Biomedical subjects

Moon Hee Han

Publications and source records attributed to Moon Hee Han.

At least 19 recordsLinked to original sources

PubMed2006

Coil embolization of "kissing aneurysms" associated with distal basilar artery fenestration.

The authors present an extremely rare case of kissing aneurysms associated with fenestration of the distal basilar artery. The two aneurysms were successfully treated with endovascular coil embolization. We provide two-dimensional (2D) and three-dimensional (3D) angiographic features of the kissing aneurysms, and procedural details of coil embolization. To the best of our knowledge, this is the first demonstration of kissing aneurysms at the fenestrated distal basilar artery.

Angiography, Digital Subtraction↗

PubMed2006

Cervical lymph node metastases: MR imaging of gadofluorine M and monocrystalline iron oxide nanoparticle-47 in a rabbit model of head and neck cancer.

PURPOSE: To prospectively compare the accuracy of gadofluorine M with that of monocrystalline iron oxide nanoparticle (MION)-47 for the depiction of cervical lymph node metastases at magnetic resonance (MR) imaging in a rabbit model of head and neck cancer by using histologic analysis as the reference standard. MATERIALS AND METHODS: Experiments were approved by the animal care committee. VX2 carcinomas were implanted in both ears of 11 rabbits 4 weeks before MR imaging. T2-weighted, T2*-weighted, and T1-weighted MR images were acquired, and sequential T1-weighted MR imaging was performed immediately and 30 minutes after administration of gadofluorine M (0.05 mmol gadolinium per kilogram body weight). T2-weighted and T2*-weighted MR imaging were performed 24 hours after administration of MION-47 (2.6 mg iron per kilogram body weight). Gadofluorine M- and MION-47-enhanced MR imaging were performed separately and independently by two radiologists who had no knowledge of histopathologic results, and the presence of metastases in lymph nodes was evaluated. A receiver operating characteristic analysis was conducted to compare the diagnostic value of gadofluorine M- and MION-47-enhanced MR imaging. RESULTS: Metastases were confirmed in 20 of 77 lymph nodes at histopathologic analysis. The area under the curve was significantly greater for gadofluorine M-enhanced MR imaging (0.997 and 0.981 for readers 1 and 2, respectively) than for MION-47-enhanced MR imaging (0.889 and 0.846 for readers 1 and 2, respectively). For gadofluorine M-enhanced MR imaging, sensitivity was 100% for both readers and specificity was 89.5% for reader 1 and 87.7% for reader 2. For MION-47-enhanced MR imaging, sensitivity was 80.0% for both readers and specificity was 75.4% for reader 1 and 71.9% for reader 2. CONCLUSION: Gadofluorine M-enhanced MR imaging has higher accuracy for depicting lymph node metastases than does MION-47-enhanced MR imaging.

Animals↗

PubMed2006

Repeat endovascular treatment in post-embolization recurrent intracranial aneurysms.

OBJECTIVE: The purpose of this study was to describe clinical situations requiring repeat embolization in patients previously treated by endovascular coil embolization for intracranial aneurysms, and to report on our experiences of repeat embolization (RE). METHODS: A total of 466 patients harboring 522 intracranial aneurysms were treated by endovascular coil embolization at our institution during the period between December 1992 and August 2004. We studied 32 patients who underwent repeat coil embolization (RE) owing to recanalization or aneurysm recurrence. Radiological and clinical data were reviewed to determine the reasons, results, and technical problems of RE. RESULTS: Thirty-nine sessions of RE were performed in 32 patients; four patients underwent RE twice and another patient three times. The major reason for RE was asymptomatic aneurysmal recanalization owing to coil compaction and/or loosening. The time interval between RE and the previous embolization was 12 months or less in 27 sessions. Complete or near complete occlusion of the aneurysm was achieved in all cases without procedure-related morbidity or mortality. Radiolucent gaps between the coil masses were observed in 17 cases. CONCLUSION: RE is a safe and effective treatment option in cases of recanalized or recurrent aneurysms. Close follow-up evaluation is essential in patients with intracranial aneurysms after coil embolization.

Adult↗

PubMed2006

Protection filter-related events in extracranial carotid artery stenting: a single-center experience.

