OBJECTIVE. Hyper-IgE recurrent infection syndrome (HIES or Job's syndrome) is a rare disorder affecting the immune system and connective tissues. The purpose of this study is to describe the coronary abnormalities in genetically confirmed HIES patients as depicted by coronary MDCT angiography (MDCTA).

CONCLUSION. Coronary MDCTA has provided an opportunity for noninvasive evaluation of the coronary arteries in patients with HIES. These coronary abnormalities vary from tortuosity to ectatic dilation and focal aneurysms of the coronary arteries. Such an evaluation has potential value in identifying new aspects of this disease and thereby providing better understanding of the pathophysiology of the disorder.

OBJECTIVE. The purpose of this study was to evaluate according to size and degree of cellular differentiation the multiphasic MDCT enhancement pattern of hepatocellular carcinoma (HCC) smaller than 3 cm in diameter in patients with cirrhosis.

MATERIALS AND METHODS. In 155 consecutively registered patients (126 men, 29 women; mean age, 58.4 years), 204 pathologically proven HCCs smaller than 3 cm were detected at multiphasic MDCT. Three radiologists in consensus classified the relative attenuation of the tumors compared with the surrounding liver parenchyma as hyperattenuation, isoattenuation, or hypoattenuation on biphasic (n = 86) and triphasic (n = 69) CT scans.

RESULTS. The prevalent enhancement patterns of HCC differed depending on tumor size. The prevalent pattern of HCC measuring 20–29 mm was arterial hyperattenuation with venous washout (47%, 47/101). The prevalent enhancement patterns of HCC smaller than 10 mm and HCC measuring 10–19 mm were isoattenuation during the arterial and portal venous phases (29%, 6/21) and hyperattenuation and isoattenuation during the arterial and portal venous phases (33%, 27/82). The typical HCC enhancement pattern (arterial hyperattenuation with venous washout) was identified in 48% (67/141) of the moderately and poorly differentiated HCCs and in 13% (8/63) of well-differentiated HCCs.

CONCLUSION. The prevalent enhancement patterns of HCC smaller than 3 cm on multiphasic MDCT scans differed depending on tumor size and cellular differentiation. HCCs smaller than 2 cm and well-differentiated HCCs frequently had atypical enhancement patterns.

OBJECTIVE. The purpose of this article is to describe the "pseudo washout" sign of high-flow hepatic hemangioma that mimics hypervascular tumor on gadoxetic acid–enhanced MRI.

CONCLUSION. High-flow hemangiomas might show relatively low signal intensity because of gadoxetic acid contrast uptake in the surrounding normal liver parenchyma during the equilibrium (3-minute delay) phase. Such findings are called pseudo washout and can mimic hypervascular hepatic tumors. However, high-flow hemangioma can be diagnosed by observing bright signal intensity on T2-weighted imaging, arterial phase–dominant enhancement, pseudo washout sign during the equilibrium phase, and isointense or slightly increased signal intensity on subtraction images.

OBJECTIVE. The objective of this article is to provide a practical illustrated review of PET/CT in the imaging evaluation of transitional cell carcinoma.

CONCLUSION. Local evaluation of the primary tumor in patients with transitional cell carcinoma on PET is often limited by the obscuring effect of excreted FDG, but assessment of metabolic activity may still be possible through close correlation with CT images. PET/CT may also be helpful in the detection of disease outside the bladder at nodal or more distant sites and in the assessment of recurrent disease.

OBJECTIVE. The objective of this article is to describe the different stages of spinal neuroarthropathy as assessed by CT and MRI and to discuss their contribution to the management of affected patients.

CONCLUSION. Early-stage findings consisted of inflammatory changes involving adjacent vertebral endplates and mimicking degenerative disk disease with inflammation. Subsequently, progression of the lesions led to complete destruction of the intervertebral joint. Knowledge of the initial features of spinal neuroarthropathy may allow earlier treatment, which may improve outcomes.

OBJECTIVE. Bidimensional tumor measurements indicating a greater than 25% increase in tumor size are generally accepted as indicating tumor progression. We hypothesized that use of digital images and a homogeneous reader population would have lower interobserver variability than in previous studies.

SUBJECTS AND METHODS. Eight board-certified radiologists measured tumor diameters in three planes in two consecutive MRI examinations of 22 patients with contrast-enhancing high-grade brain tumors. Products of tumor measurements were calculated, and determinations were made about tumor progression (> 25% increase in area). A variance components model was run on diameter products and the ratios of consecutive maximal diameter products. The variance components included patient examination effect, reader effect, and residual effect.

