Figure 1
Axial flair weighted MRI sequence
Spherical parietal right cystic lesion with CSF like signal and very thin wall.
Hydatid cyst of the brain: MRI and MRS findings
SectionNeuroradiology
Case TypeClinical Cases
AuthorsHasni Bouraoui I, Moulahi H, Gamaoun W, khlifa M,Arifa N, Jemni H, Tlili Graeiss K.
Connected authors
24 years, female
Clinical History
A 24 year old female presented with intracranial hypertension. MRI and MR Spectroscopy (MRS) were performed and a cerebral cystic lesion was discovered.
Imaging Findings
A 24 year old female from a rural area was admitted to our neurosurgery department with complaints of headache and vomiting. Physical exam noted a left hemiparesis.
MRI demonstrated a huge (80 x 7 x 7 mm) cystic mass in the right parietal region with lateral ventricle compression. No peripheral oedema was noted around the cyst(fig1,2,3). In diffusion weighted images the cyst was like cerebrospinal flud(4). Single voxel MRS at a short TE (35ms) revealed lactate and pyruvate(Fig5,6). The diagnosis of hydatid cyst of the brain was made. The thorax and abdomen were also observed with CT scans. No lesion was seen on careful examination of the liver, lungs, and other organs. Serological tests for hydatid diseases were negative.
The patient was operated and the cyst was removed unruptured. The pseudocyst capsule was then completely removed. Surgery and histology confirmed the hydatid disease.
MRI demonstrated a huge (80 x 7 x 7 mm) cystic mass in the right parietal region with lateral ventricle compression. No peripheral oedema was noted around the cyst(fig1,2,3). In diffusion weighted images the cyst was like cerebrospinal flud(4). Single voxel MRS at a short TE (35ms) revealed lactate and pyruvate(Fig5,6). The diagnosis of hydatid cyst of the brain was made. The thorax and abdomen were also observed with CT scans. No lesion was seen on careful examination of the liver, lungs, and other organs. Serological tests for hydatid diseases were negative.
The patient was operated and the cyst was removed unruptured. The pseudocyst capsule was then completely removed. Surgery and histology confirmed the hydatid disease.
Discussion
The disease is endemic in many parts of the world but it is important to be aware of the condition even in non endemic parts of the world, where only occasional cases are encountered, because of the rapid movement of large human groups from endemic to non endemic areas [1]. Radiologists must be familiar with hydatid disease findings.
Cerebral hydatidosis accounts for approximately 1–3% of all cases of hydatid disease [2]. Primary multiple cysts of the brain result from arterial embolism secondary to ingestion of multiple larvae and without any radiological or clinical evidence of hydatid disease elsewhere in the body [3].
It is most commonly seen in children and young adults in approximately 50-70% of cases [3]. Intracranial hypertension and motor weakness due to increased intracranial pressure are the most common clinical manifestations of hydatid disease. Because of their indolent nature, hydatid cysts may not cause focal neurological signs until they are very large [2,3].
Most commonly, cerebral hydatid cysts are single lesions and locate anywhere within the brain, but are especially located in the middle cerebral artery territory. The parietal lobe is the most frequently involved region [1,2].
Hydatid cysts of the brain are usually single, spherical, unilocular, and may be large; in rare instances, they can be multiple and embolic [3].
Both CT and MRI demonstrate a spherical and well-defined, smooth, thin walled, homogeneous cystic lesion with fluid density similar to the cerebrospinal fluid, with or without septations or calcification. The cyst wall usually showed a rim of low signal intensity on both T1- and T2-weighted images. Compression of the midline structures and ventricles are seen in most of the cases, however surrounding oedema and rim enhancement are usually absent in untreated or uncomplicated cases [4].
The differential diagnosis of intracerebral hydatid cysts includes cystic lesions such as porencephalic cyst, arachnoid cyst, cystic tumor of the brain and pyogenic abscess [1]. The hydatid cyst is usually hypointense in diffusion weighted images and Proton MR Spectroscopy demonstrate lactate, alanine and pyruvate within the lesion. Pyruvate is very characteristic of hydatid cyst. This metabolite may be a marker of parasitic etiology and perhaps that of viability of such intracranial cysts [4].
CT scan and MRI are excellent techniques to diagnose and localize the lesions [3]. The serologic tests are of little practical value in confirming the diagnosis of cerebral echinococcal disease [2].
Surgery is the standard and most effective treatment for intracranial hydatid cysts. The preoperative diagnosis is very important both in planning the surgery and taking the measures against spillage of daughter cysts and scolices at surgery. Rupture is associated with the well-recognized problems of anaphylaxis, meningitis, or local recurrence from spillage of the cyst contents [3].
