Efficacy and safety of transcatheter arterial embolization of omental artery aneurysm: A single-center experience.

BACKGROUND: Omental artery aneurysm (OAA) is an extremely rare visceral artery aneurysm. Ruptured OAAs are associated with a high mortality rate. Transcatheter arterial embolization (TAE) has been used to treat OAA in recent years. However, the risk of omental ischemia due to TAE remains unclear. Therefore, this study aimed to investigate the efficacy and safety of TAE of OAA as a first-line treatment. METHODS: Fifteen patients with true aneurysms or pseudoaneurysms who underwent OAA-TAE between 1 April 2010 and 31 December 2022 were included in this study. The technical and clinical outcomes, the incidence of omental infarction after TAE as a major complication, OAA-TAE techniques, radiological findings on computed tomography angiography and angiogram, and patient characteristics were evaluated. RESULTS: Fifteen patients (nine men, six women; age, 69.8 ± 18.59 years) underwent TAE of OAAs (mean aneurysm size of 9.30 ± 6.10 mm) located in the right gastroepiploic (n = 9), left gastroepiploic (n = 1), and epiploic (n = 5) arteries. All patients with ruptured (n = 6) and unruptured (n = 9) OAA successfully underwent TAEs using coils, n-butyl-2-cyanoacrylate, or gelatin sponges. Hepatic artery thrombosis and coil migration were observed during the procedure; however, these adverse events were manageable. Transfusion of red blood cell units (4.66 ± 1.63 units) was required only in cases with ruptured OAAs after TAE. Additional surgery or TAE due to rupture or rerupture of OAA and omental infarction was not required during the postoperative and follow-up periods. CONCLUSION: The OAA-TAE can effectively treat ruptured and unruptured OAAs, and the risk of omental infarction after OAA-TAE may not be high.

Percutaneous trans-bladder drainage of a pelvic abscess caused by sigmoid diverticulitis: Two case reports.

Sigmoid diverticulitis can potentially lead to the development of pelvic abscesses. Mortality rate from intra-abdominal abscesses is as high as 35%, and patients with diverticulitis complicated by an abscess are at a high risk of recurrent diverticulitis. Recently, image-guided drainage has been performed using computed tomography or ultrasonography for the treatment of pelvic abscesses. Standard radiological pelvic abscess image-guided drainage methods consist of transabdominal, transgluteal, or cranio-caudal puncture approaches. However, these standard approaches have technical limitations due to intrapelvic organ structures. Therefore, we performed image-guided drainage using a percutaneous trans-bladder approach with a simpler 1-step puncture method and a less invasive 7-Fr drainage catheter in 2 cases of a 72-year-old female and a 53-year-old female with relapsed pelvic abscesses complicated by sigmoid diverticulitis due to difficulties involving the standard approach. The abscesses in both cases disappeared on follow-up computed tomography scans, demonstrating no pelvic abscess recurrence. Our results showed that trans-bladder image-guided drainage is an effective alternative method for treating pelvic abscesses.

Radiotherapy after radical prostatectomy for prostate cancer: clinical outcomes and factors influencing biochemical recurrence.

BACKGROUND: Radiotherapy (RT) after radical prostatectomy (RP) includes adjuvant radiotherapy (ART) and salvage radiotherapy (SRT), which can prevent or cure biochemical recurrence. AIMS: To evaluate long-term outcomes of RT after RP and to examine factors affecting biochemical recurrence-free survival (bRFS). METHODS: Sixty-six received ART and 73 received SRT between 2005 and 2012 were included. The clinical outcomes and late toxicities were evaluated. Univariate and multivariate analyses were performed to examine factors affecting bRFS. RESULTS: Median follow-up from RP was 111 months. Five-year bRFS and 10-year distant metastasis-free survival from RP were 82.8% and 84.5% in ART, and 74.6% and 92.4% in SRT, respectively. The most frequent late toxicity was hematuria, which was higher in ART (p = .01). No recurrence within RT field was occurred. On univariate analysis, pelvic RT was associated with favorable bRFS in ART (p = .048). In SRT, post-RP prostate-specific antigen (PSA) level (< 0.05 ng/mL), PSA nadir after RT (≤ 0.01 ng/mL), and time to PSA nadir (≥ 10 months) were associated with favorable bRFS (p = .03, p < .001, and p = .002, respectively). On multivariate analysis, post-RP PSA level and time to PSA nadir were independent predictive factors for bRFS in SRT (p = .04 and p = .005). CONCLUSIONS: ART and SRT had favorable outcomes with no recurrence within RT field. In SRT, the time to PSA nadir after RT (≥ 10 months) was found to be a new predictor for favorable bRFS and useful in assessing treatment efficacy.

