[Show abstract][Hide abstract] ABSTRACT: Primary hepatic actinomycosis is one of the chronic abscess-forming infections of the liver. Accurate diagnosis is frequently delayed due to its indolent course and nonspecific clinical and radiological manifestations. We report a case of a 57-year-old man presenting with asymptomatic multiple hepatic masses on follow-up abdominal computed tomography performed 1 year after stomach cancer surgery. Although a percutaneous liver biopsy procedure was conducted twice in order to obtain confirmative pathology, only a nonspecific organizing abscess with plasma cell infiltration was revealed, without identification of any organism in the tissue cultures. Ultimately, actinomycosis was diagnosed following the detection of sulfur granules on open surgical biopsied tissue. This case suggests that primary hepatic actinomycosis should be considered as one of the possible causes for enigmatic inflammatory lesions of the liver.
[Show abstract][Hide abstract] ABSTRACT: Fibroblast growth factor signaling is involved in hepatocarcinogenesis. The aim of this study was to determine the fibroblast growth factor receptor (FGFR) isotype expression in hepatocellular carcinoma (HCC) and neighboring nonneoplastic liver tissue, and elucidate its prognostic implications.
Immunohistochemical staining of FGFR1, -2, -3, and -4 was performed in the HCCs and paired neighboring nonneoplastic liver tissue of 870 HCC patients who underwent hepatic resection. Of these, clinical data for 153 patients who underwent curative resection as a primary therapy were reviewed, and the relationship between FGFR isotype expression and overall survival was evaluated (development set). This association was also validated in 73 independent samples (validation set) by Western blot analysis.
FGFR1, -2, -3, and -4 were expressed in 5.3%, 11.1%, 3.8%, and 52.7% of HCCs, respectively. Among the development set of 153 patients, FGFR2 positivity in HCC was associated with a significantly shorter overall survival (5-year survival rate, 35.3% vs. 61.8%; P=0.02). FGFR2 expression in HCC was an independent predictor of a poor postsurgical prognosis (hazard ratio, 2.10; P=0.02) in the development set. However, the corresponding findings were not statistically significant in the validation set.
FGFR2 expression in HCC could be a prognostic indicator of postsurgical survival.
[Show abstract][Hide abstract] ABSTRACT: Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) and intraductal papillary mucinous neoplasm of the pancreas (IPMN-P) have striking similarities and are recognized as counterparts. However, simultaneous occurrence of IPMN-B and IPMN-P is extremely rare. A 66 year-old female presented with recurrent epigastric pain and fever. During the past 9 years, she had three clinical episodes related to intrahepatic duct stones and IPMN-P in the pancreas head and was managed by medical treatment. Laboratory test results at admission revealed leukocytosis (12,600/mm(3)) and elevated CA 19-9 level (1,200 U/mL). Imaging study demonstrated liver abscess in the Couinaud's segment 4, IPMN-B in the left lobe, and IPMN-P in the whole pancreas with suspicious malignant change. Liver abscess was drained preoperatively, followed by left lobectomy with bile duct resection and total pancreatectomy with splenectomy. On histologic examination, non-invasive intraductal papillary mucinous carcinoma arising from various degree of dysplastic mucosa of the liver and pancreas could be observed. However, there was no continuity between the hepatic and pancreatic lesions. This finding in our case supports the theory that double primary lesions are more likely explained by a diffuse IPMN leading to synchronous tumors arising from both biliary and pancreatic ducts rather than by a metastatic process. Herein we present a case of simultaneous IPMN of the bile duct and pancreas which was successfully treated by surgical management. (Korean J Gastroenterol 2014;63:129-133).
