Head and neck radiology: role of multidetector computed tomography in the evaluation of the tympanic canaliculus.

PURPOSE: This study was undertaken to evaluate the potential of multidetector computed tomography (MDCT) for multiplanar visualisation of the tympanic canaliculus both in healthy individuals and in patients affected by chronic inflammatory disease of the middle ear. MATERIALS AND METHODS: A preliminary study was performed on three dried skulls by placing a metal landmark inside the tympanic canal lumen with a view to optimising depiction by multiplanar CT. Subsequently, 50 patients were enrolled in a prospective study. Three of the 100 petrous pyramids studied were excluded owing to the presence of jugulotympanic glomus tumour with severe bone changes. RESULTS: The entire course of the tympanic canaliculus was identified in 80/97 petrous pyramids (82.4%), 57 of which were normal (75.4% detection rate) and 40 pathological (90% detection rate). To assess the tympanic canaliculus in the pathological petrous pyramids and evaluate its possible role in the disease process, some qualitative criteria were introduced: canal enlargement, loss of margin sharpness, focal erosion of canal margins and presence of pathological tissue. CONCLUSIONS: MDCT represents the only technique allowing evaluation of the tympanic canal in vivo and with multiplanar images in a large number of cases (82.4%).

Small bronchogenic carcinomas presenting as solitary pulmonary nodules. Bioptic approach guided by CT-positive bronchus sign.

To evaluate the utility of the CT bronchus sign in making a choice between transbronchial biopsy (TBB) and transthoracic needle aspiration (TTNA) as the first diagnostic procedure in a patient with a solitary pulmonary nodule (SPN), we reviewed the results of TBB and TTNA in 26 patients who had a bronchogenic carcinoma less than 3 cm, studied with thin-section CT. The patients were divided into two groups. Group 1 included ten cases with a third- to fifth-order bronchus sign. Group 2 included two cases with a sixth-order bronchus sign and 14 cases with absence of a bronchus sign. TBB was performed in all the patients; conversely, TTNA was carried out in 22 patients. In group 1, TBB gave a diagnostic yield in eight (80 percent) of ten patients, while TTNA was positive in three (42 percent) of seven patients (p > 0.05). Conversely, in group 2, results of TBB were normal in all the patients, while TTNA gave a diagnosis in 10 (66 percent) of 15 patients (p < 0.05). We think that TBB should be considered the method of choice in diagnosing SPNs associated with a third- to fifth-order bronchus sign; conversely, TTNA is more useful than TBB in diagnosing SPNs in the presence of a more peripheral bronchus sign or with the absence of a bronchus sign. In conclusion, we suggest routine evaluation with thin-section CT of each SPN to optimize diagnostic management.

Chronic infiltrative lung diseases: value of gadolinium-enhanced MRI in the evaluation of disease activity--early report.

STUDY OBJECTIVE: To determine the value of gadolinium-enhanced MRI in the assessment of disease activity in chronic infiltrative lung diseases (CILDs). DESIGN: Retrospective study. SETTING: University hospital. MATERIALS AND METHODS: Twenty-five consecutive patients with CILD were studied. The following diseases were diagnosed: sarcoidosis (n = 10), bronchiolitis obliterans organizing pneumonia (n = 3), usual interstitial pneumonia (n = 4), radiation pneumonia (n = 2), desquamative interstitial pneumonia (n = 1), rheumatoid lung (n = 1), vasculitis (n = 1), alveolar proteinosis (n = 1), bronchioloalveolar carcinoma (n = 1), and chronic eosinophilic pneumonia (n = 1). In each patient, the disease activity was assessed by one or more of the following studies: BAL (n = 18), gallium-radioisotope lung scanning (n = 6), serum angiotensin-converting enzyme assay (n = 10), and open lung biopsy (n = 4). T1-weighted breath-hold MRI studies were obtained before and after IV injection of gadolinium. The MRI examinations were analyzed to assess the presence or absence of lesional enhancement. RESULTS: The presence of enhanced pulmonary lesions was seen in 14 patients. All of these patients had active disease. Of the 17 patients with active disease, 14 had enhanced lesions, and 3 had unenhanced lesions. Pulmonary lesions were not enhanced in any patients with inactive disease. The difference was statistically significant (Fisher Exact Test, p < 0.05). CONCLUSION: Gadolinium-enhanced MRI may prove to be a useful tool in assessing disease activity in CILDs.