Percutaneous transhepatic obliteration of a large portosystemic shunt associated with hepatic encephalopathy using a technique of n-butyl-2-cyanoacrylate injection inside hydrogel-coated coils: A case report.

Portosystemic shunts with cirrhosis may lead to hepatic encephalopathy (HE), which is often pharmacotherapy-resistant. We report a case of a 66-year-old female patient diagnosed with alcoholic cirrhosis and uncontrolled HE. She underwent percutaneous transhepatic obliteration (PTO) for treatment of a large portosystemic shunt from the left and right gastric veins to the azygos vein. We embolized the target veins using hydro-coated coils and filled them with n-butyl-2-cyanoacrylate (NBCA), leading to firmed obstruction of the large portosystemic shunt without NBCA migration, thus reducing the number of coils required. The HE symptoms improved after PTO and could thereafter be controlled with conservative therapy. Our results showed that PTO using an NBCA injection inside hydrogel-coated coils for a large portosystemic shunt associated with HE is effective and safe.

Efficacy and safety of endovascular therapy for delayed hepatic artery post-pancreatectomy hemorrhage: development of extrahepatic collateral circulation and complications of post endovascular therapy.

BACKGROUND: Endovascular therapy (ET) for delayed hepatic artery post-pancreatectomy hemorrhage (HA-PPH) may require complete hepatic artery occlusion (HAO). Nonetheless, the development of extrahepatic collateral circulation (EHC) and the relationship between radiological factors (EHC, portal vein stenosis, and HAO) and adverse hepatic events after ET remain unclear. This study aimed to evaluate the efficacy and safety of ET for delayed PPH and examine the development of EHC. METHODS: A total of 19 ET cases for delayed HA-PPH were reviewed. Hepatic adverse events, portal vein stenosis, HAO, and mortality rate after ET were evaluated. Moreover, EHC from the left gastric artery (LGA), right inferior phrenic artery (RIPA), left inferior phrenic artery (LIPA), right internal thoracic artery (RITA), left internal thoracic artery (LITA), renal artery (RA), omental artery (OA), intercostal artery (IA), and branch of superior mesenteric artery (BSMA) was assessed using angiogram and computed tomography angiography (CTA). RESULTS: All cases were successfully treated using transcatheter arterial embolization (n = 17) and stent-graft placement (n = 2) without mortality. EHC from the LGA (8/19), RIPA (10/19), LIPA (4/19), and RITA (3/19) was observed on post-ET CTA. The incidence of hepatic adverse events was significant in the group with both HAO and portal vein stenosis (p < 0.001) and absence of EHC from LIPA and RITA (p < 0.05). CONCLUSION: ET for delayed HA-PPH might be effective and safe. While avoiding both HAO and portal vein stenosis is important, the development of EHCs from LIPA and RITA may prevent hepatic adverse events after ET.

Assessment of squamous cell carcinoma of the floor of the mouth with magnetic resonance imaging.

PURPOSE: We aimed to use magnetic resonance imaging (MRI) to determine the relationship between the pathological depth of invasion (DOI), undetectability, and tumor thickness of squamous cell carcinoma of the floor of the mouth. MATERIALS AND METHODS: We retrospectively evaluated the relationship between pathological DOI and MRI detectability, as well as the relationship between pathological DOI and tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging or coronal T2-weighted imaging. RESULTS: We analyzed 30 patients with squamous cell carcinoma of the floor of the mouth; MRI revealed that the pathological DOI of the 11 undetectable lesions (median 2 mm) was smaller than that of the 19 detectable lesions (median 14 mm) (p < 0.001), and the cut-off value was 3 mm (sensitivity, 0.84; specificity, 0.91; area under the curve, 0.89). Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was assessed in all 19 detectable lesions; however, tumor thickness on coronal T2-weighted imaging could not be assessed in eight cases. Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was found to be significantly associated with the pathological DOI. CONCLUSIONS: Undetectability on MRI indicates superficial lesions with a pathological DOI value that is less than 3 mm. In detectable lesions, tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging is associated with pathological DOI.

Radiological differences in computed tomography findings and texture analysis between cystic lymph node metastases of human papillomavirus-positive oropharyngeal cancer and second branchial cysts.