RESULTS. Complete agreement was found among readers in 10 cases (45%), all indicating stable disease. In the other 12 cases, at least one reader considered progressive disease present. The variance components model showed variance due to readers was small, indicating only modest bias among readers. The residual variance component was large (0.038), indicating that repeated measurements on the same image likely are variable even for the same reader. This variability in measurement implies that repeated measurements by the typical reader have an inherent 14% false-positive rate in the diagnosis of progression of tumors that are stable.

CONCLUSION. Our hypothesis was disproved. We found substantial interreader disagreement and indications that the very nature of the measurement method produces a high rate of false-positive readings of stable tumors. These findings should be considered in interpretation of images with this widely accepted criterion for brain tumor progression.

OBJECTIVE. The objective of our study was to illustrate the spectrum of appearances of peritoneal diseases on ¹⁸F-FDG PET/CT, show the usefulness of fused FDG PET/CT as a diagnostic tool for the peritoneum, and discuss the pitfalls in FDG PET/CT interpretation of peritoneal disease.

CONCLUSION. Malignant and benign diseases may have peritoneal involvement, which can manifest as various imaging patterns on FDG PET/CT. Awareness of these patterns and of potential interpretation issues is important to optimize diagnostic accuracy.

OBJECTIVE. Thrombotic disorders detected on PET/CT are usually incidental findings and may change the treatment strategy and patient's disease prognosis. The purpose of this article is to present the spectrum of venous thrombotic disorders found on PET/CT.

CONCLUSION. The division of thrombotic disorders into metabolically nonactive and active thrombus may be helpful for differential diagnosis of underlying diseases causing thrombus formation. IV contrast media administration during PET/CT makes it possible to visualize the thrombus itself and helps to distinguish between benign and malignant metabolically active thrombus.

OBJECTIVE. Patterns of periosteal disruption are important factors in assessing the mechanism of injury of radiologically evident Salter-Harris (SH) fractures. The purpose of this study is to assess the frequency of posterior periosteal disruption on MRI in radiographically occult or subtle SH type II fractures of the distal femur and to evaluate associated soft-tissue findings that support a hyperextension mechanism of injury.

CONCLUSION. We found that all children in our experience with occult or subtle SH type II fractures of the distal femur have posterior periosteal disruption and other MRI findings to indicate a hyperextension mechanism of injury. Direct indicators of fracture may be inconspicuous, and the presence of posterior periosteal disruption is a clue that should prompt a search for other features of this serious pediatric injury, which may be followed by limb shortening or angular deformity.

OBJECTIVE. Time-resolved MR angiography (MRA) is a technique designed for fast vascular imaging. The purpose of this article is to introduce the multiple potential uses for time-resolved MRA in the body and peripheral vascular system in the hope that time-resolved MRA will become a more widely used technique.

CONCLUSION. Time-resolved MRA is a useful technique with many clinical applications.

OBJECTIVE. The purpose of this study was to compare a novel MRI sequence—3D fast-recovery fast spin-echo (FRFSE) cube—with a standard 2D FRFSE sequence for the investigation of uterine anomalies.

CONCLUSION. Compared with 2D FRFSE, 3D FRFSE cube provides superior image quality and improved 3D reconstructions in a shorter acquisition time and enables excellent visualization of uterine anatomy in any orientation, regardless of the original scanning plane.

OBJECTIVE. The purpose of this article is to discuss the development of a dedicated halfpipe coaxial cannula for stereotactic vacuum-assisted biopsy. We evaluated the system by retrieving 18 copper targets from a pig breast model in the upright position via vertical and lateral approaches.

CONCLUSION. Sampling was successful in 15 of 18 cases. Errors occurred only in superficial lesions biopsied via the vertical approach. The halfpipe coaxial cannula shows promise for improving positioning accuracy, avoiding target dislocation, and obviating repeated needle repositioning.

OBJECTIVE. This article reviews the chest radiographic and CT findings in patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection.

MATERIALS AND METHODS. Of 222 patients with novel S-OIV (H1N1) infection seen from May 2009 to July 2009, 66 patients (30%) who underwent chest radiographs formed the study population. Group 1 patients (n = 14) required ICU admission and advanced mechanical ventilation, and group 2 (n = 52) did not. The initial radiographs were evaluated for the pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality. Chest CT scans (n = 15) were reviewed for the same findings and for pulmonary embolism (PE) when performed using IV contrast medium.

RESULTS. Group 1 patients were predominantly male with a higher mean age (43.5 years versus 22.1 years in group 2; p < 0.001). The initial radiograph was abnormal in 28 of 66 (42%) subjects. The predominant radiographic finding was patchy consolidation (14/28; 50%) most commonly in the lower (20/28; 71%) and central lung zones (20/28; 71%). All group 1 patients had abnormal initial radiographs; extensive disease involving ≥ 3 lung zones was seen in 93% (13/14) versus 9.6% (5/52) in group 2 (p < 0.001). No group 2 patients had > 20% overall lung involvement on initial radiographs compared with 93% of group 1 patients (13/14). PEs were seen on CT in 5/14 (36%) of group 1 patients.

