Double somatic mutations in CTNNB1 and GNA11 in an aldosterone-producing adenoma.

Double somatic mutations in CTNNB1 and GNA11/Q have recently been identified in a small subset of aldosterone-producing adenomas (APAs). As a possible pathogenesis of APA due to these mutations, an association with pregnancy, menopause, or puberty has been proposed. However, because of its rarity, characteristics of APA with these mutations have not been well characterized. A 46-year-old Japanese woman presented with hypertension and hypokalemia. She had two pregnancies in the past but had no history of pregnancy-induced hypertension. She had regular menstrual cycle at presentation and was diagnosed as having primary aldosteronism after endocrinologic examinations. Computed tomography revealed a 2 cm right adrenal mass. Adrenal venous sampling demonstrated excess aldosterone production from the right adrenal gland. She underwent right laparoscopic adrenalectomy. The resected right adrenal tumor was histologically diagnosed as adrenocortical adenoma and subsequent immunohistochemistry (IHC) revealed diffuse immunoreactivity of aldosterone synthase (CYP11B2) and visinin like 1, a marker of the zona glomerulosa (ZG), whereas 11ß-hydroxylase, a steroidogenic enzyme for cortisol biosynthesis, was mostly negative. CYP11B2 IHC-guided targeted next-generation sequencing identified somatic CTNNB1 (p.D32Y) and GNA11 (p.Q209H) mutations. Immunofluorescence staining of the tumor also revealed the presence of activated ß-catenin, consistent with features of the normal ZG. The expression patterns of steroidogenic enzymes and related proteins indicated ZG features of the tumor cells. PA was clinically and biochemically cured after surgery. In conclusion, our study indicated that CTNNB1 and GNA11-mutated APA has characteristics of the ZG. The disease could occur in adults with no clear association with pregnancy or menopause.

Successful Balloon-Assisted Hepatic Tract Embolization Using the Pull-Through Technique to Remove a Malpositioned Chest Tube Penetrating the Liver and into the Right Ventricle.

Intra-abdominal injury is an uncommon complication of chest tube insertion. A 66-year-old man had empyema and underwent chest tube insertion for drainage. Massive hemorrhage occurred; the postprocedural radiograph showed the malpositioned chest tube in the mediastinum. Computed tomography scan showed that the tube's tip penetrated through the liver capsule and passed through the hepatic vein to the right ventricle. Hepatic tract embolization with coiling was performed during chest tube removal under a controlled condition with the hepatic tract occluded by a balloon catheter. The balloon catheter was placed from the right jugular vein using the pull-through technique, establishing a through-and-through guidewire. This is the first report of successful removal of a chest tube malpositioned in the hepatic vein by balloon-assisted hepatic tract embolization without complication.

Successful non-operative management of traumatic extrahepatic portal venous injury without intraperitoneal hemorrhage: a case report.

Case: A 52-year-old woman was admitted to our hospital with hypotension after falling from the fifth floor of an apartment building. Contrast-enhanced computed tomography showed liver injury with extravasation of contrast material from the hepatic artery, and extrahepatic portal venous injury with extravasation and pseudoaneurysm. Intra-abdominal hemorrhage was not observed, and bleeding was confined to the retroperitoneal space. Hepatic arteriography showed extravasation, while portal venography showed pseudoaneurysm but no extravasation. After transarterial embolization, the patient's vital signs improved. Non-operative management was selected for the portal venous injury. Outcome: Computed tomography on the 58th hospital day revealed disappearance of the portal venous pseudoaneurysm. The patient was discharged on the 90th hospital day without any complications. Conclusion: This case shows that non-operative management can be selected for portal venous injury when there is no retroperitoneal injury and bleeding is confined to the retroperitoneal space.

Solitary oropharyngeal neurofibroma: MR appearance with pathologic correlation and review of the literature.