The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 02/2014; 63(2):129-33. DOI:10.4166/kjg.2014.63.2.129
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE. The purpose of this study was to identify the CT features required for differentiating mucin-producing cystic neoplasms of the liver (mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct) from solitary bile duct cysts. MATERIALS AND METHODS. CT images of pathologically confirmed mucinous cystic neoplasms (n = 15), cyst-forming intraductal papillary neoplasms of the bile duct (n = 16), and solitary bile duct cysts (n = 31) were reviewed. Analysis of the CT findings included shape, presence of septa, location of septa (peripheral vs central), thickness of septa (thin vs thick), mosaic pattern, mural nodules, intracystic debris, calcification, upstream bile duct dilatation, downstream bile duct dilatation, and communication between a cystic lesion and the bile duct. The maximum size of a cystic lesion and the maximum size of the largest mural nodule were measured. RESULTS. The presence of septa, central septa, mural nodules, upstream bile duct dilatation, and downstream bile duct dilatation were found to be significant CT findings for differentiating mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct from solitary bile duct cysts (p < 0.05 for each finding). When two of these five criteria were used in combination, the sensitivity and specificity for diagnosing mucin-producing cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct were 87% (27 of 31) and 87% (27 of 31), respectively. When three of the five criteria were used in combination, the sensitivity and specificity were 58% (18 of 31) and 100%. CONCLUSION. With the use of specific CT criteria, mucin-producing cystic neoplasms of the liver can be differentiated from solitary bile duct cysts with a high degree of accuracy.
American Journal of Roentgenology 01/2014; 202(1):83-91. DOI:10.2214/AJR.12.9170 · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives To assess the value of the ultrasound (US) attenuation index for noninvasive estimation of hepatic steatosis and determine its optimal cutoff value for severe steatosis in potential living liver donors. Methods Two hundred forty potential donors underwent US-guided biopsy. The target site was scanned at 4 and 8 MHz. On the sonogram, the observer drew 3 × 3-mm square regions of interest in superficial (3-cm) and deep (5-cm) areas. The attenuation index was defined as the difference between superficial and deep echogenicity/superficial echogenicity × 100. On biopsy specimens, replacement of hepatic parenchyma was evaluated on a percentage scale. Severe steatosis was defined as macrovesicular fatty change of 30% or greater. Spearman rank correlation (ρ) was used to determine correlation coefficients between the attenuation index and steatosis degree; receiver operating characteristic analysis was performed to determine the optimal attenuation index cutoff value for severe steatosis. Results The median steatosis degree was 3% (interquartile range [IQR], 0%-10%). Severe steatosis was found in 10 donors. The attenuation index ranged from -27.4 to 36.6 (median, 4.0; IQR, -1.6-10.4) at 4 MHz and -18.0 to 78.1 (median, 14.5; IQR, 7.2-21.9) at 8 MHz. There was a minimal positive correlation between steatosis and the attenuation index at 4 MHz (total steatosis: ρ = 0.339; P < .001; macrovesicular steatosis: ρ = 0.360; P < .001). However, there was a significant moderate correlation between steatosis and the attenuation index at 8 MHz (total steatosis: ρ = 0.669; P < .001; macrovesicular steatosis: ρ = 0.645; P < .001). The optimal attenuation index cutoff value for severe steatosis at 8 MHz was 31.0. Conclusions The US attenuation index at 8 MHz is a useful indicator for noninvasive quantitative estimation of hepatic steatosis and diagnosis of severe steatosis in potential living liver donors.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 02/2013; 32(2):229-35. DOI:10.1016/j.ultrasmedbio.2013.02.380 · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To identify CT features for differentiating mucinous cystic neoplasm (MCN) and cyst-forming intraductal papillary neoplasm of the bile duct (cIPN-B) from solitary bile duct cyst (SBC).
METHOD AND MATERIALS
CT images of pathologically confirmed MCN (n = 15), cIPN-B (n = 16), and SBC (n = 31) were reviewed. Analysis of the CT findings included size, shape, presence of septa, location of septa, thin or thick septa, mosaic pattern, mural nodule, diameter of mural nodule, intracystic debris, calcification, upstream bile duct dilatation, downstream bile duct dilatation, and communication between cystic lesion and bile duct.
Presence of septa, central septa, thick septa, mural nodule, upstream bile duct dilatation, and downstream bile duct dilatation were found to be significant for differentiating MCN and cIPN-B from SBC (P < .05 for each finding). When at least two of these six criteria were used in combination, the sensitivity and specificity for diagnosing MCN and cIPN-B were 90% (28 of 31) and 87% (27 of 31). When three of these six criteria were used in combination, the sensitivity and specificity for diagnosing MCN and cIPN-B were 65% (20 of 31) and 100%.
By using specific CT criteria, MCN and cIPN-B can be differentiated from SBC with a high degree of accuracy.
Knowledge of these characteristic CT findings of hepatic cystic lesions is helpful in making an accurate preoperative diagnosis, thereby avoid incorrect treatment.
Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
[Show abstract][Hide abstract] ABSTRACT: Background/Aims: Hepatic angiomyolipoma (AML) is a rare mesenchymal tumor of the liver and demonstrates a marked histologic diversity. HMB-45 is a promising immunomarker for this tumor and especially helpful to diagnosis of some AMLs with unusual morphology. The purpose of this study was to better define the variable histologic feature of hepatic AML.Methods: Eight hepatic AMLs were examined, and all of that were resection specimens. The diagnosis was confirmed by the presence of HMB-45 positive cells. Median age was 41.5 years old, and mean size of tumor was 8.94 cm.Results: Conventional mixed type was 5 cases which showed myomatous, angiomatous and lipomatous component, and 3 cases were myomatous predominant. Variable patterns including spider web cell morphology, solid sheet-like and trabecular pattern were identified on myomatous component and variable amount and patterns of inflammatory cell infiltration was identified. Conclusions: With only histologic features, it is difficult to distinguish hepatic AML from other hepatic tumor including hepatocellular carcinoma or inflammatory pseudotumor. A correct diagnosis of hepatic AML is possible by a close histologic examination with immunohistochemical stainings such as HMB-45 which is important to patient's prognosis. (Korean J Gastroenterol 2012;60:242-248).
The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 10/2012; 60(4):242-8. DOI:10.4166/kjg.2012.60.4.242
[Show abstract][Hide abstract] ABSTRACT: Background Sclerosing angiomatoid nodular transformation (SANT) is a rare benign primary vascular lesion of the spleen. Although there have been many reports about the pathology of SANTs of the spleen, there have been no comprehensive descriptions of the imaging findings of SANTs of the spleen. Purpose To determine the clinical characteristics and imaging findings of SANTs of the spleen. Material and Methods We retrospectively evaluated seven patients with pathologically confirmed SANT, who underwent CT (n = 7), MRI (n = 4), ultrasonography (n = 4), and PET/CT (n = 3). Follow-up CT examinations were obtained in five patients. Clinical characteristics such as symptoms and concurrent disease were assessed. CT and MRI findings were evaluated by two radiologists, including the number, border, signal intensity, enhancement pattern, hemorrhage, and cystic change or necrosis. The longest diameter of each tumor was measured on CT. Echogenicity on ultrasonography and standardized uptake value on PET/CT were also evaluated. Results No specific symptom was associated with SANT. Two patients had a history of malignancy, one with cervical cancer and the other with early gastric cancer. Tumor growth was observed in four of five patients. On CT, all seven SANTs appeared as single, well-demarcated masses. CT showed a heterogeneous enhancement in seven patients. MRI showed centripetal progressive enhancement and absence of cystic change or necrosis in four patients, with three of these patients showing evidence of old hemorrhage. Ultrasonography showed heterogeneous hypoechoic mass in four patients. PET/CT showed increased standardized uptake value, ranging from 2.0 to 2.8, in three patients. Conclusion SANT of the spleen is a single, well-demarcated solid mass without cystic change or necrosis. Increased FDG activity and tumor growth on follow-up imaging are common.
[Show abstract][Hide abstract] ABSTRACT: To compare percent interval changes in the portal blood flow velocity (%PBV) and venous pulsatility index (%VPI), as determined by Doppler sonography, in patients with and without acute cellular rejection after right-lobe living donor liver transplantation.
Forty-seven patients with biopsy-proven acute cellular rejection underwent Doppler sonography. The control group consisted of 47 age- and sex-matched patients without acute cellular rejection. Doppler spectrograms of the portal vein and right hepatic vein were used to calculate mean peak PBVs and VPIs for the first 3 days after right-lobe living donor liver transplantation, defined as PBV(Baseline) and VPI(Baseline). The PBV and VPI closest in time to biopsy in the patient group or at a matched time in the control group were determined as PBV(Event) and VPI(Event), and %PBV and %VPI values were calculated.
The mean PBV(Baseline) values ± SD in the rejection and control groups were 46.0 ± 21.8 and 44.4 ± 20.5 cm/s, respectively; the PBV(Event) values were 32.2 ± 14.5 and 34.4 ± 17.1 cm/s; and the %PBV values were 19.4% ± 39.9% and 2.2% ± 75.4% (P = .73; P = .38; P = .17, respectively). The VPI(Baseline) values were 0.92 ± 0.34 and 0.93 P = .94; P < .001); and the ± 0.38; the VPI(Event) values were 0.46 ± 0.33 and 0.84 ± 0.44 (%VPI values were 45.5% ± 40.1% and 5.6% ± 47.3%, with a greater than 50% VPI observed more frequently in the rejection than in the control group (61.7% versus 12.8%; P < .001).
