Hepatic pseudolymphoma: imaging-pathologic correlation with special reference to hemodynamic analysis

OBJECTIVES

To clarify radiological findings and hemodynamic characteristics of hepatic pseudolymphoma, as compared with the histopathological findings.

METHODS

Radiological findings of ten histopathologically confirmed hepatic pseudolymphomas in seven patients were examined using US, CT, and MRI. Six patients also underwent angiography-assisted CT, including CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) to analyze hemodynamics.

RESULTS

The nodules were depicted as hypoechoic on US, hypodense on precontrast CT, hypointense on T1-weighted images, and hyperintense on T2-weighted images. On contrast-enhanced CT/MRI, they showed various degrees of enhancement, and sometimes, perinodular enhancement was observed at the arterial dominant and/or equilibrium phase. On CTAP, the nodules showed portal perfusion defects, including some in the perinodular liver parenchyma. On CTHA, irregular bordered enhancement was observed in perinodular liver parenchyma on early phase, and continued until delayed phase. Some nodules had preserved intra-tumoral portal tracts. Histopathologically, the nodules consisted of marked lymphoid cells. In perinodular liver parenchyma, stenosis or disappearance of portal venules, caused by lymphoid cell infiltration in the portal tracts, was observed.

CONCLUSIONS

Hepatic pseudolymphoma showed some characteristic radiological findings including hemodynamics on CT, MRI, and angiography-assisted CT. These findings are useful in the differentiation from hepatocellular carcinoma and other tumors.

[Hepatic arterial infusion chemotherapy with gemcitabine for patients with postoperative liver metastases from pancreatic cancer]

Herein, we describe hepatic arterial infusion (HAI) chemotherapy with gemcitabine (GEM) for the treatment of patients with postoperative liver metastases from pancreatic cancer. Seven patients received HAI with GEM plus 5-fluorouracil (5- FU) or oral S-1 from 2008 to 2010 at the Kanazawa University Hospital. Of the 7 patients, partial response (PR) and stable disease( SD) were observed in 6 patients according to the Response Evaluation Criteria In Solid Tumors( RECIST) evaluation criteria (response rate, 85.7%). The median survival time was 14 months; however, all 7 patients ultimately died of another metastatic lesion. Importantly, there were no life-threatening toxicities. However, 6 patients developed catheter- related complications, and the HAI catheter and the subcutaneous implantable port system had to be removed. Peripheral blood concentrations of GEM after HAI were analyzed in 7 other patients. At a dose level of 400 to 800 mg/standard liver volume( SLV),the GEM concentrations were less than one-tenth that of the intravenously administered 1,000 mg/m2. However, at a dose level of 1,000 mg/SLV, the GEM concentration in the peripheral blood was almost the same as that administered intravenously. In conclusion, HAI chemotherapy is safe and effective for the treatment of patients with liver metastases from pancreatic cancer. Our results suggest that a dose level of 800 mg/SLV could be considered optimal for local therapy.

Preserved renal function after percutaneous radiofrequency ablation for renal tumors: experience of a single institution

BACKGROUND

Percutaneous radiofrequency ablation (RFA) for small renal tumors has been reported to be effective in patients with poor surgical status. We retrospectively analyzed clinical outcomes, including renal function, after RFA.

PATIENTS AND METHODS

We retrospectively analyzed data of 24 patients with small renal tumors treated by RFA in our institution from January 2007 to November 2012.

RESULTS

A total of 36 tumors (35 renal cell carcinomas and one colon cancer metastasis) with a mean diameter of 21.1 mm (10-45 mm) in 24 patients were treated. Complete ablation was achieved in 22 patients (91.7%). There were two recurrences in other sites of the kidney (8.3%) and two distant metastases (8.3%) during the mean follow-up period of 21 months (1-57 months). No severe perioperative complications were observed. No significant difference in serum creatinine levels before and after RFA procedures in the 22 evaluable patients, nor in seven patients with a solitary kidney.