PURPOSE: To report the complications, rescue procedures, and consequences related to the use of an embolus protection filter during carotid artery stenting (CAS). METHODS: A retrospective review was undertaken of 72 patients (58 men; mean age 70.0+/-8.2 years, range 56-87) with extracranial atherosclerotic carotid stenosis who underwent 77 CAS procedures under filter protection. Filter-related events and rescue procedures according to each procedural step were retrospectively evaluated on CAS angiograms. In addition, neurological events and outcomes were also assessed. RESULTS: CAS using a filter was successful in 99% of cases, and the overall rate of minor stroke (n=1), major stroke (0), or mortality (n=1) was 2.6% at 30 days. Filter placement was successful in all cases. However, arterial tortuosity made it difficult for a filter to pass through the stenosis in 1 case; this was overcome with an additional supportive wire (0.018-inch). Filter-related events were flow impairment in 6 (7.8%), filter wedging in the catheter tip in 4 (5.2%), vasospasm >50% narrowing in 7 (9.1%), filling defects within the filter membrane in 5 (6.5%), retrieval failure with the provided retriever in 3 (3.9%), and insecure retrieval without filter collapse in 2 (2.6%). Flow impairment caused drowsy mentality and impaired verbal response in 4, which resolved after prompt filter retrieval. All the cases of filter wedging were resolved with a catheter pulled down into the stented segment to separate the filter element from the catheter tip. Significant vasospasm and filling defects were spontaneously resolved in all cases after filter retrieval. Inability to pass a retriever catheter through a stent was overcome with curved 5-F catheter manipulation in all 3 cases. CONCLUSION: The use of a filter during CAS may induce various angiographic or technical events at each step. For a severely stenotic and tortuous carotid lesion with difficult access, a filter may become trapped or irretrievable during flow arrest. Physicians should be aware of the preventive and rescue maneuvers to counter filter-related events, perhaps even considering another type of protection mechanism or carotid endarterectomy.

Aged↗

PubMed2005

Endovascular occlusion of direct carotid cavernous fistula with detachable balloons: usefulness of 3D angiography.

The objective of this study is to show rotational 3D angiography findings and their usefulness in the occlusion of carotid cavernous fistulas (CCFs) using detachable balloons. Five patients with direct CCF were retrospectively reviewed for details of interventional procedures and 2D and 3D angiography findings. Pretherapeutic 2D and 3D angiograms (n=2) were compared to evaluate the size of the fistula and the relative size of the cavernous sinus with respect to the fistula. Postinflation-predetachment (n=3) and postdetachment (n=4) 2D and 3D angiograms were compared in each stage to evaluate the relative location of the balloon to the internal carotid artery (ICA), presence of a pseudoaneurysm, and relative size of the balloon to the fistula. Pretherapeutic 2D and 3D angiograms were equally effective in showing the fistula and relative size of the cavernous sinus. But, 3D angiography with "cut images" at arbitrary viewing angles clearly visualized the 3D relations between the ICA, fistula, and cavernous sinus. Both postinflation-predetachment 2D and 3D images in two patients equally showed a contrast-filled pseudoaneurysm outside the ICA and intraluminal location of the balloon. However, only the 3D images showed no difference in size of the balloon compared with the fistula, which was relevant to traction-induced instability in the remaining one patient. Both postdetachment 2D and 3D angiograms were equal in terms of showing ICA compromise (60%) in one patient and an extraluminal balloon location with complete fistular occlusion in two patients. In the remainder, a small pseudoaneurysm was identified only on 3D images. Three-dimensional angiography is a useful imaging tool for capturing the complex perifistular anatomy in the pretherapeutic stage, and for providing detailed information about the degree of balloon inflation and its location, the presence of a pseudoaneurysm, and the expected traction-induced instability in the predetachment stage. Postinflation-predetachment 3D angiography may therefore offer a chance to correct an erroneous manipulation that would otherwise lead to an incomplete procedural outcome and disastrous balloon migration.

Adult↗

PubMed2005

Treatment of spinal cord perimedullary arteriovenous fistula: embolization versus surgery.

