Association between high-resolution computed tomography findings and the IASLC/ATS/ERS classification of small lung adenocarcinomas in Japanese patients.

OBJECTIVES: The detection rate of small pulmonary nodules has recently increased and new techniques have been developed to improve diagnostic yield. The IASLC/ATS/ERS classification demonstrated a difference in prognosis depending on the histological subtypes of lung adenocarcinoma. We evaluated the association between high-resolution computed tomography (HRCT) findings and the classification of these tumors. METHODS: We reviewed the data of 220 lung adenocarcinoma (≤3 cm) patients who received complete resection with lymph node dissection in our hospital. From the HRCT findings, the tumors were classified into the following 3 categories: pure-solid nodules, part-solid nodules, or pure ground-glass opacity (GGO) nodules. Pathological invasion factor (PIF) was evaluated by the degree of blood vessel invasion, lymphatic permeation, and visceral pleural invasion. RESULTS: The tumors were classified as pure GGO nodules in 16 patients, part-solid nodules in 91, and pure-solid nodules in 113 from the HRCT findings. Tumors were diagnosed as noninvasive or minimally invasive adenocarcinomas (NMIADs) in 44 patients, and invasive adenocarcinomas (IADs) in 176. Lymph node metastasis was present in 31 patients (14.1%) and PIF in 101 (45.9%). All pure-solid nodules were IADs with a high PIF frequency (75.2%) or with lymph node metastasis (26.5%). All pure GGO nodules were NMIADs or lepidic-predominant adenocarcinomas. Among the part-solid nodules, IAD was detected in 67.0% of the patients and PIF in 16.5%. The consolidation/tumor (C/T) ratio and consolidation size were associated with IAD (optimal cut-off values: 0.4 and 8mm, respectively) and PIF (0.8 and 15 mm, respectively). CONCLUSIONS: The HRCT findings correlated with the IASLC/ATS/ERS classification and were useful for evaluating the histological nature of the tumors. Most pure-solid tumors had the potential for high-grade malignancy, including PIF and lymph node metastasis. For part-solid tumors, the C/T ratio and consolidation size were important for predicting PIF and for diagnosing IAD according to this classification.

Ureteral intussusception associated with a fibroepithelial polyp: a case report.

We present a case of a 67-year-old man with intussusception of the right ureter associated with a fibroepithelial polyp. The concentric sign and line sign are characteristic radiological findings in intussusception, and these findings could be seen in the present case. Although this entity is rare, its radiological findings are specific. Multidetector row computed tomography and its multiplanar reconstruction make the diagnosis feasible, although the qualitative diagnosis of the tumor was difficult.

Survival of a surgical series of lung cancer patients with synchronous multiple ground-glass opacities, and the management of their residual lesions.

OBJECTIVES: We reviewed the medical record of a series of patients with synchronous multiple lung cancers (SMLC), in an attempt to identify the optimal treatment strategy for multiple ground-glass opacities (GGOs). MATERIALS AND METHODS: From 2004 to 2010, 1223 patients underwent complete resection of non-small cell lung cancer. Among these, there were 67 patients (5.5%) with SMLC with at least 1 of the nodules showing GGO appearance. SMLC was divided into the main cancer (MC) which was a main target based on its tumor size or radiological invasiveness and sub-nodules. According to consolidation/tumor ratio (CTR) on thin-section computed tomography, 67 cases were classified into GG-group (MC showing GGO-dominant lesion; CTR≤0.5) and GS-group (MC showing solid-dominant lesion; CTR>0.5). RESULTS: There were 24 patients in the GG-group (36%) and 43 patients in the GS-group (64%). Surgical resections included 11 sublobar resections (SLs), 32 lobectomies, 19 lobectomy+SLs, and 4 bilobectomies. There were 39 patients with a total of 118 unresected GGOs after the initial surgery. Among them, the frequency of growth was 8% on a per-nodule basis with the median tumor doubling time of 1373 days, and new GGOs emerged in 15 patients (23%). Multivariate analysis demonstrated that larger size of MC and the GS-group was associated with poor prognosis, whereas growth of the residual GGOs, the development of new GGOs, or whether or not all GGOs were treated did not affect survival. The 5-year OS proportions were 95.8% for the GG-group and 68.0% for the GS-group (p=0.009), and 92.4% for a MC of ≤25 mm and 53.6% for a MC of >25 mm (p=0.008). CONCLUSION: Survival of patients with multifocal GGOs is strongly affected by radiological findings of the MC. Strict surgical control for MC could be most important.