Although neurofibroma is a common soft tissue tumor of the head and neck, neurofibroma of the oropharynx is extremely rare. Here, we report a case of neurofibroma of the palatine tonsil. Magnetic resonance imaging was useful in demonstrating the location of the tumor as well as its well-defined appearance. The present case showed a target sign; the tumor exhibited peripheral hyperintensity and central hypointensity on T2-weighted images, reflecting its characteristic zonal anatomy.

Contrast behavior of high-spatial-resolution T1-weighted MR imaging at 3.0 T vs. 1.5 T.

Twenty-four volunteers were examined at T1-weighted images with thin sections using gradient-based sequences with a possible short and same TR at 3.0 and 1.5 T. Pancreas-to-spleen contrast measurements and scores for visual assessments of image contrast were significantly worse at 3.0 T than at 1.5 T on both sequences. The image contrast of high-spatial-resolution T1-weighted images at 3.0 T is decreased compared to that of images with the same and possible short TR at 1.5 T.

Non-contrast-enhanced hepatic MR angiography: do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

OBJECTIVE: To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. MATERIALS AND METHODS: Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2×2 and CHESS), and group C (2D-PI factor 2×2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored. RESULTS: The mean scan time was 9.5±1.0 min (mean±standard deviation), 5.9±0.8 min, and 5.8±0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P<0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P<0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P<0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences. CONCLUSION: Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

Comparison of gadolinium-EOB-DTPA-enhanced and diffusion-weighted liver MRI for detection of small hepatic metastases.

OBJECTIVE: To compare the accuracy of gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI with that of diffusion-weighted MRI (DWI) in the detection of small hepatic metastases (2 cm or smaller). METHODS: Forty-five patients underwent abdominal MRI at 3 T, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), heavily T2WI (HASTE), DWI with a b-value of 500 s/mm(2) and contrast-enhanced MRI with Gd-EOB-DTPA. Two groups were assigned and compared: group A (T1WI, T2WI, HASTE and contrast-enhanced study with Gd-EOB-DTPA), and group B (T1WI, T2WI, HASTE and DWI). Two observers independently interpreted the images obtained in a random order. For all hepatic metastases, the diagnostic performance using each imaging set was evaluated by receiver-operating characteristic (ROC) curve analysis. RESULTS: A total of 51 hepatic metastases were confirmed. The area under the ROC curve (Az) of group A was larger than that of group B, and the difference in the mean Az values between the two image sets was statistically significant, whereas, there were three metastases that lay near thin vessels or among multiple cysts and were better visualised in group B than in group A. CONCLUSION: Gd-EOB-DTPA-enhanced MRI showed higher accuracy in the detection of small metastases than DWI.

Improved detection of hepatic metastases from pancreatic cancer using periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique after SPIO administration.

OBJECTIVES: The purpose of this study was to evaluate the detection of hepatic metastases from the pancreatic cancer using different MR imaging methods, including superparamagnetic iron oxide (SPIO)-enhanced fat-saturated T2-weighted imaging with periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique. MATERIALS AND METHODS: The institutional review board approved this prospective study. Eighty-two patients (mean age, 55 years) underwent different MR imaging with a 1.5-T scanner. Diagnostic performance with receiver operating characteristics (ROC) curves and sensitivity were evaluated for the following image sets: (A) unenhanced images (T1-weighted in-phase and opposed-phase gradient-echo [GRE] images, and fat-saturated T2-weighted turbo spin-echo [TSE] images) that were included in the subsequent image sets, (B) diffusion-weighted images, (C) SPIO-enhanced fat-saturated T2-weighted TSE images with prospective acquisition correction (PACE), (D) SPIO-enhanced T2*-weighted GRE images, and (E) SPIO-enhanced fat-saturated T2-weighted TSE images acquired with PROPELLER and PACE. RESULTS: The areas under the ROC curves were 0.58 +/- 0.05 (mean +/- standard errors), 0.81 +/- 0.04, 0.70 +/- 0.05, 0.80 +/- 0.04, and 0.90 +/- 0.03, and sensitivity was 0.47, 0.69, 0.56, 0.66, and 0.77 for image sets (A) to (E), respectively, for all lesions. Image set (E) had significantly larger area under the ROC curve for detection of hepatic lesions and higher sensitivity than others. CONCLUSIONS: SPIO-enhanced fat-saturated T2-weighted MR imaging with the PROPELLER technique is more effective for detecting hepatic metastases of pancreatic cancer than diffusion-weighted MR imaging, SPIO-enhanced fat-saturated T2WI without the PROPELLER technique, or SPIO-enhanced T2*-weighted GRE imaging.