OBJECTIVE: To provide the optimal treatment strategy for perimedullary arteriovenous fistula (PMAVF). METHODS: Nineteen patients with PMAVF (Type IVa in 9 patients, Type IVb in 6, and Type IVc in 4) were treated at Seoul National University Hospital between January 1988 and March 2001. Their mean age was 28 years (range, 6-52 yr), and the male-to-female ratio was 1.7:1. The mean follow-up period was 20 months (range, 2-55 mo). Most patients presented with symptoms of slowly progressive myelopathy (13 patients). On spinal angiography, all but 2 showed fistula at the level of the conus medullaris. The feeder was the anterior spinal artery and/or the posterior spinal artery in 14 patients and the posterior spinal artery in 5. All patients underwent endovascular or surgical treatment. RESULTS: With endovascular treatment (11 patients; IVa, n = 5; IVb, n = 2; IVc, n = 4), complete angiographic obliteration of fistula was performed in 5 and partial obliteration in 4 (IVa, n = 1; IVb, n = 2; IVc, n = 1). Symptomatic improvement or arrest of progression was achieved in 5 of 9 patients with complete or partial occlusion. Embolization failed in two (IVa, n = 1; IVc, n = 1). With surgery (10 patients [IVa, n = 6; IVb, n = 4], including 2 patients with partial or failed embolization), most (9 of 10) were improved or stable. CONCLUSION: Good results were achieved with surgery for Types IVa and IVb PMAVF located at the level of the conus medullaris. For Type IVc PMAVF, a fistula located on the ventral side of the spinal cord or above the conus medullaris, endovascular treatment might be considered. Because of rapidly evolving endovascular techniques, however, further studies are warranted.

Adolescent↗

PubMed2005

Cerebellopontomandibular vascular malformation: a rare type of cerebrofacial arteriovenous metameric syndrome. Case report.

The concept of a cerebrofacial arteriovenous metameric syndrome (CAMS) recently has been posited. A 22-year-old woman presented with gait ataxia. She had unilateral angiomatous lesions involving the lower face, the auricle, and the retromastoid area, as well as the tongue on the right side. Angiography revealed the presence of extensive arteriovenous malformations (AVMs) in the ipsilateral cerebellum and pons, in addition to those located in the facial region. The authors report a case of multiple AVMs of the face, cerebellum, and pons, corresponding to CAMS Type 3, and include a review of the literature.

Adult↗

PubMed2005

MR imaging findings of uveal leiomyoma: three cases.

Leiomyoma is a rare tumor arising from the uveal tract. Fundoscopically, it appears as a yellowish-white, elevated mass and cannot be readily distinguished from melanoma or other uveal tumors. Cross-sectional imaging may have an important role, particularly when the opaque ocular media or a vitreous hemorrhage precludes a clear ophthalmoscopic view. In this respect, radiologists should be aware of suggestive findings of uveal leiomyoma to avoid an incorrect diagnosis and unnecessary radical surgery. We report MR imaging findings of three cases of uveal leiomyoma.

Adult↗

PubMed2005

Evaluation of the lenticulostriate arteries with rotational angiography and 3D reconstruction.

BACKGROUND AND PURPOSE: Anatomic evaluation of the lenticulostriate arteries (LSAs) is important, especially in cases of surgical or endovascular treatment, but biplanar angiography provides limited information. We analyzed the LSAs with rotational angiography (RA) and 3D reconstruction and compared the findings with those of previous autopsy studies. METHODS: We retrospectively reviewed the LSAs on 3D reconstructed RA images (200 sides in 159 cases) to analyze their origin, course, and supplying territories. The angiographic configurations of the LSAs were classified by using the scheme devised by Yasargil. RESULTS: LSAs from the anterior cerebral artery were demonstrated on 140 sides (70%). They originated from the A1 segment in 59 sides, from the A1-A2 junction on 41 sides, and from the A2 segment on 35 sides. They arose as a single trunk and ended as the most medial and anterior perforators in most cases. Arteries from the middle cerebral artery (MCA) were demonstrated on 190 sides (95%). They originated from the M1 segment on 131 sides, from the MCA bifurcation on 26 sides, and from the M2 segment on 33 sides; notably, all LSAs arising from the M2 segment originated from the superior division. In terms of configuration, we identified four major and 11 minor types. The most frequent LSA type was the combination of medial and lateral distal striate arteries, which comprised 53 sides (28%). CONCLUSION: Analysis of LSAs with RA and 3D reconstructed images may provide useful information in patients with cerebrovascular diseases, especially before surgical and endovascular treatment.