CONCLUSION. Chest radiographs are normal in more than half of patients with S-OIV (H1N1) and progress to bilateral extensive air-space disease in severely ill patients, who are at a high risk for PE.

OBJECTIVE. The objective of our study was to review the chest radiographic and CT findings in patients with swine-origin influenza A (H1N1) virus (S-OIV) infection.

CONCLUSION. The most common radiographic and CT findings in seven patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On MDCT, the ground-glass opacities and areas of consolidation had a predominant peribronchovascular and subpleural distribution, resembling organizing pneumonia.

OBJECTIVE. Although most cases of swine-origin influenza A (H1N1) virus (S-OIV) have been self-limited, fatal cases raise questions about virulence and radiology's role in early detection. We describe the radiographic and CT findings in a fatal S-OIV infection.

CONCLUSION. Radiography showed peripheral lung opacities. CT revealed peripheral ground-glass opacities suggesting peribronchial injury. These imaging findings raised suspicion of S-OIV despite negative H1N1 influenza rapid antigen test results from two nasopharyngeal swabs; subsequently, those results were proven to be false-negatives by reverse transcriptase polymerase chain reaction. This case suggests a role for CT in the early recognition of severe S-OIV.

OBJECTIVE. This review will focus on radiographic description of lymphangiomas, lymphangiohemangiomas, pulmonary lymphangiomatosis, lymphangiectasis, lymphangioleiomyomatosis, lymphatic dysplasia, and traumatic lymphatic injury.

CONCLUSION. Diseases of the thoracic lymphatic system have a wide variety of unique radiographic manifestations, all of which can be explained by the underlying pathophysiology and relationship to the normal distribution of lymphatics in the chest.

OBJECTIVE. Noninvasive coronary angiography has generally been contraindicated in patients with atrial fibrillation because of the difficulty in synchronizing an irregular heartbeat with table gantry movement. The objective of this study was to evaluate and compare the quality of 320-MDCT images obtained in patients with atrial fibrillation and in a control group of patients in sinus rhythm.

MATERIALS AND METHODS. Two reviewers were blinded to the patient groups and evaluated images of 15 coronary artery segments for each patient using 320-MDCT. The images were printed on glossy paper and scored subjectively as 1 or 2, meaning of diagnostic quality, or 3, meaning poor quality.

RESULTS. No statistical difference between the groups was noted in patient age: The mean age of the patients with atrial fibrillation was 67 years (age range, 52–82 years) and that of the patients in sinus rhythm was 59 years (36–86 years) (p = 0.3). Scores of 1 and 2 (diagnostic quality) were assigned to 100% in sinus rhythm and 96% in atrial fibrillation (p < 0.05). Scores of 3 were seen only in the atrial fibrillation group (7/175, 4%). Segment 15, the distal circumflex artery, was the segment that was most frequently assigned a score of 3 (2/7, 28.6%). A discrepancy in the two reviewers' scores was seen in 25 segments (7%), requiring joint consensus. The segments that most frequently required consensus reading were segments 12 and 15. The overall mean image quality score for all three coronary arteries in atrial fibrillation was 1.25 ± 0.47 (SD) and 1.08 ± 0.26 in sinus rhythm (p < 0.001). The median effective dose was 19.28 and 13.55 mSv in the atrial fibrillation and sinus rhythm groups, respectively.

CONCLUSION. The analysis of our initial experience shows that imaging in patients with atrial fibrillation is possible using 320-MDCT, with images of most segments obtained being of diagnostic quality. Segment 15 was the most difficult to see on 320-MDCT because of the small caliber of the vessel; poor visualization of that segment mostly occurred in the setting of a dominant right coronary arterial system.

OBJECTIVE. The purpose of this study was to compare transthoracic echocardiography (TTE), cardiac CT, and transesophageal echocardiography (TEE) in the evaluation of secundum atrial septal defect (ASD) for closure with an Amplatzer septal occluder in pediatric patients.

SUBJECTS AND METHODS. The cases of 28 children with ASD initially diagnosed with TTE who were scheduled for cardiac CT for evaluation for insertion of an Amplatzer septal occluder under TEE guidance were reviewed. The patients were divided into a group with small ASD (long axis < 1.5 cm) and a group with large ASD (long axis ≥ 1.5 cm). Measurements of the ASD obtained at TTE, cardiac CT, and TEE were compared. Kappa statistics were used to correlate the diagnostic value of cardiac CT assessed by two independent reviewers.