The radiology of the pterygoid canal: normal and pathologic findings.

To better define the normal anatomy and pathologic features of the pterygoid canal, 100 normal subjects and 38 patients with disease of the paranasal sinuses, nasopharynx, and base of the skull were studied with pluridirectional tomography. Particular attention was given to the normal radiographic appearance of the pterygoid canal as well as to its anatomic variants and its relationship to the paranasal sinuses. Three radiographic signs of involvement of the pterygoid canal were detected: disappearance, enlargement, and narrowing. Moreover, a brief correlation between pluridirectional tomography and CT was made. Diagnostic accuracy in evaluating the bony lesions is the same with both techniques, but CT is superior to pluridirectional tomography in evaluating involvement of the soft tissues.

Perineural spread in a case of sinonasal sarcoidosis: case report.

We report a case of sinonasal sarcoidosis with perineural spread along the trigeminal and vidian nerves in which primarily MR imaging but also CT allowed excellent visualization of this infiltration.

Computed tomography visceral adipose tissue volume measurements of Italians. Predictive equations.

OBJECTIVES: To evaluate total visceral adipose tissue (AT) volumes in relation to single slices of visceral AT area measured at different levels and to other simple anthropometric measurements. DESIGN: Only outpatients examined in a metabolic unit were considered; subjects without conditions known to affect AT distribution who gave their informed consent were recruited. SETTING: All subjects were hospitalized in the Department of Internal Medicine of the University of Messina. SUBJECTS: 90 adult subjects of which 18 men and 42 pre- and 30 post-menopausal women. Ages ranged from 18 to 69 years and body mass indexes ranged from 22 to 50. INTERVENTIONS: The AT volume was calculated by computed tomography from the AT area of five scans and from the distances between these scans. RESULTS: AT area at the level of the 2nd-3rd lumbar vertebra had by itself the highest predictive power in men (s.e. = 6.8%), in post-menopausal women (s.e. = 7.4%) and, together with age, in pre-menopausal women (s.e. = 14%). Of the non-radiological parameters it was waist circumference, together with age, which showed the highest predictive power in men (s.e. = 21%), pre-menopausal women (s.e. = 25%) and, together with height, in post-menopausal women (s.e. = 33%). CONCLUSIONS: A single scan measurement at the lumbar level was confirmed to be representative of total visceral AT volume. Waist circumference was the non-radiological parameter that best correlated with volume.

Perineural spread of nasopharyngeal carcinoma: radiological and CT demonstration.

Perineural spread is well known to be the most insidious form of tumour spread of a number of head and neck malignancies. However, perineural extension of nasopharyngeal carcinoma (NC) is a poorly recognized event. Four cases of perineural metastases from NC have been detected with pluridirectional tomography and CT. In 3 cases involvement of the Vidian nerve (nervus canalis pterygoidei) and pterygoid canal was observed. In a fourth patient, invasion of one pterygopalatine fossa and perineural spread along ipsilateral maxillary nerve with enlargement and erosion of the foramen rotundum was demonstrated. Radiological diagnosis of clinically unsuspected perineural tumour spread is important because it markedly influences treatment planning and prognosis of NC.

MR findings in thyroglossal duct cysts: report of two cases.

Two patients with thyroglossal duct cysts have been studied with CT and MR. The typical CT feature of these cystic upper-neck lesions are depicted in literature, conversely MR findings are not well known. The homogeneous high intensity on T1-weighted images, higher than simple cyst or fluid, is the most typical feature of the thyroglossal cyst.

Magnetic resonance imaging of bronchioloalveolar carcinoma.

