The purpose of this study was to determine the outcomes of surgical clipping in patients with unruptured middle cerebral artery (MCA) aneurysms.
A retrospective single-center database of 125 consecutive patients with 143 small MCA aneurysms (< 10 mm) who underwent surgical clipping was reviewed from January 2007 to December 2010. Clinical outcomes were assessed based on surgery-related complications and follow-up (mean: 17 months) using the modified Rankin scale (mRS). Angiographic outcomes were evaluated by conventional angiography (N = 96) or computed tomography angiography (N = 29) at postoperative weeks 1 and 6.
There were no cases of mortality. There were three surgery-related complications (intracranial hemorrhage, meningitis and wound infection, respectively). The hemorrhagic event caused transient neurological deficits. All patients showed good clinical outcomes during follow-up (mRS 0-1). There was angiographic evidence of complete occlusion in 137 aneurysms (95.8%), a small residual neck in three aneurysms (2.2%) and partial for three aneurysms. In the three cases with partial clipping, the decision was made preoperatively to leave the residual sac to maintain distal flow, and muscular wrapping was performed.
Our study demonstrates that surgical clipping of unruptured small MCA aneurysms yields favorable clinical and angiographic outcomes. Aneurysmal clipping can be safely recommended for patients with small unruptured MCA aneurysms.
Aneurysm; Middle cerebral artery; Surgical clip; Treatment outcome
Direct revascularization surgery is regarded as the most effective method of treatment of adults with moyamoya disease. These patients, however, have a higher risk of perioperative ischemic complications than do patients with atherosclerotic stroke, and are at risk for ischemic complications in the hemisphere contralateral to the one operated on. We investigated the incidence and risk factors for ischemic stroke in the contralateral hemisphere after surgical treatment of adults with moyamoya disease.
We retrospectively reviewed the medical records and results of neuroimaging studies on 79 hemispheres of 73 consecutive patients with adult moyamoya disease (mean±SD age, 37.96±11.27 years; range, 18-62 years) who underwent direct bypass surgery over 6 years.
Ischemic complications occurred in 4 of 79 (5.1%) contralateral hemispheres, one with Suzuki stage 3 and three with Suzuki stage 4. Three patients showed posterior cerebral artery (PCA) involvement by moyamoya vessels. Advanced stage of moyamoya disease (Suzuki stages 4/5/6; p=0.001), PCA involvement (p=0.001) and postoperative hypotension (mean arterial blood pressure <80% of preoperative mean arterial blood pressure) on the first (p<0.0001) and second (p=0.003) days after surgery were significantly correlated with postoperative contralateral ischemic complications.
In patients with advanced moyamoya disease and involvement of the PCA, intentional hypotension can result in ischemic stroke in the hemisphere contralateral to the one operated on. Careful control of perioperative blood pressure is crucial for good surgical results.
Cerebral revascularization; Complications; Moyamoya diseases; Perioperative period
A retrospective study.
To compare the clinical and radiological outcomes of autogenous bone graft and cage with bone substitute for anterior cervical discectomy and fusion.
Overview of Literature
The clinical outcomes of cage with bone substitute for anterior cervical discectomy and fusion is satisfactory.
Eighty four patients who underwent cervical spine surgery between February 2004 and April 2009 were included. Fifty-nine patients were approached anteriorly and underwent anterior cervical discectomy and fusion by the Smith-Robinson method (Group A), and 25 patients underwent fusion by decompression of the cervical spine and cage with bone substitute (Group B). We measured and evaluated the postoperative period until patients were able to ambulate, for pre- and postoperative symptomatic improvement, postoperative complications, pre- and postoperative change of lordosis, degree of endplate collapse or subsidence, and fusion rate and period of union.
By Robinson's criteria, respectively 45, 10 and 4 patients in Group A experienced excellent, good and fair symptomatic improvement, and respectively 19, 5 and 1 patients in Group B experienced excellent, good and fair symptomatic improvement. The postoperative period in which patients became ambulant and the period of hospital stay was significantly shorter in Group B. Increase of lordosis at final follow up after surgery was significantly larger in Group A, as was the fusion period. Significantly more endplate collapse occurred in Group B.
Of patients who had anterior cervical discectomy and fusion, results of both groups were both satisfactory.