RESULTS. After cardiac CT, six patients were excluded from occluder implantation; therefore, 22 patients (seven boys, 15 girls; mean age, 4.95 years; range, 2–11 years) were included in the study. There were no significant differences in the ages and sexes of the patients in the two groups, but pulmonary-to-systemic blood flow ratio in the large-ASD group was significantly greater than that in the small-ASD group (3.54 ± 1.43 vs 1.89 ± 0.36; p = 0.001). With respect to long- and short-axis lengths of the ASD, interatrial septum, and four rims and to detection of rim deficiency, neither group had a significant difference between cardiac CT findings at ventricular end-systole and TEE findings. The long axis of the ASD in the large-ASD group measured at cardiac CT at end-systole and TEE was significantly longer than the long axis measured at TTE (p = 0.012). A high diagnostic score with good interobserver correlation ( = 0.674–0.750) validated the feasibility of cardiac CT in the assessment of ASD for closure with an Amplatzer septal occluder.

CONCLUSION. The long axis of a large ASD can be underestimated at TTE. Cardiac CT seems comparable with TEE in the assessment of ASD and is helpful in noninvasive evaluation for Amplatzer septal occluder implantation, especially for large ASD.

OBJECTIVE. Reduction or elimination of catharsis with fecal tagging enhances the tolerability of CT colonography (CTC) and may increase compliance with colorectal cancer (CRC) screening recommendations. We systematically reviewed studies that prospectively evaluated performance and patient satisfaction with decreased-purgation CTC and with optical colonoscopy.

CONCLUSION. The nine studies reviewed showed moderate-to-good performance for decreased-purgation CTC; however, data are limited, and study design and data presentation are inconsistent. Further study of decreased-purgation CTC and standardization of terminology are needed.

OBJECTIVE. Surgical therapy for symptomatic polycystic liver disease is effective but has substantial mortality and morbidity. Minimally invasive options such as percutaneous aspiration with or without ethanol sclerosis have had disappointing results. The purpose of this study was to evaluate percutaneous aspiration with ethanolamine oleate sclerosis in the management of symptomatic polycystic liver disease.

SUBJECTS AND METHODS. The study included 13 patients (11 with polycystic liver disease, two with simple cysts) with 17 cysts. All patients underwent percutaneous aspiration of the liver cyst under ultrasound guidance followed by insertion of a 7-French pigtail catheter, instillation of ethanolamine oleate (10% of cyst volume), and aspiration of the ethanolamine oleate. The catheter was kept in place for 24 hours of open drainage and then removed.

RESULTS. All but one of the cysts resolved with one instillation. The one cyst, in a patient with polycystic liver disease, required two instillations 3 months apart. The mean initial volume of cysts was 589.8 mL, and the mean reduction in volume was 88.8%. Both the simple cysts resolved completely. In the cases of polycystic disease, the volume of cysts larger than 10 cm in diameter was reduced by 92.8%. Cyst resolution was gradual, and clinically significant cyst reduction was achieved within 1 year of therapy. None of the patients needed surgery. The median follow-up period was 54 months (range, 1 week–95 months). There were no significant adverse effects, and all patients had relief of symptoms after therapy.

CONCLUSION. This initial experience with a single session of percutaneous aspiration and ethanolamine oleate sclerosis resulted in sustained resolution of symptomatic polycystic liver disease with minimal morbidity, avoidance of surgery, and improvement in quality of life.

OBJECTIVE. The purpose of this study was to retrospectively determine whether there are specific CT features that can be used to differentiate polypoid early from advanced gastric cancer and to assess the performance of radiologists using specific CT findings for differentiation.

MATERIALS AND METHODS. A review of medical records yielded the cases of 46 patients, 27 with polypoid early gastric cancer and 19 with polypoid advanced gastric cancer, whose CT scans were available for review. Two radiologists retrospectively reviewed the CT images for the presence and depth of dimpling at the tumor base, the presence of vessel invagination at the dimpling site, thickening of the low-attenuating outer layer, perigastric infiltration, and transmural full-thickness enhancement of the lesion. Individual CT findings relevant as predictors were determined with univariate and multivariate analyses. Individual review of CT scans subsequently was performed by two other radiologists, who were blinded to tumor stage but aware of the results of univariate and multivariate analyses. Individual performance was evaluated with receiver operating characteristic analysis.

RESULTS. The presence of severe dimpling greater than 3.5 mm at the base of the tumor (odds ratio, 31.3) had the highest odds ratio for differentiating early from advanced gastric cancer, followed by vessel invagination (odds ratio, 12.3), the presence of dimpling (odds ratio, 9.8), perigastric infiltration (odds ratio, 5.2), and transmural full-thickness enhancement (odds ratio, 4.8). Multivariate analysis showed that the presence of dimpling greater than 3.5 mm was the only independent variable that differentiated polypoid advanced gastric cancer from polypoid early gastric cancer (p = 0.001). Subsequent differentiation of advanced from early gastric cancer with the described CT findings was very good, yielding areas under the receiver operating characteristic analysis curves of 0.827 and 0.811 for the two observers.