CONCLUSION

RFA for small renal tumors is a safe treatment with sufficient preservation of renal function, even in patients with a solitary kidney.

Hepatic arterial infusion chemotherapy with gemcitabine and 5-fluorouracil or oral S-1 improves the prognosis of patients with postoperative liver metastases from pancreatic cancer

Hepatic metastasis is a common cause of treatment failure following resection of pancreatic cancer. In this study, we report our results of hepatic arterial infusion (HAI) chemotherapy with gemcitabine (GEM) plus 5-fluorouracil (5-FU) or oral S-1 treatment for postoperative liver metastases from pancreatic cancer. Seven patients with postoperative liver metastases from pancreatic cancer received HAI with GEM plus 5-FU or oral S-1 between October, 2008 and September, 2010 at Kanazawa University Hospital (Kanazawa, Japan). Three out of the 7 cases exhibited a partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST) and stable disease (SD) was achieved in 3 out of the 7 cases (response rate, 85.7%). A decrease in serum tumor marker CA 19-9 levels was observed after 10 HAI treatment cycles in 5 out of the 7 cases. The median time to treatment failure was 8 months (range, 0–17 months). Adverse events included grade 3 leukocytopenia in 1 case and anemia in all 7 cases, although 5 out of the 7 patients were anemic prior to HAI therapy. Grade 2 thrombocytopenia was also observed in 2 cases. Non-hematological events, such as nausea, diarrhea, liver injury or neuropathy and life-threatening toxicities were not reported; however, 6 patients (85.7%) developed catheter-related complications and the HAI catheter and subcutaneous implantable port system had to be removed. These findings demonstrated that HAI may deliver high doses of chemotherapeutic agents directly into the tumor vessels, producing increased regional levels with greater efficacy and a lower incidence/severity of systemic side effects. In conclusion, HAI chemotherapy is a safe and effective treatment for liver metastases from pancreatic cancer.

Hypervascular hepatocellular carcinoma: correlation between biologic features and signal intensity on gadoxetic acid-enhanced MR images

PURPOSE

To analyze the correlation among biologic features, tumor marker production, and signal intensity at gadoxetic acid-enhanced MR imaging in hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

Institutional ethics committee approval and informed consent were obtained for this retrospective study. From April 2008 to September 2011, 180 surgically resected HCCs in 180 patients (age, 65.0 years ± 10.3 [range, 34-83 years]; 138 men, 42 women) were classified as either hypointense (n = 158) or hyperintense (n = 22) compared with the signal intensity of the background liver on hepatobiliary phase gadoxetic acid-enhanced MR images. Pathologic features were analyzed and a fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) production were compared by means of serum analysis and immunohistochemical staining. Recurrence and survival rates were also evaluated. The Mann-Whitney and Pearson correlation tests were used for statistical analysis.

RESULTS

The grade of differentiation was higher (P = .028) and portal vein invasion was less frequent in hyperintense HCCs (13.6%) than in hypointense HCCs (36.7%) (P = .039). The serum levels of AFP, Lens culinaris agglutinin reactive fraction of AFP, and PIVKA-II were lower in hyperintense than in hypointense HCCs (P = .003, .004, and .026, respectively). Immunohistochemical AFP and PIVKA-II expression were lower in hyperintense than in hypointense HCCs (both P < .001). The recurrence rate was lower in hyperintense than in hypointense HCCs (P = .039).

CONCLUSION

The results suggest that hyperintense HCCs on gadoxetic acid-enhanced MR images are less aggressive than hypointense HCCs.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120226/-/DC1.

Usefulness of Gd-EOB-DTPA-enhanced MR imaging in the evaluation of simple steatosis and nonalcoholic steatohepatitis

PURPOSE

To evaluate the usefulness of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging (EOB-MRI) in differentiating between simple steatosis and nonalcoholic steatohepatitis (NASH), as compared with MR in-phase/out-of-phase imaging. The correlations between the MR features and histological characteristics were preliminarily investigated.

