On the AJR Viewbox On the AJR Viewbox On the AJR Viewbox Downloaded from www.ajronline.org by 50.37.68.45 on 10/18/15 from IP address 50.37.68.45. Copyright ARRS. For personal use only; all rights reserved DOI:10.2214/AJR.05.0155 MDCT Demonstration of Intralobar Pulmonary Sequestration of the Right Upper Lobe in an Adult We present the chest radiographic and CT findings of a rare case of right upper lobe intralobar sequestration in an adult. Only a few pediatric cases have been reported in the literature describing this anatomic location of a sequestration [1, 2]. A 23-year-old asymptomatic woman underwent routine chest radiography (Fig. 1A) that showed an area of hyperlucency and a tortuous tubular structure originating from the right hilum raising high suspicion of pulmonary arteriovenous malformation. MDCT was then performed using 1-mm slice thickness and contrast material injection. Then, a series of expiratory high-resolution CT scans was obtained. CT showed abnormal lung parenchyma in the right lung, distinct from the right upper lobe and clearly separated from it by an unusual accessory fissure that was perforated by two large vessels, one originating from the descending aorta (Fig. 1B) and the other draining into the right upper pulmonary vein, as shown on maximum intensity projection reconstruction (Fig. 1C). On inspiratory CT, the supernumerary lung parenchyma was hyperlucent compared with the right lung. Bronchiectasis was identified within the sequestrated lung (Fig. 1B). No communication was shown between the right bronchial tree and the sequestrated lung (Fig. 1D). Air trapping occurred in the sequestrated lung. The patient was asymptomatic and refused surgery. Pulmonary sequestration is an infrequent congenital pulmonary disorder defined by nonfunctional and dysplastic pulmonary tissue lacking a normal connection with the tracheobronchial tree and the pulmonary arteries [1]. The diagnosis of sequestration relies on imaging techniques, mainly helical CT angiography [3], that can identify each of the components of A the sequestration pattern [1]: sequestered or dysplastic lung mass, aberrant arterial supply, and anomalous venous drainage. Intralobar sequestration (75% of cases) occurs in the normal lung parenchyma and does not have a separate pleural lining. The arterial supply usually originates from the aorta or its branches, and the venous return is usually (95% of cases) into the pulmonary veins. Intralobar sequestrations are usually found within the lower lobes, as emphasized in the review of the literature by Savic et al. [1], who found that 97.75% of 400 intralobar sequestrations were in such location. Only eight cases (2%) in this series were found in the upper lobes, mainly in the right side (6 of 8). Upper lobe sequestration may appear as an area of hyperradiolucency [4], pulmonary mass [2], or cystic pulmonary mass [1]. In the present case, CT clearly showed that the sequestrated lung lacked normal communication with the tracheobronchial tree in the right lung. However, the B Fig. 1—23-year-old asymptomatic woman with right upper lobe sequestration. A, Posteroanterior chest radiograph shows hyperlucency of right upper lobe and tortuous tubular structure originating from right hilum (arrow). B, High-resolution CT at full inspiration shows hyperlucent abnormal lung parenchyma located externally to right upper lobe, clearly separated from it by unusual accessory fissure. This image shows abnormal vessel originating from descending aorta (arrow), abnormal vein draining into right upper pulmonary vein (arrowhead), and cystic bronchiectasis (double arrow). (Fig. 1 continues on next page) AJR 2005; 185:1663–1665 0361–803X/05/1856–1663 © American Roentgen Ray Society AJR:185, December 2005 1663 Downloaded from www.ajronline.org by 50.37.68.45 on 10/18/15 from IP address 50.37.68.45. Copyright ARRS. For personal use only; all rights reserved On the AJR Viewbox C D Fig. 1 (continued)—23-year-old asymptomatic woman with right upper lobe sequestration. C, MDCT angiography with maximum intensity projection reconstruction shows aberrant systemic artery extending from descending aorta (arrow) and aberrant pulmonary vein (arrowhead) draining into right upper pulmonary vein. D, Coronal minimal intensity projection shows no visible communication between right bronchial tree and sequestered lung. sequestration appeared as an area of hyperlucency that increased at the end of forced expiration, confirming air trapping within the sequestration. This feature supports the hypothesis of collateral pathways between the sequestration and the right lung through pores of Kohn and probably located at the level of the lung parenchyma surrounding the vascular pedicle of the sequestration [4]. Ferretti GR, Blanc Jouvan F, Coulomb M Gilbert R. Ferretti François Blanc Jouvan Max Coulomb CHU Grenoble Grenoble, France References 1. Savic B, Birtel FJ, Tholen W, Funke HD, Knoche R. Lung sequestration: