conditions, carbon dioxide removal by the artificial lung was between 62 +/- 22 mL/L/min and 104 +/- 25 mL/L/min.

CONCLUSIONS

A pumpless respiratory assist device can remove a significant proportion of the metabolic carbon dioxide production. However, adequate mean arterial pressure is mandatory to maintain sufficient flow across the device. The technique seems attractive because of its simplicity and can be used in acute lung injury in conjunction of apneic oxygenation for prolonged respiratory support.

In vivo evaluation of a phosphorylcholine coated cardiopulmonary bypass circuit

A complete phosphorylcholine coated cardiopulmonary bypass circuit, including the Dideco D901 oxygenator, was tested for gas transfer, blood path resistance, and biocompatibility in a standardized setting. Blood compatibility was tested by measuring complement and platelet activation. Three dogs (mean body weight 28 +/- 3 kg) were placed on cardiopulmonary bypass at a flow rate of 600 mL/min during 6 hours. The animals were weaned from cardiopulmonary bypass and sacrificed electively after 7 days. Oxygen and carbon dioxide transfer were 26.6 +/- 2.4 mL/min and 33.0 +/- 1.9 mL/min, respectively. Mean pressure drop across the oxygenator was 52.6 +/- 0.2 mmHg. The respective baseline values for thromboxane B2, prostaglandin E2 and platelet factor 4 were 1817 +/- 283 pg/mL, 12783 +/- 2109 pg/mL, and 0.35 +/- 0.08 IU/mL. Thromboxane B2 and prostaglandin E2 increased slightly to 2881 +/- 868 pg/mL and 18083 +/- 3144 pg/mL at 30 minutes of bypass, whereas platelet factor 4 values remained stable curing the procedure. Concentrations of complement split products C5a were only mildly increased. After use scanning electron microscopy was performed on the inner housing, heat exchanger, and outer surface of the hollow fibers. No thrombi nor organized cellular deposits were found on any of the components. Phosphorylcholine coating of CPB seems to be very promising regarding platelet activation and complement activation.

The growth of acoustic neuromas in volumetric radiologic assessment

OBJECTIVE

The volumetric assessments of neuroma were applied for radiologic observation of tumor growth. The hypothesis that most of neuromas are stable or show only slight growth was tested.

STUDY DESIGN

This was an observational study.

SETTING

The study was performed in the university centers.

PATIENTS

The study group included 27 patients with 15 unilateral tumors and 12 bilateral tumors. All patients had at least 2 magnetic resonance imaging (MRI) examinations, and the average interval between initial and control examinations was 11.4 months.

MAIN OUTCOME MEASURE

Volume measurements were performed on T1- weighted MRI spin echo sequences after injection of gadolinium using special software. Growth of the tumors was estimated by comparison of the results of three measurements from the initial and control MRI examinations.

RESULTS

The growth was confirmed in 17 of 27 tumors (63%). Growth was found in 10 of 12 neuromas of neurofibromatosis type 2 (83.7%). In 15 unilateral neuromas, growth was found in 7 (43%). Unilateral neuromas were observed for a shorter period of time (6.3 months) than bilateral tumors (14.7 months). The correlation between a neuroma volume gain and the follow-up period was statistically significant (p = 0.003, r = 0.544).

CONCLUSIONS

The growth of tumors can be confirmed despite a short follow-up period.

[Bilateral spontaneous perirenal hematoma: an unusual complication of polyarteritis nodosa]

INTRODUCTION

Spontaneous perirenal hematoma is a serious and unusual complication of polyarteritis nodosa. Its treatment is not standardized. A review of the literature shows that therapeutic arterial embolization is an alternative to nephrectomy.

EXEGESIS

We report a new case of spontaneous bilateral perirenal hematoma due to a rupture of a renal aneurysm in a 68-year-old patient presenting with polyarteritis nodosa. The patient had no hypertension. Renal arteriography helped guide the diagnosis, and selective embolization was performed to treat the left hematoma. The right hematoma only required symptomatic treatment.

CONCLUSION

Arteriography with selective embolization appears to be a good alternative to nephrectomy in spontaneous perirenal hematoma complicating polyarteritis nodosa. However, in this case, the right hematoma required neither arteriography nor nephrectomy. This raises the questions of the necessity of selective embolization when the clinical status remains satisfying with a symptomatic treatment.