MATERIALS AND METHODS

From April 2008 to October 2011, 25 patients (13 simple steatosis and 12 NASH) who underwent both EOB-MRI and in-phase/out-of-phase imaging were analyzed. The hepatobiliary-phase enhancement ratio and signal intensity loss on opposed-phase T1-weighted images (fat fraction) were compared between the simple steatosis and NASH groups. In the simple steatosis and NASH groups, the correlations between enhancement ratio and histological grade/stage were explored. In the NASH group, fat fraction was correlated with the steatosis score.

RESULTS

The enhancement ratio in NASH was significantly lower than that in simple steatosis (P = 0.03). In the simple steatosis and NASH groups, the enhancement ratio was significantly correlated with the fibrosis stage (r = -0.469, P = 0.018). Fat fraction in NASH was strongly correlated with the steatosis score (r = 0.728, P = 0.007).

CONCLUSION

In simple steatosis and NASH, the hepatobiliary-phase enhancement ratio of EOB-MRI showed significant association with fibrosis stage, and may be a useful discriminating parameter compared with the fat fraction measured by in-phase/out-of-phase imaging.

Intranodular signal intensity analysis of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd-EOB-DTPA-enhanced MRI

OBJECTIVES

To analyze intranodular signal intensity pattern of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd-EOB-DTPA-enhanced MRI.

METHODS

A total of 73 nodules showing hypervascular foci in hypovascular high-risk borderline lesions identified by angiography-assisted CT were included in this study. The intranodular signal intensities of both the hypervascular foci and the hypovascular high-risk borderline lesions were evaluated on hepatobiliary-phase EOB-enhanced MRI obtained 20 min after intravenous injection of contrast media.

RESULTS

Among 59 hypervascular foci within hypointense hypovascular high-risk borderline lesions, 6 showed more hypointensity, 32 isointensity, and 21 hyperintensity compared to the surrounding hypointense, hypovascular portion of the nodules. Among 14 hypervascular foci within isointense hypovascular high-risk borderline lesions, 5 showed isointensity, and 9 hypointensity compared to the surrounding isointense hypovascular high-risk borderline lesions. No hypervascular foci showed hyperintensity compared to the surrounding isointense hypovascular high-risk borderline lesions.

CONCLUSIONS

In most of the hypovascular high-risk borderline lesions containing hypervascular foci within the nodule, the signal intensity was decreased in hypervascular foci as compared with hypovascular high-risk borderline lesions and the surrounding background liver parenchyma. This supports the concept of signal intensity decrease during the dedifferentiation process in multistep hepatocarcinogenesis. However, around 30% of the nodules did not follow this rule, and hypervascular foci showed hyperintensity relative to the hypovascular high-risk borderline lesions.

Relationship between signal intensity on hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging and prognosis of borderline lesions of hepatocellular carcinoma

PURPOSE

To elucidate the incidence of signal intensity patterns of borderline lesions of hepatocellular carcinoma (HCC) on hepatobiliary phase Gd-EOB-DTPA (EOB) enhanced MRI and clarify the natural histories of these lesions.

MATERIALS AND METHODS

Total 99 borderline lesions of HCC were identified by angiography-assisted CT. The signal intensity of borderline lesions on hepatobiliary phase of EOB-enhanced MRI was analyzed. Progress rate from borderline lesions to hypervascular HCC was calculated with the Kaplan-Meier method among each signal intensity groups of nodules.

RESULTS

On hepatobiliary phase of EOB-enhanced MRI, 41.4% of the borderline lesions showed hypo-, 42.4% showed iso-, and 16.2% showed hyperintense, compared to background liver. Overall progress rates from borderline lesions to HCC were 10% in 1-year, 14% in 2-year and 20% in 3-year follow-up period. Progress rates to HCC in hypointense borderline lesions were 17% in 1-year, 28% in 2-year and 41% in 3-year follow-up period, and in isointense borderline lesions were 7% in 1-year, 7% in 2-year and 7% in 3-year follow-up period. No hyperintense borderline lesions progressed to HCC in follow-up period.

