Dramatic Amelioration in Serial Magnetic Resonance Imaging in an "Isolated Brainstem" Reversible Encephalopathy Syndrome Case.

Posterior reversible encephalopathy syndrome (PRES) is characterized by transient vasogenic edema predominantly in supratentorial areas within the posterior circulation regions. Although PRES with only brainstem involvement is quite rare, accurate diagnosis is important because prompt antihypertensive therapy contributes to a favorable outcome. Herein, we report a case with isolated brainstem PRES showing dramatical improvement in an apparent diffusion coefficient (ADC) value of the lesion in magnetic resonance imaging (MRI) after clinical remission. The present case suggests the association between favorable clinical course and complete amelioration on MRI.

Investigation of myocardial extracellular volume fraction in heart failure patients using iodine map with rapid-kV switching dual-energy CT: Segmental comparison with MRI T1 mapping.

PURPOSE: To measure myocardial extracellular volume fraction (ECV) for each region or segment using iodine density image (IDI) with single-source dual-energy computed tomography (DECT) and compare the results with an MRI T1 mapping approach. MATERIALS AND METHODS: For this prospective study, 79 consecutive heart failure patients referred for MRI were included and 23 patients (14 men, 63 ± 14 years) who underwent both MRI and late contrast enhancement DECT following coronary CT angiography were evaluated. CT-ECV was computed from IDI using late acquisition projection data. MR-ECV was computed from native and post-contrast T1 maps using non-rigid image registration for segments with evaluable image quality from 3.0-T MRI. Regional CT-ECV and MR-ECV were measured based on 16-segment models. CT-ECV and MR-ECV were compared using Pearson correlations. Agreement among methods was assessed using Bland-Altman comparisons. RESULTS: In the 368 segments, although all segments were evaluable on IDI, 37 segments were rated as non-evaluable on T1 maps. Overall, 331 segments were analyzed. Mean CT-ECV and MR-ECV were 31.6 ± 9.1 and 33.2 ± 9.1, respectively. Strong correlations were seen between CT-ECV and MR-ECV for each region, as follows: all segments, r = 0.837; septal, r = 0.871; mid-septal, r = 0.895; anterior, r = 0.869; inferior, r = 0.793; and lateral, 0.864 (all p < 0.001). Differences between CT-ECV and MR-ECV were as follows: all segments, 1.13 ± 4.98; septal, -1.51 ± 4.37; mid-septal, -1.85 ± 4.22; anterior, 2.54 ± 4.89; inferior, 1.2 ± 5.78; and lateral, 2.65 ± 3.98. CONCLUSION: ECV using DECT and from cardiac MRI showed a strong correlation on regional and segmental evaluations. DECT is useful for characterizing myocardial ECV changes as well as MRI.

Myocardial delayed enhancement on dual-energy computed tomography: The prevalence and related factors in patients with suspicion of coronary artery disease.

BACKGROUND: We aimed to assess the prevalence of myocardial delayed enhancement (MDE) in patients with suspected obstructive coronary artery disease (CAD), and to investigate factors related to the presence or absence of MDE. METHODS: We retrospectively evaluated 191 consecutive patients who underwent coronary computed tomography angiography (CCTA) with MDE imaging for clinical suspicion of CAD from December 2014 to December 2016. The presence of MDE on iodine-density images using dual-energy CT was assessed by two independent readers. Multivariable logistic regression analyses were used to determine factors associated with the presence of MDE. RESULTS: MDE was detected in 58 (30%) patients. Male gender, hypertension, prior heart failure (HF) hospitalization, and CCTA-detected CAD were independent factors related to the presence of MDE. When CCTA-detected CAD was excluded to narrow down the analysis to factors obtainable before CCTA, interventricular septum thickness (IVST) ≥12 mm was added as another independent factor. The combination of the following four factors: female gender, no history of hypertension, no history of prior HF hospitalization, and IVST < 12 mm demonstrated high specificity (98.3%) and positive predictive value (96.2%) for predicting the absence of MDE. CONCLUSIONS: Male gender, hypertension, prior HF hospitalization, and CAD were independently associated with the presence of MDE in patients with suspected CAD. The combination of female gender, no history of hypertension, no history of prior HF hospitalization, and IVST < 12 mm is likely to be a helpful predictor in discriminating patients without MDE before CCTA.

Compressed Amplatzer Vascular Plug II Embolization of the Left Subclavian Artery for Thoracic Endovascular Aortic Repair is Efficient and Safety Method Comparable to Conventional Coil Embolization.