PURPOSE: The study aimed to analyse radiological differences in computed tomography (CT) findings and texture analysis between cystic lymph node metastases (CNM) in human papillomavirus (HPV)-positive oropharyngeal cancer (OPC) and second branchial cleft cysts (2nd BC). MATERIAL AND METHODS: Patients with pathological evidence of CNM-HPV-OPC and 2nd BC, who underwent contrast-enhanced CT, were retrospectively evaluated. The evaluated characteristics include age, sex, and CT findings. CT findings included the maximum and minimum transverse diameters, maximum caudal diameter, thickness of the peripheral wall, presence of internal septation, presence of surrounding fat stranding, location, and 40 texture parameters. RESULTS: A total of 13 patients had CNM-HPV-OPC (19 lesions), while 20 patients had 2nd BC (20 lesions). Patients with 2nd BC were significantly younger than those with CNM-HPV-OPC (p < 0.001). In terms of diameter, 2nd BC lesions were significantly larger than the CNM-HPV-OPC lesions (p < 0.001). CNM-HPV OPC lesions had significantly thicker walls than 2nd BC lesions (p < 0.001). CNM-HPV-OPC lesions had significantly higher association with internal septations than 2nd BC lesions (p < 0.001). Second BC lesions were significantly less common at level III than CNM-HPV-OPC lesions (p = 0.047). Among the 40 texture parameters measured, 8 had significant differences (p ≤ 0.001). CONCLUSIONS: There were significant differences in CT findings and textural parameters between CNM-HPV-OPC and 2nd BC lesions. These results may help in differentiating one from the other.

Non-echoplanar diffusion weighed imaging and T1-weighted imaging for cholesteatoma mastoid extension.

OBJECTIVES: A broad mastoid extension limits cholesteatoma resection via a transmeatal approach including endoscopic ear surgery. Therefore, a preoperative diagnosis of mastoid extension is a the most critical factor to determine whether to perform mastoidectomy. The purpose of this study was to assess the efficacy of non-echoplanar diffusion-weighted imaging (non-EPI DWI) and T1-weighted imaging in the evaluation of mastoid extension in cholesteatomas of the middle ear. METHODS: Patients who underwent magnetic resonance imaging (MRI) for pretreatment evaluation before primary surgery for pars flaccida or tensa cholesteatoma, which revealed a high-signal intensity in the mastoid on T2-weighed imaging were retrospectively evaluated. Two board-certified radiologists retrospectively evaluated the extent of cholesteatomas on MRI with non-EPI DWI, non-EPI DWI- and T1-weighted axial imaging. The presence of a high signal intensity on non-EPI DWI or low or high signal intensity on T1-weighted imaging in the mastoid was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative). RESULTS: A total of 59 patients with middle ear cholesteatoma were evaluated. There were 37 M+ cases and 22 M- cases. High-signal intensity on non-EPI DWI exhibited a sensitivity of 0.89 and specificity of 0.82, whereas partial low-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.84 and specificity of 0.91 for detecting mastoid involvement. Complete high-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.73 and specificity of 0.89 for detecting non-involvement of the mastoid. The sensitivity (0.92) and specificity (0.96) of combined non-EPI DWI and T1-weighted imaging evaluation were higher than those of with non-EPI DWI or T1-weighted imaging alone. The interobserver agreement for the presence of high-signal intensity in the mastoid cavity on non-EPI DWI was very good at 0.82, that of a partial low-signal intensity area in the mastoid cavity lesions on T1-weighted imaging was good, at 0.76 and that of complete high-signal intensity in the mastoid cavity lesions on T1-weighted imaging was good, at 0.67. CONCLUSIONS: The signal intensity on non-EPI DWI and T1-weighted imaging of the mastoid could be used to accurately assess the extent of middle ear cholesteatoma, which could facilitate surgical treatment planning.

Pre-treatment MRI predictor of high-grade malignant parotid gland cancer.