Cervical vertbrae; Anterior cervical discectomy and fusion; Autobone graft; Cage; Bone substitutes
To investigate the efficacy of extracranial-intracranial (EC-IC) bypass surgery using a radial artery interposition graft (RAIG) for surgical management of cerebrovascular diseases.
The study involved a retrospective analysis of 13 patients who underwent EC-IC bypass surgery using RAIG at a single neurosurgical institute between 2003 and 2009. The diseases comprised intracranial aneurysm (n=10), carotid artery occlusive disease (n=2), and delayed stenosis in the donor superficial temporal artery (STA) following previous STA-middle cerebral artery bypass surgery (n=1). Patients were followed clinically and radiographically.
Bypass surgery was successful in all patients. At a mean follow-up of 53.4 months, the short-term patency rate was 100%, and the long-term rate was 92.3%. Twelve patients had an excellent clinical outcome of Glasgow Outcome Scale (GOS) 5, and one case had GOS 3. Procedure-related complications were a temporary dysthesia on the graft harvest hand (n=1) and a hematoma at the graft harvest site (n=1), and these were treated successfully with no permanent sequelae. In one case, spasm occurred which was relieved with the introduction of mechanical dilators.
EC-IC bypass using a RAIG appears to be an effective treatment for a variety of cerebrovascular diseases requiring proximal occlusion or trapping of the parent artery.
EC-IC arterial bypass; Radial artery interposition graft; Revascularization
As medical advances have increased life expectancy, it has become imperative to develop specific treatment strategies for intracranial aneurysms in the elderly. We therefore analyzed the clinical characteristics and outcomes of the treatment of unruptured intracranial aneurysms in patients older than 70 years.
We retrospectively reviewed the medical records and results of neuroimaging modalities on 54 aneurysms of 48 consecutive patients with unruptured intracranial aneurysms. (mean±SD age, 72.11±1.96 years; range, 70-78 years) who underwent surgical clipping over 10 years (May 1999 to June 2010).
Of the 54 aneurysms, 22 were located in the internal carotid artery, 19 in the middle cerebral artery, 12 in the anterior cerebral artery, and 1 in the superior cerebellar artery. Six patients had multiple aneurysms. Aneurysm size ranged from 3 mm to 17 mm (mean±SD, 6.82±3.07 mm). Fifty of the 54 aneurysms (92.6%) were completely clipped. Three-month outcomes were excellent in 50 (92.6%) aneurysms and good and poor in 2 each (3.7%), with 1 death (2.0%). Procedure-related complications occurred in 7 aneurysms (13.0%), with 2 (3.7%) resulting in permanent neurological deficits, including death. No postoperative subarachnoid hemorrhage occurred during follow-up. The cumulative rates of stroke- or death-free survival at 5 and 10 years were 100% and 78%, respectively.
Surgical clipping of unruptured intracranial aneurysms in elderly group could get it as a favorable outcome in well selected cases.
Unruptured intracranial aneurysm; Surgical clipping; Elderly; Outcome
Giant serpentine aneurysms are rare and have distinct angiographic findings. The rarity, large size, complex anatomy and hemodynamic characteristics of giant serpentine aneurysms make treatment difficult. We report a case of a giant serpentine aneurysm of the right middle cerebral artery (MCA) that presented as headache. Treatment involved a superficial temporal artery (STA)-MCA bypass followed by aneurysm resection. The patient was discharged without neurological deficits, and early and late follow-up angiography disclosed successful removal of the aneurysm and a patent bypass graft. We conclude that STA-MCA bypass and aneurysm excision is a successful treatment method for a giant serpentine aneurysm.
Angiographic feature; Bypass surgery; Giant serpentine aneurysm
This study examined the prognostic factors that affect the surgical outcome of laminoplasty in cervical spondylotic myelopathy patients by comparative analysis.
Thirty nine patients, 26 males and 13 females, who were treated with laminoplasty for cervical myelopathy from September 2004 to March 2008 and followed up for 12 months or longer, were enrolled in this study. The mean age of the subjects was 62.4 years (range, 37 to 77 years). The patients' age, number of surgical segments, spinal cord compression ratio, segment number, level, localized marginal pattern of high signal intensity within the spinal cord in the T2 image, preoperative Japanese Orthopaedic Association Scoring System (JOA) score with the recovery ratio were compared respectively. The JOA score was used for an objective assessment of the patients' preoperative and postoperative clinical status. The recovery ratios of surgery were graded using the Hirabayashi equation. Statistical analysis was carried out using Pearson correlation analysis.