Two cases of sclerosing angiomatoid nodular transformation of the spleen with gradual growth: usefulness of diffusion-weighted imaging.

Sclerosing angiomatoid nodular transformation (SANT) is a recently recognized and rare, nonneoplastic lesion of the spleen. Some papers have reported an increased SANT diameter during the follow-up period. We present two cases of SANT whose size increased during the follow-up period. Diffusion-weighted magnetic resonance imaging (DWI) findings correlated well with the pathological findings of SANT, the multinodular high-intensity area as the angiomatoid nodules and the peripheral low-intensity area as fibrous tissues. Therefore, DWI may be a useful imaging tool.

Correlation between whole tumor size and solid component size on high-resolution computed tomography in the prediction of the degree of pathologic malignancy and the prognostic outcome in primary lung adenocarcinoma.

BACKGROUND: The presence of ground glass opacity (GGO) on high-resolution computed tomography (HRCT) is well known to be pathologically closely associated with adenocarcinoma in situ. PURPOSE: To determine whether it is more useful to evaluate the whole tumor size or only the solid component size to predict the pathologic high-grade malignancy and the prognostic outcome in lung adenocarcinoma. MATERIAL AND METHODS: Using HRCT data of 232 patients with adenocarcinoma who underwent curative resection, we retrospectively measured the whole tumor and solid component sizes with lung window setting (WTLW and SCLW) and whole tumor sizes with a mediastinal window setting (WTMW). RESULTS: There was significant correlation between the WTLW and the measurements of pathological whole tumor (pWT) (r = 0.792, P < 0.0001). The SCLW and WTLW values significantly correlated with the area of pathological invasive component (pIVS) (r = 0.762, P < 0.0001 and r = 0.771, P < 0.0001, respectively). The receiver operating characteristics area under the curve for WTLW, SCLW, and WTMW used to identify lymph node metastasis or lymphatic or vascular invasion were 0.693, 0.817, and 0.824, respectively. Kaplan-Meier curves of disease-free survival (DFS) and overall survival (OS) were better divided according to SCLW and WTMW, compared with WTLW. Multivariate analysis of DFS and OS revealed that WTMW was an independent prognostic factor (HR = 0.72, 95% confidence interval [CI] = 0.58-0.90, P = 0.004 and HR = 0.74, 95% CI = 0.57-0.96, P = 0.022, respectively). CONCLUSION: The predictive values of the solid tumor size visualized on HRCT especially in the mediastinal window for pathologic high-grade malignancy and prognosis in lung adenocarcinoma were greater than those of whole tumor size.

Effectiveness of CT assists for intraarterial chemotherapy: therapeutic outcome of chemoradiation for advanced head and neck cancer extending across the anatomical midline.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of CT assist for intraarterial chemotherapy in relation to the therapeutic outcomes of intraarterial chemoradiation for advanced head and neck cancer with extension across the anatomical midline (EAM). METHODS: This retrospective study evaluated 64 consecutive patients. In total, 26 and 38 patients had cancer with or without EAM, respectively. These patients underwent an intraarterial cisplatin infusion (200 mg/m(2), days 1 and 35) and intravenous 5-FU infusion (800 mg/m(2), days 1-5 and 36-39) concomitantly with radiotherapy. Angiography-assisted CT was performed to confirm complete coverage during the intraarterial chemotherapy. The accuracy of diagnosing tumor vessels by digital subtraction angiography (DSA) was evaluated using receiver-operating characteristic analysis by two radiologists. The overall survival and locoregional control rates were calculated by the Kaplan-Meier method. RESULTS: DSA was not useful for diagnosing tumor vessels. The 2-year overall survival rates for the patients with cancer with or without EAM were 83 and 90 %, while the 2-year locoregional control rates were 95 and 82 %, respectively. Locoregional control or the overall survival rates showed no significant differences. CONCLUSIONS: Intraarterial chemotherapy using angiography-assisted CT during chemoradiation therapy can achieve comparable therapeutic outcomes for cancer with and without EAM.

