[Erosive intervertebral joint lesions. A case of pigmented villonodular synovitis]

Pigmented villonodular synovitis (PVNS) is a rare proliferative lesion that can affect synovial membranes, tendon sheaths, and bursae. It is usually a monarticular disease of the lower extremities, and so far fewer than 30 cases of spinal involvement have been reported in the literature. We describe a patient with progressive lumbar pain and spinal claudication, in whom a CT scan of the lumbar spine revealed destruction fo facet joints L3 to L5. An open biopsy was performed, which led to the diagnosis fo PVNS. The patient underwent successful surgical resection of the tumour mass and stabilization of segments L3 to S1. Two years after surgery the patient has no signs of recurrence. Differential diagnosis of erosive vertebral joint disease is discussed.

Helical CT of the small bowel with an alternative oral contrast material in patients with Crohn disease

BACKGROUND

We assessed the usefulness of helical computed tomography (CT) with a negative oral contrast material for detecting Crohn disease.

METHODS

Thirty-eight patients with proven Crohn disease were examined. We administered a large volume of a new negative oral contrast material (Mucofalk suspended in water) and then proceeded with helical CT scanning. This technique is an alternative to CT and conventional enteroclyses that use a nasojejunal tube. Two radiologists interpreted the scans, and patients were interviewed about their tolerance of the procedure. We created multiplanar reformatted images in all cases. Potential of small bowel distention by Mucofalk was evaluated by two observers on a three-point scale, and interobserver agreement was calculated with kappa statistics.

RESULTS

All patients who underwent enteroclysis stated that CT was the more comfortable method, the taste of the peroral contrast medium was considered good by 52.6% and acceptable by 47.4%. Small bowel distention was excellent in 55% of cases, moderate in 26%, and poor in 19%, with an interoberserver agreement of 78%. CT findings correlated with enteroclysis in 27 patients who underwent both methods. Analysis of CT versus enteroclysis showed a sensitivity of 89% for CT versus 78% for small bowel enteroclysis.

CONCLUSION

Mucofalk CT is a simple, rapid, noninvasive, and accurate method of evaluating extramucosal manifestations of Crohn disease. The tubeless procedure improved patients' comfort and decreased time, cost, and radiation exposure.

Bilateral orbital pseudotumour due to Ormond's disease: MR imaging and CT findings

We present the MRI and CT findings in a 43-year old patient with bilateral orbital pseudotumour due to Ormond's disease.

Multislice CT-image-guided endoscopic sinus surgery using an electromagnetic tracking system

Our objective was to assess the practicability and accuracy of a computer-assisted multislice CT-guided frameless electromagnetic tracking for endoscopic sinus surgery. Eighty-two patients with various paranasal sinus diseases were evaluated. Prior to surgery, axial multislice spiral-CT scans with 2.5-mm collimation, 0.8-mm reconstruction increment, and a pitch of 3 were acquired. After Ethernet transfer of the CT data set to the guidance system, coronal and sagittal images were reconstructed. For intraoperative navigation the Insta Trak System (Visualization Technology, Boston, Mass.) was used. Navigational procedures are described in detail in the paper. Accuracy was assessed by means of visual landmarks which could be clearly identified endoscopically as well as on CT images. A second parameter for accuracy was calculated by the system itself as the root mean square (RMS). The system was able to display the position of the aspirating tip relative to anatomical structures with an average accuracy of 0.70 +/- 0.40 mm. Root mean square values showed a mean value of 0.40 +/- 0.20 mm. During surgical procedures the Insta Trak System provides the surgeon with additional image-based information to the endoscopic view. The device accuracy is high and the system proves to be practicable and efficient in ENT surgery.