Adolescent↗

PubMed2005

Endovascular treatment of wide-necked aneurysms by using two microcatheters: techniques and outcomes in 25 patients.

BACKGROUND AND PURPOSE: The endovascular occlusion of aneurysms with unfavorable configurations such as a broad neck and an important branch from the fundus remains a technical challenge. The purpose of this study was to evaluate the radiologic and clinical results of complicated aneurysm treatment by using two microcatheters. METHODS: Twenty-five aneurysms in 25 patients were treated by using two microcatheters, from August 2001 to February 2004. Fourteen patients presented with a subarachnoid hemorrhage (SAH) and 11 had unruptured aneurysms. The aneurysms were of the basilar top (7), middle cerebral artery bifurcation (4), posterior communicating artery (4), anterior communicating artery (3), superior cerebellar artery (2), ophthalmic artery (2), and one aneurysm of each of cavernous internal carotid artery (ICA), dorsal ICA, and midbasilar artery. In 16 aneurysms (64%), the width of the aneurysm was the same or longer than the height. In 19 (76%), important branches arose from the aneurysm base, and some were even incorporated with the aneurysm fundus. The mean dome (height)-to-neck ratio was 1.23 +/- 0.37 (range, 0.65-2.33), and this was greater than or equal to 1.0 in 19 aneurysms (76%). RESULTS: All aneurysms were successfully embolized. Immediate postembolization angiography showed no residual contrast filling in eight aneurysms (32%), and some residual contrast filling in 16. The aneurysm remnants, however, were intentionally left to preserve important branches in 12 of the 16 aneurysms with incomplete occlusion. Two complications occurred, including one thromboembolic and one coil protrusion, but they were successfully resolved and produced no clinical symptoms. All patients except one showed excellent clinical outcomes. One patient revealed moderate cognitive dysfunction. During the follow-up period, no new bleeding occurred. CONCLUSION: Our experience with 25 cerebral aneurysm patients shows that the technique of using two microcatheters is feasible and safe for coil embolization of aneurysms with unfavorable configurations. Although the lack of angiographic follow-up prevents us from drawing conclusions about its effectiveness as compared with other techniques such as stent placement and balloon-neck protection, we believe that this technique offers a reliable alternative for endovascular therapy of complicated aneurysms.

Adult↗

PubMed2005

Short-term outcome of intracranial aneurysms treated with polyglycolic acid/lactide copolymer-coated coils compared to historical controls treated with bare platinum coils: a single-center experience.

BACKGROUND AND PURPOSE: Aneurysm recanalization is an innate problem in endovascular treatment of aneurysms with coils. A coated coil system, covered with a bioabsorbable polymeric material (polyglycolic acid/lactide copolymer, PGLA), was developed to accelerate intra-aneurysmal clot organization and fibrosis. The purpose of this study was to evaluate the efficacy and safety of the PGLA-coated coils in patients with intracranial aneurysms and to compare the outcome with that of bare platinum coils. PATIENTS AND TECHNIQUES: Fifty-one patients harboring 56 intracranial aneurysms underwent endovascular embolization with the PGLA-coated coils. In the control group were 78 consecutive patients, harboring 87 aneurysms, who underwent coil embolization with bare platinum coils. The authors compared coil volume, packing attenuation, degree of occlusion of aneurysms, procedure-related complications, and follow-up results between the 2 groups. RESULTS: The PGLA-coil group showed comparable data regarding rate of total or near-total occlusion of the aneurysm, incidence procedure-related thromboembolism, and management outcome. Mean coil volume deployed and packing attenuation of the PGLA-coil group were significantly higher than those of the bare-coil group (P = .0026 and P < .0001, respectively). Radiologic follow-up evaluation revealed recanalization in 14 of 39 aneurysms (major recanalization in 5 [13%] and minor recanalization in 9 [23%]) among the PGLA-coil group and in 29 of 64 aneurysms (major recanalization in 9 [14%] and minor recanalization in 20 [31%]) among the bare-coil group. CONCLUSION: In this study, the incidence of recanalization was not different in aneurysms treated with PGLA-coated coils compared with historical controls treated with bare platinum coils.