High-quality 3-dimensional image simulation for pulmonary lobectomy and segmentectomy: results of preoperative assessment of pulmonary vessels and short-term surgical outcomes in consecutive patients undergoing video-assisted thoracic surgery†.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of 3-dimensional computed tomography (3D-CT) software in short-term surgical outcomes and the assessment of variations of pulmonary vessel branching patterns on performing video-assisted thoracic surgery (VATS). METHODS: The study included 179 consecutive patients who had undergone VATS anatomical lung resection, of which 172 were lobectomies (96%) and 7 were segmentectomies (4%), from May 2011 through January 2013. There were 124 patients (69%) in whom 3D-CT was performed and 55 patients (31%) who had not undergone 3D-CT. Observed actual pulmonary vessel branching patterns by intraoperative findings or footage were compared with the 3D image findings. Various surgical outcomes, including the occurrence of postoperative complications, in this study defined as those of Grade 2 or above under the Clavien-Dindo classification system, and total operative time, were retrieved from available clinical records. RESULTS: Among the 124 patients with preoperative 3D imaging, there were 5 (4%) conversions from VATS to thoracotomy. The incidence rate of patients with postoperative complications was 8% (n = 10), and there were no 30-day or 90-day mortalities. Pulmonary artery (PA) branches were precisely identified for 97.8% (309 of 316) of branches on 3D images, and the sizes of the seven undetected branches (five in the right upper lobe, two in the left upper lobe) ranged from 1 to 2 mm. The 3D images accurately revealed 15 cases (12%) of anomalous or unusual PA branches and 5 cases (4%) of variant pulmonary veins. Multivariate logistic regression analysis of the association with postoperative complications and operative time in 165 lung cancer patients demonstrated that male gender was the only statistically significant independent predictor of complications (risk ratio: 5.432, P = 0.013), and patients without 3D imaging tended to have operative complications (risk ratio: 2.852, P = 0.074), whereas conducting the 3D-CT (risk ratio: 2.282, P = 0.021) as well as intraoperative bleeding amount (risk ratio: 1.005, P = 0.005) had significant association with operative time. CONCLUSIONS: High-quality 3D-CT images clearly revealed the anatomies of pulmonary vessels, which could play important roles in safe and efficient VATS anatomical resection.

High-speed 3-dimensional imaging in robot-assisted thoracic surgical procedures.

We used a high-speed 3-dimensional (3D) image analysis system (SYNAPSE VINCENT, Fujifilm Corp, Tokyo, Japan) to determine the best positioning of robotic arms and instruments preoperatively. The da Vinci S (Intuitive Surgical Inc, Sunnyvale, CA) was easily set up accurately and rapidly for this operation. Preoperative simulation and intraoperative navigation using the SYNAPSE VINCENT for robot-assisted thoracic operations enabled efficient planning of the operation settings. The SYNAPSE VINCENT can detect the tumor location and depict surrounding tissues quickly, accurately, and safely. This system is also excellent for navigational and educational use.

Is diffusion-weighted imaging a significant indicator of the development of vascularization in hypovascular hepatocellular lesions?

OBJECTIVE: The objective was to evaluate the efficacy of diffusion-weighted imaging (DWI) in predicting the development of vascularization in hypovascular hepatocellular lesions (HHLs). MATERIALS AND METHODS: Forty-two HHLs that were diagnosed by computed tomographic (CT) arteriography were evaluated retrospectively. The lesion on DWI was classified as isointense, hypointense, or hyperintense. Follow-up studies that included intravenous dynamic CT or magnetic resonance imaging were performed. RESULTS: The 730-day cumulative developments of vascularization in hypointense, isointense, and hyperintense lesions were 17%, 30%, and 40%, respectively. The differences among these developments were not statistically significant. CONCLUSION: The signal intensity on DWI showed no significant difference in the development of vascularization.

Cryptogenic organizing pneumonia associated with radiation: A report of two cases.