report of seven cases and review of 540 published cases. Thorax 1979; 34:96–101 2. Hoeffel JC, Bernard C. Pulmonary sequestration of the upper lobe in children. Radiology 1986; 160:513–514 3. Lee EY, Siegel MJ, Sierra LM, Foglia RP. Evaluation of angioarchitecture of pulmonary sequestration in pediatric patients using 3D MDCT angiography. AJR 2004; 183:183–188 4. Stern EJ, Webb WR, Warnock ML, Salmon CJ. Bronchopulmonary sequestration: dynamic, ultrafast, high-resolution CT evidence of air trapping. AJR 1991; 157:947–949 1664 DOI:10.2214/AJR.05.0067 Resolution of Temporal Lobe Epilepsy and MRI Abnormalities After Coiling of a Cerebral Aneurysm A 49-year-old known hypertensive woman presented with severe headaches suggesting subarachnoid hemorrhage (SAH). The headaches were associated with 2–3 episodes of olfactory aura, which she described as smelling like burning Bakelite. There was no associated nausea, vomiting, or evidence of meningism. Physical examination and fundi were normal. A CT scan of the brain showed a left middle cerebral artery (MCA) aneurysm. A lumbar puncture including CSF spectrophotometry excluded SAH. MRI of the brain showed the aneurysm and intrinsic temporal lobe changes seen as high signal on FLAIR-weighted images (Fig. 2A). It was felt that the temporal lobe epilepsy was caused by the aneurysm and endovascular coiling was considered appropriate because of the risk of hemorrhage (Fig. 2B). The aneurysm was successfully occluded with coils. The olfactory hallucinations significantly reduced in frequency immediately after coiling. She was discharged on antihypertensive medications and low-dose aspirin. Follow-up MRI 6 months after coiling showed good packing of the aneurysm with a tiny neck re- currence, but the intrinsic signal in the temporal lobe had resolved (Fig. 2C). The patient has not suffered from olfactory hallucinations in the 2 years since coiling. Temporal lobe epilepsy as a presenting feature of unruptured cerebral aneurysm is unusual but well recognized [1, 2]. Aneurysms associated with epilepsy are usually large and are often of the MCA. Several mechanisms have been postulated including direct pressure effect, subclinical hemorrhage, and ischemia from thromboembolism as the cause of the seizures [3]. Vasogenic edema can be observed in the brain parenchyma surrounding a thrombosed intracranial aneurysm, possibly due to enlargement of acutely thrombosing aneurysms resulting in loss of vasoresponsivity and ischemia or an inflammatory process in the brain parenchyma surrounding the thrombosed aneurysm [4]. No chemical mediators have yet been linked to perianeurysmal vasogenic edema, and the exact mechanism remains unclear. It is also well known that obliteration of the aneurysm can lead to resolution of seizures, and some authors recommend temporal lobe surgery in the presence of permanent changes in the adjacent brain [1, 5]. The white matter changes seen in the temporal lobe may well represent edema or chronic AJR:185, December 2005 Downloaded from www.ajronline.org by 50.37.68.45 on 10/18/15 from IP address 50.37.68.45. Copyright ARRS. For personal use only; all rights reserved On the AJR Viewbox A B Fig. 2—49-year-old woman with left middle cerebral artery (MCA) aneurysm. A, Axial FLAIR MRI of brain shows aneurysm involving left MCA and high signal changes in adjacent temporal lobe. B, Frontal view in cerebral catheter angiogram shows left MCA aneurysm. C, Axial FLAIR MRI of brain after coiling shows resolution of high signal changes in temporal lobe surrounding coiled aneurysm. C ischemia, though the predominant white matter involvement and typical fingerlike appearances would favor vasogenic edema. The resolution of the temporal lobe signal changes seen on MRI is suggestive of vasogenic edema. The unique feature in this case is that the resolution seen on MRI correlated with clinical resolution of the olfactory hallucinations. Patankar T, Hughes D Tufail Patankar David Hughes Hope Hospital, Salford, United Kingdom AJR:185, December 2005 References 1. Gnanalingham KK, Colquhoun I, van Dellen J. Temporal lobe seizures: unusual presentation of a giant unruptured posterior communicating artery aneurysm. Br J Neurosurg 2003; 17:370–371 2. Provenzale JM, Gorecki JP, Koen JL. Cerebral aneurysms associated with seizures but without clinical signs of rupture: seemingly distinctive MR imaging findings in two patients. AJR 1996; 167:230–232 3. Tanaka K, Hirayama K, Hattori H, et al. A case of cerebral aneurysm associated with complex partial seizures. Brain Dev 1994; 16:233–237 4. Hammoud D, Gailloud P, Olivi A, Murphy KJ. Acute vasogenic edema induced by thrombosis of a giant intracranial aneurysm: a cause of pseudostroke after therapeutic occlusion of the parent vessel. Am J Neuroradiol 2003; 24:1237–1239 5. Ellamushi H, Thorne L, Kitchen N. Unruptured cerebral aneurysms causing seizure disorder (report of two cases). Seizure 1999; 8:310–312 1665