CONCLUSION

Although borderline lesions of HCC may show hypo-, iso- and hyperintensity on hepatobiliary phase of EOB-enhanced MRI, hypointense borderline lesions are high risk to progress HCC.

Hepatocyte transporter expression in FNH and FNH-like nodule: correlation with signal intensity on gadoxetic acid enhanced magnetic resonance images

PURPOSE

Our aim was to evaluate the hepatocyte transporters in focal nodular hyperplasia (FNH) and FNH-like lesions and to correlate the grade of its expression with signal intensity on the hepatobiliary phase (HB phase) of gadoxetic-acid-enhanced magnetic resonance imaging (EOB-MRI).

MATERIALS AND METHODS

Thirteen histopathological confirmed cases including eight with EOB-MRI were studied. Immunohistochemical staining for transporter was performed and its grade semiquantitatively analyzed.

RESULTS

Histopathologically, ten cases showed almost equal organic anion transporter polypeptide (OATP) 8 expression relative to the surrounding liver; the remaining three showed stronger OATP8 expression. In eight cases with EOB-MRI, two demonstrated more hyperintensity on the HB phase, and their OATP8 expression was stronger compared with the surrounding liver. The remaining six cases showed isointensity on the HB phase and revealed almost equal OATP8 expression. The expression of export transporter multi-drug-resistant proteins (MRP) 1 and 2 were almost equal relative to the surrounding liver in most cases (11/12, 92 %; 11/12, 92 %, respectively), whereas MRP3 focally overexpressed in 75 % (9/12) of cases.

CONCLUSION

FNH and FNH-like nodules revealed equal or stronger OATP8 expression than background liver. OATP8 expression showed significant correlation with signal intensity on the HB phase.

[A safely resected case of hypervascular pancreatic giant tumor after preoperative arterial embolization]

A 73-year-old woman visited our hospital for a treatment of pancreatic tumor that increased steadily in size of 6 cm in diameter in 1999 to 13 cm in 2008, while remaining in asymptomatic condition throughout this follow-up time. The tumor was big and flowed from many vessels such as portal and superior mesenteric veins and the celiac and superior mesenteric arteries. These were critical for determining tumor respectability and the risk of massive intra-operative hemorrhage was felt to be considerable. Therefore, preoperative embolization of the tumor-feeding arteries arising from the celiac axis (gastroduodenal, splenic and dorsal pancreatic arteries) was performed on the previous day of operation. Tumor resection with pancreaticoduodenectomy and partial resection of portal vein and reconstruction were performed. We got to SMA with the use of "paraduodenal mesenteric approach", we called, and we finished the operation without a blood transfusion. The final pathology confirmed the diagnosis of serous microcystic adenoma.

The uptake transporter OATP8 expression decreases during multistep hepatocarcinogenesis: correlation with gadoxetic acid enhanced MR imaging

OBJECTIVES

To clarify the changes in organic anion-transporting polypeptide 8 (OATP8) expression and enhancement ratio on gadoxetic acid-enhanced MR imaging in hepatocellular nodules during multistep hepatocarcinogenesis.

METHODS

In imaging analysis, we focused on 71 surgically resected hepatocellular carcinomas (well, moderately and poorly differentiated HCCs) and 1 dysplastic nodule (DN). We examined the enhancement ratio in the hepatobiliary phase of gadoxetic acid enhanced MR imaging [(1/postcontrast T1 value-1/precontrast T1 value)/(1/precontrast T1 value)], then analysed the correlation among the enhancement ratio, tumour differentiation grade and intensity of immunohistochemical OATP8 expression. In pathological analysis, we focused on surgically resected 190 hepatocellular nodules: low-grade DNs, high-grade DNs, early HCCs, well-differentiated, moderately differentiated and poorly differentiated HCCs, including cases without gadoxetic acid-enhanced MR imaging. We evaluated the correlation between the immunohistochemical OATP8 expression and the tumour differentiation grade.

