A differential risk assessment and decision model for Transarterial chemoembolization in hepatocellular carcinoma based on hepatic function.

BACKGROUND: The decision of transarterial chemoembolization (TACE) initiation and/or repetition remains challenging in patients with unresectable hepatocellular carcinoma (HCC). The aim was to develop a prognostic scoring system to guide TACE initiation/repetition. METHODS: A total of 597 consecutive patients who underwent TACE as their initial treatment for unresectable HCC were included. We derived a prediction model using independent risk factors for overall survival (OS), which was externally validated in an independent cohort (n = 739). RESULTS: Independent risk factors of OS included Albumin-bilirubin (ALBI) grade, maximal tumor size, alpha-fetoprotein, and tumor response to initial TACE, which were used to develop a scoring system ("ASAR"). C-index values for OS were 0.733 (95% confidence interval [CI] = 0.570-0.871) in the derivation, 0.700 (95% CI = 0.445-0.905) in the internal validation, and 0.680 (95% CI = 0.652-0.707) in the external validation, respectively. Patients with ASAR< 4 showed significantly longer OS than patients with ASAR≥4 in all three datasets (all P < 0.001). Among Child-Pugh class B patients, a modified model without TACE response, i.e., "ASA(R)", discriminated OS with a c-index of 0.788 (95% CI, 0.703-0.876) in the derivation, and 0.745 (95% CI, 0.646-0.862) in the internal validation, and 0.670 (95% CI, 0.605-0.725) in the external validation, respectively. Child-Pugh B patients with ASA(R) < 4 showed significantly longer OS than patients with ASA(R) ≥ 4 in all three datasets (all P < 0.001). CONCLUSIONS: ASAR provides refined prognostication for repetition of TACE in patients with unresectable HCC. For Child-Pugh class B patients, a modified model with baseline factors might guide TACE initiation.

Diagnostic accuracy of contrast-enhanced dynamic CT for small hypervascular hepatocellular carcinoma and assessment of dynamic enhancement patterns: Results of two-year follow-up using cone-beam CT hepatic arteriography.

OBJECTIVE: To evaluate the accuracy of CT for small, hypervascular hepatocellular carcinomas (HCCs) and assess the enhancement patterns on CT. MATERIALS AND METHODS: Ninety-nine patients who underwent cone-beam CT hepatic arteriography (CBCT-HA) during initial chemoembolization for HCC suspected on CT were enrolled in this study. A total of 297 hypervascular HCCs (142 ≥ 1 cm, 155 < 1 cm) were confirmed as HCCs based on two-year follow-up CT and CBCT-HA images. During the two-year follow-up, pre-existing hypervascular foci on CBCT-HA were regarded as HCCs at the initial presentation. Two radiologists categorized HCCs according to the following enhancement patterns on CT: type I, arterial enhancement and washout; type II, arterial enhancement without washout; and type III, no arterial enhancement. Two blinded reviewers rated the possibility of HCC. RESULTS: For the 297 HCCs, the enhancement patterns according to size were as follows: type I ≥1 cm in 114 HCCs; type I <1 cm in 40 HCCs; type II ≥1 cm in 16 HCCs; type II <1 cm in 37 HCCs; type III ≥1 cm in 12 HCCs; and type III <1 cm in 10 HCCs. The remaining 68 HCCs (22.9%) were not detected on CT. The detection rates of HCCs ≥ 1 cm were 83.1%, 76.8%, and 83.1% in the formal report for reviewer 1 and reviewer 2. In comparison, the detection rates of HCCs < 1 cm were 20.6%, 17.4%, and 17.4% in the formal report for reviewer 1 and reviewer 2. CONCLUSION: Many subcentimeter sized hypervascular HCCs were frequently missed or not evident on CT at the initial diagnostic workup. CT has limitations for diagnosing HCCs that are <1 cm in size or have atypical enhancement patterns.

Cone-beam computed tomography with automated bone subtraction in preoperative embolization for pelvic bone tumors.