The patients' JOA score increased from a preoperative score of 11.1 (range, 5 to 16) to a postoperative score of 14.9 (range, 7 to 17). The average recovery ratio was 65.8% (range, 0 to 100%). The number of segments with high signal changes in the T2 image, a localized marginal pattern with high signal change, signal intensity changes in the upper cervical spinal cord were inversely associated with the recovery ratio, whereas the spinal cord compression ratio showed a significant positive correlation. However, the currently known prognostic factors, such as number of surgical segment, age, and preoperative JOA score, showed no statistically significant correlation.
The number of segments, localized marginal pattern, rostral location of signal intensity changes with a high signal change in the T2 image and a low spinal cord compression ratio in cervical spondylotic myelopathy patients treated by laminoplasty can indicate a poor prognosis.
Cervical spondylosis; Myelopathy; Laminoplasty; Prognostic factor
The standard treatment strategy of intracranial aneurysms includes either endovascular coiling or microsurgical clipping. In certain situations such as in giant or dissecting aneurysms, bypass surgery followed by proximal occlusion or trapping of parent artery is required.
The authors assessed the result of extracranial-intracranial (EC-IC) bypass surgery in the treatment of complex intracranial aneurysms in one institute between 2003 and 2007 retrospectively to propose its role as treatment modality. The outcomes of 15 patients with complex aneurysms treated during the last 5 years were reviewed. Six male and 9 female patients, aged 14 to 76 years, presented with symptoms related to hemorrhage in 6 cases, transient ischemic attack (TIA) in 2 unruptured cases, and permanent infarction in one, and compressive symptoms in 3 cases. Aneurysms were mainly in the internal carotid artery (ICA) in 11 cases, middle cerebral artery (MCA) in 2, posterior cerebral artery (PCA) in one and posterior inferior cerebellar artery (PICA) in one case.
The types of aneurysms were 8 cases of large to giant size aneurysms, 5 cases of ICA blood blister-like aneurysms, one dissecting aneurysm, and one pseudoaneurysm related to trauma. High-flow bypass surgery was done in 6 cases with radial artery graft (RAG) in five and saphenous vein graft (SVG) in one. Low-flow bypass was done in nine cases using superficial temporal artery (STA) in eight and occipital artery (OA) in one case. Parent artery occlusion was performed with clipping in 9 patients, with coiling in 4, and with balloon plus coil in 1. Direct aneurysm clip was done in one case. The follow up period ranged from 2 to 48 months (mean 15.0 months). There was no mortality case. The long-term clinical outcome measured by Glasgow outcome scale (GOS) showed good or excellent outcome in 13/15. The overall surgery related morbidity was 20% (3/15) including 2 emergency bypass surgeries due to unexpected parent artery occlusion during direct clipping procedure. The short-term postoperative bypass graft patency rates were 100% but the long-term bypass patency rates were 86.7% (13/15). Nonetheless, there was no bypass surgery related morbidity due to occlusion of the graft.
Revascularization technique is a pivotal armament in managing complex aneurysms and scrupulous prior planning is essential to successful outcomes.
Cerebral aneurysm; Extracranial-intracranial bypass; Outcomes
A retrospective study.
This is a study of the diagnosis and treatment of tuberculous spondylitis and pyogenic spondylitis in atypical cases.
Overview of Literature
There have been several reports about clinical, hematological, pathological and radiological findings to differentiate pyogenic & tuberculous spondylitis.
We screened 55 patients diagnosed with tuberculous spondylitis and pyogenic spondylitis from January 1999 to June 2003. There were seven cases where it was difficult to make an accurate diagnosis. We reviewed the clinical manifestation, laboratory tests, radiological findings and confirmed the diagnoses by the use of biopsies and/or clinical response to treatment.
Four cases, which were initially diagnosed as pyogenic spondylitis, had a clinical presentation of fever (37.4~38.5℃) on the day of hospitalization. These cases later turned out to be tuberculous spondylitis, as confirmed by an open biopsy and pathologic study. Three cases initially diagnosed as pyogenic spondylitis were treated with broad-spectrum antibiotics. Symptoms were aggravated in these cases, but improved after the use of an anti-tubercular drug. Bony union was observed in all cases in an averageof 4 months (range, 3~6 months).