RESULTS

The enhancement ratio of HCCs decreased in accordance with the decline in tumour differentiation (P < 0.0001, R = 0.28) and with the decline of OATP8 expression (P < 0.0001, R = 0.81). The immunohistochemical OATP8 expression decreased from low-grade DNs to poorly differentiated HCCs (P < 0.0001, R = 0.15).

CONCLUSIONS

The immunohistochemical expression of OATP8 significantly decreases during multistep hepatocarcinogenesis, which may explain the decrease in enhancement ratio on gadoxetic acid-enhanced MR imaging.

Pilot study of hepatic arterial infusion chemotherapy with gemcitabine and 5-fluorouracil for patients with postoperative liver metastases from pancreatic cancer

Hepatic metastasis is a common cause of treatment failure after curative resection of pancreatic cancer. We report a pilot study of hepatic arterial infusion (HAI) chemotherapy with gemcitabine and 5-fluorouracil (5-FU) for postoperative liver metastases from pancreatic cancer. Five patients who had undergone curative resection of liver metastases from pancreatic cancer received HAI of gemcitabine and 5-FU between October 2008 and September 2010 at Kanazawa University Hospital. Gemcitabine at a dose of 800 mg was infused over 30 min via a bedside pump. After gemcitabine administration, 250 mg of 5-FU was infused continuously over 24 h on days 1-5, comprising one cycle of therapy. These treatment cycles were continued biweekly. In the evaluation according to RECIST criteria, a partial response was obtained in 2 of the 5 cases, with stable disease being achieved in the remaining 3 cases (response rate, 100%). In 4 of the 5 cases, a decrease in serum tumor marker CA19-9 was observed after 10 HAI treatment cycles. The median time to treatment failure was 10 months (range 3-17). As to adverse events, leukocytopenia was grade 3 in 1 of 4 affected cases and all 5 were anemic, although 4 of the 5 cases had anemia prior to HAI therapy. Grade 2 thrombocytopenia was observed in 2 cases. No nonhematologic events, such as nausea, diarrhea, liver injury and neuropathy, occurred. There were no life-threatening toxicities, but 4 cases (80%) developed catheter complications, and the HAI catheter and subcutaneous implantable port system had to be removed. HAI delivers high doses of chemotherapeutic agents directly into tumor vessels, producing increased regional levels with greater efficacy and a lower incidence/severity of systemic side effects. In conclusion, HAI chemotherapy is useful and safe for the treatment of malignancies confined to the liver.

Hepatic arterial infusion chemotherapy for post-operative liver metastases from pancreatic cancer in a patient with leukocytopenia: A case report

Here, we present a case of post-operative liver metastases from pancreatic head cancer in a patient with leukocytopenia, who was safely treated by hepatic arterial infusion (HAI) chemotherapy consisting of gemcitabine and 5-FU. The patient was a 61-year-old woman who underwent pancreaticoduodenectomy for pancreatic head cancer, but was found to be an unsuitable candidate for adjuvant systemic chemotherapy due to the presence of leukocytopenia. Five months after surgery, a follow-up CT revealed two liver metastases. Intravenous systemic chemotherapy was also contraindicated due to the leukocytopenia. In the apparent absence of recurrence, excepting the liver metastases, we decided to administer HAI chemotherapy, which had already been administered following the curative surgery. HAI chemotherapy has been shown to be associated with a lower incidence of systemic side effects. Gemcitabine at a dose of 400 mg was administered via a bedside pump and infused over 30 min. After gemcitabine infusion, 250 mg of 5-FU was infused continuously over 24 h from days 1 to 5. This comprised 1 cycle of therapy. The treatment cycles were continued biweekly. After 10 cycles without severe side effects, it was found that though the size of the metastatic tumors was not reduced, tumor vascularity was. However, after the 13th treatment cycle, local recurrence and lymph node metastases were detected. By this time, the patient had recovered from the leukocytopenia, and could thus be administered systemic chemotherapy. In conclusion, HAI chemotherapy is useful and safe for the treatment of malignancies confined to the liver, even in cases where the patient is in a reduced physical condition.