PURPOSE: To evaluate the usefulness of cone-beam computed tomography with automated bone subtraction (CBCT-ABS) in the preoperative embolization of hypervascular tumors located in the pelvic bone. MATERIALS AND METHODS: This retrospective study included 26 patients with pelvic bone tumors who underwent preoperative embolization between January 2014 and October 2016. A CBCT-ABS scan was taken in a total of 17 patients (CBCT-ABS group), and only a series of digital subtraction angiographies (DSAs) was taken in the remaining 9 patients (DSA group). The percent devascularization, number of angiographic runs, total dose-area product (DAP), fluoroscopy time, interventional procedure time, operative time, and estimated blood loss were compared between the two groups using Mann-Whitney test. RESULTS: The percent devascularization, interventional procedure time, fluoroscopy time, operative time, and estimated blood loss were not statistically different between the two groups (p > 0.05). On the other hand, the number of angiographic runs in the CBCT-ABS group was significantly lower than that in the DSA group (p = 0.029). The total DAP of the CBCT-ABS group (mean, 17700.7 µGym2) was higher than that of the DSA group (mean, 8939.4 µGym2) (p = 0.002). CONCLUSIONS: The use of CBCT-ABS during the preoperative embolization of pelvic bone tumors significantly reduces the number of angiographic runs at the cost of an increased radiation dose.

Feasibility of 320-row area detector CT coronary angiography using 40 mL of contrast material: assessment of image quality and diagnostic accuracy.

OBJECTIVES: To assess the image quality and diagnostic accuracy of 320-row area detector CT (320-ADCT) coronary angiography using 40 mL of contrast material in comparison with 60-mL protocol. METHODS: This retrospective study included 183 patients who underwent 320-ADCT coronary angiography using 40 mL of contrast and additional 183 sex- and body mass index-matched patients using 60 mL of contrast constituting the control group. Both groups used the same 5-mL/sec injection rate. Quantitative image quality measurements and diagnostic accuracies were calculated and compared. RESULTS: Mean attenuation and contrast-to-noise ratio (CNR) at the aorta and all coronary arteries were lower in the 40-mL group than in the 60-mL group (all, p < 0.05), except for the CNR at proximal coronary arteries at 100 kVp (p = 0.073). However, the proportion of coronary segments with vessel attenuation >250 HU was not different between groups (all, p > 0.05), except for distal coronary arteries at 80 kVp (p = 0.001). Furthermore, there were no differences in per-patient and per-segment diagnostic accuracies between the groups (all, p > 0.05). CONCLUSIONS: 320-ADCT coronary angiography using 40 mL of contrast showed image quality and diagnostic accuracy comparable to the 60-mL protocol, demonstrating the clinical feasibility of lowering the risk of contrast-induced nephropathy through contrast volume reduction. KEY POINTS: • 320-ADCT might enable reduction of contrast material volume. • A 40-mL contrast protocol for 320-ADCT provided acceptable image quality. • A 40-mL contrast protocol for 320-ADCT demonstrated sufficient diagnostic accuracy.

Quantitative Assessment of Foot Blood Flow by Using Dynamic Volume Perfusion CT Technique: A Feasibility Study.

