1.Mucosa-Associated Lymphoid Tissue Lymphoma of the Cheek Mimicking Benign Entities: a Case Report
Hyun HWANG ; Jae Ho SHIN ; Yon Kwon IHN ; Sungjun HAN ; Hong Sik PARK
Investigative Magnetic Resonance Imaging 2021;25(2):129-134
The prevalence of cheek lymphoma, especially a mucosa-associated lymphoid tissue lymphoma (MALT), is very rare. Non-specific symptoms and image findings of cheek lymphoma may mimic benign entities and make it difficult to diagnose. In this case report, we present a case of MALT lymphoma of the cheek mimicking benign entities on computed tomography and magnetic resonance imaging.
2.Mucosa-Associated Lymphoid Tissue Lymphoma of the Cheek Mimicking Benign Entities: a Case Report
Hyun HWANG ; Jae Ho SHIN ; Yon Kwon IHN ; Sungjun HAN ; Hong Sik PARK
Investigative Magnetic Resonance Imaging 2021;25(2):129-134
The prevalence of cheek lymphoma, especially a mucosa-associated lymphoid tissue lymphoma (MALT), is very rare. Non-specific symptoms and image findings of cheek lymphoma may mimic benign entities and make it difficult to diagnose. In this case report, we present a case of MALT lymphoma of the cheek mimicking benign entities on computed tomography and magnetic resonance imaging.
3.Endovascular Treatment of a Lumbar Spinal Epidural Arteriovenous Fistula with Radiculopathy:A Case Report
Hyun HWANG ; Jae Ho SHIN ; Jae Taek HONG ; Yon Kwon IHN
Journal of the Korean Radiological Society 2021;82(6):1628-1633
Spinal epidural arteriovenous fistulas (SEDAVFs) are rare spinal vascular malformations that are difficult to diagnose and treat. SEDAVFs can be asymptomatic; however, symptoms can arise from the compression of adjacent nerve roots by dilated vein and perimedullary venous reflux, caused by shunting into the epidural venous plexus. A 31-year-old male presented to our institution with a 2-year history of progressively worsening low-back pain, radiating thigh pain, and sensory changes in his lower extremities. MRI and CT angiography demonstrated dilated epidural vascular lesion compressing the nerve root. The SEDAVF was embolized with multiple coils, which alleviated the nerve root compression from the engorged venous varix and improved the patient’s radiculopathy. Our experience from this case shows that endovascular coil embolization using the transarterial approach can be an effective treatment for SEDAVF and an alternative to surgical ligations.
4.Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels
Yon-Kwon IHN ; Bum-soo KIM ; Hae Woong JEONG ; Sang Hyun SUH ; Yoo Dong WON ; Young-Jun LEE ; Dong Joon KIM ; Pyong JEON ; Chang-Woo RYU ; Sang-il SUH ; Dae Seob CHOI ; See Sung CHOI ; Sang Heum KIM ; Jun Soo BYUN ; Jieun RHO ; Yunsun SONG ; Woo Sang JEONG ; Noah HONG ; Sung Hyun BAIK ; Jeong Jin PARK ; Soo Mee LIM ; Jung-Jae KIM ; Woong YOON
Neurointervention 2021;16(3):240-251
Purpose:
To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL).
Materials and Methods:
Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution.
Results:
Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group.
Conclusion
Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.
5.Whirling technique for thyroid fine needle aspiration biopsy: a preliminary study of effectiveness and safety
Jae Ho SHIN ; Seung Wan HAN ; Hyang Lim LEE ; Yon Kwon IHN
Ultrasonography 2021;40(1):147-157
Purpose:
This study was aimed to compare thyroid fine needle aspiration biopsy (FNAB) techniques (conventional vs. whirling) in terms of cell harvesting ability ex vivo, the unsatisfactory rate and complication rate in vivo, and multi-operator performance in a phantom study.