In infectious spondylitis, it is important to establish an accurate diagnosis. An accurate diagnosis can be made by laboratory findings and by estimation of the response to treatment during follow-up. If there is no response or aggravation of symptoms despite treatment based on an initial diagnosis, the etiologic organism must be re-evaluated. A biopsy and observation of clinical response are needed to confirm the diagnosis.
Tuberclous spondylitis; Pyogenic spondylitis
Intraosseous arteriovenous malformation (AVM) in the craniofacial region is rare. When it occurs, it is predominantly located in the mandible and maxilla. We encountered a 43-year-old woman with Klippel-Trenaunay syndrome affecting the right lower extremity who presented with a left orbital chemosis and proptosis mimicking the cavernous sinus dural arteriovenous fistula. Computed tomography angiography revealed an intraosseous AVM of the sphenoid bone. The patient's symptoms were completely relieved after embolization with Onyx. We report an extremely rare case of intraosseous AVM involving the sphenoid bone, associated with Klippel-Trenaunay syndrome.
Arteriovenous malformations; Hemangioma; Primary intraosseous vascular malformation; Klippel-Trenaunay-Weber syndrome
Superior cerebellar artery (SCA) aneurysms are regarded as being as difficult to treat surgically as posterior circulation aneurysms. We describe here a series of 33 of these aneurysms treated with microsurgery or embolization.
Between June 1997 and August 2007, 33 patients (9 men, 24 women; age, 29 to 76 years) with SCA aneurysms underwent microsurgical (n = 12) or endovascular (n = 21) treatment. Twenty two patients presented with subarachnoid hemorrhage. Thirty aneurysms were located in the junction between the SCA and the basilar artery (BA), two in the proximal SCA (S1) and one in the distal SCA (S2-3).
Of the 29 SCA aneurysms, located in the junction between the SCA and BA, which were available on conventional angiography, 20 were lateral-superior, six lateral-horizontal, two lateral inferior, and one posterior type. Of the 12 patients treated microsurgically, eight had clinically excellent or good outcomes. Causes of poor outcomes included initial poor clinical status (n = 2), infarction due to parent artery compromise (n = 1), and artery of Heubner injury due to surgery for a coexisting anterior communicating artery aneurysm (n = 1). Of the 21 patients treated endovascularly, 17 had clinical good or excellent outcomes. Causes of clinically poor outcomes included initial poor clinical status (n = 2) and infarction due to thrombosis of exposed coil mesh (n = 1). One patient underwent embolization resulted in death due to vasospasm. Three patients required additional embolization for coil compaction.
There was no morbidity related to perforator injury, regardless of the treatment modality. Embolization or microsurgery is an effective modality, with relatively low procedural morbidity and mortality rates.
Aneurysm; Endovascular; Microsurgery; Superior cerebellar artery
The authors report a case of renal cell carcinoma in a right malrotated (horizontal axis) kidney. The patient was treated by hand-assisted laparoscopic radical nephrectomy. This is the first report of a horizontal axis malrotated kidney with renal cell carcinoma.
Carcinoma, Renal cell; Malrotation; Nephrectomy
Difficulty exists in interpreting the significance of atypical urine cytology. This study was performed to assess the diagnostic utility of nuclear matrix protein-22 (NMP-22) testing when atypical cells are detected during urine cytology.
Materials and Methods
Among patients whose urine cytology was reported as atypical between January 2004 and December 2009, a total of 275 who also underwent NMP-22 testing were enrolled in the present study. These patients were further divided into the screening group (143 patients examined as outpatients for hematuria) and the follow-up group (132 patients followed up for previously diagnosed bladder cancer). The sensitivity, specificity, positive and negative predictive values, and accuracy were assessed for atypical cytology alone and in conjunction with NMP-22.
Of the 275 patients exhibiting atypical urine cytology, cancer was confirmed in 85, yielding a positive predictive value of 30.9% (85/275). Of the 96 patients testing positive for NMP-22, 58 were diagnosed with bladder cancer. The positive predictive value in conjunction with NMP-22 was 60.4% (58/96). The sensitivity, specificity, negative predictive value, and accuracy were 68.2% (58/85), 80.0% (152/190), 84.9% (152/179), and 76.2% (210/275), respectively. Testing for NMP-22 in the screening and follow-up groups increased the positive predictive value from 30.0% (43/143) to 64.0% (32/50) and from 31.3% (42/132) to 56.5% (26/46), respectively; there was no significant difference between the screening and follow-up groups (p=0.106).
