MR Features of Juxta-Articular Venous Malformations of the Knee to Predict the Clinical Outcome of Sclerotherapy

PurposeTo analyze and correlate preinterventional magnetic resonance (MR) imaging findings with clinical symptoms after percutaneous sclerotherapy of venous malformations (VMs) adjacent to the knee.Materials and MethodsTwenty-five patients (mean age, 24 y; range, 7–55 y; 11 female) with 26 VMs adjacent to the knee undergoing sclerotherapy (direct puncture, diagnostic angiography, sclerosant injection) were identified, and MR imaging findings were analyzed. The VM involved the synovium of the knee joint in 19 of 26 cases (76%). These lesions were associated with joint effusion (3 of 19; 16%), hemarthrosis (4 of 19; 21%), or synovial thickening (16 of 19; 84%). Follow-up ended 6–8 weeks after the first or second sclerotherapy session if complete pain relief was achieved or 3 months after the third sclerotherapy session. Treatment outcomes were categorized as symptom improvement (complete or partial pain relief) or poor response (unchanged or increased pain).ResultsForty-nine percutaneous sclerotherapy sessions were performed. Despite the absence of signs of knee osteoarthritis, patients with a VM involving the synovium (8 of 14; 57%) showed a poor response to sclerotherapy (1 of 8 [13%] pain-free after 1 sclerotherapy session). Among patients with VMs with no associated joint alteration and no synovial involvement (6 of 14; 43%), 5 of 6 (83%) showed improvement of symptoms after 1 sclerotherapy session (P < .05).ConclusionsJuxta-articular VMs of the knee are frequently associated with hemarthrosis and synovial thickening. Patients with signs of osteoarthritis and synovial involvement of the VM on presclerotherapy MR imaging deserve special consideration, as these findings predict worse clinical symptoms after sclerotherapy.     

MRI-guided percutaneous sclerotherapy of venous malformations: initial clinical experience using a 3T MRI system

PurposeVenous malformations (VMs) are low-flow vascular anomalies that are commonly treated with image-guided percutaneous sclerotherapy. Although many VMs can be safely accessed and treated using ultrasonography and fluoroscopy, some lesions may be better treated with magnetic resonance imaging (MRI)–guided sclerotherapy. The aim of this study is to evaluate the feasibility, efficiency, and outcomes of MRI-guided sclerotherapy of VMs using a 3T MRI system.MethodsSix patients with VMs in the neck (n = 2), chest (n = 1), and extremities (n = 3) underwent sclerotherapy with 3T MRI guidance. Feasibility was assessed by calculating the technical success rate and procedural efficiency. Efficiency was evaluated by using planning, targeting, intervention, and total procedure times. Outcomes were assessed by measuring VM volumes before and after sclerotherapy, patient-reported pain scores, and occurrence of complications.ResultsTechnical success was achieved in all 6 procedures. There was a non-significant 30% decrease in mean VM volume after the procedure (P = .350). The procedure resulted in a decrease in mean pain score (on an 11-point scale) of 2.6 points (P = .003). After the procedure, 4 patients reported complete pain resolution, 1 reported partial pain resolution, and 1 reported no change in pain. Procedural efficiency was consistent with similar sclerotherapy procedures performed at our institution. There were no major or minor complications.Conclusion3T MRI guidance is feasible for percutaneous sclerotherapy of VMs, with promising initial technical success rates, procedural efficiency, and therapeutic outcomes without complications.     

Percutaneous ethanol sclerotherapy of venous malformations of the tongue

BACKGROUND AND PURPOSE: Percutaneous ethanol sclerotherapy has been reported to be efficacious for head and neck venous malformations. We sought to evaluate the safety and efficacy of percutaneous sclerotherapy by using ethanol for treatment of symptomatic venous malformations of the tongue. METHODS: Eleven sclerotherapy procedures were performed in seven patients from January 1995 to February 2001. Patient age ranged from 19 months to 57 years (mean age, 32 years). Four patients were male and three were female. Mean follow-up was 36 months. The volume of ethanol used per treatment session ranged from 2 to 32 cc (mean, 16 cc). RESULTS: Sclerotherapy provided significant improvement or resolution of symptoms for all patients. There were no major complications. One patient had a small (3 x 2 cm) area of skin blistering at the injection site. All patients experienced pain and swelling to a variable degree. Sclerotherapy resulted in resolution of symptoms in six of seven patients. Three patients had resolution of symptoms after one procedure. Four patients each underwent two sclerotherapy procedures. One patient who remained symptomatic but improved after undergoing two procedures underwent an anterior glossectomy and is now asymptomatic. CONCLUSION: Percutaneous ethanol sclerotherapy is a safe and effective method of treating symptomatic venous malformations of the tongue.     