Methods:
In the ex vivo study, cell counts per background at ×100 magnification were compared between both techniques. In the in vivo study, 70 patients who underwent whirling FNAB from July 2019 to November 2019 were retrospectively compared to 140 matched patients who underwent conventional FNAB from January 2018 to November 2019 regarding the unsatisfactory rate and complication rate. As a subgroup analysis, thyroid nodules in difficult biopsy situations (nodule diameter <10 mm and location within 3 mm from major anatomical structures) were compared. In the phantom study, eight operators with varying experience recorded levels of dexterity and needle tip visualization, and their preferences for both techniques.
Results:
In the ex vivo study, cell counts were comparable between both techniques in all thyroid nodule mimickers (80.0% vs. 87.5%, P=0.178). In the in vivo study, the unsatisfactory rate was comparable between the two groups (15.7% vs. 12.9%, P=0.859). In the subgroup analysis, the whirling technique demonstrated a lower unsatisfactory rate (5.9% vs. 24.2%, P=0.045) and a lower complication rate (0% vs. 6.1%, P=0.553). In the phantom study, the whirling technique demonstrated better dexterity and needle tip visualization and was preferred by all operators.
Conclusion
This newly proposed whirling technique for thyroid FNAB may be effective and safe, especially in difficult biopsy situations.
6.Patient Radiation Exposure During Diagnostic and Therapeutic Procedures for Intracranial Aneurysms: A Multicenter Study.
Yon Kwon IHN ; Bum Soo KIM ; Jun Soo BYUN ; Sang Hyun SUH ; Yoo Dong WON ; Deok Hee LEE ; Byung Moon KIM ; Young Soo KIM ; Pyong JEON ; Chang Woo RYU ; Sang Il SUH ; Dae Seob CHOI ; See Sung CHOI ; Jin Wook CHOI ; Hyuk Won CHANG ; Jae Wook LEE ; Sang Heum KIM ; Young Jun LEE ; Shang Hun SHIN ; Soo Mee LIM ; Woong YOON ; Hae Woong JEONG ; Moon Hee HAN
Neurointervention 2016;11(2):78-85
PURPOSE: To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms across multi-centers and propose a diagnostic reference level (DRL). MATERIALS AND METHODS: We studied a sample of 490 diagnostic and 371 therapeutic procedures for intracranial aneurysms, which were performed at 23 hospitals in Korea in 2015. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time and total angiographic image frames were obtained and analyzed. RESULTS: Total mean DAP, CAK, fluoroscopy time, and total angiographic image frames were 106.2 ± 66.4 Gy-cm2, 697.1 ± 473.7 mGy, 9.7 ± 6.5 minutes, 241.5 ± 116.6 frames for diagnostic procedures, 218.8 ± 164.3 Gy-cm², 3365.7 ± 2205.8 mGy, 51.5 ± 31.1 minutes, 443.5 ± 270.7 frames for therapeutic procedures, respectively. For diagnostic procedure, the third quartiles for DRLs were 144.2 Gy-cm² for DAP, 921.1 mGy for CAK, 12.2 minutes for fluoroscopy times and 286.5 for number of image frames, respectively. For therapeutic procedures, the third quartiles for DRLs were 271.0 Gy-cm² for DAP, 4471.3 mGy for CAK, 64.7 minutes for fluoroscopy times and 567.3 for number of image frames, respectively. On average, rotational angiography was used 1.5 ± 0.7 times/session (range, 0-4; n=490) for diagnostic procedures and 1.6 ± 1.2 times/session (range, 0-4; n=368) for therapeutic procedures, respectively. CONCLUSION: Radiation dose as measured by DAP, fluoroscopy time and image frames were lower in our patients compared to another study regarding cerebral angiography, and DAP was lower with fewer angiographic image frames for therapeutic procedures. Proposed DRLs can be used for quality assurance and patient safety in diagnostic and therapeutic procedures.
Angiography
;
Cerebral Angiography
;
Fluoroscopy
;
Humans
;
Intracranial Aneurysm*
;
Korea
;
Patient Safety
;
Radiation Exposure*
7.Patient Radiation Dose in Diagnostic and Interventional Procedures for Intracranial Aneurysms: Experience at a Single Center.
