Focal calvarial bone lesions. Comparison of logistic regression and neural network models

RATIONALE AND OBJECTIVES

To assess the accuracy of logistic regression (LR) and artificial neural networks (NN) in the diagnosis of calvarial lesions using computed tomography (CT) and to establish the importance of the different features needed for the diagnosis.

METHODS

One hundred sixty-seven patients with calvarial lesions as the only known disease were enrolled. The clinical and CT data were used for LR and NN models. Both models were tested with the leave-one-out method. The final results of each model were compared using the area under receiver operating characteristic curves (Az).

RESULTS

Of the lesions, 73.1%, were benign and 26.9% were malignant. There was no statistically significant difference between LR and NN in differentiating malignancy. In characterizing the histologic diagnoses, NN was statistically superior to LR. Important NN features needed for malignancy classification were age and edge definition, and for the histologic diagnoses matrix, marginal sclerosis, and age.

CONCLUSION

NNs offer wide possibilities over statistics for the study of calvarial lesions other than their superior diagnostic performance.

Calvarial eosinophilic granuloma: diagnostic models and image feature selection with a neural network

RATIONALE AND OBJECTIVES

The authors analyzed the accuracy of diagnostic features used by an artificial neural network compared with logistic-regression analysis in the diagnosis with computed tomography (CT) of calvarial eosinophilic granuloma.

MATERIALS AND METHODS

Thirty-one of 167 patients with calvarial lesions were found to have eosinophilic granuloma. Clinical and CT data were used for logistic-regression and neural network models. Both models were tested by using the leave-one-out method. The final results of each model were compared by means of the area under the receiver operating characteristic curve (Az).

RESULTS

Identification of eosinophilic granuloma was significantly more accurate with the neural network than with logistic regression (Az = 0.9846 +/- 0.0157 [standard deviation] vs 0.9117 +/- 0.0373) (P = .001). The most important diagnostic features identified with the neural network were patient age and marginal sclerosis. For logistic regression, the most important features were age, shape, and lobularity.

CONCLUSION

The neural network is a useful tool for analyzing the features of calvarial eosinophilic granuloma. Age and marginal sclerosis are important diagnostic features.

Neurofibromatosis type 1 in children: MR imaging and follow-up studies of central nervous system findings

PURPOSE

To determine the frequency, evolution and diagnostic impact of characteristic central nervous system MR imaging lesions in children with neurofibromatosis type 1 (NF1).

SUBJECTS

We reviewed 89 children with established or clinically suspected disease. A final diagnosis of NF1 was made in 72 (age range, 10 months to 14 years).

RESULTS

Hyperintense lesions on long TR images were detected in 78% of patients, principally involving the basal ganglia, cerebellum and brain stem. In 30% of the globus pallidus lesions, hyperintensity was seen on short TR images, being usually isointense on IR T1 weighted images. Globus pallidus lesions did not enhance. Eight patients presented atypical unenhanced lesions showing either edema, mass effect or hypointensity on short TR images; 2 of them were considered symptomatic brain stem gliomas. Six other children showed one or more growing enhanced cerebral lesions classified as tumors. Other child developed a growing enhanced lesion that markedly decreased in the follow-up studies. Twenty patients (28%) had optic gliomas. In two children, under 6 years old, this tumor appeared de novo. Forty-five children had several follow-up MR imaging studies (mean interval, 3 years). Regression of the basal ganglia lesions, both in size and/or intensity was noticed in 42% of cases, enlargement or new appearance of lesions in 24.5%, mixed increased/decreased in 7%, and stability in 26.5%. White matter lesions of the cerebellum and brain stem decreased in size in 40%, grew in 15.5%, showed a mixed increased/decreased pattern in 11%, and remained unchanged in 33.5% of cases. An involutional tendency of these lesions occurred in children older than 10 years, while progression was more frequent in younger children (P<0.05).

CONCLUSIONS

Hyperintense lesions are highly prevalent and characteristic in patients with NF1. MR imaging contributed to a definitive diagnosis of NF1 in 53% of suspected cases. Follow-up studies are necessary in the evaluation of suspected NF1, even if the first examination is negative.

Portal vein absence and nodular regenerative hyperplasia of the liver with giant inferior mesenteric vein

We present a patient with nodular regenerative hyperplasia of the liver (NRH) and portal vein absence studied with CT, MR imaging, and MR angiography. The most striking feature was exuberant hemorrhoids due to a giant hepatofugal inferior mesenteric vein. A relationship between unbalanced portal blood flow and nodular regenerative transformation of the liver is suggested in this patient.

Eikenella corrodens skull infection: a case report with review of the literature

BACKGROUND

Subgaleal abscesses and skull osteomyelitis are very uncommon since the introduction of antibiotics. Eikenella corrodens infection is extremely rare in childhood and has never been reported in calvarial osteomyelitis.

METHODS

We present a previously healthy 9-year-old boy, with a history of frontal contusion without injury, who developed E corrodens osteomyelitis of the skull. The radiographic findings are reviewed, including skull films and computed tomographic scans. The patient underwent surgical debridement of the lesion, as well as systemic medical therapy with amoxicillin. We review the medical and surgical therapy for such lesions. The differential diagnosis of a posttraumatic scalp swelling is also reviewed.

RESULTS

Good resolution after debridement and antibiotic therapy is reported.

CONCLUSIONS

Surgical intervention is emphasized for the removal of bony sequestrum and nonviable bone while maintaining an intact dura.

Primary intraosseous meningiomas

PURPOSE

A retrospective study was performed to evaluate the clinical, radiological and histological findings of 14 intraosseous meningiomas.

MATERIAL AND METHODS

14 histologically proved intraosseous meningiomas were studied with plain skull film and CT. Pathological records were reviewed.

RESULTS

We found 9 calvarial cases and 5 spheno-orbital ones. The most common symptom in the calvarial cases was a lump in the scalp, and in the spheno-orbital lesions it was exophtalmos. Hyperostosis was present in all 5 spheno-orbital cases and in 3 out of the 9 calvarial ones; in the other 6 cases it had a mixed pattern. Enhanced dura was present in 3 calvarial cases and in 2 sphenoidal ones. Dura was involved in 5 cases: 2 with inflammatory changes, 2 with a minimal intradural tumour and one with a subdural tumour.

CONCLUSION

CT better detected both the bony reaction and the intraosseous extension of the tumour. The dural changes were not specific of tumoural involvement. The differential diagnosis comprises: fibrous dysplasia, osteoma, blastic metastasis and mainly meningioma en plaque (MEP). Comparing our findings with other series, we noticed that in some cases the term MEP was used for similar cases. As the name MEP is merely descriptive and both entities share a larger number of similarities than differences, we believe that a differentiation between hyperostotic en plaque meningioma and intraosseous meningioma can hardly be made.

Intradiploic epidermoid cysts

We studied 37 intradiploic epidermoid cysts, reviewing typical and atypical radiological features and the differential diagnosis. The most common clinical feature was a long standing lump in the scalp, occurring in 25 patients (67.7%). Plain films were the most cost-effective radiological technique in diagnosis. The typical finding was a well-defined lytic lesion with sclerotic border, seen in 29 cases (78%). Atypical lesions were those larger than 5 cm and/or with an ill-defined edge, being observed in 8 cases (22%). CT and MRI were the best methods for assessing atypical ones. In all cases with typical radiological findings a preoperative diagnosis of intradiploic epidermoid cyst was suggested.