PURPOSE: To demonstrate the feasibility of foot blood flow measurement by using dynamic volume perfusion computed tomographic (CT) technique with the upslope method in an animal experiment and a human study. MATERIALS AND METHODS: The human study was approved by the institutional review board, and written informed consent was obtained from all patients. The animal study was approved by the research animal care and use committee. A perfusion CT experiment was first performed by using rabbits. A color-coded perfusion map was reconstructed by using in-house perfusion analysis software based on the upslope method, and the measured blood flow on the map was compared with the reference standard microsphere method by using correlation analysis. A total of 17 perfusion CT sessions were then performed (a) once in five human patients and (b) twice (before and after endovascular revascularization) in six human patients. Perfusion maps of blood flow were reconstructed and analyzed. The Wilcoxon signed rank test was used to prove significant differences in blood flow before and after treatment. RESULTS: The animal experiment demonstrated a strong correlation (R(2) = 0.965) in blood flow between perfusion CT and the microsphere method. Perfusion maps were obtained successfully in 16 human clinical sessions (94%) with the use of 32 mL of contrast medium and an effective radiation dose of 0.31 mSv (k factor for the ankle, 0.0002). The plantar dermis showed the highest blood flow among all anatomic structures of the foot, including muscle, subcutaneous tissue, tendon, and bone. After a successful revascularization procedure, the blood flow of the plantar dermis increased by 153% (P = .031). The interpretations of the color-coded perfusion map correlated well with the clinical and angiographic findings. CONCLUSION: Perfusion CT could be used to measure foot blood flow in both animals and humans. It can be a useful modality for the diagnosis of peripheral arterial disease by providing quantitative information on foot perfusion status.

Late gadolinium enhancement magnetic resonance imaging for the assessment of myocardial infarction: comparison of image quality between single and double doses of contrast agents.

To compare the image quality of late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMR) using a single dose of gadolinium contrast agent versus the conventional double dose for assessing myocardial infarction. This retrospective study examined 37 patients with chronic myocardial infarction who underwent LGE CMR using both inversion recovery (IR)-turbo fast low-angle shot magnitude-reconstructed and phase-sensitive images with two different dosages of gadolinium contrast agent: a single dose of 0.1 mmol/kg gadolinium-DTPA in 17 patients and a double dose of 0.2 mmol/kg in 20 patients. The contrast-to-noise ratio (CNR) and visual conspicuity between infarct and normal myocardium (CNRinfarct-normal, conspicuityinfarct-normal) and between infarct and left ventricular cavity (CNRinfarct-LVC, conspicuityinfarct-LVC) were compared. Interobserver agreement for the maximal transmural extent of infarction was also evaluated. CNRinfarct-normal was significantly higher with double-dose gadolinium contrast agent (15.5 ± 20.7 vs. 40.4 ± 16.1 in magnitude images and 9.5 ± 2.8 vs. 11.2 ± 2.7 in phase-sensitive images, P < 0.001) while conspicuityinfarct-normal showed no significant difference between the two groups (P > 0.05). Both CNRinfarct-LVC (7.7 ± 10.7 vs. -6.6 ± 19.0 in magnitude images and 4.1 ± 2.3 vs. -0.4 ± 4.1 in phase-sensitive images, P < 0.05) and conspicuityinfarct-LVC were significantly better with single-dose gadolinium contrast. Interobserver agreement for assessing the transmural extent of infarction was moderate in both groups: 0.591 for single-dose and 0.472 for double-dose. LGE CMR using a single dose of gadolinium contrast agent showed significantly better contrast between infarcted myocardium and left ventricular cavity lumen without a significant decrease in visual contrast between infarcted myocardium and normal myocardium, compared to a double dose.

Comparison of costs of endovascular repair versus open surgical repair for abdominal aortic aneurysm in Korea.

This study was designed to compare the hospital-related costs of elective abdominal aortic aneurysm (AAA) treatment and cost structure between endovascular aneurysm repair (EVAR) and open surgical repair (OSR) in Korean health care system. One hundred five primary elective AAA repairs (79 OSRs and 26 EVARs) performed in the Seoul National University Hospital from 2005 to 2009 were included. Patient characteristics were similar between two groups except for older age (P = 0.004) and more frequent history of malignancy (P = 0.031) in EVAR group. Thirty-day mortality rate was similar between two groups and there was no AAA-related mortality in both groups for 5 yr after repair. The total in-hospital costs for the index admission were significantly higher in EVAR patients (mean, KRW19,857,119) than OSR patients (mean KRW12,395,507) (P < 0.001). The reimbursement was also significantly higher in EVAR patients than OSR patients (mean, KRW14,071,081 vs KRW6,238,895, P < 0.001) while patients payments was comparable between two groups. EVAR patients showed higher follow-up cost up to 2 yr due to more frequent imaging studies and reinterventions for type II endoleaks (15.4%). In the perspective of cost-effectiveness, this study suggests that the determination of which method to be used in AAA treatment be more finely trimmed and be individualized.