When only cases with atypical urine cytology were examined, NMP-22 testing increased the detection rate of bladder cancer regardless of whether the test was used in screening hematuria or in following up patients.
Cytology; Nuclear matrix; Urinary bladder neoplasms
Embolization of an aneurysm at the proximal A1 segment of the anterior cerebral artery (ACA) is technically challenging. We treated four consecutive patients with unruptured aneurysms at the proximal portion of the A1 segment of the ACA. We tested various microcatheter tip shapes before we successfully embolized a lesion with a zigzag-shaped microcatheter tip, which was made by steam shaping. The shape of this microcatheter tip resembled the letter "Z", had a relatively long distal straight segment and was helpful in prompt catheterization of the aneurysm sac and stable placement of the catheter and delivery of coils.
Anterior cerebral artery; Endovascular techniques; Intracranial aneurysms; Catheters
Large to giant middle cerebral artery aneurysm is a challenging disease, especially when incorporating important perforating arteries. Surgical risk increases by perforator infarction and anatomical complexity. In this clinical setting, extensive consideration of surgical options is needed. The two cases described here were unruptured and had rather stable wall. Because of their large and giant size, hardness and incorporated arteries, it was not affordable to isolate them by means of clipping or trapping. The procedure as the alternative to conventional treatment modalities, extracranial-intracranial bypass followed by clipping of only the efferent artery successfully treated the aneurysms.
Aneurysm; Bypass; Clip; Middle cerebral artery
Surgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging due to limited surgical accessibility. Endovascular approach has a benefit of avoiding direct injury to the brainstem or lower cranial nerves. Therefore, it has recently been considered an alternative or primary modality for PICA aneurysms. We retrospectively assessed outcomes following detachable coil embolization of saccular PICA aneurysms.
From February 1997 to December 2007, we performed endovascular procedures to treat 15 patients with 15 PICA aneurysms. Fourteen patients with 14 PICA aneurysms morphology of which was saccular were reviewed retrospectively. Twelve patients had ruptured aneurysms. The aneurysms arose from the PICA origin site (n = 12), the PICA lateral medullary segment (n = 1), or the PICA tonsilomedullary segment (n = 1).
Complete aneurysm occlusion was achieved in 10 patients, residual neck in 3, and residual sac in one. Radiological follow-up was performed in 7 patients with mean duration of 34.7 months (range, 1-97 months) and showed stable or complete occlusion in 6 patients. There were no rebleeding or retreatment after endovascular treatment. Thromboembolism was the only procedure-related complication (n = 4 ; 28.6%). Asymptomatic PICA infarction occurred in two patients and symptomatic PICA infarction in two elderly patients with poor clinical grade. Of these procedural PICA infarction cases, 1 symptomatic PICA infarction patient developed ventriculitis and septic shock leading to death. The clinical outcome was good in 10 patients (71.4%).
In the present study, detachable coil embolization has shown as an efficient modality for PICA saccular aneurysms challenging indications of microsurgery. However, thromboembolic complications should be considered, especially in poor clinical elderly patients with ruptured aneurysms.
Posterior inferior cerebellar artery; Endovascular; Microsurgery; Thromboembolism
The criteria for the evaluation of spinal impairment are diverse, complex, and have no standardized form. This makes it difficult and somewhat troublesome to accurately evaluate spinal impairment patients. A standardized guideline was studied for the evaluation of spinal impairment, based on the American Medical Association (AMA) Guides and the McBride method. This guideline proposal was developed by specialty medical societies under the Korean Academy of Medical Sciences. In this study, the grades of impairment were assessed by dividing patients into three different categories: spinal cord impairment, spinal injury impairment and spinal disorder impairment. The affected regions of the spine are divided into three: the cervical region, the thoracic region, and the lumbosacral region. The grade of impairment was differentially evaluated according to the affected region. The restricted range of motion was excluded in the evaluation spinal impairment because of low objectivity. Even though the new Korean guideline for the evaluation of spinal impairment has been proposed, it should be continuously supplemented and revised.
Korean Guideline; Spine Impairment; AMA Guides; McBride
We aimed to analyze clinical and radiological outcomes retrospectively in patients with basilar apex aneurysms treated by coiling or clipping.
Outcomes of basilar bifurcation aneurysms were assessed retrospectively in 77 consecutive patients (61 women, 16 men), ranging in age from 25 to 79 years (mean, 53.7 years) from 1999 to 2007.