The VPI(Event) was significantly lower and a greater than 50% VPI was significantly more frequent in patients with than without acute cellular rejection after right-lobe living donor liver transplantation.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 06/2012; 31(6):845-51. · 1.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aims of this study were to assess the confounding effects of hepatic iron deposition, inflammation, and fibrosis on hepatic steatosis (HS) evaluation by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) and to assess the accuracies of MRI and MRS for HS evaluation, using histology as the reference standard.
In this institutional review board-approved prospective study, 56 patients gave informed consents and underwent chemical-shift MRI and MRS of the liver on a 1.5-T magnetic resonance scanner. To estimate MRI fat fraction (FF), 4 analysis methods were used (dual-echo, triple-echo, multiecho, and multi-interference), and MRS FF was calculated with T2 correction. Degrees of HS, iron deposition, inflammation, and fibrosis were analyzed in liver resection (n = 37) and biopsy (n = 19) specimens. The confounding effects of histology on fat quantification were assessed by multiple linear regression analysis. Using the histologic degree of HS as the reference standard, the accuracies of each method in estimating HS and diagnosing an HS of 5% or greater were determined by linear regression and receiver operating characteristic analyses.
Iron deposition significantly confounded estimations of FF by the dual-echo (P < 0.001) and triple-echo (P = 0.033) methods, whereas no histologic feature confounded the multiecho and multi-interference methods or MRS. The MRS (r = 0.95) showed the strongest correlation with histologic degree of HS, followed by the multiecho (r = 0.92), multi-interference (r = 0.91), triple-echo (r = 0.90), and dual-echo (r = 0.85) methods. For diagnosing HS, the areas under the curve tended to be higher for MRS (0.96) and the multiecho (0.95), multi-interference (0.95), and triple-echo (0.95) methods than for the dual-echo method (0.88) (P ≥ 0.13).
The multiecho and multi-interference MRI methods and MRS can accurately quantify hepatic fat, with coexisting histologic abnormalities having no confounding effects.
[Show abstract][Hide abstract] ABSTRACT: To determine a highly specific liver attenuation threshold at unenhanced CT for biopsy-proven moderate to severe hepatic steatosis (≥30% at histology).
315 asymptomatic adults (mean age ± SD, 31.5 ± 10.1 years; 207 men, 108 women) underwent same-day unenhanced liver CT and ultrasound-guided liver biopsy. Blinded to biopsy results, CT liver attenuation was measured using standard region-of-interest methodology. Multiple linear regression analysis was used to assess the relationship of CT liver attenuation with patient age, gender, BMI, CT system, and hepatic fat and iron content.
Thirty-nine subjects had moderate to severe steatosis and 276 had mild or no steatosis. A liver attenuation threshold of 48 HU was 100% specific (276/276) for moderate to severe steatosis, with no false-positives. Sensitivity, PPV and NPV at this HU threshold was 53.8%, 100% and 93.9%. Hepatic fat content was the overwhelming determinant of liver attenuation values, but CT system (P < 0.001), and hepatic iron (P = 0.035) also had a statistically significant independent association.
Unenhanced CT liver attenuation alone is highly specific for moderate to severe hepatic steatosis, allowing for confident non-invasive identification of large retrospective/prospective cohorts for natural history evaluation of incidental non-alcoholic fatty liver disease. Low sensitivity, however, precludes effective population screening at this threshold.
• Unenhanced CT liver attenuation is highly specific for diagnosing moderate/severe hepatic steatosis. • Unenhanced CT can identify large cohorts for epidemiological studies of incidental steatosis. • Unenhanced CT is not, however, effective for population screening for hepatic steatosis.
European Radiology 12/2011; 22(5):1075-82. DOI:10.1007/s00330-011-2349-2 · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
The true clinical significance of isolated hepatic steatosis is uncertain, but moderate-severe disease (≥30% fat content at histopathology) may confer a higher risk for progression to steatohepatitis, fibrosis, and cirrhosis. The primary goal of this study was to assess the specificity and other performance measures of noncontrast CT for detecting moderate-severe hepatic steatosis.