High spatial resolution 3D MR cholangiography with high sampling efficiency technique (SPACE): comparison of 3T vs. 1.5T.

PURPOSE: The aim of this study was to evaluate image quality of 3D MR cholangiography (MRC) using high sampling efficiency technique (SPACE) at 3T compared with 1.5T. METHODS AND MATERIALS: An IRB approved prospective study was performed with 17 healthy volunteers using both 3 and 1.5T MR scanners. MRC images were obtained with free-breathing navigator-triggered 3D T2-weighted turbo spin-echo sequence with SPACE (TR, >2700ms; TE, 780ms at 3T and 801ms at 1.5T; echo-train length, 121; voxel size, 1.1mmx1.0mmx0.84mm). The common bile duct (CBD) to liver contrast-to-noise ratios (CNRs) were compared between 3 and 1.5T. A five-point scale was used to compare overall image quality and visualization of the third branches of bile duct (B2, B6, and B8). The depiction of cystic duct insertion and the highest order of bile duct visible were also compared. The results were compared using the Wilcoxon signed-ranks test. RESULTS: CNR between the CBD and liver was significantly higher at 3T than 1.5T (p=0.0006). MRC at 3T showed a significantly higher overall image quality (p=0.0215) and clearer visualization of B2 (p=0.0183) and B6 (p=0.0106) than at 1.5T. In all analyses of duct visibility, 3T showed higher scores than 1.5T. CONCLUSION: 3T MRC using SPACE offered better image quality than 1.5T. SPACE technique facilitated high-resolution 3D MRC with excellent image quality at 3T.

Unenhanced MR portography with a half-Fourier fast spin-echo sequence and time-space labeling inversion pulses: preliminary results.

OBJECTIVE: For this study, we aimed to selectively visualize the intrahepatic portal veins using 3D half-Fourier fast spin-echo (FSE) MR angiography (MRA) with a time-space labeling inversion pulse (T-SLIP) and to optimize the acquisition protocol. SUBJECTS AND METHODS: Respiratory-triggered 3D half-Fourier FSE scans were obtained in 25 healthy adult subjects combined with two different T-SLIPs: one placed on the liver and the thorax to suppress signals of the liver parenchyma, hepatic veins, and abdominal arteries and the other on the lower abdomen to suppress the ascending signal of the inferior vena cava. One of the most important factors was the inversion time (TI) of the inversion pulse for the liver and thorax. Image quality was evaluated in terms of signal-to-noise ratio, contrast-to-noise ratio, and mean visualization scores at four different TIs: 800, 1,200, 1,600, and 2,000 milliseconds. RESULTS: Selective visualization of the portal vein was successfully achieved in all volunteers, and anatomic variations were also seen in three subjects. A TI of 1,200 milliseconds was optimal in our protocol because it was sufficient for peripheral portal vein visualization and was most suitable for signal suppression of the hepatic veins and liver parenchyma. CONCLUSION: Half-Fourier FSE scanning with T-SLIPs enabled selective visualization of the portal vein without an exogenous contrast agent.

Non-contrast-enhanced MR portography with time-spatial labeling inversion pulses: comparison of imaging with three-dimensional half-fourier fast spin-echo and true steady-state free-precession sequences.