CONCLUSION. Greater than 3.5 mm dimpling and other ancillary CT findings are helpful in differentiating polypoid advanced gastric cancer from polypoid early gastric cancer and contribute to good individual accuracy for differentiation.

OBJECTIVE. The objective of our study was to determine the usefulness of the apparent diffusion coefficient (ADC) of liver parenchyma for determining the severity of liver fibrosis.

MATERIALS AND METHODS. This study investigated 78 patients who underwent diffusion-weighted imaging (DWI) with 1.5-T MRI and pathologic staging of liver fibrosis based on biopsy. DWI was performed with b values of 50 and 400 s/mm². ADCs of liver were measured using 2.0- to 3.0-cm² regions of interest in the right and left lobes of the liver; the mean ADC value was used for analysis. Pathologic METAVIR scores for liver fibrosis stage were used as a reference standard.

RESULTS. The mean ADC values for fibrosis pathologically staged using the METAVIR classification system as F0 (n = 11), F1 (n = 16), F2 (n = 10), F3 (n = 14), and F4 (n = 27) were 125.9, 105.0, 104.5, 103.2, and 99.1 x 10^-5 s/mm², respectively. The correlation between the ADC values and the degree of liver fibrosis was moderate (Spearman's test, = –0.36). There was a significant difference in ADC values between patients with nonfibrotic liver (F0) and those with cirrhotic liver (F4) (p = 0.008). The best cutoff ADC value to distinguish between these groups was 118 x 10^-5 s/mm². However, ADC values were not useful for differentiating viral hepatitis patients with F2 fibrosis or higher from those with a lower degree of fibrosis (area under the receiver operating characteristic curve [AUC] = 0.66) or for differentiating low-stage fibrosis in all patients from high-stage fibrosis in all patients (AUC = 0.54).

CONCLUSION. The ADCs in cirrhotic livers are significantly lower than those in nonfibrotic livers. However, ADC values measured using the current generation of scanners are not reliable enough to replace liver biopsy for staging hepatic fibrosis.

OBJECTIVE. The purpose of this study was to evaluate the reliability of polyp measurements at CT colonography and the factors that affect the measurements.

MATERIALS AND METHODS. Fifty colonoscopically proven cases of polyps 6 mm in diameter or larger were analyzed by two observers who measured each polyp in supine and prone views. Manual measurements of 2D volume by summation of areas, 2D maximum diameter, and 3D maximum diameter and automated measurements of 3D maximum diameter and volume were recorded for each observer and were repeated for one of the observers. Intraobserver and interobserver agreement was calculated. Analysis was performed to determine the measurement parameter that correlated most with summation-of-areas volume. Supine and prone measurements as a surrogate for tracking change in polyp size over time were analyzed to determine the measurement parameter with the least variation.

RESULTS. Maximum diameter measured manually on 3D images had the highest correlation with summation-of-areas volume. Manual summation-of-areas volume was found to have the least variation between supine and prone measurements.

CONCLUSION. Linear polyp measurement in the 3D endoluminal view appears to be the most reliable parameter for use in the decision to excise a polyp according to current guidelines. In our study, manual calculation of volume with summation of areas was found to be the most reliable measurement parameter for observing polyp growth over serial examinations. High reliability of polyp measurements is essential for adequate assessment of change in polyp size over serial examinations because many patients with intermediate-size polyps are expected to choose surveillance.

OBJECTIVE. The purpose of our study was to evaluate the effect of varying volumes and rates of contrast material, use of a saline chaser, and cardiac output on aortic enhancement characteristics in MDCT angiography (MDCTA) using a physiologic phantom.

MATERIALS AND METHODS. Volumes of 75, 100, and 125 mL of iopamidol, 370 mg I/mL, were administered at rates of 4, 6, and 8 mL/s. The effect of a saline chaser (50 mL of normal saline, 8 mL/s) was evaluated for each volume and rate combination. Normal, reduced (33% and 50%), and increased (25%) cardiac outputs were simulated. Peak aortic enhancement and duration of peak aortic enhancement were recorded. Analysis of variance models were run with these effects, and the estimated mean levels for the sets of factor combinations were determined.