BACKGROUND: Left subclavian artery (LSA) embolization is occasionally required to prevent type II endoleak in the thoracic endovascular aortic repair (TEVAR) procedure. This is a retrospective study comparing compressed Amplatzer Vascular Plug II embolization (CAE) and conventional coil embolization (CCE) in preventing retrograde flow into the aneurysmal sac through the LSA after TEVAR. METHODS: We retrospectively reviewed the records of patients who underwent CAE or CCE of the LSA during TEVAR from June 2013 to March 2016 in our hospital. The efficacy, safety and cost of each method were compared between two groups. RESULTS: Thirty patients underwent LSA embolization during TEVAR. Six CCEs in 6 patients were performed from June 2013 to November 2013, while twenty-four CAEs in 24 patients were performed from December 2013 to March 2016. Technical success was achieved in all patients in both groups. No embolization-related complications or type II endoleaks from LSA were recorded during the follow-up period in all patients. In both groups, all embolic materials were detected in the proximal portion of the LSA from the LSA orifice to the vertebral artery origin and no vertebral artery occlusions were detected. The mean compression ratio of AVP II was 58 ± 5.9% of predicted length of standard procedure. In the CAE group, one AVP II was sufficient to achieve complete LSA occlusion in all patients. On the other hand, multiple coils (10.2 ± 2.7) were used in the CCE group (P < .01), resulting in a significantly lower cost incurred in the CAE group (CAE: 129,000 JPY vs. CCE: 639,600 ± 140,060 JPY; P < .01). CONCLUSION: The CAE is a useful and cost-effective procedure for TEVAR-related LSA embolization.

Usefulness of Preoperative 18F-FDG PET/CT for Patients with Thymic Epithelial Tumors.

BACKGROUND: The purpose of this study was to investigate the relationship between preoperative FDG-PET parameters and the World Health Organization (WHO) classification or Masaoka staging system of thymic epithelial tumors. METHODS: We retrospectively reviewed 32 patients with histologically proven thymic epithelial tumors who underwent FDG-PET/CT before surgical resection. FDG-PET parameters, including the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolytic activity (TLG), were measured. These PET parameters were compared in the Masaoka staging system and WHO classification. A receiver operating characteristics (ROC) analysis was performed to identify the cut-off values of PET parameters for the accurate differentiation of early and advanced stages in the Masaoka staging system. RESULTS: There were 17 low-risk thymomas (1 type A, 9 type AB, and 7 type B1), 8 high-risk thymomas (4 type B2 and 4 type B3), and 7 thymic carcinomas (7 squamous cell carcinoma). Their Masaoka stages were as follows: 24 in the early stage (stages I and II) and 8 in the advanced stage (stage III). Regarding the WHO classification, only SUVmax showed a significant difference (P < 0.05). In the Masaoka stage, all PET parameters were significantly higher in the advanced stage than in the early stage (P < 0.05). In the ROC analysis to predict the early and advanced stages in thymic epithelial tumors, the area under the curve was the highest for TLG among the PET parameters examined and the cut-off value of TLG for discriminating the early from advanced stage with maximal sensitivity and specificity was 30.735. CONCLUSION: Although volumetric PET parameters, such as MTV and TLG, did not correlate with the WHO classification, a significant correlation was observed between SUVmax and the WHO classification. In the Masaoka staging system, volumetric PET parameters may achieve more precise staging than SUVmax.

The utility of the combined use of 123I-FP-CIT SPECT and neuromelanin MRI in differentiating Parkinson's disease from other parkinsonian syndromes.