PURPOSE: To compare and evaluate images acquired with two different MR angiography (MRA) sequences, three-dimensional (3D) half-Fourier fast spin-echo (FSE) and 3D true steady-state free-precession (SSFP) combined with two time-spatial labeling inversion pulses (T-SLIPs), for selective and non-contrast-enhanced (non-CE) visualization of the portal vein. MATERIALS AND METHODS: Twenty healthy volunteers were examined using half-Fourier FSE and true SSFP sequences on a 1.5T MRI system with two T-SLIPs, one placed on the liver and thorax, and the other on the lower abdomen. For quantitative analysis, vessel-to-liver contrast (Cv-l) ratios of the main portal vein (MPV), right portal vein (RPV), and left portal vein (LPV) were measured. The quality of visualization was also evaluated. RESULTS: In both pulse sequences, selective visualization of the portal vein was successfully conducted in all 20 volunteers. Quantitative evaluation showed significantly better Cv-l at the RPVs and LPVs in half-Fourier FSE (P < 0.0001). At the MPV, Cv-l was better in true SSFP, but was not statistically different. Visualization scores were significantly better only at branches of segments four and eight for half-Fourier FSE (P = 0.001 and 0.03, respectively). CONCLUSION: Both 3D half-Fourier FSE and true SSFP scans with T-SLIPs enabled selective non-CE visualization of the portal vein. Half-Fourier FSE was considered appropriate for intrahepatic portal vein visualization, and true SSFP may be preferable when visualization of the MPV is required.

Hepatic lesions: improved image quality and detection with the periodically rotated overlapping parallel lines with enhanced reconstruction technique--evaluation of SPIO-enhanced T2-weighted MR images.

PURPOSE: To evaluate the effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for superparamagnetic iron oxide (SPIO)-enhanced T2-weighted magnetic resonance (MR) imaging with respiratory compensation with the prospective acquisition correction (PACE) technique in the detection of hepatic lesions. MATERIALS AND METHODS: The institutional human research committee approved this prospective study, and all patients provided written informed consent. Eighty-one patients (mean age, 58 years) underwent hepatic 1.5-T MR imaging. Fat-saturated T2-weighted turbo spin-echo images were acquired with the PACE technique and with and without the PROPELLER method after administration of SPIO. Images were qualitatively evaluated for image artifacts, depiction of liver edge and intrahepatic vessels, overall image quality, and presence of lesions. Three radiologists independently assessed these characteristics with a five-point confidence scale. Diagnostic performance was assessed with receiver operating characteristic (ROC) curve analysis. Quantitative analysis was conducted by measuring the liver signal-to-noise ratio (SNR) and the lesion-to-liver contrast-to-noise ratio (CNR). The Wilcoxon signed rank test and two-tailed Student t test were used, and P < .05 indicated a significant difference. RESULTS: MR imaging with the PROPELLER and PACE techniques resulted in significantly improved image quality, higher sensitivity, and greater area under the ROC curve for hepatic lesion detection than did MR imaging with the PACE technique alone (P < .001). The mean liver SNR and the lesion-to-liver CNR were higher with the PROPELLER technique than without it (P < .001). CONCLUSION: T2-weighted MR imaging with the PROPELLER and PACE technique and SPIO enhancement is a promising method with which to improve the detection of hepatic lesions. (c) RSNA, 2009.

Non-contrast-enhanced MR angiography for selective visualization of the hepatic vein and inferior vena cava with true steady-state free-precession sequence and time-spatial labeling inversion pulses: preliminary results.

