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Diagnostic Imaging Brain Osborn 2nd Edition Pdf Download Extra Quality

In the present paper, the authors described difficulties in employing diagnostic imaging in differentiating between type II (open-lip) schizencephaly and much more common intracranial fluid spaces of a different origin (arachnoid cysts and hydrocephalus).

diagnostic imaging brain osborn 2nd edition pdf download

The method of choice in diagnostic imaging of schizencephaly is MRI. CT is also useful, but to a lesser degree, since it provides poorer images of the gray matter, which are the key factor in differentiating between the malformation and other fluid-associated CNS abnormalities. Schizencephaly may be also diagnosed in prenatal or postnatal ultrasonography, but this is true for type II (open-lip) only.

A particular problem in differentia diagnosis is posed by open-type schizencephaly, which in medical imaging is seen as a fluid-filled space. Inappropriate interpretation of the image may result in inappropriate further management. In cases when imaging studies demonstrate intracranial fluid-filled spaces, especially when they are situated in the middle cranial fossa, differential diagnosis needs to take into consideration several pathologies. In the majority of cases, in this location, arachnoid cysts are seen. A very rare congenital pathology is schizencephaly. Differentiation between these two malformations poses a significant diagnostic problem. Inasmuch as therapeutic management of symptomatic forms of arachnoid cysts consists in a surgical intervention, in case of schizencephaly, the value of the method is doubtful and the modality is additionally associated with consequences in the form of postoperative complications.

The most differentiating important element in imaging studies is the presence of heterotrophic gray matter that lines the margins of the cleft in case of schizencephaly and absence of such a lining in arachnoid cysts or fluid-filled spaces with other background. Moreover, arachnoid cysts may cause a mass effect manifested as displacement of the longitudinal fissure of the brain, compression of the ventricular system, or local obliteration of brain sulci and fissures, what is not evident in schizencephaly. In rare instances of arachnoid cysts, thinning and bulging of cranial bones are seen in areas where they adhere to the cyst.

Initial diagnostic MRI results for both groups are summarized in Table 3. PCNSL lesions were generally localized supratentorially (66.7%). PCNSL affected both white and grey matter, basal ganglia involvement was present in 55.6%, and cortical grey matter was affected in 51.9%. Cortical grey matter was involved by both enhancing and non-enhancing tumorous infiltration in 37.1% of cases, only enhancing portion was present in 3.7% of cases, only non-enhancing infiltration was seen in 11.1% of cases. Solitary affection of white matter was found only in 7.4%; in 3.8% an isolated involvement of basal ganglia was present and in one case (1.9%) solitary infiltration of hypothalamus or vestibular nerve was found. At time of initial MRI, PCNSL appeared as multiple infiltrative lesions in 51.9% of cases, as a solitary infiltrative lesion in 20.4% of cases and as a diffuse infiltrative affection in 24.1% (Fig. 1). Solitary demarcated lesions were rare (3.7%). PCNSL enhanced homogenously (64.8%), vasogenic perifocal edema was present in most cases (92.6%), and diffusion restriction was detected in 97% of cases (Fig. 2). Optic nerves and tracts were infiltrated in 42.6% of cases (Fig. 3). Other cranial nerves were affected in 5.6% of PCNSL cases; in one case (1.9%) the optic and trigeminal nerve was affected, and in one case (1.9%) the optic nerves and both auditory and facial nerves were involved and in one case (1.9%) solitary infiltration of the auditory nerve was present without other brain lesions (Fig. 4a, b). PCNSL typically reached the surface of the brain (87%) with meningeal infiltration present in 35.2% of cases and ependymal infiltration in 53.7% of cases. Signs of bleeding (5.6%) were rare.

Our MRI findings in GBM are in agreement with those reported previously [17]. However, our findings in PCNSL are only partially consistent with those reported by Haldorsen et al. [18]. In the present study, immunocompetent PCNSL patients presented with multiple lesions in 51.9% of cases, and with involvement of the basal ganglia in 55.6% cases. In contrast, Haldorsen et al. reported multiple lesions in only 35% of PCNSL cases, with basal ganglia involvement in 32% of cases [18]. However, they also reported disseminating lesions in 7% of cases [18]. In our study we used category diffused infiltrative affection and probably this category is equal to Haldorsens disseminating lesions. We found diffuse infiltrative brain affection by PCNSL in 24.1% of cases. They also did not report the presence or absence of cranial nerve infiltration [18]. In our study, optic pathways involvement was present in 42.6% of PCNLS cases, other cranial nerves were affected in 5.6%. In one case, solitary auditory nerve involvement was present without other lesions. Several case reports have been published describing solitary involvement of the auditory nerves in PCNSL manifesting by sudden hearing lost [19, 20]. Cranial nerve and leptomeningeal involvement is considered very common in secondary CNS lymphoma [21]; however, systematic lymphoma was excluded in our patients. One difficulty in comparing our results to those reported previously is that many studies are limited by small sample sizes [22, 23]. Therefore, we consider the study of Haldorsen et al. as the most reliable for comparison with our results [18]. Their population-based study evaluated CT/MRI features in 75 AIDS-negative patients in Norway between the years 1989-2003 [18]. However, only 52 patients underwent MRI, the rest of patients were examined only by CT, and considering the fact that sensitivity of CT is significantly lower than MRI, some lesions may have been missed [18]. Haldorsen et al. also included patients with immunosuppression therapy (5%) and also 6 patients, in whom only imaging after corticosteroid therapy was available. Differences between our results are partly explainable by designs of patient selection. We could also a little bit hypothesize about changing imaging findings in the time.

PCNSL and GBM are serious malignant brain tumors with different therapeutic management. Histological verification of PCNSL before oncological treatment is mandatory. Open surgery in PCNSL is not necessary; the diagnostic method of choice is stereotactic biopsy, which is not without complication [26]. We believe that the MRI morphological differences between PCNSL and GBM reported in the present study may be useful in daily radiological practice and may help to differentiate between both malignant entities.

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