The purpose of this study is to describe the magnetic resonance (MR) features of bronchioloalveolar carcinoma. MR examinations of 18 patients with proven bronchioloalveolar carcinoma were reviewed. Detection at computed tomography (CT) and pathologic confirmation were the entry criteria. Nine patients had a solitary nodule, three patients a lobar consolidation, and six patients had diffuse disease. For each patient, both breath-hold T2-weighted fast spin-echo, and breath-hold T1-weighted gradient-echo images, before and after injection of gadolinium, were available. Nine patients with pulmonary consolidation or diffuse disease had also heavily T2-weighted MR imaging (Haste or TSE 240; Siemens, Erlangen, Germany). MR imaging showed pulmonary abnormalities in 17 of 18 patients. Unenhanced T1-weighted and T2-weighted images depicted tumor in 16 of 18 patients. Contrast-enhanced T1-weighted images showed tumor in 17 of 18 patients. In no case did MR imaging depict abnormalities corresponding to the ground-glass opacities seen on CT scans. In three patients with mucinous bronchioloalveolar carcinoma, heavily T2-weighted images showed lesions isointense with respect to static fluid of the human body. In conclusion, the ability of MR imaging in detecting small nodules and ground-glass opacities is limited. However, heavily T2-weighted sequences are able to show the presence of mucin. This is useful information because mucinous bronchioloalveolar carcinoma carries a poor prognosis.

Computed tomography halo sign in pulmonary nodules: frequency and diagnostic value.

On computed tomography (CT) scanning, a ground-glass opacity zone surrounding a pulmonary nodule has been named the computed tomography (CT) halo sign. To investigate the frequency and diagnostic value of the CT halo sign, the authors reviewed the CT examinations of 305 patients with proven diseases producing solitary or multiple nodules. The CT halo sign was seen in 22 patients (7%). Eleven patients had a solitary nodule; five patients had multiple nodules; and six patients had nodules associated with areas of pulmonary consolidation, or ground-glass opacity, or both. Solitary nodules were the result of bronchioloalveolar carcinoma (n = 5), tuberculoma (n = 2), squamous cell carcinoma, non-Hodgkin lymphoma, myxovirus infection, and metastasis (n = 1 each). Multiple nodules were the result of metastasis (n = 2), Kaposi sarcoma (n = 2), and Wegener granulomatosis (n = 1). Nodules associated with areas of consolidation or ground-glass opacity were the result of metastasis (n = 2), bronchioloalveolar carcinoma, bronchiolitis obliterans organizing pneumonia, eosinophilic pneumonia, and invasive pulmonary aspergillosis (n = 1 each). The data showed that the CT halo sign is a nonspecific finding. It is known that in immunocompromised patients the CT halo sign should suggest invasive pulmonary aspergillosis, Kaposi sarcoma, and lymphoproliferative pulmonary disorders. However, in immunocompetent patients, the authors found that a solitary nodule with the CT halo sign and pseudocavitations has a high likelihood of being a bronchioloalveolar carcinoma.

Synovial osteochondromatosis of the ankle: MR findings.

The authors present a case of primary synovial osteochondromatosis of the ankle, as demonstrated by magnetic resonance (MR). Ankle involvement by osteochondromatosis is unusual. The characteristic MR findings are: target appearance of some loose bodies with a low intensity peripheral rim and a center isointense to the soft tissues on T1-weighted images, which remain unchanged on T2-weighted images. Conversely, other loose bodies were characterized by homogeneous hyperintensity close to the bone marrow on T1-weighted images, with loss of signal on T2-weighted images. The authors believe that these findings are quite pathognomonic of a long-standing synovial osteochondromatosis.

[Tomodensitometric evaluation of parosteal sarcoma. Concerning a case]. / Evaluation tomodensitométrique du sarcome parostal. Au sujet d'un cas.

The authors report a case of metaphyso-diaphyseal parosteal sarcoma of the thigh-bone. They analyse the CT signs and describe the possibilities of this method to acquire others tumour's signs, and to program a relatively conservative surgical act.

