Birgitta Ramgren

Endovascular Treatment Using Predominantly Stent-Assisted Coil Embolization and Antiplatelet and Anticoagulation Management of Ruptured Blood Blister–Like Aneurysms

BACKGROUND AND PURPOSE: BBA is a rare type of intracranial aneurysm that is difficult to treat both surgically and endovascularly and is often associated with a high degree of morbidity/mortality. The aim of this study was to present clinical and angiographic results, as well as antiplatelet/anticoagulation regimens, of endovascular BBA treatment by using predominantly stent-assisted coil embolization. MATERIALS AND METHODS: Thirteen patients (men/women, 6/7; mean age, 49.3 years) with ruptured BBAs were included from 2 different institutions. Angiographic findings, treatment strategies, anticoagulation/antiplatelet protocols, and clinical (mRS) and angiographic outcome were retrospectively analyzed. RESULTS: Eleven BBAs were located in the supraclinoid ICA, and 2 on the basilar artery trunk. Nine of 13 were ≤3 mm in the largest diameter, and 8/13 showed early growth before treatment. Primary stent-assisted coiling was performed in 11/13 patients, double stents and PAO in 1 patient, each. Early complementary treatment was required in 3 patients, including PAO in 2. In stent-placement procedures, altered periprocedural antiplatelet (11/12) and postprocedural heparin (6/12) protocols were used without evidence of thromboembolic events. Two patients had early rehemorrhage, including 1 major fatal SAH. Twelve of 13 BBAs showed complete or progressive occlusion at late angiographic follow-up. Clinical midterm outcome was good (mRS scores, 0–2) in 12/13 patients. CONCLUSIONS: Stent-assisted coiling of ruptured BBAs is technically challenging but can be done with good midterm results. Reduced periprocedural and postprocedural antiplatelet/anticoagulation protocols may be used with a low reasonable risk of thromboembolic complications. However, regrowth/rerupture remains a problem underlining the importance of early angiographic follow-up and re-treatment, including PAO if necessary.

Impact of coil embolization on overall management and outcome of patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE:We report on the consequences of introducing coil embolization for the total management of and outcome in patients with subarachnoid hemorrhage (SAH). METHODS:In southern Sweden, a prospective analysis of all patients with SAH of verified aneurysmal origin was conducted during the 3 years when coiling was gradually being introduced. The incidence of acute or chronic hydrocephalus, vasospasm, delayed ischemic deterioration, and outcome at 3 to 6 months after bleeding was analyzed. RESULTS:Coiling of aneurysms was used progressively more compared with clipping during the study period. The number of patients subjected to coiling was 26 (36%) of 73 patients during calendar year 1997, 43 (53%) of 81 patients in 1999, and 55 (74%) of 74 patients in 2001 (P < 0.0001). Gradually, more elderly patients were admitted during the study period. Virtually all aneurysms located in the posterior circulation were treated by coil embolization, even at the start of the study, whereas aneurysms at all other locations were progressively more likely to be treated similarly. The incidence of hydrocephalus in the acute (average for all 3 yr, 39%) or chronic (16%) phase, vasospasm as measured by Doppler sonography (33%), and delayed ischemic deterioration (29%), as well as outcome at 3 to 6 months (61% good recovery, 13% deceased), did not change significantly during the study. The main cause of unfavorable outcome was the severity of the SAH. CONCLUSION:The increasing use of coil embolization for ruptured aneurysms in the anterior circulation did not have any significant impact on the overall incidence of SAH-related complications or outcome. The main determinant for outcome after SAH is still the severity of the SAH.

Long-term results after adolescent Blount's disease

A long-term follow-up study was made of 23 patients with an average age of 47 years (range 38-68 years) who had adolescent Blounts disease. Four patients had bilateral disease (27 affected knees). Nine knees had no treatment during childhood, 11 were treated by physiodesis, and seven were treated by osteotomy of the proximal tibia. At follow-up, most of the patients had no pain or mild pain from their knee. Nine knees showed arthrosis. We conclude that most children with adolescent Blounts disease will have a straight leg at middle age without arthrosis and that this result can be obtained in one of four patients without treatment.

CT angiography of intracranial arterial vessels: impact of tube voltage and contrast media concentration on image quality.