Forty-nine patients out of 77 patients (63.6%) presented with subarachnoid hemorrhages of the 49 patients treated with coiling, 27 (55.1%) showed complete occlusion of the aneurysm sac. Of these, 13 patients (26.5%) developed coil compaction on angiographic or MRI follow-up, with recoiling required in 9 patients (18.4%). Procedural complications of coiling were acute infarction in nine patients and the bleeding of the aneurysms in six patients. The remaining 28 patients underwent microsurgery: twenty-six of these (92.9%) with microsurgery followed up with conventional angiography. Complete occlusion of the aneurysm sac was achieved in 19 patients (73.1%). Operation-related complications of microsurgery were thalamoperforating artery injuries in three patients, retraction venous injury in two, postoperative epidural hemorrhage (EDH) in one, and transient partial or complete occulomotor palsy in 14 patients. Glasgow Outcome Scores (GOS) were 4 or 5 in 21 of 28 (75%) patients treated with microsurgery at discharge, and at 6 month follow-up, 20 of 28 (70.9%) maintained the same GOS. In comparison, GOS of four or 5 was observed in 36 of 49 (73.5%) patients treated with coiling at discharge and at 6 month follow-up, 33 of 49 patients (67.3%) maintained the GOS from discharge.
Basilar top aneurysms were still challenging lesions based on our series. Endovascular or microsurgery endowed with its inborn risks and procedural complications for the treatment of basilar apex aneurysms individually. Microsurgery provided better outcome in some specific basilar apex aneurysms. For reaching the most favorable outcome, endovascular modality as well as microsurgery was inevitably considered for each specific basilar apex aneurysm.
Aneurysm; Basilar artery; Endovascular; Microsurgery
Direct surgical clipping of paraclinoid aneurysms poses technical challenges to even very experienced neurosurgeons, making endovascular treatment an alternative treatment modality in many centers. We have therefore retrospectively evaluated the safety and efficacy of endovascular detachable coil embolization of paraclinoid aneurysms.
From June 1997 to June 2007, 65 patients underwent endovascular detachable coiling for 67 paraclinoid aneurysms (of which 9 were ruptured and 58 were unruptured) in our institute. Their medical records, radiological images and readings, and operation records were reviewed retrospectively.
After the initial embolization procedure, complete occlusion was achieved in 29 (43.3%) of the aneurysms treated by endovascular detachable coiling. Six aneurysms required retreatment, with two each requiring one, two, or three additional endovascular procedures. Fifty-five (82.1%) aneurysms were measured by three-dimensional time of flight (TOF) magnetic resonance images (MRI) or transfemoral cerebral angiography (TFCA) at a mean follow-up of 29.7 months (range from 4 to 94 months), with 39 aneurysms (70.9%) showing complete occlusion. Thromboembolic events (3.8%) were the most frequent complication. Rupture did not occur during or after any of the procedures. According to the Glasgow Outcome Scale (GOS), 98.4% of the patients treated by coil embolization had a score of 4 or 5.
Our results indicate that endovascular detachable coiling is a safe and effective treatment modality in paraclinoid aneurysms.
Paraclinoid; Aneurysms; Endovascular
We report a case of trigonal cavernous malformation (CM) radiologically mimicking meningioma. The computed tomographic (CT) head angiography and magnetic resonance imaging (MRI) showed a partially calcified lesion with slight contrast enhancement located in the area of the left atrium of lateral ventricle. The lesion was completely removed using microsurgery with a parieto-occipital transcortical approach. The resected mass was histologically confirmed as CM. CM should be considered as differential diagnosis in case of the atrial mass lesion due to lack of hemosiderin ring characteristically seen other seated CM.
Cavernous malformation; Meningioma; Trigone; Atrium
One of the main reasons for the soaring interest in acute ischemic stroke among radiologists is the advent of new magnetic resonance techniques such as diffusion-weighted imaging. This new modality has prompted us to seek a better understanding of the pathophysiologic mechanisms of cerebral ischemia/infarction. The ischemic penumbra is an important concept and tissue region because this is the target of various recanalization treatments during the acute phase of stroke. In this context, it is high time for a thorough review of the concept, especially from the imaging point of view.
Brain blood flow; Brain perfusion; Brain ischemia; Brain MR; Brain PET; Review