METHOD AND MATERIALS
Informed consent was obtained from all subjects in this IRB-approved study. A total of 276 potential liver donors (mean age±SD, 31.1±10.0; M/F, 171/105) who underwent same-day noncontrast liver CT and US-guided liver biopsy had either no steatosis (n=96) or mild steatosis (1-29% fat; n=180) at histology, whereas 39 potential donors (mean age±SD, 34.4±10.4; M/F, 36/3) had moderate or severe steatosis (≥30% fat at histology). Liver attenuation measurement (HU) was obtained by averaging eight 1.5 cm2 circular ROIs placed in Couinaud segments V, VI, VII, and VIII – blinded to the biopsy results. Multiple linear regression analysis was used to assess effect of patient age, gender, hepatic iron grade (0 to 4), and specific MDCT vendor on liver attenuation.
A noncontrast CT liver attenuation threshold of 47 HU (or lower) was 100% specific (276/276) in this cohort for detecting moderate-severe steatosis (≥30% fat at histology). Sensitivity, PPV, and NPV for moderate-severe steatosis at this 47 HU cut-off was 53.8% (21/39), 100% (21/21), and 93.9% (276/294), respectively. Multiple regression analysis showed that hepatic iron grade (P=.035) and MDCT vendor (GE versus Siemens) (P<.001) had a significant influence on liver attenuation values. Eighteen patients who had false-negative results were significantly associated with higher degrees of hepatic iron than the 21 patients with true-positive results (P=.037). For the GE MDCT scanner, a 51 HU threshold was 100% specific (126/126) for moderate-severe steatosis.
Noncontrast CT liver attenuation alone is highly specific for detecting moderate or severe degrees of hepatic steatosis, which may preclude the need for biopsy in some positive cases. The optimal HU threshold value is vendor-specific. Sensitivity is decreased somewhat by increased hepatic iron content.
The high specificity of noncontrast CT liver attenuation allows for confident noninvasive diagnosis of moderate-severe steatosis when liver ROI measurement falls below the relevant HU threshold.
Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011
[Show abstract][Hide abstract] ABSTRACT: Focal nodular hyperplasia (FNH) and FNH-like lesions are hypervascular masses that can mimic hepatocellular carcinoma (HCC). We have investigated the clinical, radiological and pathological features of FNH and FNH-like lesions of the liver, with particular focus on the aspect of diagnosis.
A total of 84 patients, 77 with pathologically-proven FNH and seven with FNH-like lesions of the liver, were analyzed retrospectively.
Of the 84 patients, seven had underlying liver cirrhosis, including two with Budd-Chiari syndrome and one with cardiac cirrhosis. These cases were therefore classified as having FNH-like lesions. Two of the remaining 77 patients without underlying liver cirrhosis were positive for hepatitis B surface antigen. Seven of 50 (14.0%) patients evaluated by four-phase computed tomography (CT) showed portal or delayed washout, and three of 28 (10.7%) patients analyzed by three-phase CT showed washout on the portal phase. Collectively, three of nine (33.3%) patients with risk factors for HCC could have been wrongly diagnosed with HCC based on the non-invasive diagnostic criteria for HCC. A central scar was observed in 30 patients (35.7%) radiologically. Among 62 patients who underwent percutaneous needle biopsy, four patients (6.5%) were misdiagnosed as having HCC and two patients (3.2%) had inconclusive results by a first needle biopsy.
The presence of a hepatic lesion with arterial hypervascularity and/or portal/delayed washout is not necessarily diagnostic of HCC, particularly in patients without risk factors for HCC. These radiological findings can also occur in cirrhotic patients with FNH-like lesions, including those with hepatic outflow obstruction.
Journal of Gastroenterology and Hepatology 06/2011; 26(6):1004-9. DOI:10.1111/j.1440-1746.2011.06659.x · 3.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Noninvasive criteria for diagnosing hepatocellular carcinoma (HCC) suggested by the American Association for the Study of Liver Diseases (AASLD) in 2005 consisted of serum α-fetoprotein (AFP) level >200 ng/ml or a typical enhancement pattern (arterial enhancement and portal/delayed washed out) on dynamic imaging of hepatic mass(es) >2 cm in a cirrhotic liver.