BACKGROUND: Neuromelanin magnetic resonance imaging (NmMRI) and 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) provide specific information that distinguishes Parkinson's disease (PD) from non-degenerative parkinsonian syndrome (NDPS). PURPOSE: To determine whether a multiparametric scoring system (MSS) could improve accuracy compared to each parameter of DAT-SPECT and NmMRI in differentiating PD from NDPS. MATERIAL AND METHODS: A total of 49 patients, including 14 with NDPS, 30 with PD, and five with atypical parkinsonian disorder (APD) underwent both NmMRI and DAT-SPECT and were evaluated. The average (Ave) and the asymmetry index (AI) were calculated in the substantia nigra compacta area (SNc-area), SNc midbrain-tegmentum contrast ratio (SNc-CR), and specific binding ratio (SBR). Cut-off values were determined, using receiver operating characteristic (ROC) analysis, for the differentiation of PD from NDPS on the statistically significant parameters. All cases were scored as either 1 (PD) or 0 (NDPS) for each parameter according to its threshold. These individual scores were totaled for each case, yielding a combined score for each case to obtain a cut-off value for the MSS. RESULTS: The Ave-SNc-area, Ave-SNc-CR, and Ave-SBR in PD were significantly lower than those in NDPS. The AI-SNc-area and AI-SBR in PD were significantly higher than those in NDPS. Of the five parameters, the highest accuracy was 93% for the Ave-SNc-area. For the MSS, a cut-off value of 3 was the accuracy of 96%. Besides, no significant difference was observed between PD and APD on all parameters. CONCLUSION: An MSS has comparable or better accuracy compared to each parameter of DAT-SPECT and NmMRI in distinguishing PD from NDPS.

Quantitative evaluation of non-ischemic dilated cardiomyopathy by late iodine enhancement using rapid kV switching dual-energy computed tomography: A feasibility study.

OBJECTIVES: The aim of this study was to evaluate the feasibility of myocardial iodine density and extracellular volume fraction (ECV) from delayed iodine density images using dual-energy computed tomography (DECT) for differentiation between non-ischemic dilated cardiomyopathy (NIDCM) patients and normal subjects. METHODS: Forty-six subjects were imaged, including 35 normal subjects and 11 patients with NIDCM. All subjects underwent myocardial delayed enhancement (MDE) imaging on rapid-kVp switching DECT. Global and segmental iodine density and ECV were calculated from MDE images. Histogram analysis was also performed. Receiver-operator characteristic (ROC) analysis was used to determine the cut-off value and diagnostic performances in differentiating NIDCM patients from normal subjects. RESULTS: Global iodine density and ECV were significantly higher in NIDCM compared with normal controls (iodine: 14.19 ±â€¯3.90 vs. 10.69 ±â€¯1.88 in 100 µg/cm3, p = 0.015; ECV: 31.35 ±â€¯2.53% vs. 26.62 ±â€¯2.69%, p < 0.001). In histogram analyses, kurtosis was higher in NIDCM than in controls (0.47 ±â€¯0.46 vs. 1.26 ±â€¯0.88, p < 0.001). On segmental analysis, ECV showed higher values in NIDCM than in controls for all segments. ECV could differentiate between normal myocardium and NIDCM with 91.0% sensitivity and 86.0% specificity at a cut-off of 28.82% (area under the curve of ROC, 0.906). Iodine density could differentiate between normal myocardium and NIDCM with 91% sensitivity and 60% specificity at a cut-off of 11.18 (area under the curve of ROC, 0.812). CONCLUSIONS: Iodine density and ECV values from DECT may provide indices offering high diagnostic accuracy for discriminating between NIDCM and normal myocardium.

Detection and Classification of Myocardial Delayed Enhancement Patterns on MR Images with Deep Neural Networks: A Feasibility Study.

PURPOSE: To evaluate whether deep neural networks trained on a similar number of images to that required during physician training in the American College of Cardiology Core Cardiovascular Training Statement can acquire the capability to detect and classify myocardial delayed enhancement (MDE) patterns. MATERIALS AND METHODS: The authors retrospectively evaluated 1995 MDE images for training and validation of a deep neural network. Images were from 200 consecutive patients who underwent cardiovascular MRI and were obtained from the institutional database. Experienced cardiac MR image readers classified the images as showing the following MDE patterns: no pattern, epicardial enhancement, subendocardial enhancement, midwall enhancement, focal enhancement, transmural enhancement, and nondiagnostic. Data were divided into training and validation datasets by using a fourfold cross-validation method. Three untrained deep neural network architectures using the convolutional neural network (CNN) technique were trained with the training dataset images. The detection and classification accuracies of the trained CNNs were calculated with validation data. RESULTS: The 1995 MDE images were classified by human readers as follows: no pattern, 926; epicardial enhancement, 91; subendocardial enhancement, 458; midwall enhancement, 118; focal enhancement, 141; transmural enhancement, 190; and nondiagnostic, 71. GoogLeNet, AlexNet, and ResNet-152 CNNs demonstrated accuracies of 79.5% (1592 of 1995 images), 78.9% (1574 of 1995 images), and 82.1% (1637 of 1995 images), respectively. CONCLUSION: Deep learning with CNNs using a limited amount of training data, less than that required during physician training, achieved high diagnostic performance in the detection of MDE on MR images.© RSNA, 2019Supplemental material is available for this article.