Magnetic resonance imaging patterns of the development of the sphenoid sinus: a review of 800 patients

Accurate knowledge of age-related development and pneumatisation of the paranasal sinuses has become an important issue in diagnosing paranasal sinus diseases in infants and young adults. Magnetic resonance imaging (MRI) has the potential to assess bone marrow conversion and pneumatisation of the paranasal sinuses. We retrospectively reviewed 800 children aged 0-14 years undergoing brain MRI for various indications. T1-weighted sagittal and T2-weighted axial scans were evaluated for bone marrow conversion and development of pneumatisation of the sphenoid sinus. The sphenoid sinus had a uniformly low signal intensity on T1-weighted images in all children less than four months old. Signal intensity began to change to hyperintense marrow at the age of four months. Onset of pneumatisation was observed in 19% at the age of 12-15 months. Pneumatisation was complete in all patients older than 10 years. In conclusion, these data can be used as baseline standards of normal age-related development of the sphenoid sinus and can be of great value for the diagnostic and therapeutic management of pathologic conditions of the child's sphenoid sinus and its surrounds.

Pulmonary embolism: comparison of gadolinium-enhanced MR angiography with contrast-enhanced spiral CT in a porcine model

RATIONALE AND OBJECTIVES

The purpose of this study was to compare gadolinium-enhanced magnetic resonance (MR) angiography with contrast material-enhanced computed tomography (CT) for the detection of small (4-5-mm) pulmonary emboli (PE), with a methacrylate cast of the porcine pulmonary vasculature used as the diagnostic standard.

MATERIALS AND METHODS

In 15 anesthetized juvenile pigs, colored methacrylate beads (5.2 and 3.8 mm diameter-the size of segmental and subsegmental emboli in humans) were injected via the left external jugular vein. After embolization, MR angiographic and CT images were obtained. The pigs were killed, and the pulmonary arterial tree was cast in clear methacrylate, allowing direct visualization of emboli. Three readers reviewed CT and MR angiographic images independently and in random order.

RESULTS

Forty-nine separate embolic sites were included in the statistical analysis. The mean sensitivity (and 95% confidence intervals) for CT and MR angiography, respectively, were 76% (68%-82%) and 82% (75%-88%) (P > .05); the mean positive predictive values, 92% (85%-96%) and 94% (88%-97%) (P > .05). In this porcine model, PE were usually seen as parenchymal perfusion defects (98%) with MR angiography and as occlusive emboli (100%) with CT.

CONCLUSION

MR angiography is as sensitive as CT for the detection of small PE in a porcine model.

Peripheral primitive neuroectodermal tumour of the kidney: CT findings

Peripheral primitive neuroectodermal tumour in the kidney is a rare entity with high malignant potential. The distinctive demographic, clinical and radiological findings, as described in the present case, should suggest this aggressive tumour in the differential diagnosis of renal neoplasms in adolescents.

Talcosis associated with IV abuse of oral medications: CT findings

OBJECTIVE

Our objective was to evaluate the CT appearance of talcosis associated with IV abuse of oral medications and to compare the findings of talcosis related to methylphenidate with those findings seen with other drugs.

MATERIALS AND METHODS

The CT scans of 12 patients with talcosis (seven men, five women), 33-54 years old (mean age, 44 years), were analyzed retrospectively. Seven patients had abused methylphenidate; five patients had no history of abuse. The diagnosis of talcosis was made histologically in 11 patients and at funduscopy in one patient. CT was performed with 1- to 1.5-mm collimation (n = 10 patients) or 5- to 10-mm collimation (n = 2).

RESULTS

The predominant abnormalities seen on CT consisted of a diffuse fine nodular pattern (n = 2), a combination of nodules and lower lobe panacinar emphysema (n = 3), and ground-glass attenuation (n = 2). Emphysema was the only abnormality seen in the remaining five patients (lower lobe panacinar, n = 4; upper lobe centrilobular, n = 1). No significant difference in the prevalence of nodules and ground-glass attenuation was seen between the methylphenidate and non-methylphenidate groups. Lower lobe panacinar emphysema was more common in methylphenidate abusers (six [86%] of seven patients) than in non-mnethylphenidate drug abusers (one [20%] of five, p<0.05, Fisher's exact test).

CONCLUSION

The CT manifestations of talcosis consist of a fine micronodular pattern, ground-glass attenuation, and emphysema. A significantly increased prevalence of lower lobe panacinar emphysema is seen in IV drug addicts who abuse methylphenidate.

Mycoplasma pneumoniae pneumonia: radiographic and high-resolution CT features in 28 patients

OBJECTIVE

The aim of the study was to compare the radiographic and the high-resolution CT findings of Mycoplasma pneumoniae pneumonia.