Chang Woo CHUN ; Bum Soo KIM ; Cheol Hyoun LEE ; Yon Kwon IHN ; Yong Sam SHIN
Korean Journal of Radiology 2014;15(6):844-849
OBJECTIVE: To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms in a large sample size from a single center. MATERIALS AND METHODS: We studied a sample of 439 diagnostic and 149 therapeutic procedures for intracranial aneurysms in 480 patients (331 females, 149 males; median age, 57 years; range, 21-88 years), which were performed in 2012 with a biplane unit. Parameters including fluoroscopic time, dose-area product (DAP), and total angiographic image frames were obtained and analyzed. RESULTS: Mean fluoroscopic time, total mean DAP, and total image frames were 12.6 minutes, 136.6 +/- 44.8 Gy-cm2, and 251 +/- 49 frames for diagnostic procedures, 52.9 minutes, 226.0 +/- 129.2 Gy-cm2, and 241 frames for therapeutic procedures, and 52.2 minutes, 334.5 +/- 184.6 Gy-cm2, and 408 frames for when both procedures were performed during the same session. The third quartiles for diagnostic reference levels (DRLs) were 14.0, 61.1, and 66.1 minutes for fluoroscopy time, 154.2, 272.8, and 393.8 Gy-cm2 for DAP, and 272, 276, and 535 for numbers of image frames in diagnostic, therapeutic, and both procedures in the same session, respectively. The proportions of fluoroscopy in DAP for the procedures were 11.4%, 50.5%, and 36.1%, respectively, for the three groups. The mean DAP for each 3-dimensional rotational angiographic acquisition was 19.2 +/- 3.2 Gy-cm2. On average, rotational angiography was used 1.4 +/- 0.6 times/session (range, 1-4; n = 580). CONCLUSION: Radiation dose in our study as measured by DAP, fluoroscopy time and image frames did not differ significantly from other reported DRL studies for cerebral angiography, and DAP was lower with fewer angiographic image frames for embolization. A national registry of radiation-dose data is a necessary next step to refine the dose reference level.
Adult
;
Aged
;
Aged, 80 and over
;
Cerebral Angiography
;
Databases, Factual
;
Embolization, Therapeutic
;
Female
;
Fluoroscopy
;
Humans
;
Intracranial Aneurysm/*diagnosis/*radiotherapy
;
Male
;
Middle Aged
;
Patients
;
Radiation Dosage
;
Retrospective Studies
8.Coil-Protected Embolization Technique for a Branch-Incorporated Aneurysm.
Yon Kwon IHN ; Byung Moon KIM ; Sang Hyun SUH ; Dong Joon KIM ; Dong Ik KIM
Korean Journal of Radiology 2013;14(2):329-336
OBJECTIVE: A small branch-incorporated aneurysm is an aneurysm with a small branch incorporated into the sac or the neck. It is one of the most difficult aneurysms to treat with coil embolization. The aim of this study was to evaluate the safety and effectiveness of the coil-protected embolization technique for small-branch incorporated aneurysm. MATERIALS AND METHODS: Fourteen aneurysms (2 ruptured and 12 unruptured) in 12 patients (mean age, 56 years, range, 40-73 years; 6 men and 6 women) were treated with the coil-protected embolization technique during the period between February 2007 and October 2011. Clinical and angiographic outcomes were retrospectively evaluated. RESULTS: All aneurysms were successfully treated without any complications during the procedure. Immediate post-treatment angiographies demonstrated complete or near complete occlusion in 12 and incomplete occlusion in 2 patients. Two patients had a delayed small embolic infarction in the relevant posterior circulation territory and middle cerebral artery territory 10 days and 14 days later, respectively, but both recovered completely or almost completely (modified Rankin scale score [mRS score], 0 and 1, respectively). During the clinical follow-up period (mean, 21 months; range: 2-58 months), all patients reported an mRS score of 0 (n = 10) or 1 (n = 2). Vascular imaging follow-up (catheter angiography: n = 3 and MR angiography: n = 8) was available in 11 aneurysms at 6-12 months. All 11 aneurysms showed complete occlusion except for 1 minor neck recurrence that did not require further treatment. CONCLUSION: In this series of cases, the coil-protected embolization technique seems to be feasible and effective in the treatment of small-branch incorporated aneurysms.