Polidocanol sclerotherapy for painful venous malformations: evaluation of safety and efficacy in pain relief

The aim of this study was to retrospectively evaluate the safety and efficacy of polidocanol sclerotherapy in pain relief for painful venous malformations (VMs). Thirty-one patients with painful VMs underwent polidocanol sclerotherapy. Pain intensity was assessed with an 11-point verbal numerical rating scale. Sclerotherapy was technically successful in 58 (98.3%) of 59 sessions. Twenty-six (89.7%) out of 29 patients experienced an improvement in pain after sclerotherapy at follow-up, a mean of 46 months after treatment. The mean pain score improved from 6.6?±?2.5 before treatment to 2.4?±?2.9 after treatment (P <.001). The factors that significantly influenced the therapeutic effect were size of lesion (P?=?.008), margin of lesion (P?=?.006), and stasis of sclerosant (P?=?.032). Adverse events included hypotension and bradycardia during the procedure. No major complication occurred. Polidocanol sclerotherapy is safe and most efficacious in providing pain relief for patients with small VMs (equal to or less than 10 cm in diameter), VMs with a well-defined margin, and VMs with good stasis of sclerosant during sclerotherapy.     

Venous vascular malformations in pediatric patients: comparison of results of alcohol sclerotherapy with proposed MR imaging classification

PURPOSE: To compare the clinical results of percutaneous sclerotherapy of venous vascular malformations (VVMs) with the authors' proposed magnetic resonance (MR) imaging classification. MATERIALS AND METHODS: MR findings and clinical results of percutaneous alcohol sclerotherapy in 59 pediatric patients with VVMs were retrospectively reviewed. Before treatment, lesions were graded with MR imaging on the basis of margins and size, respectively: grade 1, well defined, less than or equal to 5 cm; grade 2A, well defined, greater than 5 cm; grade 2B, ill defined, less than or equal to 5 cm; and grade 3, ill defined, greater than 5 cm. Regression models were used to test trends in therapy across the MR classification grades, including the repeat sclerotherapies, volumes of ethanol and metrizamide administered for each lesion, and number of access sites. Clinical response to sclerotherapy, which was evaluated with consensus by a multidisciplinary team, was graded as poor, good, or excellent. Association between MR imaging grade and clinical assessment was tested with the Fisher exact test. RESULTS: There were 14 grade 1 lesions, nine grade 2A, 15 grade 2B, and 21 grade 3. Twenty-four patients had a poor response to sclerotherapy; 19, good; and 16, excellent. Ten of 14 (71%) grade 1 lesions had an excellent response; none, a poor response. Twelve of 21 (57%) grade 3 lesions had a poor response; none, an excellent result. Grade 2 lesions were relatively equally distributed among the three categories, with the exception of nine of 15 (60%) grade 2B lesions that had a poor response (P <.001). There was a trend with increasing lesion grade for increasing numbers of sclerotherapy sessions, volumes of ethanol and metrizamide for each lesion, and numbers of access sites. CONCLUSION: There is a strong association between this proposed MR imaging classification and the results of percutaneous sclerotherapy.     

Ethanol sclerotherapy of peripheral venous malformations

BACKGROUND: Venous malformations are congenital lesions that can cause pain, decreased range of movement, compression on adjacent structures, bleeding, consumptive coagulopathy and cosmetic deformity. Sclerotherapy alone or combined with surgical excision is the accepted treatment in symptomatic malformations after failed treatment attempts with tailored compression garments. OBJECTIVES: To report our experience with percutaneous sclerotherapy of peripheral venous malformations with ethanol 96%. PATIENTS AND METHODS: 41 sclerotherapy sessions were performed on 21 patients, aged 4-46 years, 15 females and 6 males. Fourteen patients were treated for painful extremity lesions, while five others with face and neck lesions and two with giant chest malformations had treatment for esthetic reasons. All patients had a pre-procedure magnetic resonance imaging (MRI) study. In all patients, 96% ethanol was used as the sclerosant by direct injection using general anesthesia. A minimum of 1-year clinical follow-up was performed. Follow-up imaging studies were performed if clinically indicated. RESULTS: 17 patients showed complete or partial symptomatic improvement after one to nine therapeutic sessions. Four patients with lower extremity lesions continue to suffer from pain and they are considered as a treatment failure. Complications were encountered in five patients, including acute pulmonary hypertension with cardiovascular collapse, pulmonary embolus, skin ulcers (two) and skin blisters. All patients fully recovered. CONCLUSION: Sclerotherapy with 96% ethanol for venous malformations was found to be effective for symptomatic improvement, but serious complications can occur.     

