Background & Objective: Determining the level of lesion in lumber disc disease might be difficult, especially when there is a transitional vertebrae. MRI is one the methods widely used in presurgery however, presence of sacralization or lumbarization may lead to a incorrect diagnosis. This study aimed at evaluating the agreement degree between the results of MRI and surgery with the post-operative radiographic findings in patients with lumber disc herniation.

 Methods:�Thirty patients with lumber disc herniation were evaluated in a diagnostic value study during a 15-month period of time. Presurgery MRI results, as well as the findings during operation regarding the level of herniated lumbar disc were compared with the radiographic findings, numbering the vertebra below the C2 after surgery. The radiologic assessment of involved segment was considered as the gold standard method. Transitional vertebrae were determined on the basis of radiologic findings.

 Results:�There were thirty patients with lumber disc herniation, 16 males and 14 females, with the mean age of 40.83±12.57 years in the study. There was a high and significant degree of compatibility agreement between the results of MRI and findings during surgery with the radiologic data (kappa=0.719, p<0.001 kappa=0.859, p<0.001). The results of MRI and surgery were incorrect in 4 and 2 cases, respectively. All these cases had a transitional vertebra in lumbosacral segment (totally 6 patients with transitional vertebra) i.e. MRI and surgery were able to detect the right level of herniation in 33.3% and 66.7% of patients with either sacralization or lumbarization, respectively. The sensitivity of MRI and surgery was 87% and 93%, respectively.

 Conclusion:�Our results showed that MRI and surgery can reveal the right level of LDH in majority of patients however, when there is a transitional vertebra, this ability may significantly be decreased.

  Background &objectives: Echinococcosis, referred to as hydatid disease or hydatidosis, is a parasitic disease caused by larval stage of Echinococcus granulosus. In the life cycle of this parasite, dogs and other carnivores are definitive hosts and herbivores are intermediate hosts. Humansin this cycle may incidentally involve by ingestion of parasite eggs and play as intermediate host. Hydatid disease can involve any organ but liver and lung are the most commonly affected organs and kidney, brain, heart, bone may also be affected to a lesser degrees. Cerebral hydatid cyst occurs in about 2% of all echinococcosis cases. In this paper we report two cases of cerebral echinococcosis in whom diagnoses were made based on MRI findings and confirmed by pathology reports after surgery.

  First Case Report: The first case was a 30 years old man who was admitted after an episode of generalized tonic-clonicseizure. The MRI imaging performedand patient underwent surgery with diagnosis of a right frontal cystic lesion. The patient was improved progressively and there was no seizure attack and recurrence during 18 months follow up period.

  Second Case Report: The second case was a 28 years old woman presented by headache and abnormal behavior. MRI of this patient revealed a large cystic lesion in left frontal lobe and then underwent surgery. No complication was seen during postoperative period. The headache and behavioral disorder were improved completely and there was no sign of recurrence during 18 months follow up period.

  Conclusion: Hydatid cyst should be considered as a differential diagnosis of cystic brain lesions in endemic areas. Although hydatid cyst is a benign lesion but surgical removal of it without rupture is very important for prevention of probable future complications.