Adult
;
Aged
;
Aneurysm, Ruptured/diagnosis/*therapy
;
Embolization, Therapeutic/instrumentation/*methods
;
Female
;
Humans
;
Intracranial Aneurysm/diagnosis/*therapy
;
Magnetic Resonance Angiography
;
Male
;
Middle Aged
;
Retrospective Studies
;
Treatment Outcome
9.Transvenous Embolization of Cavernous and Paracavernous Dural Arteriovenous Fistula through the Facial Vein: Report of 12 Cases.
Myeong Jin KIM ; Yong Sam SHIN ; Yon Kwon IHN ; Byung Moon KIM ; Pyeong Ho YOON ; Se Yang OH ; Bum Soo KIM
Neurointervention 2013;8(1):15-22
PURPOSE: The aim of this study was to evaluate the feasibility and safety of the transfacial venous embolization of cavernous or paracavernous dural arteriovenous fistula (DAVF) in which approach via inferior petrosal sinus (IPS) was not feasible. MATERIALS AND METHODS: We identified the cases of transfacial venous embolization of cavernous sinus (CS) or adjacent dural sinuses from the neurointerventional database of three hospitals. The causes and clinical and angiographic outcomes of transfacial venous embolization were retrospectively evaluated. RESULTS: Twelve patients with CS (n = 11) or lesser wing of sphenoid sinus (LWSS, n = 1) DAVF were attempted to treat by transvenous embolization via ipsilateral (n = 10) or contralateral (n = 2) facial vein. Trans-IPS access to the target lesion was impossible due to chronic occlusion (n = 11) or acute angulation adjacent the target lesion (n = 1). In all twelve cases, it was possible to navigate through facial vein, angular vein, superior ophthalmic vein, and then CS. It was also possible to further navigation to contralateral CS through intercavernous sinus in two cases, and laterally into LWSS in one case. Post-treatment control angiography revealed complete occlusion of the DAVF in eleven cases and partial occlusion in one patient, resulting in complete resolution of presenting symptom in eight and gradually clinical improvement in four patients. There was no treatment-related complication during or after the procedure. CONCLUSION: In the cavernous or paracavernous DAVF in which trans-IPS approach is not feasible, the facial vein seems to be safe and effective alternative route for transvenous embolization.
Angiography
;
Arteriovenous Fistula
;
Cavernous Sinus
;
Caves
;
Central Nervous System Vascular Malformations
;
Humans
;
Retrospective Studies
;
Sphenoid Sinus
;
Veins
10.Antegrade Recanalization of Parent Artery after Internal Trapping of Ruptured Vertebral Artery Dissecting Aneurysm.
Yon Kwon IHN ; Jae Hoon SUNG ; Je Hoon BYUN
Journal of Korean Neurosurgical Society 2012;51(5):301-304
We report a patient with a ruptured vertebral artery (VA) dissecting aneurysm that was treated by internal trapping of the aneurysm and parent artery using detachable coils with subsequent antegrade recanalization of occluded vertebral artery during the follow-up period. A 38-year-old man was admitted with a ruptured right VA dissecting aneurysm just distal to origin of right posterior inferior cerebellar artery. The dissected segment of the VA was occluded by coil embolization. The 14 months follow-up angiography showed that dissected aneurysm was completely occluded, but the parent artery was recanalized in an antegrade fashion. Based on this unique case, the authors suggest that careful angiographic follow-up of dissecting aneurysm is required, even in patients successfully treated with endovascular occlusion of the affected artery and aneurysm.
Adult
;
Aneurysm
;
Aneurysm, Dissecting
;
Angiography
;
Arteries
;
Follow-Up Studies
;
Humans
;
Parents
;
Vertebral Artery

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