Iterative reconstruction of dual-source coronary CT angiography: assessment of image quality and radiation dose.

To assess the image quality and radiation dose of low-dose dual-source CT (DSCT) coronary angiography reconstructed using iterative reconstruction in image space (IRIS), in comparison with routine-dose CT using filtered back projection (FBP). Eighty-one patients underwent low-dose coronary DSCT using IRIS with two protocols: (a)100 kVp and 200 mAs per rotation for body mass index (BMI) < 25 (group I), (b)100 kVp and 320 mAs for BMI ≥ 25 (II). For comparison, two sex-and BMI-matched groups using standard protocols with FBP were selected: (a)100 kVp and 320 mAs for BMI < 25 (III), (b)120 kVp and 320 mAs for BMI ≥ 25 (IV). Image noise, signal to noise ratio (SNR) and modulation transfer function (MTF) 50% were objectively calculated. Two blinded readers then subjectively graded the image quality. Radiation dose was also measured. Image noise tended to be lower in IRIS of low-dose protocols: 22.0 ± 4.5 for group I versus 24.8 ± 4.0 for III (P < 0.001); 20.9 ± 4.5 for II versus 21.6 ± 4.9 for IV (P = 0.6). SNR was better with IRIS: 25.8 ± 4.4 for I versus 22.7 ± 4.6 for III (P < 0.001); 24.6 ± 5.4 for II versus 18.7 ± 4.5 for IV (P < 0.001). No differences in MTF 50% or image quality scores were seen between each two groups (P > 0.05). Radiation reduction was 40% for I and 51% for II, compared to standard protocols. Compared with routine-dose CT using FBP, low-dose coronary angiography using IRIS provides significant radiation reduction without impairment to image quality.

Hepatic resection versus radiofrequency ablation for very early stage hepatocellular carcinoma: a Markov model analysis.

UNLABELLED: No adequate randomized trials have been reported for a comparison between hepatic resection (HR) versus radiofrequency ablation (RFA) for the treatment of patients with very early stage hepatocellular carcinoma (HCC), defined as an asymptomatic solitary HCC <2 cm. For compensated cirrhotic patients with very early stage HCC, a Markov model was created to simulate a randomized trial between HR (group I) versus primary percutaneous RFA followed by HR for cases of initial local failure (group II) versus percutaneous RFA monotherapy (group III); each arm was allocated with a hypothetical cohort of 10,000 patients. The primary endpoint was overall survival. The estimates of the variables were extracted from published articles after a systematic review. In the parameter estimations, we assumed the best scenario for HR and the worst scenario for RFA. The mean expected survival was 7.577 years, 7.564 years, and 7.356 years for group I, group II, and group III, respectively. One-way sensitivity analysis demonstrated that group II was the preferred strategy if the perioperative mortality rate was greater than 1.0%, if the probability of local recurrence following an initial complete ablation was <1.9% or if the positive microscopic resection margin rate was >0.3%. The 95% confidence intervals for the difference in overall survival were -0.18-0.18 years between group I and II, 0.06-0.36 years between group I and III, and 0.13-0.30 years between group II and III, respectively. CONCLUSION: Primary percutaneous RFA followed by HR for cases of initial local failure was nearly identical to HR for the overall survival of compensated cirrhotic patients with very early stage HCC.

Transcatheter arterial chemoembolization for hepatocellular carcinoma: prospective assessment of the right inferior phrenic artery with C-arm CT.