Cryptogenic organizing pneumonia (COP) following radiotherapy is occasionally diagnosed as radiation pneumonitis or bacterial pneumonia. The current study presents two cases of COP following radiotherapy: A 48-year-old premenopausal female with breast cancer and an 84-year-old male with non-small cell lung cancer. In the cases of breast cancer and lung cancer, patients were first diagnosed with bacterial pneumonia and radiation pneumonitis, respectively. In the two cases, computed tomography disclosed the migration of ground glass shadows, which were finally resolved without any fibrotic changes. The two cases were finally diagnosed as COP associated with radiotherapy. When an infiltrating shadow is present outside of the irradiated field, COP must be included in the differential diagnosis.

Measuring hepatic functional reserve using low temporal resolution Gd-EOB-DTPA dynamic contrast-enhanced MRI: a preliminary study comparing galactosyl human serum albumin scintigraphy with indocyanine green retention.

OBJECTIVE: To investigate if tracer kinetic modelling of low temporal resolution dynamic contrast-enhanced (DCE) MRI with Gd-EOB-DTPA could replace technetium-99 m galactosyl human serum albumin (GSA) single positron emission computed tomography (SPECT) and indocyanine green (ICG) retention for the measurement of liver functional reserve. METHODS: Twenty eight patients awaiting liver resection for various cancers were included in this retrospective study that was approved by the institutional review board. The Gd-EOB-DTPA MRI sequence acquired five images: unenhanced, double arterial phase, portal phase, and 4 min after injection. Intracellular contrast uptake rate (UR) and extracellular volume (Ve) were calculated from DCE-MRI, along with the ratio of GSA radioactivity of liver to heart-plus-liver and per cent of cumulative uptake from 15-16 min (LHL15 and LU15, respectively) from GSA-scintigraphy. ICG retention at 15 min, Child-Pugh cirrhosis score (CPS) and postoperative Inuyama fibrosis criteria were also recorded. Statistical analysis was with Spearman rank correlation analysis. RESULTS: Comparing MRI parameters with the reference methods, significant correlations were obtained for UR and LHL15, LU15, ICG15 (all 0.4-0.6, P < 0.05); UR and CPS (-0.64, P < 0.001); Ve and Inuyama (0.44, P < 0.05). CONCLUSION: Measures of liver function obtained by routine Gd-EOB-DTPA DCE-MRI with tracer kinetic modelling may provide a suitable method for the evaluation of liver functional reserve. KEY POINTS: • Magnetic resonance imaging (MRI) provides new methods of measuring hepatic functional reserve. • DCE-MRI with Gd-EOB-DTPA offers the possibility of replacing scintigraphy. • The analysis method can be used for preoperative liver function evaluation.

Recanalization of iatrogenic dissection of the superior mesenteric artery: a case report.

We present a case of acute abdominal pain due to a long-segment iatrogenic superior mesenteric artery dissection, which was immediately treated successfully with balloon fenestration of the intimal flap, resulting in complete resolution of the symptoms without recurrence during the 2-year follow-up period.

Virtual segmentectomy based on high-quality three-dimensional lung modelling from computed tomography images.

OBJECTIVES: The aim of this study was to demonstrate the feasibility and efficacy of a novel simulation software called, virtual segmentectomy. METHODS: We developed the segmentectomy simulation system, which was programmed to analyse the detailed 3D bronchovascular structure and to predict the appropriate segmental surface and surgical margin, based on lung modelling from CT images. RESULTS: We have attempted this novel technique for 3 cases of pulmonary metastases and 1 case of multiple lung cancer. For validation, the predicted resection margin was compared with the actual resected specimen. The surgical surface, as estimated by the simulation, was compared with the surface of the specimen and a surgical video. To test its feasibility, the operation time, blood loss, durations of chest tube placement and hospitalization as well as pathological findings were assessed. CONCLUSIONS: Preoperative simulation and intraoperative guidance by virtual segmentectomy could contribute significantly to determining the most appropriate anatomical segmentectomy and curative resection.

Three dimensional computed tomography lung modeling is useful in simulation and navigation of lung cancer surgery.