Cryoablation of Venous Malformations: A Systematic Review

This study aimed to review systematically the efficacy, safety, and technical aspects of cryoablation in the treatment of venous malformations (VMs) and to provide the groundwork for future studies. A literature search for clinical studies utilizing percutaneous cryoablation of VMs was performed. All clinical studies related to primary or secondary treatment of VMs with percutaneous cryoablation were included in this review. These selected studies were evaluated for patient characteristics, cryoablation technique, technical success, lesion size and pain scores before and after cryoablation, and adverse outcomes. Random effects analysis of postprocedural changes in lesion volume and pain scores was performed. There were 54 patients with 55 cases of cryoablation of VMs. Of these cases, 27 recorded changes in lesion volume and 31 recorded changes in pain scores. The weighted mean postprocedural decrease in lesion size was 92.0% (raw average, 71.7%). The weighted mean reduction in pain score was 77% (raw average, 78.2%). Considering all treated cases (55), complete resolution of symptoms was seen in 35 cases (63.6%) and overall (complete or partial) improvement in 52 cases (94.5%). Common postprocedural symptoms included pain, bruising, swelling and numbness lasting less than 2 weeks. There were two major adverse events (3.7%), with both cases due to persistent dysesthesia. Patients with a history of prior sclerotherapy demonstrated lower preprocedural and postprocedural pain scores (4.7 and 1.3) than patients without prior treatments (5.8 and 2.8). Cryoablation of VMs appears to be potentially safe and effective on limited short-interval follow-up.     

Usefulness of percutaneous sclerosing treatment for low-flow vascular lesions]

Peripheral vascular lesions may occur as a result of various clinical problems, cosmetic or dysfunctional causes, or bleeding. In severe cases, coagulopathy and congestive heart failure may occur. Although the efficacy of transarterial embolization (TAE) for arterial vascular lesions is well known, TAE has no effect on low-flow vascular lesions (venous malformations, venous angiomas, and venous components of arteriovenous malformation). Therefore, in such cases, a percutaneous approach is the best method, and we consider sclerotherapy to be the most useful conservative treatment. The primary objective of this study was to confirm the efficacy of percutaneous sclerosing treatment for peripheral low-flow vascular lesions. Lesions were classified on the basis of state of blood flow and morphologic features, and infiltration was classified on the basis of angiographic features and magnetic resonance imaging (MRI) findings. In sclerosing treatment, we used 5% solutions of polidocanol, absolute ethanol, and N-butyl-2-cyanoacrylate (NBCA) as sclerosing agents. Each type of lesion, static or slow-flow, cystic, or localized, showed remarkable improvement after sclerosing treatment with only polidocanol. However, for moderate-to-fast-flow lesions, another sclerosing agent (absolute ethanol/NBCA) was needed. With diffuse infiltrative lesions, surgical repair might be needed, but we recognize the usefulness of sclerosing treatment for functional or cosmetic improvement in these cases.     

Craniofacial cavernous venous malformations: percutaneous sclerotherapy with use of ethanolamine oleate

PURPOSE: To assess the efficacy of percutaneous sclerotherapy with use of ethanolamine oleate for craniofacial cavernous venous malformations. MATERIALS AND METHODS: From 1991 to 2001, sclerotherapy (average of two procedures per patient) was performed in 29 patients (mean age, 22 y; 10 male) with craniofacial venous malformations. Direct puncture venography was performed with use of water-soluble contrast media to delineate the extent of the lesions. CO(2) gas was used as contrast medium in addition to water-soluble contrast media in five patients in whom lesions had large nondependent areas. Coil embolization with a transvenous approach was performed in two patients when the lesions had large draining veins. Then, a mixture of 5% ethanolamine oleate and iodized oil (ratio, 5:1-5:2) was injected manually into the lesions under fluoroscopic guidance to monitor the process. A total of 59 procedures were performed. Clinical follow-up was obtained in 25 of 29 patients. The duration of follow-up ranged from 10 days to 6 years (mean, 8.5 mo). The effectiveness of sclerotherapy was assessed on the basis of clinical, surgical, and radiologic findings. RESULTS: The procedures were effective in 14 of 16 patients who underwent sclerotherapy only. The procedures were beneficial for all nine patients who underwent sclerotherapy and surgery. There was no skin injury or nerve damage. The trismus that appeared in two patients with lesions in the masticator space was treated well by conservative therapy. CONCLUSION: Percutaneous sclerotherapy with use of ethanolamine oleate is a safe and effective treatment of craniofacial cavernous venous malformations. However, renal function was not specifically evaluated after treatment, and therefore occult renal dysfunction cannot be excluded.     