Giant serous microcystic adenoma of the pancreas safely resected after preoperative arterial embolization

Serous microcystic adenomas are rare and account for 1-2% of all exocrine pancreatic tumors and 25% of all pancreatic cystic neoplasms. Recently, with advances in imaging techniques, these adenomas have been identified at an increasing frequency. A 63-year-old woman visited her doctor in 1999 due to a gastric deformity detected by upper gastrointestinal endoscopy. An abdominal computed tomography scan revealed a cystic lesion measuring 6.0 cm in diameter, resulting in a diagnosis of serous microcystic adenoma of the pancreatic head. During follow-up, the tumor increased steadily in size, measuring 6.0 cm in diameter in 1999 and 13.0 cm in 2008, while remaining asymptomatic throughout this period of time. The risk of malignant transformation appears to be low even over the long-term. However, some cases of malignant transformation to serous cystadenocarcinoma have recently been reported. In this case, assessment of the relationship between the tumor and adjacent vascular structures, such as massive drainage vein development on the surface or tumor flow into the portal and superior mesenteric veins and the celiac and superior mesenteric arteries, was critical for determining tumor resectability. The risk of massive intra-operative hemorrhage was felt to be considerable, given the extent of the veins on the surface of the tumor, as well as the size and location of the primary pancreatic mass. Therefore, preoperative embolization of the tumor-feeding arteries arising from the celiac axis (gastroduodenal, splenic and dorsal pancreatic arteries) was performed. Tumor resection with pancreaticoduodenectomy was performed without a blood transfusion, with an estimated blood loss of 570 ml. The final pathology confirmed the diagnosis of serous microcystic adenoma. The patient is currently alive and disease-free. Preoperative partial embolization of the tumor feeding arteries and intra-operative resection of the right gastric and inferior pancreatoduodenal arteries, allowed the tumor blood supply to be arrested without preoperative tumor necrosis. Subsequently, intraoperative blood loss was reduced. Preoperative partial embolization of the feeding arteries is useful for the resection of hypervascular large tumors of the pancreas.

Hepatocellular carcinoma: signal intensity at gadoxetic acid-enhanced MR Imaging--correlation with molecular transporters and histopathologic features

PURPOSE

To analyze the correlation between signal intensity in the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance (MR) imaging and the expression of hepatocyte transporters with histopathologic features in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Institutional ethics committee approval and informed consent were obtained. Forty surgically resected HCCs were classified as hypointense (n = 32) or iso- or hyperintense (n = 8) on the basis of findings in the hepatobiliary phase of gadoxetic acid-enhanced MR imaging. The following were compared between hypointense and iso- or hyperintense HCCs: the time-signal intensity curves at gadoxetic acid-enhanced MR imaging, the expression levels of seven transporters (four organic anion-transporting polypeptides [OATPs] and three multidrug-resistant proteins [MRPs]) at polymerase chain reaction (PCR) (for 22 nodules), results of immunostaining of OATP8, and histologic features. Statistical analysis (unpaired t test, Mann-Whitney test, chi(2) test, and Fisher exact test) was performed for each result.

RESULTS

On the time-signal intensity curves, hypointense HCCs showed a decreasing pattern, whereas iso- or hyperintense HCCs showed an increasing pattern after the dynamic phase. PCR revealed that expression of OATP8 (an uptake transporter) in hypointense HCCs was lower and that in iso- or hyperintense HCCs was higher than in background liver (P < .001). The expression level of MRP3 (a sinusoidal export transporter) showed a similar trend to that of OATP8 (P < .001). Immunostaining revealed that OATP8 expression was weak in hypointense HCCs, whereas it was sustained in iso- or hyperintense HCCs (P < .001). At histologic examination, a pseudoglandular proliferation pattern with bile plugs was more commonly observed in iso- or hyperintense HCCs than in hypointense HCCs (P = .01 for proliferation patterns and P = .006 for bile plugs).