Nevertheless, hydatid cyst is a benign lesion, appropriate and timely diagnosis and management are mandatory for reducing mortality and morbidity [3,4].
Cerebral hydatidosis accounts for approximately 1–3% of all cases of hydatid disease [2]. Primary multiple cysts of the brain result from arterial embolism secondary to ingestion of multiple larvae and without any radiological or clinical evidence of hydatid disease elsewhere in the body [3].
It is most commonly seen in children and young adults in approximately 50-70% of cases [3]. Intracranial hypertension and motor weakness due to increased intracranial pressure are the most common clinical manifestations of hydatid disease. Because of their indolent nature, hydatid cysts may not cause focal neurological signs until they are very large [2,3].
Most commonly, cerebral hydatid cysts are single lesions and locate anywhere within the brain, but are especially located in the middle cerebral artery territory. The parietal lobe is the most frequently involved region [1,2].
Hydatid cysts of the brain are usually single, spherical, unilocular, and may be large; in rare instances, they can be multiple and embolic [3].
Both CT and MRI demonstrate a spherical and well-defined, smooth, thin walled, homogeneous cystic lesion with fluid density similar to the cerebrospinal fluid, with or without septations or calcification. The cyst wall usually showed a rim of low signal intensity on both T1- and T2-weighted images. Compression of the midline structures and ventricles are seen in most of the cases, however surrounding oedema and rim enhancement are usually absent in untreated or uncomplicated cases [4].
The differential diagnosis of intracerebral hydatid cysts includes cystic lesions such as porencephalic cyst, arachnoid cyst, cystic tumor of the brain and pyogenic abscess [1]. The hydatid cyst is usually hypointense in diffusion weighted images and Proton MR Spectroscopy demonstrate lactate, alanine and pyruvate within the lesion. Pyruvate is very characteristic of hydatid cyst. This metabolite may be a marker of parasitic etiology and perhaps that of viability of such intracranial cysts [4].
CT scan and MRI are excellent techniques to diagnose and localize the lesions [3]. The serologic tests are of little practical value in confirming the diagnosis of cerebral echinococcal disease [2].
Surgery is the standard and most effective treatment for intracranial hydatid cysts. The preoperative diagnosis is very important both in planning the surgery and taking the measures against spillage of daughter cysts and scolices at surgery. Rupture is associated with the well-recognized problems of anaphylaxis, meningitis, or local recurrence from spillage of the cyst contents [3].
Nevertheless, hydatid cyst is a benign lesion, appropriate and timely diagnosis and management are mandatory for reducing mortality and morbidity [3,4].
Differential Diagnosis List
Hydatid cyst of the brain
Final Diagnosis
Hydatid cyst of the brain
References
[1] Bükte Y, Kemaloglu S, Nazaroglu H (2004) Cerebral hydatid disease: CT and MR imaging findings. Swiss Med Wkly 134(31-32):459-67 (PMID: 15389350)
[2] Cemil B, Tan K, GuarcayA (2009) Cranial epidural hydatid cysts: Clinical report and review of the literature. Acta Neurochir 151(6):659-62 (PMID: 19319472)
[3] Cavu?o?lu H, Tuncer C, Ozdilma瀀 A (2009) Multiple intracranial hydatid cysts in a boy. Turk Neurosurg 19(2):203-7 (PMID: 19431138)
[4] Tlili-Graiess K, El-Our F, Gharbi-Jemni H (2006) [Cerebral hydatid disease: imaging features]. J Neuroradiol 33(5):304-18 (PMID: 17213758)
Case information
| URL: | https://www.eurorad.org/case/8562 |
| DOI: | 10.1594/EURORAD/CASE.8562 |
| ISSN: | 1563-4086 |
Figure 2
Axial flair weighted MRI sequence
There is no surrounding edema. Impotent right ventricle compression
Figure 3
Coronal T2 weighted MRI sequence
Frank hyperintensity of the cystic content and hyposignal of the cystic rim
Figure 4
Diffusion weighted sequence
the cyst is hypointense like CSF
Figure 5
MRS, Single Voxel
Single Voxel within the cyst
Figure 6
fig6
High level of lactate with doublet at 1,33ppm and pyruvate at 2,4ppm very suggestive of hydatid cyst
Axial flair weighted MRI sequence
Spherical parietal right cystic lesion with CSF like signal and very thin wall.
Axial flair weighted MRI sequence
There is no surrounding edema. Impotent right ventricle compression
Coronal T2 weighted MRI sequence
Frank hyperintensity of the cystic content and hyposignal of the cystic rim
Diffusion weighted sequence
the cyst is hypointense like CSF
MRS, Single Voxel
Single Voxel within the cyst
fig6
High level of lactate with doublet at 1,33ppm and pyruvate at 2,4ppm very suggestive of hydatid cyst