N.C. Chiu and E.Y. Shen

Color Doppler Sonography of an of the Middle Cerebral in a Child

Nan-Chang Chiu1,2 and Ein-Yiao Shen1,3

A 4-month-old boy had a cerebral aneurysm detected on color Doppler sonography as a colorful cystic lesion at the junction of the right frontal and parietal lobes. Three-dimensional color Doppler sonography after the first operation revealed residual anomalous vessels related to the right middle cerebral artery. Blood flow in the feeding vessel was faster, but the resistance index and pulsatility index were lower than in the contralateral vessel. This case demonstrates that Doppler sonography is a valuable diagnostic technique for detecting intracranial and for following any associated anomalies.

(J Med Ultrasound 2003;11:18–21)

KEY WORDS: • aneurysm • power Doppler ultrasonography • three-dimensional ultrasonography

INTRODUCTION Doppler cerebral sonography (5.0 MHz sector scan, SSA-260A, Toshiba, Tokyo, Japan) revealed Doppler sonography allows visualization of a colorful cystic lesion with a separation zone at intracranial aneurysms and their hemodynamic the junction of the right frontal and parietal lobes changes [1, 2]. Color power Doppler and three- (Fig. 1A). Brain computed (CT) scan dimensional sonography have an advantage over showed contrast medium within the cyst and conventional Doppler imaging in that cerebral hydrocephalus with intraventricular blood. vascular anomalies can be seen in greater detail [3, A craniotomy was performed and the aneurysm 4]. We report a child with an aneurysm of the was clipped. Pathology showed tortuous dilated middle cerebral artery (MCA) detected by conven- vessels with a thin, loose fibrous wall consistent tional Doppler sonography. Postoperative color power with an aneurysm. Three days after , we Doppler angiosonography and three-dimensional performed power Doppler angiosonography (Fig. 1B) sonography revealed a residual aneurysm. and three-dimensional color Doppler sonography from the anterior fontanel towards the posterior over the CASE REPORT course of several seconds (Fig. 1C). A residual aneurysm of the right MCA was found. A 4-month-old boy had sudden-onset tonic seizures. Seizures recurred about 1 month later. Follow- His cerebrospinal fluid was xanthochromic. Color up cerebral sonography revealed hydrocephalus and

Received: June 12, 2003. Accepted: July 10, 2003. 1Department of Pediatrics, Mackay Memorial Hospital, 2Mackay Junior College of Nursing, and 3Department of Pediatrics, Taipei Municipal Wan Fang Hospital, Taipei, Taiwan. Address correspondence and reprint requests to: Dr. Nan-Chang Chiu, Department of Pediatrics, Mackay Memorial Hospital, 92 Chung-San North Road Section 2, Taipei, Taiwan.

© 2003 Elsevier. All rights reserved.

18 J Med Ultrasound 2003 • Vol 11 • No 1 Sonography of a Middle Cerebral Artery Aneurysm

subdural effusion requiring external ventricular A drainage (EVD). Another craniotomy to clip the residual aneurysm was performed 1.5 months after the first craniotomy. However, due to a complicated clinical course, the patient underwent external subdural drainage, a second EVD, and subduro- peritoneal shunting over the next month (Fig. 2). Serial cerebral sonography revealed that the resistance index (RI) of the intracranial fluctuated when conditions causing changes in intracranial pressure appeared, i.e. hydrocephalus and/or subdural effusion. Blood flow velocities in the right MCA were higher but the RI and pulsatility index (PI) were lower than those in the left MCA (Table). B The patient’s condition stabilized after subduroperitoneal shunting. Although focal seizures recurred a few months later, they were well controlled with anticonvulsants. Mild motor developmental delay was noted initially, but 5 years later, there were no significant neurologic sequelae except for attention deficit disorder with hyperactivity.