Role of Neuroimaging on Differentiation of Parkinson's Disease and Its Related Diseases.

An accurate diagnosis of Parkinson's disease (PD) is a prerequisite for therapeutic management. In spite of recent advances in the diagnosis of parkinsonian disorders, PD is misdiagnosed in between 6 and 25% of patients, even in specialized movement disorder centers. Although the gold standard for the diagnosis of PD is a neuropathological assessment, neuroimaging has been playing an important role in the differential diagnosis of PD and is used for clinical diagnostic criteria. In clinical practice, differential diagnoses of PD include atypical parkinsonian syndromes such as dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, caused by a striatal dopamine deficiency following nigrostrial degeneration. PD may also be mimicked by syndromes not associated with a striatal dopamine deficiency such as essential tremor, drug-induced parkinsonism, and vascular parkinsonism. Moreover, difficulties are associated with the clinical differentiation of patients with parkinsonism from those with Alzheimer's disease. In this review, we summarize the typical imaging findings of PD and its related diseases described above using morphological imaging modalities (conventional MR imaging and neuromelanin MR imaging) and functional imaging modalities (99mTc-ethyl cysteinate dimer perfusion single photon emission computed tomography, 123I-metaiodobenzylguanidine myocardial scintigraphy, and 123I-FP-CIT dopamine transporter single photon emission computed tomography) that are clinically available in most hospitals. We also attempt to provide a diagnostic approach for the differential diagnosis of PD and its related diseases in clinical practice.

Assessment of myocardial fibrosis using T1-mapping and extracellular volume measurement on cardiac magnetic resonance imaging for the diagnosis of radiation-induced cardiomyopathy.

Radiation-induced heart disease (RIHD) is a serious side effect of thoracic radiation therapy (RT) and is associated with significant morbidity and mortality. Radiation-induced cardiomyopathy (RICM) is one of the manifestations of RIHD, which represents with left ventricular (LV) systolic and diastolic dysfunction due to myocardial fibrosis. Although the diagnosis of RIHD is challenging and is generally an exclusion diagnosis, multimodality imaging including echocardiography, cardiac computed tomography and cardiac magnetic resonance (CMR) imaging could help the diagnosis. Herein, we report a case of 70-years-old male, who had been treated with chemo-radiation therapy for early esophageal cancer, was suffered from medically refractory heart failure due to severely reduced LV systolic function and constrictive pericarditis 8 years after chemo-radiation therapy. Although no gadolinium-enhancement (LGE) was detected on CMR, T1 mapping depicted increased extracellular matrix volumes of 45%, which suggested global myocardial fibrosis. Histopathological analysis by endomyocardial biopsy (EBM) revealed marked degeneration of myocytes and interstitial fibrosis, while vacuolation in myocytes which is characteristics of chemotherapy induced cardiomyopathy was not specific by electron microscopy. Therefore, we diagnosed that the present case was likely to the RICM. .

Myocardial Delayed Enhancement CT for the Evaluation of Heart Failure: Comparison to MRI.

Purpose To assess the diagnostic performance of dual-energy CT with myocardial delayed enhancement (MDE) in the detection and classification of myocardial scar in patients with heart failure, with late gadolinium enhancement (LGE) MRI as the standard of reference. Materials and Methods MDE CT and LGE MRI were performed in 44 patients with heart failure (30 men; mean patient age, 66 years ± 14) between 2013 and 2016, and images were retrospectively analyzed. The presence and patterns of MDE on iodine-density and virtual monochromatic (VM) images were assessed by two independent readers. Contrast-to-noise ratio (CNR) and percentage signal intensity increase relative to normal myocardium were measured. Diagnostic performance and area under the receiver operating characteristic curve for MDE CT and kappa values for reader agreement were determined. Results Thirty-five of the 44 patients (80%) demonstrated a focal area of LGE, with a nonischemic pattern in 22 of the 44 patients (50%) and an ischemic pattern in 13 (30%). Iodine-density images demonstrated the highest CNR and percentage signal intensity increase on CT images (P < .05), resulting in the highest diagnostic performance in the detection of any MDE CT abnormality (92% sensitivity [195 of 213 segments] and 98% specificity [481 of 491 segments]). The areas under the receiver operating characteristic curve for iodine-density images and 40-keV VM images in the detection of MDE were 0.97 and 0.95, respectively (P < .001). Kappa values for reader agreement were 0.82 for iodine-density images and 0.72 for 40-keV VM images. Conclusion Myocardial delayed enhancement CT enables accurate detection and localization of scar in patients with heart failure when compared with late gadolinium enhancement MRI, the reference standard.

