We investigated the diagnostic potential of transcranial color-coded real-time sonography in 52 individuals using a phased-array ultrasound system with color-coded blood flow representation. Ultrasound scans in the axial and coronal planes were feasible through temporal acoustic bone windows in 49 subjects, enabling depiction of the main parenchymal and vascular structures as well as the ventricular system. Color-coded representation of blood flow in the cerebral vessels allowed unequivocal identification of the circle of Willis within the anatomic black-and-white B-mode image of the parenchymal structures. In Doppler mode, vascular blood flow phenomena may be analyzed semiquantitatively using the Doppler frequency spectrum. This noninvasive, serially applicable, mobile bedside method may complement conventional neuroradiologic imaging methods, allowing on-line studies of functional processes within the adult brain. {Stroke 1990;21:1680-1688) S ince Pape et al 1 reported two-dimensional sonographic illustration of cerebral damage in preterm infants in 1979, B-mode ultrasound scanning of the infant brain has become a standard pediatric examination method. The adult brain with its intact skull remained inaccessible to sophisticated ultrasound investigation until the pioneering work in 1982 of Aaslid et al, 2 who described pulsed-wave transcranial Dopplersonography. Recently, Schoning et al 34 indicated that B-mode sonography of the central nervous system (CNS) is feasible through the intact temporal plate of the adolescent and adult cranium. As a further development, we introduce transcranial color-coded real-time sonography of the adult brain and describe the application techniques, ultrasound anatomy, and feasibility in an adult population. Subjects and MethodsWe examined 52 individuals (13 normal healthy controls and 39 neurologic patients without CNS involvement; 17 women, mean age 51.7 years and 35 men, mean age 46.9 years). Duration of the bedside examinations varied from <5 minutes for the initial screening to 30 minutes for a complete sonographic evaluation.We used a phased-array ultrasound system with color-coded blood flow representation (Sonoline CF, From the Department of Neurology, Julius-Maximilians University Wurzburg, Wurzburg, F.R.G.Address for correspondence: Ulrich Bogdahn, MD, Department of Neurology, Intensive Care Unit, Josef-Schneider StraBe 11, D-8700 Wurzburg, F.R.G.Received March 28, 1990; accepted July 12, 1990. Siemens AG, Erlangen, F.R.G.) combined with a special 48-element, 2.25-MHz 90°-sector probe. Real-time (B-mode) sonography was performed with high frameto-frame averaging (ratio of memory information to new information 60% : 40%). Blood flow velocity and direction were displayed in real time as color for every pixel within a selectable subsector of the image. Blood flow toward the probe was displayed as shades of red/yellow and that away from the probe as shades of blue/turquoise. The colors were superimposed on the anatomic black-and-white B-mode image. 5 -7 High temporal and...

The diagnostic work up of patients with peripheral neuropathy largely depends on clinical and electrophysiological investigations. In contrast to disorders of the CNS, magnetic resonance imaging (MRI) has not been widely used as a diagnostic tool in the PNS except for detection of nerve compressing mass lesions. Normal nerves appear isointense to the surrounding tissue on T1- and T2-weighted (w) MRIs, but upon injury the nerves become hyperintense and thus visible on T2-w MRI. These signal alterations can be exploited to diagnose nerve damage in vivo and to follow regeneration. In patients with peripheral nerve disorders, MRI has been especially useful in detecting focal intrinsic and extrinsic nerve lesions and may reveal treatable conditions even in the absence of gross electrophysiological alterations. This clinical review provides practical guidelines on the performance of nerve imaging by MRI and will focus on focal lesions exemplified by case presentations.

Transcranial color-coded real-time sonography (TCCS) was performed in 57 patients with primary intracranial brain tumors (n = 49) or arteriovenous malformations (n = 8) to evaluate its diagnostic potential. In 46 patients (81%), lesions could be identified employing this technique. In 7 patients, transcranial ultrasound examination was not feasible because of bone thickness; in the remaining 4 patients, the tumor was indistinguishable from adjacent brain tissue despite sufficient insonation, suggesting that these neoplasms are isoechogenic. The sonographic features of brain tumors were very similar: a hyperechogenic matrix of the lesion was interspersed by hypoechogenic pixels. Larger hypoechogenic areas (0.5-1 cm) gave evidence of tumor necrosis. Differences between the findings of TCCS and computed tomography concerning tumor size were found in 7 patients, in whom TCCS revealed an area of smaller extension within the corresponding hypodense area on the computed tomographic scan. Perifocal brain edema could not be detected by ultrasound examination. In 13 patients, a thin, hypoechogenic peritumoral halo was disclosed that did not correlate with perifocal brain edema identified by computed tomography and that may have been due to compression of adjacent parenchyma. In patients with arteriovenous malformations, TCCS permitted the identification of the main feeders, the nidus, and the draining venous system by color-coded depiction of intravascular blood flow. In conclusion, TCCS is an additional method for initial diagnosis and highly suitable for follow-up in tumor patients and provides valuable information about tissue characteristics and blood flow.

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In this prospective study the role of intra-operative Colour-Duplex-Sonography (= CDS) during surgery of arteriovenous malformations (= AVM) is evaluated. During the last three years 20 consecutive patients with supratentorial AVMs were examined by intra-operative CDS in order to evaluate the potential of CDS to 1) localize the AVM, 2) differentiate between embolized and perfused parts, 3) identify feeding and draining vessels and 4) control the complete excision of the AVM. All AVMs were localized supratentorially, 9 were grade I and II (according to Spetzler and Martin [31]), 8 grade III and 3 grade IV. 11 were partly embolized and 8 associated with an intracerebral bleeding. In all cases the nidus was correctly localized sonographically by its typical bidirectional flow pattern in Colour-mode. CDS guided the surgeon directly to all (11 cases) deep-seated AVMs (2 to 4 cm subcortically). The smallest nidus measured 10 mm. 28 of 34 angiographically defined main feeding and 18 of 23 draining vessels were identified. 14 patients were controlled sonographically at the end of the resection regarding the completeness of excision. In 11 patients CDS was negative and was confirmed by either postoperative angiography or MRI in 10 patients. In one case residual AVM tissue was missed by CDS. Positive CDS findings in 3 cases were all confirmed by microscopic re-inspection, angiography and CCT. Our results suggest that CDS is able to localize AVMs intra-operatively with minimal instrumentation. It allows safe navigation to deep-seated malformations with high accuracy. Feeding and draining vessels can be identified and completeness of resection can be controlled.