The number of minimally invasive operations, such as video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy, has enormously increased in recent years. These operations require extreme knowledge of the anatomy of pulmonary vessels and bronchi in each patient, and surgeons must carefully dissect the branches of pulmonary vessels during operation. Thus, foreknowledge of the anatomy of each patient would greatly contribute to the safety and accuracy of the operation. The development of multi-detector computed tomography (MDCT) has promoted three dimensional (3D) images of lung structures. It is possible to see the vascular and bronchial structures from the view of the operator; therefore, it is employed for preoperative simulation as well as navigation during operation. Due to advances in software, even small vessels can be accurately imaged, which is useful in performing segmentectomy. Surgical simulation and navigation systems based on high quality 3D lung modeling, including vascular and bronchial structures, can be used routinely to enhance the safety operation, education of junior staff, as well as providing a greater sense of security to the operators.

Assessing liver function using dynamic Gd-EOB-DTPA-enhanced MRI with a standard 5-phase imaging protocol.

PURPOSE: To evaluate liver function obtained by tracer-kinetic modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data acquired with a routine gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced protocol. MATERIALS AND METHODS: Data were acquired from 25 cases of nonchronic liver disease and 94 cases of cirrhosis. DCE-MRI was performed with a dose of 0.025 mmol/kg Gd-EOB-DTPA injected at 2 mL/sec. A 3D breath-hold sequence acquired 5 volumes of 72 slices each: precontrast, double arterial phase, portal phase, and 4-minute postcontrast. Regions of interest (ROIs) were selected semiautomatically in the aorta, portal vein, and whole liver on a middle slice. A constrained dual-inlet two-compartment uptake model was fitted to the ROI curves, producing three parameters: intracellular uptake rate (UR), extracellular volume (Ve), and arterial flow fraction (AFF). RESULTS: Median UR dropped from 4.46 10(-2) min(-1) in the noncirrhosis to 3.20 in Child-Pugh A (P = 0.001), and again to 1.92 in Child-Pugh B (P < 0.0001). Median Ve dropped from 6.64 mL 100 mL(-1) in the noncirrhosis to 5.80 in Child-Pugh A (P = 0.01). Other combinations of Ve and AFF changes were not significant for any group. CONCLUSION: UR obtained from tracer kinetic analysis of a routine DCE-MRI has the potential to become a novel index of liver function.

Distinguishing hepatic hemangiomas from metastatic tumors using T1 mapping on gadoxetic-acid-enhanced MRI.

OBJECTIVE: The objective was to evaluate the usefulness of T1 mapping in distinguishing hepatic hemangiomas from metastatic tumors on gadoxetic-acid-enhanced magnetic resonance imaging. METHODS: We examined 20 hemangiomas in 14 patients and 21 metastatic tumors in 11 patients. We performed T1 mapping using the double-flip angle method before and after the injection of gadoxetic acid. Quantitative evaluation was carried out using the pre- and post-contrast enhancement ratios (CERs), and qualitative evaluation was conducted to evaluate the added value of T1 mapping using receiver operating characteristics analysis. RESULTS: The mean CERs of metastatic tumors at 70 s, 240 s and 20 min after the injection of gadoxetic acid were 1.54 (95% confidence interval: 1.37-1.71), 1.47 (1.34-1.6) and 1.30 (1.19-1.41); those of hemangiomas were 3.36 (2.41-4.31), 3.06 (2.44-3.68) and 2.20 (2.02-2.38), respectively. The mean CERs of hemangiomas were significantly higher than those of metastatic tumors (P<.05). When the mean CER cutoff value 20 min after the injection was set at 1.6, the diagnostic sensitivity of hepatic hemangiomas was 100%. There was no added value observed statistically in the qualitative evaluation of T1 mapping (P>.05). CONCLUSION: It is valuable to evaluate quantitatively T1 mapping 20 min after hepatobiliary phase acquisition in the case of difficulty in distinguishing hepatic hemangiomas from metastatic tumors qualitatively.

MR characterization of focal nodular hyperplasia: gadoxetic acid versus superparamagnetic iron oxide imaging.