OBJECTIVES: We aimed to evaluate pre-treatment MRI predictors of high-grade malignant parotid gland cancer by comparing MRI findings and texture parameters between high-grade and intermediate/low-grade parotid gland cancers. METHODS: Patients underwent a pre-treatment MRI and had a parotid gland cancer resection with pathological evaluation. Evaluation objectives included attributive factors such as age and gender, several MRI findings of T1- and T2-weighted images, post-contrast fat suppression T1-weighted images, ADC value and 40 texture parameters calculated from T2-weighted axial images. Such objects were compared between high-grade and intermediate/low-grade lesions. RESULTS: Of the parotid gland cancers surveyed, 39 were included for analysis. Of these, 18 were high-grade lesions, 2 were intermediate-grade lesions, and 19 were low-grade lesions. The high-grade group was significantly older than the low- and intermediate-grade groups (p = 0.01). There were more males in the high-grade group than in the low- and intermediate-grade groups (p = 0.01). There were also significantly more MRI findings of neck lymph node metastases in the high-grade group than in the low- and intermediate-grade groups (p < 0.001). Other MRI findings and texture parameters did not show significant differences between the two groups (p = 0.07-1.00). CONCLUSIONS: Morphological assessment on MRI and texture parameters alone is not sufficient to estimate the grade of parotid cancer. MRI findings of neck lymph node metastases, as well as patient characteristics such as age (older patients) and gender (male) can be suggestive of high-grade parotid gland cancer in pre-treatment evaluation.

Correlation between the magnetic resonance imaging features of squamous cell carcinoma of the buccal mucosa and pathologic depth of invasion.

OBJECTIVE: The objective of this study was to determine correlations between magnetic resonance imaging (MRI) features including radiologic depth of invasion (r-DOI) and pathologic DOI (p-DOI) of squamous cell carcinoma of the buccal mucosa. STUDY DESIGN: In total, 31 lesions were retrospectively evaluated. MRI findings included detectability, buccinator muscle invasion (positive: BMI+, negative: BMI-), buccal fat pad invasion (positive: BFPI+, negative: BFPI-), and r-DOI measured on T2-weighted images (T2-DOI) and contrast-enhanced T1-weighted images (CET1-DOI). These findings were compared to the p-DOI of the tumors. RESULTS: The p-DOI values of undetectable lesions were smaller than those of detectable lesions (P < .001), and the cutoff value was 1 mm. BMI+ and BFPI+ lesions had significantly larger p-DOI values than the corresponding BMI- and BFPI- lesions (P < .001), with cutoff values of 5 and 6 mm, respectively. The correlation coefficient between CET1-DOI and p-DOI was 0.68 (P < .001). CET1-DOI values were larger than p-DOI (P < .001) and the average difference between them was 3.4 mm. T2-DOI was inconclusive in 50% of cases. Interobserver agreements of MRI evaluation were good to very good. CONCLUSION: MRI-derived parameters were useful in estimating p-DOI and may be helpful in predicting the depth of invasion of tumors and the risk of lymph node metastasis.

Preoperative predictive criteria for mastoid extension in pars flaccida cholesteatoma in assessments using temporal bone high-resolution computed tomography.

OBJECTIVES: We aimed to clarify the usefulness of high-resolution computed tomography (HRCT) and establish HRCT criteria for presurgical assessment of the mastoid extension in pars flaccida cholesteatomas of the middle ear. METHODS: Retrospective observational study. Patients who underwent primary surgery for pars flaccida cholesteatoma and those who underwent temporal bone HRCT for pretreatment evaluation were reviewed. The distance in the anterior-most portion of the mastoid sinus on HRCT was measured, and the presence of surgically verified mastoid extension of cholesteatoma was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative). RESULTS: A total of 107 patients with pars flaccida cholesteatoma were included. The distance in the M+ cases was significantly longer than that in the M- cases, and the cutoff value was 3.6 mm. The difference between the ipsilateral/diseased-side distance and the contralateral/evaluable side (difference value) in M+ cases was larger than that in M- cases, with a cutoff value of 0.6 mm. The inter-rater reliability of this distance measurement was excellent, regardless of imaging experience. CONCLUSIONS: The cutoff values of the distance and the difference value can be used for pretreatment HRCT evaluation of mastoid extension in middle ear cholesteatoma with relatively high accuracy, regardless of the experience and skill levels of the evaluator.

Radiological approach for the newly incorporated T staging factor, depth of invasion (DOI), of the oral tongue cancer in the 8th edition of American Joint Committee on Cancer (AJCC) staging manual: assessment of the necessity for elective neck dissection.