Background Computed tomography angiography (CTA) of intracranial arteries has high demands on image quality. Important parameters influencing vessel enhancement are injection rate, concentration of contrast media and tube voltage. Purpose To evaluate the impact of an increase of contrast media concentration from 300 to 400 mg iodine/mL (mgI/mL) and the effect of a decrease of tube voltage from 120 to 90 kVp on vessel attenuation and image quality in CT angiography of intracranial arteries. Material and Methods Sixty-three patients were included into three protocol groups: Group I, 300 mgI/mL 120 kVp; Group II, 400 mgI/mL 120 kVp; Group III, 400 mgI/mL 90 kVp. Hounsfield units (HU) were measured in the internal carotid artery (ICA) and the M1 and M2 segments of the middle cerebral artery. Image quality grading was performed regarding M1 and M2 segments, volume rendering and general image impression. Results The difference in mean HU in ICA concerning the effect of contrast media concentration was statistically significant (P = 0.03) in favor of higher concentration. The difference in ICA enhancement due to the effect of tube voltage was statistically significant (P < 0.01) in favor of lower tube voltage. The increase of contrast medium concentration raised the mean enhancement in ICA with 18% and the decrease of tube voltage raised the mean enhancement with 37%. Image quality grading showed a trend towards improved grading for higher contrast concentration and lower tube voltage. Statistically significant better grading was found for the combined effect of both measures except for general impression (P 0.01–0.05). Conclusion The uses of highly concentrated contrast media and low tube voltage are easily performed measures to improve image quality in CTA of intracranial vessel.

Long-term results after infantile Blount's disease

A long-term follow-up of 49 patients with an average age of 38 years (range: 25–67 years) who had experienced infantile Blounts disease was done. Thirty-seven patients had bilateral disease, giving a total of 86 affected knees. Thirty-eight knees had conservative or no treatment during childhood; 13 were treated by epiphysiodesis, and 35 by osteotomy. At follow-up, 11 knees showed arthrosis, and 9 were graded as mild. Ten knees had been surgically treated by medial meniscectomy at an average age of 29 years (range: 19–45 years), after the diagnosis of Blounts disease. Four of the knees showed arthrosis. Most of the patients had a straight leg and mild or no pain from their knee. It is concluded that most children with infantile Blounts disease will, at the age of 40 years, have a straight leg without arthrosis and that one third can reach this result without any treatment.

Diffusion- and perfusion-weighted MRI in therapeutic neurointerventional procedures

Abstract We describe three patients in whom we used MRI, including diffusion- and perfusion-weighted imaging (DWI, PWI) in conjunction with endovascular therapy. Two had intracranial aneurysms and one an arteriovenous malformation (AVM). The aneurysms were treated by coil embolisation or detachable balloons for proximal artery occlusion; the AVM was obliterated by intranidal glue injection. All patients had transient or permanent neurological deficits after treatment. The MRI techniques and interventional procedures are described and the DWI and PWI patterns found are correlated with the clinical features. We discuss how the information gained from MRI may increase our understanding of procedure-related complications and its potential impact on our therapeutic interventions, in order to prevent or limit the clinical consequences of such events.

Hybrid Iterative Reconstruction Algorithm Improves Image Quality in Craniocervical CT Angiography

OBJECTIVE The purpose of this study was to evaluate the potential of a hybrid iterative reconstruction algorithm for improving image quality in craniocervical CT angiography (CTA) and to assess observer performance. SUBJECTS AND METHODS Thirty patients (mean age, 58 years; range 16-80 years) underwent standard craniocervical CTA (volume CT dose index, 6.8 mGy, 2.8 mSv). Images were reconstructed using both filtered back projection (FBP) and a hybrid iterative reconstruction algorithm. Five neuroradiologists assessed general image quality and delineation of the vessel lumen in seven arterial segments using a 4-grade scale. Interobserver and intraobserver variability were determined. Mean attenuation and noise were measured and signal-to-noise and contrast-to-noise ratios calculated. Descriptive statistics are presented and data analyzed using linear mixed-effects models. RESULTS In pooled data, image quality in iterative reconstruction was graded superior to FBP regarding all five quality criteria (p < 0.0001), with the greatest improvement observed in the vertebral arteries. Iterative reconstruction resulted in elimination of arterial segments graded poor. Interobserver percentage agreement was significantly better (p = 0.024) for iterative reconstruction (69%) than for FBP (66%) but worse than intraobserver percentage agreement (mean, 79%). Noise levels, signal-to-noise ratio, and contrast-to-noise ratio were significantly (p < 0.001) improved in iterative reconstruction at all measured levels. CONCLUSION The iterative reconstruction algorithm significantly improves image quality in craniocervical CT, especially at the thoracic inlet. Despite careful study design, considerable interobserver and intraobserver variability was noted.