MATERIALS AND METHODS

The chest radiographs and 1.5-mm collimation CT scans obtained in 28 patients with serologically proven M. pneumoniae pneumonia were retrospectively reviewed. The radiographs and CT scans were analyzed independently by two observers.

RESULTS

The most common finding on radiography was the presence of air-space opacification (n = 24), which was patchy and segmental (n = 9) or nonsegmental (n = 15) in distribution. On high-resolution CT, areas of ground-glass attenuation were seen in 24 patients (86%) and air-space consolidation in 22 (79%). In 13 patients (59%), the areas of consolidation had a lobular distribution evident on CT. Nodules were seen more commonly on high-resolution CT (25 of 28 patients, 89%) than on radiography (14 patients, 50%) (p < 0.01, chi-square test). In 24 (86%) of the 28 patients, the nodules had a predominantly centrilobular distribution on CT. Thickening of the bronchovascular bundles was identified more commonly on CT (23 of 28 patients, 82%) than on radiography (five patients, 18%) (p < 0.01, chi-square test).

CONCLUSION

The lobular distribution, centrilobular involvement, and interstitial abnormalities in M. pneumoniae pneumonia are often difficult to recognize on radiography but can usually be seen on high-resolution CT.

[Computer assisted localization in endoscopic sinus surgery--state of the art? The Insta Trak system]

BACKGROUND

Image-guided surgery is increasingly acknowledged as useful technology also for endoscopic sinus surgery. For many years our department has been involved in the development and testing of devices for image-guided endoscopic sinus surgery. Since January 1997 we have been testing the "Insta Trak" System, which is based on electromagnetic tracking and was especially designed for use in endoscopic sinus surgery.

METHODS

We tested practicability and accuracy of the system in a wide range of cases from standard sphenoethmoidectomies to tricky frontal sinus surgery, from endoscopic tumour surgery to endoscopic repair of CSF fistulas. System accuracy was assessed by means of visual landmarks which could be clearly identified endoscopically as well as via computer screen. Additionally we measured the time for setting up the system, total operating time and rating of the subjective surgeon's assessment of the system's usefulness in each particular case.

RESULTS

We present the results according accuracy and practicability in 45 patients, who were operated on under computer-aided guidance. Our overall experience with the "Insta Trak" system was very positive. It was no longer the indeed promising, but still rather circumstantial and not always reliable technique we were used to. Operating the system was relatively easy and did not require excessive computer skills. We measured an average accuracy of 0.69 mm with a maximum deviation of 2 mm in a single test measurement. Incorrect use of the device, however, may significantly increase the possible weight of system errors.

CONCLUSIONS

The system accuracy was high and "Insta Trak" proved to be practicable and efficient in daily clinical routine. Especially in complicated cases like revision surgery "Insta Trak" proved to be extremely helpful. Whether a system like "Insta Trak" will be definitely able to lower complication rates in FESS is still an open question. Certainly in the near future no such navigational device will become a substitute for the surgeon's understanding of anatomy. In our opinion and experience "Insta Trak" is a significant development in sinus surgery. However, one must be aware of the fact that it cannot be more than yet another and indeed helpful tool.

Cytomegalovirus associated neonatal pneumonia and Wilson-Mikity syndrome: a causal relationship?

Lung injury caused by intrauterine inflammation has recently been strongly implicated in the pathogenesis of Wilson-Mikity syndrome (WMS). This article supports this theory by suggesting a causative role of intrauterine cytomegalovirus (CMV) infection for the development of WMS. A male premature infant, born at 33 weeks of gestational age, developed chronic lung disease compatible with WMS and diagnostic evaluation was positive for CMV infection. High-resolution computed tomography scan and lung histology revealed typical features of WMS in association with signs of interstitial pneumonia. CMV was found in urine, breastmilk, bronchoalveolar lavage material and lung tissue from open lung biopsy. Follow-up after treatment with ganciclovir and steroids showed resolving lung disease at the age of 6, 10 and 16 months, with lung function signs of mild obstruction. Assuming that a chance coexistence of cytomegalovirus pneumonia and Wilson-Mikity syndrome is rather unlikely, it is possible that intrauterine cytomegalovirus infection caused a pattern of lung injury consistent with Wilson-Mikity syndrome. Further cases of Wilson-Mikity syndrome should be investigated as to a possible role of congenital infection.