PURPOSE: To selectively visualize the hepatic vein and inferior vena cava (IVC) using three-dimensional (3D) true steady-state free-precession (SSFP) MR angiography with time-spatial labeling inversion pulse (T-SLIP), and to optimize the acquisition protocol. MATERIALS AND METHODS: Respiratory-gated 3D true SSFP scans were conducted in 23 subjects in combination with two different T-SLIPs (one placed in the thorax to suppress the arterial signal and the other in the abdomen to suppress the portal venous signal). One of the most important factors was the inversion time (TI) of abdominal T-SLIP, and the image quality was evaluated at four different TIs of 800, 1200, 1600, and 2000 msec in terms of relative signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and mean visualization scores. RESULTS: No significant difference was observed in SNR and CNR between each TI. However, IVC visualization scores were better at TIs of 1600 and 2000 msec, and overall image quality was better at TIs of 1200 and 1600 msec. Therefore, the TI of 1600 msec was considered to provide the optimal balance between IVC visualization and signal suppression of the portal vein in our protocol. CONCLUSION: True SSFP scan with T-SLIPs enabled selective visualization of the hepatic vein and IVC without an exogenous contrast agent.

Non-contrast-enhanced hepatic MR angiography with true steady-state free-precession and time spatial labeling inversion pulse: optimization of the technique and preliminary results.

OBJECTIVE: To selectively visualize the hepatic arteries using the respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequence with time spatial labeling inversion pulse (T-SLIP), and describe the optimization of this protocol. MATERIALS AND METHODS: Twenty healthy volunteers were examined in this study. A respiratory-triggered 3D true SSFP combined with T-SLIP was performed. Among several key factors that affect the image quality, the most important is the inversion time (TI). Therefore, according to the difference in TI, four image groups: group A (TI of 800 ms), group B (TI of 1000 ms), group C (TI of 1200 ms), and group D (TI of 1400 ms), were assigned and compared to detect the optimal TI for hepatic artery visualization. For quantitative assessment, the relative signal intensity, i.e., Cv-l (vessel-to-liver contrast) of the right hepatic artery was measured. For qualitative evaluation, the quality of vessel visualization and the order of identified hepatic artery branches were evaluated by two radiologists. RESULTS: Selective and high-contrast visualization of the hepatic arteries was acquired in all cases. Regarding the quantitative assessment, Cv-l decreased in group D due to background signal recovery, but there was no significant difference between groups (p-value >0.05). Regarding the qualitative evaluation, there were significant differences between group A and the other groups (p-value <0.01) and between groups B and C (p-value <0.05). In group C, both the image quality score and mean value for the order of the hepatic artery branches were highest, and a TI of 1200 ms was thought to be optimal regarding the balance between vessel-to-liver contrast and peripheral hepatic artery visualization. CONCLUSION: The MR angiographic technique using true SSFP with T-SLIP enabled the selective visualization of hepatic arteries without the need for an exogenous contrast agent or breath-hold.

F-18 fluorodeoxyglucose uptake in a solid pseudopapillary tumor of the pancreas mimicking malignancy.

Solid pseudopapillary tumors (SPTs), predominantly affecting young women, are rare pancreatic tumors. It is reported that imaging features of SPT are solid and cystic components, and there is intratumoral hemorrhage and calcification. However, findings of positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) with pathologic correlation have not been fully evaluated. We present a case of SPT that mimicked malignancy on FDG-PET.

MRI artifact reduction and quality improvement in the upper abdomen with PROPELLER and prospective acquisition correction (PACE) technique.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER [BLADE in the MR systems from Siemens Medical Solutions]) with a respiratory compensation technique for motion correction, image noise reduction, improved sharpness of liver edge, and image quality of the upper abdomen. SUBJECTS AND METHODS: Twenty healthy adult volunteers with a mean age of 28 years (age range, 23-42 years) underwent upper abdominal MRI with a 1.5-T scanner. For each subject, fat-saturated T2-weighted turbo spin-echo (TSE) sequences with respiratory compensation (prospective acquisition correction [PACE]) were performed with and without the BLADE technique. Ghosting artifact, artifacts except ghosting artifact such as respiratory motion and bowel movement, sharpness of liver edge, image noise, and overall image quality were evaluated visually by three radiologists using a 5-point scale for qualitative analysis. The Wilcoxon's signed rank test was used to determine whether a significant difference existed between images with and without BLADE. A p value less than 0.05 was considered to be statistically significant. RESULTS: In the BLADE images, image artifacts, sharpness of liver edge, image noise, and overall image quality were significantly improved (p < 0.001). CONCLUSION: With the BLADE technique, T2-weighted TSE images of the upper abdomen could provide reduced image artifacts including ghosting artifact and image noise and provide better image quality.