DISCUSSION

This case demonstrates that real-time sonography can be used as a primary diagnostic alternative to CT, magnetic resonance imaging (MRI), or conventional in the detection of C intracranial aneurysms. Sonography is also useful to evaluate serial cerebral pathologic changes. Conventional color Doppler sonography shows the direction of blood flow and the shape of an aneurysm [1, 5]. In the mid-aneurysm plane, the aneurysm is seen as a round or oval mass divided by a colorless separation zone into red and blue areas [6]. Small aneurysms or thrombosed aneurysms may be missed, so careful visual inspection by an experienced ultrasonographer is mandatory. Power Doppler angiosonography and three- dimensional Doppler sonography more clearly demonstrate the course of the artery feeding the Fig. 1. (A) Coronal view of cerebral color Doppler aneurysm [3, 4, 7–9]. After the first craniotomy, we sonography before the first operation, showing a colorful used power angiosonography and three-dimensional cystic lesion at the junction of the right frontal and color Doppler sonography with a 5 MHz hand-held parietal lobes with a separation zone between the red and probe to inspect the residual aneurysm. Power blue areas. (B) Power Doppler angiosonography showing a postoperative residual aneurysm (arrow). (C) Three- Doppler angiosonography revealed trivial blood flow, dimensional color Doppler sonography demonstrating the but could not show the direction of flow and could course of the aneurysm (arrowhead). Lt = left; Rt = right; show only a single cutting plane of the vessels in RMCA = right middle cerebral artery. each picture. Three-dimensional images were acquired

J Med Ultrasoundd 2003 • Vol 11 • No 1 19 N.C. Chiu and E.Y. Shen

0.8 –

0.6 –

➝

➝ 1 ➝ 3

2 ➝ A 4

➝

➝ 5 6 AC 0.4 –

f

RI o

0.2 –

0 – D0 D3 D5 D10 D15D21 D29 D34 D36 D50 D51 D75 D137 H ++ + –– +++++ ++ +++ +++ + ++ S – –– +++++ ++ ++ ++ +++ ++ ++ +

1 = Craniotomy & aneurysm clipping 4 = External subdural drainage – = No ++ = Moderate 2 = External ventricular drainage 5 = External ventricular drainage + = Mild +++ = Severe 3 = Craniotomy & aneurysm clipping 6 = Subduroperitoneal shunting

Fig. 2. Serial sonographic examinations showing the resistance index of the anterior cerebral artery fluctuating as hydrocephalus and/or subdural effusion appeared or improved after medical and surgical treatment. The arrows indicate the timing of surgical procedures. RI = resistance index; ACA = anterior cerebral artery; D = days after admission; H = hydrocephalus; S = subdural effusion. by slowly moving the probe to obtain sector arrays. Comparison of the cerebral blood flow velocities Although they were not real-time, live, three- on both sides is valuable for discovering abnormal dimensional images, we found that, with practice, vascular flow. Blood flow in the feeding vessels of we could trace the stereo vascular course. In some an aneurysm is usually faster, but the RI and PI may studies, echo contrast enhancement has been used be either lower or higher than in the contralateral to increase aneurysm detection [4, 10]. However, the normal vessels [2, 11, 12]. Vasospasm and collateral visualization of an intracranial aneurysm is dependent blood flow may be responsible for the high-velocity on location, size, and morphology; contrast flow. The size of the aneurysm and the presence enhancement may not be necessary in all cases, as of thrombosis influence the RI and PI [2]. demonstrated here. One major advantage of ultrasonography is that

Table. Hemodynamic indices of the middle cerebral arteries

Days after Vs (cm/sec) Vd (cm/sec) Vm (cm/sec) RI PI admission RLRLRLRLRL

Day 10 186 142 109 67 166 88 0.41 0.60 0.57 0.97 Day 21 133 81 77 24 101 48 0.42 0.700.55 1.19 Day 29 140 144 89 60 112 102 0.36 0.58 0.46 0.82 Average 153 103 107 50 126 79 0.40 0.63 0.53 0.99

Vs = peak systolic velocity; Vd = end diastolic velocity; Vm = mean velocity; RI = resistance index; PI = pulsatility index; R = right; L = left.

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