Imaging of head and neck venous malformations

Venous malformations (VMs) are non proliferative lesions that consist of dysplastic venous channels. The aim of imaging is to characterise the lesion and define its anatomic extent. We will describe the plain film, ultrasound (US) (including colour and duplex Doppler), computed tomography (CT), magnetic resonance imaging (MRI), conventional angiographic and direct phlebographic appearances of venous malformations. They will be illustrated at a number of head and neck locations, including orbit, oral cavity, superficial and deep facial space, supraglottic and intramuscular. An understanding of the classification of such vascular anomalies is required to define the correct therapeutic procedure to employ. Image-guided sclerotherapy alone or in combination with surgery is now the first line treatment option in many cases of head and neck venous malformations, so the radiologist is now an integral part of the multidisciplinary management team.     

Soft-tissue venous malformations in pediatric and young adult patients: diagnosis with Doppler US.

PURPOSE: To describe the diagnostic features, appearance, and vascularization pattern of venous malformations (VMs) at Doppler ultrasonography (US). MATERIALS AND METHODS: Between February 1991 and May 1997, 51 soft-tissue VMs were studied with Doppler US in patients between 1 day and 21 years of age (mean age, 9 years). These VMs were located in the maxillofacial region (n = 19), trunk (n = 5), and upper (n = 10) and lower (n = 17) extremities. Twenty-three VMs had venographic confirmation, seven had only histologic confirmation, and 21 had both venographic and histologic confirmation. US was performed with 7.5- or 7-10-MHz linear transducers, a low pulse repetition frequency (mean, 1,680 Hz), and the lowest wall filter (25-50 Hz). RESULTS: At gray-scale US, VMs appeared as hypoechoic, heterogeneous lesions in 82% of cases. All lesions displayed compressibility. In eight lesions (16%), phleboliths were identified, thus confirming the diagnosis of VM. Analysis of vascular flow revealed monophasic, low-velocity flow in 40 VMs (78%), with an average flow velocity of 0.22 kHz. Biphasic flow was noted at the periphery of three lesions, which is indicative of a mixed capillary-venous malformation. The remaining eight lesions did not display any flow. CONCLUSION: In pediatric patients, Doppler US is a noninvasive, easily available, and rapid mode of investigation of vascular lesions and can help confirm the diagnosis of VM when it shows a characteristic flow pattern.     

Evaluation of the results of various technics of non-surgical therapy of varicocele

A new method of non-surgical treatment of varicocele syndrome is described: it consists in sclerotherapy of spermatic vein by trans-femoral percutaneous catheterization with balloon-catheters. In 8 cases venous thrombosis has been induced by direct electric clotting. The techniques and a 6 months follow-up are discussed. It is pointed out that this procedure should be considered as the method of choice for tubular lesions and sub-fertility prophylaxis in young people and in childhood.     

眼眶血管畸形介入硬化栓塞治疗的临床观察

目的探讨介入硬化栓塞治疗眼眶血管畸形的方法,评价其临床疗效及安全性。 方法回顾性分析2013年1月至2019年1月在我院收治的46例眼眶血管畸形患者（包括静脉畸形、动静脉畸形）的临床资料,其中静脉畸形33例,动静脉畸形13例。静脉畸形治疗均为经皮局部硬化治疗（药物为聚多卡醇/无水乙醇）,动静脉畸形以经导管动脉硬化栓塞（栓塞剂为弹簧圈）及经皮局部硬化（药物为聚多卡醇/无水乙醇）联合治疗。随访时间15～57个月（中位随访时间35个月）。 结果33例静脉畸形接受局部硬化治疗次数2～5次（平均3.5次）,13例动静脉畸形接受介入治疗次数2～6次（平均3.9次）。33例静脉畸形至随访期结束时,13例治愈、11例症状明显缓解、9例部分缓解。13例动静脉畸形至随访期结束时,5例自觉血管搏动消失或明显缓解、8例眶周肿胀较前缓解。所有患者均有术后一过性眶周肿胀,未发生眶周皮肤破溃、视力衰退、眼球萎缩及异位栓塞等严重并发症。 结论眼眶血管畸形行介入治疗安全,可以有效地缓解眶周症状。     