CONCLUSION

The enhancement ratio of HCCs in the hepatobiliary phase of gadoxetic acid-enhanced MR imaging positively correlated with expression levels of OATP8 and MRP3, indicating that gadoxetic acid is taken up by OATP8 and excreted by MRP3.

[Quantitative evaluation of Gd-EOB-DTPA uptake in phantom study for liver MRI]

Gd-EOB-DTPA is a new liver specific MRI contrast media. In the hepatobiliary phase, contrast media is trapped in normal liver tissue, a normal liver shows high intensity, tumor/liver contrast becomes high, and diagnostic ability improves. In order to indicate the degree of uptake of the contrast media, the enhancement ratio (ER) is calculated. The ER is obtained by calculating (signal intensity (SI) after injection-SI before injection) / SI before injection. However, because there is no linearity between contrast media concentration and SI, ER is not correctly estimated by this method. We discuss a method of measuring ER based on SI and T(1) values using the phantom. We used a column phantom, with an internal diameter of 3 cm, that was filled with Gd-EOB-DTPA diluted solution. Moreover, measurement of the T(1) value by the IR method was also performed. The ER measuring method of this technique consists of the following three components: 1) Measurement of ER based on differences in 1/T(1) values using the variable flip angle (FA) method, 2) Measurement of differences in SI, and 3) Measurement of differences in 1/T(1) values using the IR method. ER values calculated by these three methods were compared. In measurement made using the variable FA method and the IR method, linearity was found between contrast media concentration and ER. On the other hand, linearity was not found between contrast media concentration and SI. For calculation of ER using Gd-EOB-DTPA, a more correct ER is obtained by measuring the T(1) value using the variable FA method.

Radioanatomical study of a true tracheal bronchus using multidetector computed tomography

PURPOSE

True tracheal bronchus (TTB) is a rare anomaly in which a lobar or segmental ectopic bronchus arises from the trachea. We examined the frequency and multidetector computed tomography (MDCT) appearances of TTB.

MATERIALS AND METHODS

We retrospectively analyzed 9781 chest MDCT examinations. In cases in which there was an abnormal bronchus suggesting TTB on axial CT images, the following imaging of the abnormal bronchi was undertaken: multiplanar reformation (MPR), multiprojection volume reconstruction (MPVR), volume rendering (VR), and virtual endoscopy (VE).

RESULTS

Of 9781 MDCT examinations, 30 TTBs were observed in 10 females and 20 males. The frequency of TTB was 0.21% among 4622 females, 0.39% among 5159 males (0.31 % in the overall patient population). TTBs arose from the right lateral wall of the trachea; 17 TTBs were of the displaced type and 13 of the supernumerary type. With the displaced type, all segments of the right upper lobe were supplied by the TTB in 8 patients, and the apical segment was supplied in 8 patients. With the supernumerary type, TTBs showed blind termination in 10 patients, and the TTB had a small lobule in 3 patients. All TTBs were clearly visualized on MPR, MPVR, VR, and VE.

CONCLUSION

TTB was identified by MDCT with an incidence of 0.31%.

[Intractable pneumothorax secondary to pulmonary metastasis of angiosarcoma]

A 68-year-old male suffered from right pneumothorax and was admitted to our hospital. He had a previous history of angiosarcoma of the scalp, and had received local resection and chemoradiotherapy. Chest computed tomography (CT) on admission revealed right pneumothorax and bilateral multiple thin-walled cavities of the lung. We performed partial resection of right lung. Histopathological examination showed a small metastatic lesion around the thin-walled cavities of the lung. Four months after the 1st lung resection, he suffered left pneumothorax. We performed partial resection of the left lung. Ten days after the 2nd lung resection, left pneumothorax recurred. Nine days later, he also developed right pneumothorax. We performed the 3rd operation for right lung. Thoracoscopy demonstrated multiple bullas in right lung and it showed impossibility for radical surgery. Although surgical resection for pneumothorax secondary to metastatic lung cancer is usually efficient, it is very hard to manage the pneumothorax of metastatic angiosarcoma.