Imaging of angiomyolipomas

In this article we review renal angiomyolipomas (AMLs) from cases in the world literature and 60 cases from our own institution. We also analyze the role and the place of the various imaging techniques in the detection and diagnosis of AMLs. Discussion is focused on the natural history of this benign neoplasm as an isolated form or as a part of the tuberous sclerosis (TS) complex or as part of a third less certain group of multiple AML without stigmata of TS. We also consider the growth patterns and hemorrhagic risks of AML to help define an approach to the current management of this lesion.

Sequential evaluation of pulmonary function and bronchial hyperresponsiveness in patients with nasal polyposis: a prospective study

Nasal polyposis (NP) is commonly associated with nonspecific bronchial hyperresponsiveness (BHR) and/or asthma. The aim of this prospective study was to investigate the changes of pulmonary function and BHR in patients with nasal polyposis. Forty-four consecutive patients with NP were included in the study and were followed for 12 mo. Nonspecific BHR was assessed by a carbachol challenge test to determine the provocating dose (PD20) necessary to decrease FEV1 by 20% from baseline values; 17 of 22 patients who demonstrated BHR also exhibited asthma. Spirometric measurements and carbachol challenge were performed before initiating any treatment and 12 mo later. All patients were treated first with beclomethasone (600 microg/d). Intranasal ethmoidectomy was performed in 23 patients who did not improve when treated with topical steroids alone (nonresponders); in contrast, 21 patients were successfully treated with beclomethasone alone (responders). PD20 significantly decreased in the group of nonresponders (p = 0.018), whereas it remained unchanged in responders (p = 0.95). FEV1 (% pred) and FEF25-75 (% pred) significantly decreased in nonresponders (p < 0.001), whether BHR existed or not, whereas no significant change was observed in responders. Our results demonstrate that nonresponders who required nasal surgery exhibited an enhancement of BHR and a slight but significant decrease of FEV1 and FEF25-75 values. However, no change in pulmonary symptoms and/or asthma severity occurred. Clinical and functional follow-up of these patients should assess the long-term evolution of these parameters and their clinical relevance.

Urachal remnants: sonographic assessment

OBJECTIVE

To evaluate the frequency of the visualization of urachal remnants (UR) with ultrasound and to determine their sonographic patterns.

SUBJECTS AND METHODS

Two hundred and fifty consecutive patients were referred for abdominal and/or pelvic ultrasonography, 83 who had urinary tract symptoms. Patient age ranged from 1 month to 91 years (mean = 35 years). Patients were classified into four groups: (1) < 16 years (n = 47) (2) 16-35 years (n = 100), (3) 36-55 years (n = 49), (4) > or = 56 years (n = 54). Ultrasonography was performed using 3.75 MHz and 7.5 MHz transducers. Ultrasound criterion for diagnosis was a midline mass located between the rectus abdominus muscle and the upper part of the anterior bladder wall.

RESULTS

UR were found in 90 cases (36%). UR demonstration was more frequent in groups 1 (61.7%) and 2 (49%) and 3 (20.4%) and 4 (3.7%). UR were nodular (87%) or tubular in structure (13%). Echogenicity was similar to or greater than adjacent muscle in 51% and less than in 49%. The length, width, and thickness mean and standard deviation values were 13.5 +/- 4.7 mm, 12.6 +/- 5 mm, and 5.2 +/- 1.5 mm, respectively. UR were observed in 50% of the asymptomatic patients of groups 1 and 2.

CONCLUSION

Urachal remnants are commonly demonstrated with ultrasound, particularly in young patients. They should be considered to be a normal variant unless there is an increase in size or they are accompanied by clinical signs, without other possible causes for symptoms.

Petrous bone extension of middle-ear acquired cholesteatoma

PURPOSE

To describe CT and MR features of extension to the petrous bone, which is a rare complication of acquired cholesteatoma (AC).

MATERIAL AND METHODS

Postcontrast CT was performed in 4 patients, in axial (n=4) and coronal planes (n=2). The section thickness was 1.2 or 2.5 mm. MR was performed in 3 cases, using T1- and T2-weighted images (n=3) and postcontrast T1-weighted images (n=2).