Chronic spinal subdural haematoma associated with intracranial subdural haematoma: CT and MRI

Chronic spinal subdural haematoma is a uncommon. We describe the CT and MRI appearances of chronic spinal and intracranial subdural haematomas following minor trauma. The aetiology, pathogenesis and differential diagnosis are discussed.

High-resolution CT findings in Wilson-Mikity syndrome: a case report

Wilson-Mikity syndrome (WMS), an uncommon cause of respiratory distress presenting after birth, is radiologically characterised by varying degrees of interstitial thickening and bilateral cyst-like foci of hyperinflation. Aetiology and pathogenesis are still unknown. There are few reports of WMS in the paediatric literature and none describing the features and value of high-resolution CT. The purpose of this report is to describe the radiographic findings and high-resolution CT appearance of WMS and to correlate them with the histopathological findings.

Detection of pulmonary nodules with helical CT: comparison of cine and film-based viewing

OBJECTIVE

The purpose of our study was to determine whether cine viewing of helical CT scans of the chest improves the detection of pulmonary nodules in patients with known extrathoracic malignancy.

SUBJECTS AND METHODS

Identical helical CT studies of the chest of 60 patients with known extrathoracic malignancy were reviewed for detection of pulmonary nodules. Four radiologists interpreted the helical CT studies. Pulmonary nodules were divided into four groups according to maximum diameter: group 1, nodules smaller than or equal to 5 mm; group 2, nodules larger than 5 mm but smaller than or equal to 10 mm; group 3, nodules larger than 10 mm but smaller than or equal to 20 mm; group 4, nodules larger than 20 mm. Interpreters also assigned a lesion conspicuity score of pulmonary nodules based on a four-point scale: one point for poor visibility, two points for adequate visibility, three points for good visibility, and four points for excellent visibility. Static film-based images printed on a laser printer were viewed on a light box. Cine viewing of helical CT scans from the same examinations was done on a commercially available workstation. The number, diameter, and conspicuity scores of pulmonary nodules detected at lung window settings were documented.

RESULTS

Interpreters saw 266 nodules on cine viewing, whereas 237 nodules were seen with static film-based viewing. A significantly higher percentage of nodules that were smaller than or equal to 5 mm in diameter was found with cine viewing (n = 106) than with static film-based viewing (n = 81) (p < .05). Cine viewing (n = 105) also allowed a slightly but not significantly higher detection rate of nodules that were larger than 5 mm but smaller than or equal to 10 mm in diameter than did static film-based viewing (n = 101). We found no differences between cine (n = 55) and static film-based viewing (n = 55) in the detection of pulmonary nodules that were larger than 10 mm in diameter. The mean conspicuity score of nodules was significantly higher with cine viewing (2.9 +/- 0.2) than with film-based viewing (2.4 +/- 0.2) (p < .05).

CONCLUSION

Cine viewing of helical CT scans significantly increases the detection rate of pulmonary nodules that are smaller than or equal to 5 mm in diameter. However, we found no significant difference between cine and film-based viewing in the detection rate of pulmonary nodules that were larger than 5 mm in diameter. The advantages of cine viewing may be attributed to both the larger image size and the ability to scroll through images for improved differentiation between vessels and nodules.

HRCT features in a 5-year-old child with follicular bronchiolitis

High-resolution CT (HRCT) is the most sensitive radiographic method to image small airways disease. We discuss the HRCT features of follicular bronchiolitis in a 5-year-old boy and correlate them with the histopathological findings. The changes described include centrilobular nodules, bronchiectasis and bronchiolectasis, branching opacities and areas of reduced lung attenuation.

[Dissecting aneurysm of an aberrant right subclavian artery: diagnosis with ultrafast-CT]

An aneurysm of an aberrant right subclavian artery is a very rare cause for dysphagia. We describe such a case in a 67-year-old patient, diagnosed with Ultrafast-CT and discuss it together in concert with the embryology and the radiological findings.