To validate these criteria in a Korean population and to evaluate whether these criteria are applicable to patients without cirrhosis at a high risk of developing HCC.
We prospectively investigated 206 consecutive patients with hepatic mass(es) >2 cm who underwent biopsy or surgical resection. Patients were evaluated by four-phase dynamic computed tomography (CT) and by assays of serum AFP concentrations at baseline. Patients were classified according to the presence of risk factors or cirrhosis, and the diagnostic accuracy of each test was determined.
The positive predictive values (PPV) of typical CT findings or serum AFP >200 ng/ml were 97.8% in cirrhotic patients, 89.6% in high-risk patients without cirrhosis and 82.4% in low-risk patients. The PPVs of typical CT findings alone in these groups were 98.8, 97.6 and 87.5% respectively. In high-risk patients without cirrhosis, the addition of serum AFP levels to typical CT findings minimally increased the diagnostic sensitivity from 81.6 to 87.8% but reduced the PPV from 97.6 to 89.6%.
Serum AFP concentration is not a suitable diagnostic criterion for HCC. Typical CT findings can be used to diagnose HCC >2 cm both in cirrhotic patients and in high-risk patients without cirrhosis.
Liver international: official journal of the International Association for the Study of the Liver 04/2011; 31(10):1468-76. DOI:10.1111/j.1478-3231.2011.02529.x · 4.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To establish the reference range for hepatic attenuation minus splenic attenuation difference (CT(L-S)) values on nonenhanced computed tomographic (CT) images obtained in adults with a biopsy-proved nonsteatotic liver and determine the CT(L-S) criterion for diagnosing hepatic steatosis.
This retrospective study was institutional review board approved, and all subjects had provided written informed consent. The CT(L-S) was measured in 315 liver donor candidates (207 men, 108 women; mean age, 31.5 years ± 10.1 [standard deviation]) who underwent nonenhanced CT of the liver and subsequent ultrasonographically guided liver biopsy on the same day. Nonenhanced liver CT was performed with a 16-section multidetector scanner in 154 individuals and with a 64-section multidetector scanner in 161 individuals. Biopsy specimens were analyzed for degree of hepatic steatosis and iron deposition. The CT(L-S) reference range was determined according to Clinical and Laboratory Standards Institute guideline C28-A3 in individuals with a histologically proved nonsteatotic liver. The sensitivity of nonenhanced CT for the diagnosis of 5% or greater and 30% or greater hepatic steatosis with use of the lower limit of the reference range as the diagnostic cutoff was determined. The effects of subject age and sex, CT scanner type, and hepatic iron on the CT(L-S) were evaluated by using multiple linear regression analysis.
Ninety-six subjects (48 men, 48 women) were found to have a histologically proved nonsteatotic liver, with an estimated reference range for CT(L-S) values of 1-18 HU. With a CT(L-S) of less than 1 HU as the criterion for hepatic steatosis, the sensitivities of nonenhanced CT for 5% or greater and 30% or greater hepatic steatosis were 18.6% (29 of 156 subjects) and 67% (26 of 39 subjects), respectively. Subject age had a significant but negligible effect on CT(L-S) (0.076-HU increase per year of age, P = .009), subject sex and scanner type had no effects on CT(L-S), and hepatic iron deposition significantly increased the CT(L-S) (1.434-HU increase per increase in iron deposition grade, P = .011).
The histologically proved reference range of CT(L-S) values for nonsteatotic livers was 1-18 HU. A CT(L-S) of less than 1 HU could be used as a conservative criterion for diagnosing hepatic steatosis with nonenhanced CT more consistently.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To compare the pathologic and prognostic characteristics of visually isoattenuating pancreatic adenocarcinoma (IPA) with those of usual hypoattenuating pancreatic adenocarcinoma (UPA).
METHOD AND MATERIALS
Of 743 consecutive pathology-proven pancreatic ductal adenocarcinoma patients over a 30-month period, 644 patients who had undergone both arterial- and portal-phase contrast-enhanced CT, were included. IPA was defined as lesion isoattenuation on both scan phases. Pathology findings of surgically resected IPAs were compared with the same number of size-matched, randomly chosen, surgically resected UPAs. Survival after curative-intent surgery was compared between IPA and UPA patients using the Kaplan-Meier method and the log-rank test. The adjusted hazard ratio was calculated for IPA vs. UPA using the multivariate cox proportional hazard analysis, which accounted for confounders including age, gender, T and N stages, tumor size, histologic grade, surgical resection margin status, and lymphovascular invasion.