Bilateral Ovarian Tumors on MRI: How Should We Differentiate the Lesions?

BACKGROUND: We investigated the distinguishing pathological features of bilateral ovarian tumors using magnetic resonance (MR) imaging. METHODS: Eighty-six patients with bilateral ovarian tumors on MR imaging were evaluated. The pathological diagnosis was investigated, and the results were subjected to statistical analysis using Mann-Whitney U test, Fisher's exact test, Chi-squared test and receiver operating characteristic (ROC) curve to determine the features useful for the differentiation of distinct types of lesions. RESULTS: The diagnosis of bilateral ovarian tumors was confirmed in eighty-one patients and the majority of the lesions were further classified into serous carcinoma (n = 36), mature teratoma (n = 20) and metastasis (n = 12). We assessed the existence of factors useful for the MR imaging differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors. Cancer antigen (CA) 125 serum level and maximum tumor diameter were significantly different between metastasis and serous carcinoma and similarly, between metastasis and primary malignant ovarian tumors. MR imaging morphology, ascites and peritoneal implants did not show any significant difference between the different types of lesions. CONCLUSION: Within our patient cohort, most bilateral ovarian tumor lesions were determined to be serous carcinoma, mature teratoma or metastasis. CA 125 serum level and maximum tumor diameter are useful markers for the differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors.

The Utility of the Combined Use of 123I-FP-CIT and 123I-MIBG Myocardial Scintigraphy in Differentiating Parkinson's Disease from Other Parkinsonian Syndromes.

BACKGROUND: 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy and 123I-FP-CIT dopamine transporter single photon emission computed tomography (DAT-SPECT) provide specific information that distinguish Parkinson's disease (PD) from parkinsonian syndromes other than PD (non-PD), including atypical parkinsonian disorder (APD) and non-PD other than APD (nPD-nAPD). The purpose of this study was to determine whether combining DAT-SPECT and MIBG myocardial scintigraphy using multiparametric scoring system (MSS) could improve diagnostic test accuracy in discriminating PD from APD or discriminating PD from nPD-nAPD. METHODS: A total of 52 patients, including 36 PD, eight APD and eight nPD-nAPD, underwent both MIBG myocardial scintigraphy and DAT-SPECT, were evaluated. The heart-to-mediastinum (H/M) ratios (early and delayed), washout-rate (WR), the average (Ave) and asymmetry index (AI) of specific binding ratio (SBR) were calculated. Cutoff values were determined, using ROC analysis, for discriminating PD from APD and for discriminating PD from nPD-nAPD, on five parameters. All cases were scored as either 1 (PD) or 0 (nPD-nAPD or APD) for each parameter according to its threshold in each discrimination. These individual scores were summed for each case, yielding a combined score to obtain a cutoff value for the MSS in each discrimination. RESULTS: For discriminating PD from nPD-nAPD, the highest accuracy was 80% at a cutoff value of 19% for the WR and a cut off value of 2 improved diagnostic accuracy to 84% for MSS. For discriminating PD from APD, the highest accuracy was 86% at a cutoff value of 2.8 for the H/M ratio (late) and a cut off value of 2 showed diagnostic accuracy of 86% for MSS. CONCLUSION: A MSS has comparable or better accuracy compared to each parameter of MIBG myocardial scintigraphy and DAT-SPECT in distinguishing PD from nPD-nAPD or distinguishing PD from APD.

Vanishing Parotid Tumors on MR Imaging.