PURPOSE: We evaluated the diagnostic efficacy of gadoxetic acid- and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for focal nodular hyperplasia (FNH). MATERIALS AND METHODS: We retrospectively evaluated 11 patients with 11 FNHs. Both gadoxetic acid- and SPIO-enhanced MR imaging were performed. A 3-dimensional (3D) volumetric interpolated breath-hold examination was used with the gadoxetic acid dynamic study. SPIO-enhanced MR imaging included T2- and T2*-weighted images. We quantitatively and qualitatively compared lesion-specific enhancement of both contrast media. RESULTS: The mean signal-to-noise (S/N) ratio of the FNH lesions differed significantly on pre- and postenhanced imaging of each contrast medium (P<0.05); mean contrast-to-noise (C/N) ratio did not (P>0.05). All observers described all lesions as hyperintense in the arterial phase on gadoxetic acid-enhanced MR imaging and observed the presence of central scar, fibrous septa, and rim most clearly in gadoxetic acid-enhanced hepatobiliary phase images. CONCLUSION: Gadoxetic acid-enhanced MR imaging was more useful than SPIO-enhanced MR imaging in characterizing FNH.

Histological grade of differentiation of hepatocellular carcinoma: comparison of the efficacy of diffusion-weighted MRI with T2-weighted imaging and angiography-assisted CT.

INTRODUCTION: The purpose of this study is to determine the usefulness of diffusion-weighted imaging (DWI) for evaluating the histological grade of differentiation of hepatocellular carcinoma (HCC) compared with T2-weighted imaging (T2WI) and tumour haemodynamics. METHODS: We retrospectively evaluated 32 patients with 42 pathologically confirmed HCC nodules. These patients underwent MRI, CT during arterial portography and CT hepatic arteriography. We evaluated the relationship between the histological grade of differentiation and the apparent diffusion coefficient (ADC) values, conspicuity of tumour on DWI, DWI and T2WI contrast-to-noise (C/N) ratios and tumour haemodynamics. RESULTS: There was no correlation between the histological grade of differentiation and the ADC values. The DWI C/N ratio was significantly different among all histological grades, but the T2WI C/N ratio was not. Tumour conspicuity on DWI correlated well with the histological grade of differentiation, but tumour haemodynamics only partially correlated with the histological grade of differentiation. CONCLUSION: DWI was useful for evaluating the histological grade of differentiation of HCC.

High-resolution computed tomography findings in a case of severe leptospira infection (Weil disease) complicated with Jarisch-Herxheimer reaction.

In this report, we describe a case of Weil disease. Chest x-ray and computed tomography (CT) findings showed temporary deterioration 1 day after the initiation of antibiotic treatment, and high-resolution CT findings with the patient's physical findings made us suspect pulmonary alveolar hemorrhage (PAH). We believed that the PAH had been induced by Weil disease and subsequently caused Jarisch-Herxheimer reaction. We confirmed the patient's contact history with mice, and symptoms improved immediately after starting appropriate treatments. Leptospirosis is a relatively rare cause of PAH. Therefore, the possibility of this disease should be included in the differential diagnosis, especially when high-resolution CT findings indicate PAH, and the imaging findings deteriorate rapidly after antibiotic therapy.

Diagnostic efficacy of gadoxetic acid-enhanced MRI for hepatocellular carcinoma and dysplastic nodule.

AIM: To evaluate the relationship between the signal intensity of hepatobiliary phase images on gadoxetic acid-enhanced magnetic resonance imaging (MRI) and histological grade. METHODS: Fifty-nine patients with 82 hepatocellular lesions were evaluated retrospectively. Hepatobiliary phase images on gadoxetic acid-enhanced MRI were classified into 3 groups: low, iso or high. Angiography-assisted computed tomography (CT) findings were also classified into 3 groups: CT during arterial portography, and CT hepatic arteriography: A: iso, iso or low; B: slightly low, iso or low; and C: low, high. We correlated angiography-assisted CT, hepatobiliary phase findings during gadoxetic acid-enhanced MRI and histological grades. Furthermore, correlations between MRI findings and histological grade for each hemodynamic pattern were performed. Correlations among radiological and pathological findings were statistically evaluated using the chi-square test and Fisher' s exact test. RESULTS: There was a significant correlation between histological grade and hemodynamic pattern (P < 0.05). There was a significant correlation between histological grade and signal intensity in the hepatobiliary phase (P < 0.05) in group A lesions. There was no significant correlation between histological grade and signal intensity in the hepatobiliary phase in group B or C lesions (P > 0.05). CONCLUSION: Signal intensity in the hepatobiliary phase correlated with histological grade in the lesions that maintained portal blood flow, but did not correlate in lesions that showed decreased or defective portal blood flow.