Thirty-five and 609 patients were identified as having IPA and UPA, respectively. Of those, 30 and 233 patients received curative-intent surgery. The 30 surgically resected IPAs were 1.5-4 cm (median, 3 cm). Pathology findings of IPAs differed from those of UPAs: lower tumor cellularity (tumor cellularity less than 50% in 28/30 vs. 9/30), more frequent intratumoral acinar tissue and islet cells (19/30 vs. 9/30), less prominent tumor necrosis (5/30 vs. 20/30), and scanty extracellular mucin deposit (P≤.019). Median survival after curative-intent surgery was significantly longer in IPA patients than in UPA patients: longer than 30 months vs. 15.6 months (95% CI, 13.8-17.4 months) (P=.002). IPA was independently associated with a better survival after the surgery compared with UPA: the adjusted hazard ratio of 0.43 (95% CI, 0.235-0.787) (P=.006).
IPA represents a small but meaningful subset of pancreatic cancers, which has different pathologic characteristics and a better post-surgery survival than UPA.
The more favorable post-surgery survival of IPA patients makes it imperative for radiologists to be knowledgeable about the disease and to correctly diagnose them at surgically resectable stages.
Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 12/2010
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To prospectively compare the accuracy of dual-echo, triple-echo, and multi-echo chemical shift gradient-echo MR imaging (CS-MRI) and MR spectroscopy (MRS) in the evaluation of hepatic steatosis (HS) in patients with chronic liver disease.
METHOD AND MATERIALS
Fifty five consecutive patients with chronic liver disease underwent CS-MRI with six opposed- and in-phase acquisitions and MR spectroscopy (MRS) with five-echo acquisitions (20, 30, 40, 50, and 60 msec) on a 1.5T-MR scanner. For CS-MRI, fat fractions (FFs) were estimated with the dual-echo method and with two T2*-correction algorithms, i.e. triple-echo and multi-echo methods. For MRS, T2-corrected FF was calculated using an exponential least-squares fitting algorithm. Pathologic specimens of the liver were analyzed for the degree of HS, iron deposition, inflammation, and fibrosis. With histologic degree of HS as the reference standard, the accuracy of each imaging method in the quantitative estimation and the diagnosis of HS were compared using the linear regression and the receiver operating characteristic analyses. Confounding effect of iron deposition, inflammation, and fibrosis on fat quantification was assessed using the multifactorial linear regression analysis for each imaging method.
MRS (r=.95) had the strongest correlation with the histologic degree of HS, followed by multi-echo (r=.92), triple-echo (r=.90), and dual-echo CS-MRI (r=.85); the difference in the correlation coefficient was significant only between MRS and dual-echo CS-MRI (p<.001). For the diagnosis of HS≥5%, the areas under the curve for MRS (0.96), multi-echo CS-MRI (0.95), and triple-echo CS-MRI (0.95) tended to be higher than that of dual-echo CS-MRI (0.88) (p≥.13). Histologic findings other than the degree of HS had no significant effect on estimating FF with MRS and multi-echo CS-MRI (p≥.51), whereas the degree of iron deposition had a significant confounding effect on estimating FF with dual-echo (p<.001) and triple-echo CS-MRI (p=.04).
For the assessment of HS in patients with chronic liver disease, multi-echo CS-MRI has a similar accuracy to MRS and permits to eliminate the confounding effect of iron deposition more effectively than triple-echo CS-MRI.
Given its comparable accuracy and wider spatial coverage compared with MRS, multi-echo CS-MRI may be practical alternative to MRS for the evaluation of HS in patients with chronic liver disease.
Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 11/2010
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To evaluate the effect of iron deposition on the fat quantification using chemical shift gradient-echo MR imaging (CS-MRI) and the efficacy of T2*-correction algorithms for minimizing the confounding effect of iron.