The 8th edition of American Joint Committee on Cancer's (AJCC) Cancer Staging Manual was modified by incorporating depth of invasion (DOI) in the T categorization of oral cavity cancer. This is because DOI is strongly associated with cervical lymph node metastasis, which is the most important negative prognostic factor of oral cavity cancer. This major change in the AJCC Cancer Staging Manual caused re-staging of T category in several cases. Although, the DOI on MRI and CT (radiological DOI; r-DOI) strongly correlated with pathological DOI (p-DOI), it is often 2-3 mm larger than p-DOI. Due to this variance, estimation of p-DOI based on r-DOI may not be accurate. However, when a lesion is undetectable on MRI, p-DOI was often smaller than 4 mm. On the other hand, when MRI depicts lesions with styloglossus and hyoglossus muscle invasion, p-DOI was always larger than 4 mm. These correlations between MRI findings and p-DOI are important when assessing the need for elective neck dissection, as the National Comprehensive Cancer Network (NCCN) recommends elective neck dissection in cases with DOI greater than 4 mm.

MR imaging of palatine gland lesion-associated IgG4-related disease: a preliminary study.

PURPOSE: The purpose of this study was to present the novel MRI findings of palatine gland lesion-associated IgG4-related disease (PGL-IgG4-RD) and to compare the imaging features with those in normal individuals. MATERIALS AND METHODS: We retrospectively evaluated the MRI scans of 12 patients with PGL-IgG4-RD and 12 control individuals. We measured the thickness of the palatal regions and calculated the T2-weighted signal intensity ratio of palatal regions to cerebral white matter (HWR) and compared them between the PGL-IgG4-RD and control groups. RESULTS: In univariate analysis, the HWR of the palatal regions on T2-weighted imaging was smaller in the PGL-IgG4-RD group than in the control group (average = 1.2 vs. 1.9, p < 0.001). The palate thickness in patients with PGL-IgG4-RD was significantly greater than that in controls (average = 12 vs 6 mm, p < 0.001). The cut-off value of the between-group palate thickness on coronal MRI was 8 mm. CONCLUSION: The thickening of the palatal regions seen with low signal intensity on T2-weighted imaging may be a characteristic imaging feature of PGL-IgG4-RD. Such findings will be useful for the timely diagnosis and subsequent treatment planning of IgG4-RDHP.

Magnetic resonance imaging findings of styloglossus and hyoglossus muscle invasion: Relationship to depth of invasion and clinical significance as a predictor of advisability of elective neck dissection in node negative oral tongue cancer.

PURPOSE: By comparing styloglossus and hyoglossus muscle invasion (SHMI) of oral tongue squamous cell cancer (OTSCC) on MR imaging to pathological depth of invasion (DOI) and prognosis, we aimed to evaluate the clinical significance of MR imaging findings of SHMI. METHOD: Forty-five, early stages and clinically N0 OTSCCs were retrospectively reviewed. Data included pathological DOI, DOI on MR imagings, two-year potential cervical lymph node positive, locoregional control, disease-free survival, and overall survival. Data were statistically compared between the groups with MR evidence of SHMI (SHMI+) and without MR evidence of SHMI (SHMI-). RESULTS: There were 17 SHMI + and 28 SHMI-. Elective neck dissections performed on 13 cases revealed five node positive cases, all of which were SHMI + . Pathological DOI in SHMI + was significantly larger than SHMI- (average 9.0 vs 4.6 mm, p < 0.001). All SHMI + revealed pathological DOI larger than 4 mm. The two-year potential cervical lymph node positive rate of SHMI + was significantly higher than SHMI- (p =  0.01). Locoregional control rate and disease-free survival of SHMI+ were significantly lower than in SHMI- (p =  0.02). There was no significant difference in overall survival. Interobserver agreement in evaluation of SHMI on MR imaging was good (kappa value = 0.72, p <  0.001). CONCLUSIONS: Pathological DOIs of SHMI + were all larger than 4 mm, which is the cut-off point that National Comprehensive Cancer Network recommends for neck dissection, and SHMI + had a worse prognosis than SHMI-. SHMI + can be used as a criterion for elective neck dissection.

Symposium: Imaging modalities for drug-related osteonecrosis of the jaw (4), CT and MR imaging findings of antiresorptive agent-related osteonecrosis of the jaws/medication-related osteonecrosis of the jaw (secondary publication).

Generally, CT and MR images of antiresorptive agent-related osteonecrosis of the jaw (ARONJ)/medication-related osteonecrosis of the jaw (MRONJ) show nonspecific findings as seen in active osteomyelitis．However, there are some characteristics as follows; unilateral maxillary sinusitis adjacent to ipsilateral maxillary ARONJ/MRONJ, DRONJ presenting larger sequestrum and periosteal reaction more frequently than BRONJ, BRONJ resulting from intravenous administration of the drug presenting larger and more frequent buccolingual cortical bone perforations than BRONJ from oral administration, and better diagnostic accuracy of extent of perilesional soft tissue inflammation on MR imaging than CT. The CT and MR imaging features of ARONJ/MRONJ are summarized in this report.