RESULTS

CT demonstrated a well-outlined lesion involving the petrous bone (n=4). Density could be assessed in 3 cases, showing a hypodense unenhanced mass. Lateral (n=1), superior (n=2), and posterior (n=2) semicircular canals were affected in 3 patients. AC extended to the vestibula, cochlea, and internal acoustic meatus (IAM) in 3 patients. Two ACs extended to the level of IAM, whereas 2 extended further, to the petrous apex. In one case the sphenoid sinus was affected. On MR imaging the lesion was hypointense relative to brain on T1-weighted images and hyperintense on T2-weighted images. MR imaging helped to delineate the lesion and to distinguish it from other cystic lesions of the petrous bone.

CONCLUSION

CT and MR offer accurate preoperative assessment of the extension of cholesteatoma, which helps to choose the surgical approach.

Renal angiomyolipoma: growth followed up with CT and/or US

PURPOSE

To follow up the growth of renal angiomyolipomas (AMLs).

MATERIALS AND METHODS

Patients with known AML (n = 55) were divided into three groups on the basis of initial clinical and computed tomographic (CT) findings: group 1, isolated AML (n = 43); group 2, multiple AMLs without tuberous sclerosis (TS) (n = 6); group 3, multiple AMLs with TS (n = 6). Follow-up ultrasonography (US) and CT were performed in 55 and 31 patients, respectively. Growth of the AMLs (n = 59) was evaluated on the basis of area on initial and follow-up images.

RESULTS

Mean percentage growth was 17%, 128%, and 47%, and mean growth rate per year was 5%, 22%, and 18% in groups 1, 2, and 3, respectively. New renal lesions were noted in three patients in groups 1 and 2, but no new lesions were detected in group 3, because of the large number of AMLs. New extrarenal lesions were observed in four, two, and three patients in groups 1, 2, and 3, respectively. No correlation was found between percentage of fatty tissue and growth rate.

CONCLUSION

Multiple AMLs show more growth than solitary AMLs.

Ultrasound assessment of ovarian stroma hypertrophy in hyperandrogenism and ovulation disorders: visual analysis versus computerized quantification

OBJECTIVE

To extend our previous findings on the diagnostic validity of ovarian stroma hypertrophy in women with hyperandrogenic and/or menstrual disorders.

DESIGN

Transvaginal ultrasonography was performed in 69 patients complaining of hyperandrogenism and/or menstrual disorders and in 48 normal ovulatory women in early follicular phase. To check the validity of stroma assessment by visual analysis, we used computer-assisted analysis, which allowed selective measurement of the stromal area on a longitudinal ovarian cut. Sensitivity and specificity of each method were estimated by using the normative data from the control group.

RESULTS

Stromal area was considered to be increased using visual analysis and computer-assisted analysis in 74% and 61% patients, respectively. Specificity of this sign was 84% and 96% by visual analysis and computer-assisted analysis, respectively. In patients, the increase in stromal area correlated very significantly with the one of total ovarian area, whose upper normal limit was 5.5 cm2 per ovary.

CONCLUSION

Visual assessment of stroma may be misleading in some cases, with the risk of overestimating its hypertrophy. An increased total ovarian area > 5.5 cm2 (which can easily be detected by carefully shaping a strict longitudinal ovarian cut) has the same diagnostic value as an increased stromal area by computerized measurement.

Congenital cholesteatoma of the temporal bone: MR findings and comparison with CT

PURPOSE

To describe the MR findings of temporal bone congenital cholesteatoma and MR usefulness in preoperative diagnosis and follow-up, in comparison with CT.

METHODS

Seven patients underwent CT and MR studies for facial palsy (n = 3), deafness (n = 3), vertigo (n = 1), tinnitus (n = 1), and otalgia (n = 1). Three patients had for congenital cholesteatoma previously undergone surgery. One of them was free of symptoms and referred for follow-up. Final diagnosis was obtained from surgical data in all the cases but one.

RESULTS

Congenital cholesteatoma signal intensity was low or intermediate on T1-weighted images and high on T2-weighted images in all the cases. MR was useful in diagnosis in six cases, helping to differentiate congenital cholesteatoma from other nonenhancing tumors. When temporal bone wall erosion was observed with CT (n = 6), MR ruled out intracranial extension in five cases; in one case, MR found an associated epidermoid cyst of the cerebellopontine angle not identified with CT. However, CT assessed relationships with labyrinthine structures more easily.

CONCLUSION

MR and CT are complementary in initial diagnosis and follow-up.