RESULTS. Lowering the volume of contrast material resulted in reduced peak enhancement (example, -56.2 HU [p < 0.0001] with 75 vs 125 mL) and reduced duration of 75% peak enhancement (example, -9.0 seconds [p < 0.0001] with 75 vs 125 mL). Increasing the rate resulted in increased peak enhancement (example, 104.5 HU [p < 0.0001] with a rate of 8 vs 4 mL/s) and decreased duration of 75% peak enhancement (example, -13.0 seconds [p < 0.001]). Use of a saline chaser resulted in increased peak enhancement, and this increase was inversely proportional to contrast material volume. Peak enhancement increased when reduced cardiac output was simulated. Peak enhancement decreased when increased cardiac output was simulated.

CONCLUSION. Reducing contrast material volume from 125 to 75 mL, increasing the rate to 6 or 8 mL/s, and use of a saline chaser result in an aortic enhancement profile that better matches the approximately 5-second imaging window possible with 64-MDCTA of the abdomen and pelvis. Even smaller volumes of contrast material may be adequate in patients with reduced cardiac output.

OBJECTIVE. The purpose of our study was to evaluate the normal postsurgical findings and appearance of gastrointestinal tract complications in patients who have undergone biliopancreatic diversion with duodenal switch bariatric surgery. We performed a 4-year retrospective review of 218 patients who underwent duodenal switch surgery.

CONCLUSION. The most common complications of duodenal switch surgery were bowel obstruction, followed by ventral hernias and anastomotic leaks. Only 2% of cases required repeat surgery for management.

OBJECTIVE. The purpose of this study was to compare apparent diffusion coefficients, metabolic ratios, and vascularity values within histologically defined prostate tumors with those in nontumor tissue to determine which functional parameter or combination of parameters is best for differentiating tumor from nontumor tissue.

SUBJECTS AND METHODS. Twenty patients due for prostatectomy underwent endorectal MRI at 1.5 T. Transverse T2-weighted, diffusion-weighted, 2D chemical shift, and dynamic contrast-enhanced images were acquired. After prostatectomy, the gland was sectioned transversely. Fresh slices and stained whole-mount sections with histologically defined tumor outlines were photographed. The tumor outlines were mapped onto images, and the apparent diffusion coefficient (ADC), choline-to-citrate (Cho/cit) ratio, and vascularity of the histologically defined tumor, normal peripheral zone, and central gland were quantitatively measured. Area under the receiver operating characteristics (ROC) curve (A_z) was used to determine the sensitivity and specificity of parameter combinations in cancer detection.

RESULTS. In tumor regions larger than 1 cm², the Cho/cit ratio was higher in tumor than in nontumor tissue (p < 0.001), in the peripheral zone alone (p = 0.007), and in the central gland alone (p = 0.005). ADC was lower and tumor vascularity greater in tumor than in nontumor tissue (ADC, p = 0.003; initial area under the gadolinium plasma concentration–time curve [initial gadolinium AUC], p = 0.012; forward rate constant [K^trans], p = 0.011; return rate constant [k_ep], p = 0.036). No single parameter had a significantly greater A_z (ADC, 0.71; Cho/cit ratio, 0.79; initial gadolinium AUC, 0.60; K^trans, 0.62; k_ep, 0.65). Pairs of parameters, however, did increase A_z: ADC and initial gadolinium AUC (A_z = 0.94) versus ADC (p = 0.001) and initial gadolinium AUC (p < 0.001); ADC and Cho/cit ratio (A_z = 0.94) versus ADC (p = 0.001) and Cho/cit ratio (not significant); and Cho/cit ratio and initial gadolinium AUC (A_z = 0.88) versus Cho/cit ratio (not significant) and initial gadolinium AUC (p < 0.001). All three functional techniques together had an A_z of 0.95, showing no further improvement.

CONCLUSION. The combination of two functional parameters is associated with significant improvement in prostate cancer detection over use of any parameter alone. Use of a third parameter does not increase the rate of detection.

OBJECTIVE. Considerable variation in radiologic procedures, protocols, policies, and workflows exists across the nation, sometimes even within departments. This lack of standardization fosters idiosyncratic behavior and outcomes, undermining the effort to implement best practices across institutions. The purpose of this article is to discuss the need for rapidly implementing recognized standards and best practices when they exist.

CONCLUSION. The use of information systems to monitor a wide variety of quality metrics offers managers the opportunity to standardize radiology and departmental practices, with the goal of transforming these practices into those that are more efficient and cost-effective and of higher quality.

OBJECTIVE. Previous studies of the sensitivity and specificity of MRI in the diagnosis of meniscal tear have not included correction for verification bias. The purpose of this study was to investigate the extent to which verification bias affected assessment of the utility of MRI in the diagnosis of meniscal tear.