PURPOSE: To assess the usefulness of C-arm computed tomography (CT) of the right inferior phrenic artery (RIPA) in transcatheter arterial chemoembolization of patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: From December 2007 to April 2008, C-arm CT of the RIPA was prospectively performed in 32 patients with HCC. Two interventional radiologists who performed C-arm CT assessed the additional information provided with C-arm CT as grade 1 (no additional information), grade 2 (added information without an effect on the treatment plan), or grade 3 (added information with an effect on the treatment plan). Tumor feeders and feeders of a systemic-to-pulmonary shunt were recorded. RESULTS: The information provided by C-arm CT was classified as grade 1 for nine of the 32 patients (28%), grade 2 for 20 patients (63%), and grade 3 for three patients (9%). The most common additional information from C-arm CT scans of the RIPA was the differentiation between the tumor and the systemic-to-pulmonary shunt. A systemic-to-pulmonary shunt from the RIPA was observed in 22 patients (69%), and the most common feeder of a systemic-to-pulmonary shunt was the azygoesophageal branch. CONCLUSIONS: C-arm CT of the RIPA provides additional imaging information for the differentiation of a tumor from a nontumorous condition during chemoembolization for HCC with a suspected blood supply from an RIPA.

Assessment of hepatic arterial anatomy in keeping with preservation of the vasculature while performing pancreatoduodenectomy: an opinion.

BACKGROUND: Pancreatic surgeons often must make decisions regarding hepatic artery (HA) resection while performing a pancreatoduodenectomy (PD). The purpose of this report was to review and summarize HA resection experience with a focus on vascular preservation during PD and to develop a useful guideline for pancreatic surgeons in dealing with these needs. METHODS: We reviewed 1324 cases that had available computed tomographic and angiographic findings and summarized the problematic HA variations encountered in PD. In reviewing our PD series (n = 254), we have created a set of guidelines that enable a pragmatic approach to the unique variations in HA and the risks of cancer invasion. RESULTS: Challenging HA variations during PD were found in 20.1% of the cases and included the common HA arising from the superior mesenteric artery (SMA) (2.34%), a replaced right HA (RHA) from the SMA (9.82%), an RHA or left HA from the gastroduodenal artery (0.97%), and the right anterior or right posterior HA from the SMA (1.06%), among others. In our PD series, the problematic HAs (15.8%) were preserved, except for a single case (0.4%) in which PD involved en bloc resection of the RHA from the SMA due to a cancerous invasion and without right hemihepatectomy. CONCLUSIONS: Surgeons should have knowledge of the anatomically variable vasculature of the HA when planning for PD. Preoperative imaging studies can aid and should be performed in anticipation of the potential HA variations during PD.

Assessment of lymph node metastases by contrast-enhanced MR imaging in a head and neck cancer model.

OBJECTIVE: We wanted to investigate the accuracy of contrast-enhanced MR imaging for the detection of lymph node metastases in a head and neck cancer rabbit model. MATERIALS AND METHODS: The metastatic lymph node model we used was created by inoculating VX2 tumors into the auricles of six New Zealand White rabbits. T1-weighted MR images were obtained before and after injecting gadopentetate dimeglumine at three weeks after tumor cell inoculation. The sizes, signal intensity ratios (i.e., the postcontrast signal intensities of the affected nodes relative to the adjacent muscle) and the enhancement patterns of 36 regional lymph nodes (parotid and caudal mandibular nodes) were evaluated on MR images and then compared with the histopathologic findings. RESULTS: No statistical difference was found between the sizes of 12 metastatic (10.5+/-3.2 mm) and 24 hyperplastic (8.0+/-3.6 mm) lymph nodes (p > 0.05). On the contrast-enhanced T1-weighted MR images, nine metastatic and four hyperplastic lymph nodes had peripheral high and central low signal intensity, whereas three metastatic and 20 hyperplastic lymph nodes had homogeneous high signal intensity. Using a signal intensity ratio less than one as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity and positive and negative predictive values of the enhanced MR images were 75% (9/12), 83% (20/24), 69% (9/13) and 87% (20/23), respectively, with areas under receiver-operating-characteristic curve values of 0.81. CONCLUSION: This experimental study confirms that metastatic and hyperplastic lymph nodes can be differentiated using MR images on the basis of the contrast uptake patterns, but that they cannot be differentiated using any particular size criteria.