Undetectability of oral tongue cancer on magnetic resonance imaging; clinical significance as a predictor to avoid unnecessary elective neck dissection in node negative patients.

METHODS:: We retrospectively reviewed early stage oral tongue cancer patients treated with radical surgery with clinically N0, between May 2009 and February 2016. Collected data include age, sex, pathological DOI, DOI on MRI, locoregional control rate, disease-free survival rate, and overall survival rate. These data were statistically compared between the detectable lesion (DL) group and undetectable lesion (UL) group on MRI. Interobserver agreement in evaluation of detectability of the oral tongue cancer was assessed by k statistics. RESULTS:: Total of 53 patients were studied, and 28 were DLs and 25 ULs. Pathological DOI in UL was significantly smaller than that of DL (average 1.7 vs 4.6 mm, p < 0.001). Cut-off value between UL group and DL group was 3.5 mm (sensitivity 96 %, specificity 75 %). 96 % of ULs had pathological DOI smaller than 4 mm, the recommended cut-off value for neck dissection. There was no significant difference in locoregional control rate (p = 0.24), disease-free survival rate (p = 0.24) or overall survival rate (p = 0.92). Interobserver agreement in evaluation of detectability on MRI was very good ( k-value = 0.89, p < 0.001). CONCLUSIONS:: When oral tongue cancer is not detected on MRI, it indicates pathological DOI being smaller than 4 mm, which may imply that elective neck dissection is unnecessary.

Essentials on Oncological Imaging: Postoperative Computed Tomography and Magnetic Resonance Imaging of Oral Tongue Cancer.

The contribution of diagnostic imaging in evaluating the pre- and postoperative status of tongue cancer is essential. Interpretation of postoperative images is made difficult by deformation; therefore, it is necessary to know how surgical technique, biological reaction, postoperative anatomy, and local recurrence are reflected on the images. This study explains the postoperative imaging features of tongue cancer to help in the early detection of local recurrence and avoid inappropriate treatment. We review schematic drawings of representative surgical procedures for tongue carcinoma, variable radiological features in postoperative conditions with or without complications, and typical features of local failures and their mimics. This article clarifies the important tasks of radiologists and clinicians in the postoperative evaluation of tongue carcinoma.

[Feasibility and Safety of Dexmedetomidine Sedation in Transarterial Embolization for Hepatocellular Carcinoma with Hepatitis C-Related Cirrhosis].

BACKGROUND: Dexmedetomidine (Precedex®)is an agonist of a2-adrenergic receptors in certain parts of the brain. It was approved for "procedural sedation in the non-intubation in under local anesthesia" in June 2013 in Japan. However, because of metabolism delay, dexmedetomidine has to be administered carefully to patients with liver dysfunction. PURPOSE: To evaluate the feasibility and safety of sedation using dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction. METHODS: Thirty consecutive cases of percutaneous arterial chemoembolization for hepatocellular carcinoma with hepatitis C-related cirrhosis(male, 23; female, 7; age, 74±5.9; weight, 62.7±12.3 kg; Child-Pugh A, 23; Child-Pugh B, 7)were analyzed retrospectively. Dexmedetomidine was administered at 3 mg/kg/h for 15 minutes as the initial loading dose and at 0.4 mg/kg/h as the maintenance dose. The sedation level was evaluated using the Ramsay sedation scale. RESULTS: In 30 of 30 cases, percutaneous arterial chemoembolization therapy could be performed with dexme- detomidine sedation. In 27 of 30 cases, the procedure was completed with the maintenance dose of 0.4 mg/kg/h. In 3 of 30 cases, the maintenance dose was increased to 0.6 mg/kg/h because of patient body motion. The mean administration time of dexmedetomidine was 82±30 minutes. The level of sedation measured with the Ramsay sedation scale at the end of the procedure was 3 points in 29 cases and 5 points in one case. Adverse events occurred in 3 of 30 cases. Intravenous drip leakage occurred in one case, vertigo occurred in one case, and vomiting occurred in one case. There were no adverse events requiring treatment. CONCLUSION: Sedation with dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction was feasible and safe.