MATERIALS AND METHODS. The patients included in the study were outpatients who from April 2006 through July 2008 consecutively visited a single institution for MRI of the meniscus for evaluation of knee pain. For patients who underwent arthroscopy in addition to MRI, the sensitivity and specificity of MRI were calculated. Global sensitivity analysis of data on patients who did not undergo arthroscopy was performed to estimate the influence of verification bias. Global sensitivity analysis is a method for graphically determining whether a particular pair of sensitivity and specificity estimates is compatible with observed data.

RESULTS. Eighty-two patients (23%) underwent arthroscopic verification. The sensitivity and specificity of MRI were 85% and 31%. When the possibility of meniscal tears in patients who did not undergo arthroscopy was subjected to global sensitivity analysis, the sensitivity of MRI ranged from 29% to 95% and the specificity ranged from 3% to 92%. All combinations of sensitivity and specificity produced a butterfly-shaped curve, but the base case was not inside the curve.

CONCLUSION. Verification bias greatly affected assessment of the utility of MRI in the diagnosis of meniscal tear. Sensitivity and specificity from previous studies may be incompatible with our data owing to verification bias.

OBJECTIVE. The purpose of our study was to determine the incidence of cysts in and adjacent to the lesser tuberosity and their association with rotator cuff abnormalities and subcoracoid impingement.

MATERIALS AND METHODS. A retrospective review of 1,000 consecutive MRI examinations of the shoulder was performed by consensus of two radiologists. Cysts were grouped by location into one of two groups: those within the lesser tuberosity and those adjacent to the lesser tuberosity. The rotator cuff was defined as intact, partial tear or tendinosis, or full-thickness tear. The shortest distance from the coracoid to the humeral head was measured on axial images.

RESULTS. Forty-eight patients (26 women, 22 men; age range, 35–79 years; mean age, 61 years) had cysts adjacent to or within the lesser tuberosity. Thirty-two patients (67%) had cysts just superior to the tuberosity and 16 (33%) had cysts in the lesser tuberosity, resulting in an incidence of 3.2% and 1.6%, respectively. All 16 patients (100%) with lesser tuberosity cysts had subscapularis and supraspinatus tendon abnormalities including 11 (69%) full-thickness supraspinatus tears. Patients with cysts superior to the tuberosity had 20 (63%, p = 0.004) abnormal subscapularis tendons and 28 (88%) abnormal supraspinatus tendons, including six (19%) full-thickness tears (p = 0.002). The coracohumeral distance was noted to be less than 10 mm in 10 patients (63%) with lesser tuberosity cysts as compared with 10 patients (31%, p = 0.06) with cysts superior to the tuberosity.

CONCLUSION. Cysts located within the lesser tuberosity are rare and are indicative of subscapularis and supraspinatus tendon abnormalities.

OBJECTIVE. The purpose of this study was to assess the value of the fast STIR sequence in comparison with the T1-weighted fat-suppressed contrast-enhanced sequence in the evaluation of soft-tissue tumors.

MATERIALS AND METHODS. Sixty-seven soft-tissue tumors imaged with both STIR and T1-weighted fat-suppressed contrast-enhanced sequences were evaluated. The signal-to-noise and contrast-to-noise ratios of the tumors in comparison with normal muscle, bone marrow, and fat were measured. Subjective image contrast between soft-tissue tumors and the nearest normal tissue was evaluated by two observers. The observers classified the soft-tissue tumors as benign or malignant using a 5-point scale, and sensitivity, specificity, and accuracy were calculated. The results of the two readings were assessed with receiver operating characteristic analysis.

RESULTS. The contrast-to-noise ratios of all tumors in comparison with muscle (p < 0.01), bone marrow (p < 0.05), and fat (p < 0.05) were significantly higher on the fast STIR images than on the T1-weighted fat-suppressed contrast-enhanced images. Both observers' mean ratings of benign, malignant, and all tumors in comparison with muscle on fast STIR images were significantly higher than those on T1-weighted fat-suppressed contrast-enhanced images. For both observers, the mean sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve in evaluation of the fast STIR images did not differ significantly from those in evaluation of the T1-weighted fat-suppressed contrast-enhanced images.

CONCLUSION. The fast STIR sequence is excellent for evaluation of soft-tissue tumors, and contrast-enhancement is not always needed.

OBJECTIVE. The purpose of this study was to assess the utility of high-resolution sonography in identification and characterization of the size and echogenicity of the lateral ulnar collateral ligament of the elbow in cadavers and healthy volunteers.

SUBJECTS AND METHODS. The lateral ulnar collateral ligaments of four cadaveric elbows were imaged with a high-resolution linear-array ultrasound transducer. On localization, the ligaments were injected with 0.1% methylene blue under sonographic guidance. For confirmation of identification of the ligaments, the elbows were immediately dissected to reveal the exact location of the stain. The ligaments of both elbows of 35 healthy adult volunteers were imaged.