Metaphyseal-diaphyseal angle in Blount's disease: A 30-year follow-up of 13 unoperated children

We analyzed the metaphyseal-diaphyseal angle in 13 patients with infantile Blounts disease, who had been followed without treatment during the entire growth period and without any form of realignment procedure in adulthood. On diagnosis at 23 (17-35) months of age, the metaphyseal-diaphyseal angle varied between 7 degrees and 25 degrees. At follow-up, most of the legs were almost straight. We found that the diagnosis of Blounts disease cannot be based solely on the metaphyseal-diaphyseal angle and that a bowed knee must be followed with repeated examinations before it can be decided whether treatment is needed.

CT angiography in non-traumatic subarachnoid hemorrhage: the importance of arterial attenuation for the detection of intracranial aneurysms.

Background Computed tomography angiography (CTA) is today the primary method for the detection of intracranial aneurysms. The technique has evolved considerably during the last decade, and it is important to establish criteria for high image quality, especially with regard to improving the diagnosis of small aneurysms. Purpose To evaluate diagnostic accuracy and image quality by arterial attenuation of CTA in patients with non-traumatic subarachnoid hemorrhage (SAH). Material and Methods Between 2005 and 2011, CTA and digital subtraction angiography (DSA) were performed in 326 patients with non-traumatic SAH. Sensitivity and specificity for aneurysm detection were evaluated per patient, per aneurysm, and per ruptured aneurysm. The image quality of CTA was evaluated by arterial attenuation measurements (mean Hounsfield units [HU]) in the internal carotid artery (ICA). Results In all, 285 aneurysms in 235 patients were detected by DSA, 19 aneurysms were missed on CTA, and 223 aneurysms were classified as ruptured. In 91 patients, no aneurysm was found. Correct diagnosis with CTA was made in 28 patients with perimesencephalic hemorrhage. Sensitivity and specificity (95% confidence interval) calculated per patient were 91.6% (87.3–94.9) and 87.9% (79.8–93.6), respectively, per aneurysm 93.3% (89.7–95.9) and 88% (79.9–93.6), and per ruptured aneurysm 94.9% (91.3–97.3) and 96.7% (90.7–99.3). Arterial attenuation (in HU) in CTA revealing true positive ruptured aneurysms and true negative aneurysms (mean 535 ± 110 HU) differed significantly (P = 0.02) from false negative ruptured aneurysms (mean 424 ± 30 HU). Conclusion CTA has high sensitivity and specificity for the detection of ruptured aneurysms. The sensitivity is related to arterial attenuation in the ICA.

Cerebral perfusion imaging in hemodynamic stroke: be aware of the pattern.

Reduction of the cerebral perfusion pressure caused by vessel occlusion or stenosis is a cause of neurological symptoms and border-zone infarctions. The aim of this article is to describe perfusion patterns in hemodynamic stroke, to give a practical approach for the assessment of colour encoded CT- and MR-perfusion maps and to demonstrate the clinical use of comprehensive imaging in the workup of patients with hemodynamic stroke. Five patients with different duration cause and degree of hemodynamic stroke were selected. The patients shared the typical presentation with fluctuating and transient symptoms. All were examined by MR or CT angiography and MR or CT perfusion in the symptomatic phase. All patients were examined with diffusion weighted imaging. All five cases showed the altered perfusion patterns of hemodynamic insufficiency with a slight or marked increase in CBV in the supply area of the affected vessel and only slightly reduced or maintained CBF. The perfusion disturbances were most easily detected on the MTT maps. Border-zone infarctions were seen in all cases. The typical pattern for hemodynamic insufficiency is characterized by increased CBV, normal or decreased CBF and prolonged MTT in the affected areas. The increased CBV is the hallmark of stressed autoregulation. Reading the color-encoded perfusion maps enables a quick and robust assessment of the cerebral perfusion and its characteristic patterns. Internal border-zone infarctions can be regarded as a marker for hemodynamic insufficiency. Finding of the typical rosary-like pattern of DWI lesions should call for further work up.