MR导引下经皮硬化治疗四肢静脉血管畸形

目的 探讨MR导引下经皮硬化治疗四肢静脉血管畸形的操作方法及临床应用价值.方法 在0.35 T开放式MR扫描仪的导引下应用18或20 G核磁兼容针对28例下肢静脉血管畸形患者进行经皮穿刺及硬化治疗.在治疗后6个月进行随访,分析其治疗效果.评价指标包括:(1)介入操作是否成功;(2)患者的症状有无改善;(3)有无并发症;(4)病变体积的变化;(5)病变对比信噪比(CNR)的变化.治疗前后病变体积及CNR的比较使用配对t检验进行分析.结果 28例患者先后共进行57次硬化治疗,手术操作均获得成功,没有出现严重并发症.所有患者的症状均有较明显改善,特别是疼痛、功能障碍等症状.病变体积出现不同程度的缩小,治疗前平均为(56.8±11.7)cm3,治疗后平均为(27.0±7.2)cm3,差异有统计学意义(t=8.90,P<0.01),缩小率为28.5%～74.4%,平均为(54.4±5.3)%.同时,MRI显示治疗后病变的信号降低,CNR治疗前平均为21.9±2.0,治疗后平均为8.4±0.9,差异有统计学意义(t=21.76,P<0.01),CNR降低率为40.0%～78.0%,平均为(61.0±3.6)%.结论 MR引导下经皮硬化治疗四肢静脉血管畸形是安全、有效的新技术.     

Venous malformations: Sclerotherapy with a mixture of ethanol and lipiodol

Purpose To evaluate the usefulness of a mixture of absolute ethanol and lipiodol in the management of venous malformations. Methods Percutaneous sclerotherapy was performed with a mixture of absolute ethanol and lipiodol (9∶1) in 17 patients with venous malformations, once in 12 patients, twice in 5. The therapeutic efficacy was evaluated by pain reduction. Conventional radiographs (n=15) and posttreatment magnetic resonance imaging (n=5) were obtained for the follow-up evaluation. Results Sclerotherapy was successful in all but two patients. The therapeutic effect was excellent in two patients, good in seven, fair in five, and poor in one. Radiopacity of lipiodol was beneficial for monitoring the procedure rather than for follow-up evaluations. Areas with low signal-intensity strands were increased on T2-weighted images obtained after the sclerotherapy. Conclusion Sclerotherapy with a mixture of ethanol and lipiodol is effective in treating venous malformations.     

无水乙醇联合泡沫硬化剂治疗直肠静脉畸形效果和安全性分析

【摘要】　目的?探讨无水乙醇联合泡沫硬化剂治疗直肠静脉畸形（VM）的安全性和有效性。 方法?回顾性分析2017年10月至2018年5月收治的5例出血性直肠VM患儿,根据Puig分型选择经皮硬化治疗。术后随访观察有效性、不良反应和并发症。结果?5例患儿均为PuigⅡ、Ⅲ型,接受无水乙醇联合泡沫硬化剂治疗共10次（1～3次）。无水乙醇单次应用平均剂量（0.11±0.05）mL/kg,3%聚多卡醇单次应用平均剂量（2.35±0.94） mL。术后2例治愈,2例基本治愈,1例有效,有效率为100%。随访12～18个月,患儿未再有便秘或出血情况,无皮肤坏死或严重心肺系统并发症。结论?根据Puig分型采用无水乙醇联用泡沫硬化剂治疗直肠VM,可降低无水乙醇用量,提高治疗安全性,增加疗效。     

Sclerotherapy of renal cysts using acetic acid: a comparison with ethanol sclerotherapy

This study compared percutaneous sclerotherapy using 50% acetic acid with that using 99% ethanol for patients with simple renal cysts. The study included 72 simple renal cysts in 64 patients (male/female ratio = 31/33; age range, 31-75 years). Under fluoroscopic guidance, the cyst fluid was aspirated completely. Sclerotherapy was then performed using 50% acetic acid for 32 cysts and 99% ethanol for 40 cysts. The volumes of each renal cyst before and after sclerotherapy were compared using ultrasonography or CT. Medical records were reviewed to analyse any complications. The mean follow-up period was 21.5 months (range, 3-75 months). The mean remnant volume of the cyst after sclerotherapy was 2.6% of the initial volume in the acetic acid group and 14.0% in the ethanol group. The rates of complete remission, partial remission and treatment failure were 90.6%, 9.4% and 0%, respectively, in the acetic acid group, and 60.0%, 30.0% and 10.0%, respectively, in the ethanol group. There were no complications related to sclerotherapy in either group. In conclusion, acetic acid is a safe and effective sclerosing agent, with clinical results superior to those of ethanol, and is an alternative to ethanol for sclerotherapy of renal cysts.     