METHOD AND MATERIALS
CS-MRI with six opposed- and in-phase acquisitions and MR spectroscopy (MRS) with five-echo acquisitions were performed at 1.5T for the phantoms with varying fat fractions (FFs) (0-50%), the 10% fat phantoms with varying iron concentrations (0-14.0μg/ml), and 18 patients with chronic liver disease. For CS-MRI, FFs were estimated with the dual-echo method, with the two T2*-correction algorithms (triple-echo and multi-echo methods), and with multi-interference method incorporating both T2*-correction and fat-fat signal interference. For MRS, T2-corrected FF was calculated using an exponential least-squares fitting algorithm. The 95% Bland-Altman limits-of-agreement (LOA) were calculated for each CS-MRI method with the true FFs of the phantoms and MRS FFs as reference standards for the phantom experiments and for the patient study, respectively.
In the phantoms with varying FF, MRS provided the most accurate estimation of FF (95%-LOA, -0.2%±1.2), followed by multi-interference (0.4%±1.6), multi-echo (-1.1%±2.2), triple-echo (-1.0%±4.0), and dual-echo CS-MRI methods (-5.5%±2.9%). In the phantoms with varying iron concentration, dual-echo method underestimated FFs in proportion to the iron concentration (the absolute error range, -11% to 5%), whereas the other three CS-MRI methods accurately estimated FF (the absolute error range, -0.8% to 0.3%), regardless of iron concentration. In 18 patients with chronic liver disease, the FFs estimated with triple-echo (95% LOA, 0.6%±1.8), multi-echo (-0.5%±1,4), and multi-interference CS-MRI (0.3%±1.6) had closer agreements with the MRS FFs, compared with dual-echo CS-MRI (-3.9%±6.9).
Hepatic iron deposition causes a significant bias in fat quantification using dual-echo CS-MRI, while triple-echo, multi-echo, and multi-interference CS-MRI methods are effective in minimizing the confounding effect of iron and thus enable accurate fat quantification throughout the physiologic range of iron deposition.
CS-MRI with T2*-correction algorithms may be a useful clinical tool for noninvasive evaluation of hepatic fat in patients with chronic liver disease or those with hepatic iron overload.
Radiological Society of North America 2010 Scientific Assembly and Annual Meeting; 11/2010
[Show abstract][Hide abstract] ABSTRACT: To retrospectively determine the frequency, clinical and pathologic characteristics, and computed tomographic (CT) findings of visually isoattenuating pancreatic adenocarcinomas and to investigate the utility of magnetic resonance (MR) imaging and positron emission tomography (PET)/CT for detecting them.
Institutional review board approval was obtained. Patient informed consent was waived. Of 743 consecutive patients with pathologically proved pancreatic cancer, 644 patients (392 men, 252 women; mean age, 60 years ± 9.5 [standard deviation]) who had undergone both arterial and portal phase contrast material-enhanced CT were included. Visually isoattenuating pancreatic adenocarcinoma was defined as lesion isoattenuation in both scan phases. Serum levels of carbohydrate antigen 19-9, immunoglobulin G (IgG), and IgG fraction 4 (IgG4), survival after curative-intent surgery; and pathologic findings of visually isoattenuating pancreatic adenocarcinomas were analyzed. CT findings of visually isoattenuating pancreatic adenocarcinomas and the sensitivity of MR imaging and PET/CT for detecting them were determined.
The frequency of visually isoattenuating pancreatic adenocarcinomas among pancreatic cancers was 5.4% (35 of 644). Serum levels of carbohydrate antigen 19-9, IgG, and IgG4 were elevated in 51.5% (17 of 33), 8.3% (one of 12), and 8.3% (one of 12) of patients, respectively. Visually isoattenuating pancreatic adenocarcinoma, compared with usual pancreatic adenocarcinoma, was independently associated with a better survival after curative-intent surgery: Adjusted hazard ratio was 0.430 (P = .006). Thirty surgically resected visually isoattenuating pancreatic adenocarcinomas were 1.5-4 cm (median, 3 cm). Their pathologic findings differed from those of usual pancreatic adenocarcinomas: lower tumor cellularity, more frequent intratumoral acinar tissue and islet cells, and less prominent tumor necrosis. Visually isoattenuating pancreatic adenocarcinomas showed various abnormalities at CT, which may suggest an isoattenuating mass or nodule. Sensitivities of MR imaging and PET/CT were 79.2% (19 of 24) and 73.7% (14 of 19), respectively.
Visually isoattenuating pancreatic adenocarcinoma represents a small but meaningful subset of pancreatic cancer and has characteristic clinical and pathologic features. MR imaging and PET/CT may be useful as subsequent examinations when the patient is suspected of having the lesion at CT.