BACKGROUND: Of all parotid gland tumors, only oncocytoma has been reported to appear isointense to the parotid gland, namely vanishing, on fat-saturated T2 and T1 postcontrast gadolinium-enhanced magnetic resonance imaging (MRI). The purpose of this study was to evaluate vanishing of parotid tumors on conventional MRI with and/or without postcontrast gadolinium-enhancement and on diffusion weighted imaging (DWI). METHODS: In 8 of 51 patients, ten parotid gland tumors had homogeneously enhanced lesions and were retrospectively analysed. Comparisons of signal intensity between those parotid tumors and parotid glands and evaluations of vanishing were performed on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), fat-suppressed T2WI (FS-T2WI), postcontrast gadolinium-enhanced T1WI (CE-T1WI) and fat-suppressed CE-T1WI (FS-CE-T1WI), DWI as well as apparent diffusion coefficient (ADC). RESULTS: Ten parotid gland tumors consisted of five Warthin tumors, two pleomorphic adenomas, two parotid carcinomas (small cell carcinoma and adenoid cystic carcinoma) and one oncocytoma. All tumors showed hypointensity on T1WI and hyperintensity on DWI. Nine of ten tumors showed vanishing on the other MR sequences. All Warthin tumors showed vanishing on FS-T2WI, FS-CE-T1WI and the ADC map. One oncocytoma showed vanishing on FS-T2WI and the ADC map and hyperintensity on FS-CE-T1WI. All pleomorphic adenomas showed vanishing on T2WI and CE-T1WI. One adenoid cystic carcinoma showed vanishing only on CE-T1WI. CONCLUSION: Vanishing of parotid tumors can be observed not only on FS-T2WI and FS-CE-T1WI but also on T2WI, CE-T1WI and ADC mapping.

Utility of intravoxel incoherent motion magnetic resonance imaging and arterial spin labeling for recurrent glioma after bevacizumab treatment.

Background Detecting recurrence of glioma on magnetic resonance imaging (MRI) is getting more and more important, especially after administration of new anti-tumor agent. However, it is still hard to identify. Purpose To examine the utility of intravoxel incoherent motion (IVIM) MRI and arterial spin labeling-cerebral blood flow (ASL-CBF) for recurrent glioma after initiation of bevacizumab (BEV) treatment. Material and Methods Thirteen patients (7 men, 6 women; age range = 41-82 years) with glioma (high grade, n = 11; low grade, n = 2) were enrolled in the study. IVIM parameters including apparent diffusion coefficient (ADC), true diffusion coefficient (D), and perfusion fraction (f) were obtained with 14 different b-values. We identified tumor progression during BEV therapy by MRI monitoring consisting of diffusion-weighted imaging (DWI), fluid-attenuated inversion recovery (FLAIR) imaging, and contrast-enhanced T1-weighted (CE-T1W) imaging by measuring tumor area. We also measured each parameter of IVIM and ASL-CBF, and calculated relative ADC (rADC), relative D (rD), relative f (rf), and relative CBF (rCBF) by obtaining the ratio between each area and the contralateral cerebral white matter. We calculated the rate of change (Δ) by subtracting values from those from the preceding MRI study, and obtained Spearman's rank correlation coefficient (rs). Results Tumor progression was identified in nine patients (high grade, n = 7; low grade, n = 2). Negative correlations were identified between ΔrD and ΔDWI area (rs = -0.583), and between ΔrD and ΔCE-T1W imaging area (rs = -0.605). Conclusion Tumor progression after BEV treatment can be identified by decreasing rD.

Non-Surgical Management of Bile Leakage After Hepatectomy: A Single-Center Study.

BACKGROUND: Bile leakage after hepatectomy is a common complication. The purpose of the present study was to retrospectively evaluate the usefulness of non-surgical management of bile leakage after hepatectomy, using 12-year data from a single center study. METHODS: Data from 15 patients (13 men, two women; mean age 67.1 ± 7.0 years) who had undergone non-surgical management for bile leakage between January 2005 and November 2017 were retrospectively reviewed. RESULTS: We categorized bile leakage as central (n = 5) or peripheral (n = 10) leakage based on communication with the biliary tree. Percutaneous bile leakage drainage and/or endoscopic naso-biliary drainage (ENBD) (n = 2) or the rendezvous technique (n = 3) was successfully performed in five central-type cases, while all peripheral-type cases were treated with drainage alone; only one case required additional ethanol ablation. Bacterial bile cultures were positive in 11 cases and negative in four cases. The drainage catheters were removed after complete resolution in 13 cases (86.7%), while two patients with cases of peripheral-type leakage died due to cancer progression while the drain was in place. No case needed conversion to reoperation. The mean duration of drainage therapy in all cases was 210.1 ± 163.0 days (range 17-531 days), with 316.8 ± 180.8 days in the central type and 156.7 ± 131.5 days in the peripheral type; this duration was not significantly different (P = 0.129). CONCLUSION: Non-surgical treatment is a minimally invasive and effective management strategy for postoperative bile leakage and the modality used depends on the type of bile leakage encountered.