Hemodynamics of small sclerosing hepatocellular carcinoma without fibrous capsule: evaluation with single-level dynamic CT during hepatic arteriography

The tumor drainage pathway of a hypervascular liver tumor without fibrous capsule was evaluated histologically and using single-level dynamic CT during hepatic arteriography (CTHA) in a case of sclerosing type of hepatocellular carcinoma. This tumor had a thin corona on CTHA, which represented drainage from the tumor sinusoids to the surrounding liver sinusoids. Additionally, the corona of the hypervascular tumor was thinner without than with the fibrous capsule.

Portosystemic shunt on CT during arterial portography: prevalence in patients with and without liver cirrhosis

BACKGROUND

To review various portosystemic shunts (PS) and to evaluate their prevalence by CT during arterial portography (CTAP) using a multidetector-row CT (MDCT).

METHODS

CTAP of 116 patients (liver cirrhosis 70 patients, non-liver cirrhosis 46 patients) was retrospectively reviewed. CTAP was performed with the catheter placed in the superior mesenteric artery using MDCT. Axial CT images of 0.625- and 3.75- or 2.5-mm thickness were obtained. Multiplanar reformation images and maximum intensity projection images were subjected to review.

RESULTS

A part of the veins in the ileocecal region drained into the right renal vein or the inferior vena cava (IVC) via the right gonadal vein in 57 patients (81%). A part of the veins of the ascending colon drained via the right renal capsular vein into the IVC in 37 patients (53%). In 46 patients without liver cirrhosis, the right gonadal and right renal capsular veins were opacified on CTAP in 22 patients (48%) and 20 patients (43%), respectively.

CONCLUSIONS

Portosystemic shunts in retroperitoneum were frequently recognized on CTAP images in patients with liver cirrhosis. The right gonadal vein and the right renal capsular vein were the most frequent routes of the portosystemic shunts. They may exist in physiological condition.

Use of three-dimensional computed tomographic angiography of pulmonary vessels for lung resections

BACKGROUND

Identification and appropriate treatment of the pulmonary artery (PA) is a key to successful anatomic resection of the lung. Preoperative identification of branching pattern of the PA seems to make pulmonary resection easier and safer especially when there is severe adhesion or incomplete fissure between the lobes. With the development of the multidetector row spiral computed tomography (MDCT), three-dimensional (3D) CT angiography can be obtained easily and can provide very useful information about various organs. We studied the usefulness of 3D-CT pulmonary angiography (3D-CTPA) in evaluating the PA branching pattern before anatomic pulmonary resection.

METHODS

Fourteen patients with primary lung cancer undergoing anatomic pulmonary resections were the subjects of this study. The 3D-CTPA images were obtained using MDCT. The obtained images of the PA branching pattern were compared with intraoperative findings in each case at the time of thoracotomy.

RESULTS

MDCT scanning required approximately 15 seconds per patient during a single respiratory pause and the 3D images were processed within 10 minutes after scannning. According to intraoperative findings, 98% (84 of 86) of PA branches were revealed to be successfully identified on preoperative 3D-CTPA. Two missed branches on 3D-CTPA were small vessels, which were less than 1.5 mm in actual diameter. Pulmonary vessels were clearly identified even when contrast medium was not administered intravenously.

CONCLUSIONS

Obtaining 3D-CTPA using MDCT is noninvasive yet it provides precise preoperative information regarding pulmonary vessels. This technique is a far less invasive and an easier investigation than conventional pulmonary angiography. The 3D-CTPA navigation may have the potential to increase the safety of surgical procedure and to reduce surgical morbidity in anatomic lung resection.