Adult↗

PubMed2004

Sclerotherapy for congenital lesions in the head and neck.

OBJECTIVES: This study retrospectively reviews the results of sclerotherapy using several sclerosants for congenital lesions of the head and neck. METHODS AND PATIENTS: Between May 1990 and May 2002, patients with lymphatic malformations were treated by sclerotherapy; 10 with bleomycin, and 25 with OK-432. OK-432 sclerotherapy was also applied in 9 patients with plunging ranula and in 1 patient with branchial anomaly. Percutaneous sclerotherapy with ethanolamine oleate was used in 29 patients with venous malformations, and 28 patients with pyriform sinus fistula were treated by trichloroacetic acid chemocauterization. RESULTS: Overall, two thirds of patients with these lesions showed marked to complete response. One case of mortality occurred in the bleomycin sclerotherapy group. However, no major complications by other sclerosants were found. In lymphatic malformations, history of excision before sclerotherapy was a poor prognostic factor. CONCLUSION: Sclerotherapy using these sclerosants is a safe and effective primary treatment for congenital lesions in the head and neck.

Adolescent↗

PubMed2004

Pigmented villonodular synovitis of the temporomandibular joint: MR findings in four cases.

OBJECTIVE: Although it is a rare condition, pigmented villonodular synovitis (PVNS) may involve temporomandibular joint (TMJ). The purpose of this study was to describe magnetic resonance (MR) findings of PVNS of the TMJ. METHODS AND MATERIAL: Between April 1992 and August 2000, four patients (two men and two women, 22-58-year-old) who had histologically proven diagnoses of PVNS in their TMJ were found in our institution. Their MR findings were reviewed retrospectively, and were correlated with pathologic findings. RESULTS: In all four patients, MR images invariably showed profound hypointensity on both T1- and T2-weighted sequences. This finding was seen diffusely and homogeneously throughout the lesion, and was considered to be due to paramagnetic effect attributed to heavy hemosiderin pigmentation, which was revealed by histopathological examination. MR images also showed aggressive nature of the lesions with adjacent skull base destruction and intracranial extension in two of them. CONCLUSION: As is the case in the other anatomic site, PVNS of the TMJ can be confidently diagnosed on MR imaging on the basis of the presence of hemosiderin. MR imaging also plays a pivotal role in surgical planning by precise and detailed localization of the lesion.

Adult↗

PubMed2004

Volumetric investigation of the frontal-subcortical circuitry in patients with obsessive-compulsive disorder.

The pathophysiology of obsessive-compulsive disorder (OCD) is thought to involve disturbance of the frontal-subcortical circuitry. To investigate the morphological characteristics of this circuitry, we examined the volume of the orbitofrontal cortex, anterior cingulate, thalamus, caudate, and the putamen in 36 age- and sex-matched OCD patients and normal control subjects using three-dimensional magnetic resonance (MR) brain imaging. The left orbitofrontal volumes were found to be significantly smaller in the OCD patients and showed significant negative correlations with obsessive-compulsive symptom severity. These findings suggest that a structural abnormality of this brain region is implicated in the pathophysiology of OCD.

Adult↗

PubMed2004

Postoperative 3D angiography in intracranial aneurysms.

BACKGROUND AND PURPOSE: Postsurgical evaluation of patients with intracranial aneurysms is important because there is a risk of regrowth and subarachnoid hemorrhage from residual aneurysms. We assessed the role and value of 3D angiography in this evaluation. METHODS: Images from both 3D angiography and digital subtraction angiography (DSA) were preoperatively obtained in 71 consecutive patients with 88 intracranial clipped aneurysms. We analyzed the incidence of postoperative residual aneurysms and compared the 3D angiographic and DSA images in these patients. RESULTS: With 3D angiography, 37 residual aneurysms were found among 88 clipped aneurysms. These comprised 12 large residual necks and 25 small, dog-eared remnants. DSA demonstrated 12 large, residual necks and only six small, dog-eared remnants. 3D angiography also demonstrated the clips, aneurysms, and parent arteries simultaneously, enabling us to appreciate the clip-aneurysm configuration completely. CONCLUSION: 3D angiography allowed us to detect more residual aneurysms after surgical clip placement than did conventional DSA, although none of those detected on only 3D angiography were judged to require additional treatment. 3D angiography may provide baseline data for the long-term follow-up of postsurgical aneurysms.