[Metastases of the sub-arachnoidal space from medulloblastoma. Computed tomography study]. / Métastases dans l'espace sous-arachnoïdien dues à un médulloblastome. Etude tomodensitométrique.

A detailed analysis of C.T. finding with infiltration of the diffuse sub-arachnoidal space by medulloblastoma in a infant is reported. The C.T. sign who's same a cisternography with hydrosoluble contrast was in this case more helpful in obtaining the specific diagnosis.

[Opacity of the pterygo-palatine fossa]. / Le signe de l'opacité de la fosse ptérygo-palatine.

The pterygo-palatine fossa can be opacified because the invasion by pathologic tissue. This opacification, due to the loss of normal fatty content, has been found in 19 patients on 40 subjects affected by different maxillofacial pathology. The opacification of the pterygo-palatine fossa is a non specific sign and is generally associated with signs of bony involvement. This sign appears particularly usefull when the bony involvement is very slight and of in certain evaluation.

Arteriovenous fistula of the mandible simulating an odontogenic cyst. A case report.

SUMMARY: We describe a rare case of mandibular highflow arteriovenous malformation (AVM) mimicking an odontogenic cyst in a young man. The diagnosis of mandibular AVM was made by CT angiography and confirmed by digital subtraction angiography. CT scan showed the extent of mandibular bone alteration and a double enlarged mandibular canal on the same side. An AVM containing a large aneurysm was demonstrated by CT angiography.The mandibular AVM was successfully treated by endovascular therapy with Guglielmi detachable coils. On panoramic radiogram, mandibular AVMs can appear as cystic lesions without pathognomonic features. Several benign and malignant tumours of this anatomical region must be considered in the differential diagnosis.We emphasize the radiological sign of double enlarged mandibular canal and the diagnostic role of CT, particularly CT angiography, to discriminate a mandibular AVM from neoplastic entities of this region, sparing the risks of a needle biopsy.

Role of coronal oblique reconstruction as a complement to CT study of the temporal bone: normal anatomy.

PURPOSE: The purpose of this study was to demonstrate the usefulness of coronal oblique multiplanar reconstruction computed tomography (MPR CT) reformation parallel to the basal turn of the cochlea in the evaluation of the retrotympanum and hypotympanum to complete the standard CT examination of the temporal bone obtained with axial and coronal images. MATERIALS AND METHODS: We studied 30 patients aged 18-79 years for a total of 60 normal petrous pyramids. All examinations were performed on a multislice CT (MSCT) scanner (Sensation 16, Siemens, Erlangen, Germany) with axial volumetric acquisition and completed with reformations of coronal and coronal-oblique images. MSCT scan parameters for axial acquisition were set as follows: 0.75-mm scan collimation, FOV 300 mm, 170 mAs. Axial images were reconstructed at 0.7-mm thickness and with a reconstruction increment of 0.5 mm using a high-resolution bone algorithm. RESULTS: Coronal oblique MPR CT reformations provided additional information with respect to standard CT images in all cases. In particular, they enabled measurement of the craniocaudal and laterolateral diameters of the sinus tympani. In all cases, there was optimal visualisation of the ponticulus and subiculum. Analysis of the pyramidal eminence was improved thanks to its visualisation in profile. Moreover, we obtained an optimal representation of the hypotympanum, which was always exhaustively explored with only one reconstruction. Finally, in all cases, it was possible to identify the facial nerve canal and main vascular structures and to measure the distance between these and the sinus tympani, pyramidal eminence and hypotympanum. The coronal oblique CT reformation was of no advantage in the evaluation of the fossa of the oval window and the niche of the round window. CONCLUSIONS: Coronal oblique MPR CT reformation should not be considered an alternative to the standard CT examination, but it can represent a valid integration to provide additional information on particularly crucial districts characterised by frequent involvement of inflammatory and/or expansile disease and because of their difficult endoscopic approach. Moreover, it can represent a meaningful aid to optimise surgical planning thanks to its different perspectives of observation.