Soft-tissue venous malformations in children: percutaneous sclerotherapy with Ethibloc

Thirty-eight children with soft-tissue venous malformations (VMs) were treated with percutaneous injection of a new fibrosing agent (Ethibloc). The technique, results, side effects, and complications are detailed. Direct puncture of the VM allows evaluation of the draining venous system and direct injection of Ethibloc. This procedure alone or associated with surgery led to achievement of good or excellent results in 74% of the cases (complete cure in 50%), with minimal side effects and no major complications.     

Percutaneous Transcatheter Ethanol Sclerotherapy and Catheter Drainage of Postoperative Pelvic Lymphoceles

The aim of this study is to investigate the efficacy and long-term results of percutaneous transcatheter ethanol sclerotherapy (PTES) for postoperative pelvic lymphocele treatment. Fifty-two patients who were referred for lymphocele treatment were included in this study. Sixty lymphoceles of 52 patients were treated by percutaneous treatment with or without ethanol sclerotherapy. Lymphoceles developed in 47 and 5 patients, who underwent gynecologic malignancy operation (31 ovarian cancer, 6 cervix cancer, 10 endometrial cancer) and renal transplantation, respectively. Lymphoceles were catheterized by ultrasonography and fluoroscopy guidance using the Seldinger technique. Lymphoceles smaller than 150 mL underwent single-session ethanol sclerotherapy and the others were treated by multiple-session ethanol scleortherapy. In 10 patients, percutaneous ethanol sclerotherapy could not be performed and they were treated only by percutaneous catheter drainage. The mean lymphocele volume was 329 mL (15–2900 mL). The mean catheterization duration was 11.8 days (1–60 days). The mean follow up time was 25.8 months (2–64 months). The initial treatment was successful in 46 out of 50 (91%) lymphoceles treated with PTES and 7 out of 10 (70%) lymphoceles treated with percutaneous catheter drainage. Minor complications (secondary infection and catheter dislodgement) were noted in seven (11.6%) patients. Recurrence developed in four and three patients who were treated by PTES and percutaneous catheter drainage, respectively. Five of these patients were treated with PTES without further recurrence. Percutaneous transcatheter ethanol sclerotherapy is an effective and reliable method for the treatment of postoperative lymphoceles.     

Nonresectable hepatocellular carcinoma: improved percutaneous ethanol injection therapy guided by CO(2)-enhanced sonography

OBJECTIVE: The purpose of our study was to evaluate the usefulness of percutaneous ethanol installation using CO(2)-enhanced sonography for patients with nonresectable hepatocellular carcinoma (HCC). SUBJECTS AND METHODS: Forty-six patients with 65 HCC lesions were examined with contrast-enhanced sonography with direct injection of CO(2) into the proper hepatic artery during arteriography. We performed percutaneous ethanol injection guided by CO(2)-enhanced sonography for the treatment of hypervascular HCC lesions that could not be treated with conventional percutaneous ethanol injection or with transcatheter arterial embolization. RESULTS: CO(2)-enhanced sonography detected five additional small HCC lesions before treatment (p<0.05) and 14 new lesions during follow-up (p<0.01), than conventional sonography detected. CO(2)-enhanced sonography showed positive enhancement of residual lesions after initial treatment (n = 3) and incomplete local treatment (n = 5) that were not detected on conventional sonography. These 27 lesions were successfully treated with percutaneous ethanol injection using a mixture of iodized oil and ethanol and guided by CO(2)-enhanced sonography. CONCLUSION: CO(2)-enhanced sonography is a sensitive method for detecting residual viable lesions and small new HCC lesions that cannot be detected with conventional sonography. Percutaneous ethanol injection guided by CO(2)-enhanced sonography can treat hypervascular HCC lesions that cannot be treated with conventional percutaneous ethanol injection or transcatheter arterial embolization.