Contrast behavior and image quality of magnetic resonance cholangiopancreatography imaging using variable echo times at 3.0 T.

Twenty-five volunteers were examined at three different echo times (TE) using magnetic resonance cholangiopancreatography (MRCP) images obtained with half-Fourier-acquired single-shot turbo spin echo (HASTE) thick-slab and multislice HASTE to identify the optimal TE at 3.0 T. No significant difference in the overall image quality was found comparing three different TEs within commonly used ranges. We observed an almost identical duct visibility with different TEs, while we found a trend toward superior visibility of the cystic duct at shorter TE.

High-spatial-resolution three-dimensional MR cholangiography using a high-sampling-efficiency technique (SPACE) at 3T: comparison with the conventional constant flip angle sequence in healthy volunteers.

PURPOSE: To evaluate the image quality of high-spatial-resolution three-dimensional magnetic resonance cholangiography (MRC) with a high-sampling-efficiency technique (sampling perfection with application optimized contrasts using different flip angle evolutions [SPACE]) in comparison with a conventional constant flip angle (FA) sequence at 3T. MATERIALS AND METHODS: Eighteen volunteers were examined on a 3T MR unit using MRC imaging performed with three different free-breathing three-dimensional T2-weighted turbo spin-echo (TSE) sequences: 1) SPACE (spatial resolution, 1.1x1.0x0.84 mm), 2) constant FA (1.1x1.0x0.84 mm), and 3) SPACE at a higher resolution (SPACE HR; 1.0x0.9x0.644 mm). A five-point scale was used to compare overall image quality and visualization of the third branches of the bile duct (B2, B6, and B8). Depictions of cystic duct insertion and the highest order of bile duct visible were also compared. RESULTS: MRC with SPACE and SPACE HR sequences produced significantly better overall image quality than the constant FA sequence. In all analyses of duct visibility, SPACE and SPACE HR sequences showed higher scores than the constant FA sequence. CONCLUSION: High-resolution three-dimensional MRC with SPACE at 3T allows high-quality imaging of the biliary tract, and has the ability to depict nondilated intrahepatic bile ducts (IHBD) in healthy volunteers.

Evaluation of motion correction effect and image quality with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) and parallel imaging acquisition technique in the upper abdomen.

PURPOSE: To evaluate motion correction effect and image quality in the upper abdomen with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) and parallel imaging acquisition technique. MATERIALS AND METHODS: A total of 50 consecutive patients underwent abdominal MR imaging. Fat-saturated T2-weighted turbo spin-echo sequences were obtained by respiratory triggering. The subjects were examined with three different conditions of echo train length (ETL), blade width, and percent k-space coverage in the same scanning time: 19/30/100%, 30/30/100%, and 30/52/175%, which were designated as L/C(1), L/C(2), and L/C(3), respectively. The parallel imaging acquisition technique was used to either reduce ETL from 30 to 19 in L/C(1) or increase k-space coverage from 100% to 175% in L/C(3) compared with L/C(2). Motion and streak artifacts, and overall image quality were evaluated visually by two radiologists, independently. RESULTS: Motion and streak artifacts were mostly reduced in L/C(3) condition. The L/C(3) image also gave the best overall image quality compared with other conditions (P < 0.001). The inter-rater reliability for each evaluation agreed well. CONCLUSION: In upper abdominal BLADE MRI, it was possible to reduce image artifacts and obtain better image quality by increasing the k-space coverage with parallel imaging in the same scanning time.