Adult↗

PubMed2003

Posterior fossa hemorrhage caused by dural arteriovenous fistula: case reports.

BACKGROUND: Relatively few reports are available on dural arteriovenous fistulas (AVFs) accompanied by posterior fossa hemorrhage. We now report upon two such cases and discuss the differential diagnosis and imaging findings. CASE DESCRIPTION: A 36-year-old man was admitted after experiencing sudden headache. Computerized tomography (CT) showed vermian and fourth ventricular hematoma, and magnetic resonance imaging (MRI) revealed an abnormal signal void. Angiography demonstrated a dural AVF in the region of foramen magnum. The second case, a 57-year-old man, was also admitted for the evaluation of headache. CT scan revealed tentorial subdural, subarachnoid and vermian hemorrhage. MRI showed vermian hematoma and an abnormal signal void below the tentorium. Angiography demonstrated a dural AVF in the tentorium. The first case underwent transarterial embolization, after which the dural AVF disappeared completely. The second case underwent craniotomy immediately after failure of endovascular therapy. Postoperative angiography demonstrated no remaining dural AVF. CONCLUSIONS: Dural AVF should be considered as a causative lesion in cases with posterior fossa hemorrhage with no other definitive cause.

Adult↗

PubMed2003

Primary thyroid lymphoma: CT findings.

INTRODUCTION: To evaluate the computed tomographic (CT) findings of primary thyroid lymphoma. METHODS AND MATERIAL: The clinicopathological data and CT images of nine patients with primary thyroid lymphoma were retrospectively reviewed. The CT appearances were classified into three types: type 1, a solitary nodule surrounded by normal thyroid tissue; type 2, multiple nodules in the thyroid, and type 3, a homogeneously enlarged both thyroid glands with a reduced attenuation with or without peripheral thin hyperattenuating thyroid tissue. RESULTS: All patients had a rapidly enlarging thyroid mass and coexistent Hashimoto's thyroiditis. One patient showed type 1 pattern, three type 2, and five type 3. Six patients had homogeneous tumor isoattenuating to surrounding muscles. The tumors had a strong tendency to compress normal remnant thyroid and the surrounding structure without invasion. CONCLUSION: Primary thyroid lymphoma should be included in the differential diagnosis when old female had a homogeneous thyroidal mass isoattenuating to muscles, which does not invade surrounding structures.

Aged↗

PubMed2003

Vascular responses in normal canine carotid arteries: comparison between various self-expanding stents of the same unconstrained size.

RATIONALE AND OBJECTIVES: To compare long-term vascular responses upon the insertion of various self-expandable stents, all the same unconstrained size, in canine carotid artery models. MATERIALS AND METHODS: Twenty-two stents (5 SMARTs, 5 Wallstents, 6 Niti-Ss, 6 Niti-Ds) of the same unconstrained size (6 mm in diameter, 20 mm in length) were endovascularly placed in canine common carotid arteries. The luminal changes were measured on three occasions, on prestenting, immediate poststenting, and angiograms taken before specimens were killed. After en-bloc harvest of the stented carotid arteries at 6 months, the intraluminal surface was evaluated by gross observation and scanning electron microscopy (SEM). Neointimal thickness was measured at several points both over the wire and between the wires. RESULTS: Niti-D was excluded from analysis because of high rate of poststenting occlusion. SMART stent showed the greatest expansibility with average initial luminal gain ( < 0.05) of 21.2% (Niti-S: 16.5%, Wallstent: 12.9%). At 6 months follow-up, the dilated arterial lumen had returned almost to the prestenting caliber without any significant differences among the stent types ( > 0.05). The thickness of neointimal coverage was more prominent with SMART stent (354 microm over the wire and 258 microm between the wires) than Niti-S (228 microm and 83 microm) or Wallstent (187 microm and 78 microm). CONCLUSION: Stent types with its higher initial luminal gain appeared to be associated with thicker neointimal formation at 6 months. The acute expanding force of a self-expanding stent may be the key to the cause of neointimal hyperplasia. Regardless of the inserted stent type, the variations in neointimal response were offset by luminal gains of varying degree, thus preserving the arterial patency almost to the prestenting size.

Analysis of Variance↗