RESULTS. Surgical dissection confirmed injection of methylene blue into all four cadaveric ligaments. The lateral ulnar collateral ligament was identified bilaterally over the radial head in all 35 volunteers. The mean thickness of the ligament at this point was 1.2 mm in women and men. The proximal attachment of the ligament to the humerus was well visualized bilaterally in 94.3% of volunteers. The mean thickness at this point was 1.7 mm in women and 1.6 mm in men. The distal attachment on the ulna was well visualized in 90% of elbows. The ligament was hyperechoic in relation to muscle in all volunteers. Differences in ligament measurements with regard to sex and hand dominance were not significant. Ligament thickness correlated weakly with volunteer weight, height, body mass index, and age.

CONCLUSION. High-resolution ultrasound imaging is accurate for identification and measurement of normal lateral ulnar collateral ligaments. Therefore, ultrasound may prove valuable in assessment of abnormal lateral ulnar collateral ligaments.

OBJECTIVE. The primary goal of this study was to determine the radiation dose received during diagnostic and interventional neuroangiographic procedures in a group of pediatric patients. A second goal was to approximate the total average radiation dose from all angiographic and CT studies that pediatric patients underwent during the study period and to estimate the increased risk of cancer incidence in this patient group.

MATERIALS AND METHODS. The study subjects were pediatric patients who had undergone one or more neuroangiographic procedures at Harborview Medical Center between December 1, 2004, and April 30, 2008. Recorded radiation doses were converted to entrance skin dose (ESD) and effective dose (ED) to indicate deterministic and stochastic damage, respectively. The Biologic Effects of Ionizing Radiation (BEIR) VII, phase 2, report was used to estimate the expected increased risk of cancer in the study population.

RESULTS. For diagnostic and therapeutic procedures, a mean ED of 10.4 and 34.0 mSv per procedure was calculated, respectively. The ESD values proved too low to cause deterministic harm. The estimated number of excess cases of malignancy projected from the total average radiation exposure was 890.6 per 100,000 exposed male children and 1,222.5 per 100,000 exposed females, an overall increase of approximately 1% to the lifetime attributable risk of cancer.

CONCLUSION. Although both angiography and CT have revolutionized the practice of medicine and confer benefits to patients, it is important that we continue to investigate the possible adverse effects of these technologies. Protocols that minimize radiation dose without compromising a study should be implemented.

OBJECTIVE. The purpose of this study was to evaluate cerebral blood flow, cerebral blood volume, mean transit time, time to peak, and delay in a selected sample of patients with visually normal or increased cerebral blood volume to facilitate detection of a postischemic CT perfusion hyperperfusion–reperfusion phenomenon that may mask subacute and acute infarcts.

MATERIALS AND METHODS. Ten patients were included who had visually normal or elevated cerebral blood volume in infarcts larger than 1.5 cm confirmed on diffusion-weighted MR images within 48 hours of perfusion CT. The cases were selected from 371 perfusion CT studies of stroke patients (99 associated with positive diffusion-weighted imaging findings) reviewed over 2.5 years on a 64-MDCT scanner. The perfusion CT images were fused to the diffusion-weighted images for measurement of cerebral blood volume, cerebral blood flow, mean transit time, time to peak, and delay in each infarct versus the contralateral hemisphere. Two neuroradiologists reviewed the images in consensus.

RESULTS. The mean time between symptom onset and perfusion CT was 3.9 days. Infarcts were in the middle cerebral artery (n = 7) and posterior cerebral artery (n = 3) distributions. Significant differences versus the contralateral finding were found in cerebral blood volume (p = 0.016; mean increase, 30.0%), mean transit time (p = 0.007; mean increase, 38.1%), time to peak (p = 0.005; mean increase, 17.7%), and delay (p = 0.030; mean increase, 124.9%). The difference in cerebral blood flow (p = 0.785; mean increase, 1.8%) was not statistically significant. Infarcts became enhanced on the dynamic perfusion CT images of eight of 10 patients and on the contrast-enhanced T1-weighted MR images of six of nine patients.

CONCLUSION. Visual inspection of cerebral blood volume and cerebral blood flow maps alone is insufficient in the evaluation of infarcts. Mean transit time, time to peak, and delay maps also should be reviewed with dynamic source images to prevent misinterpretation of findings as false-negative. This phenomenon is unlikely to occur hyperacutely (< 8 hours after onset).

OBJECTIVE. The aim of this study was to evaluate prospectively the effects of respiratory gating during FDG PET/CT on the determination of lesion size and the measurement of tracer uptake in patients with pulmonary nodules in a clinical setting.

SUBJECTS AND METHODS. Eighteen patients with known pulmonary nodules (nine women, nine men; mean age, 61.4 years) underwent conventional FDG PET/CT and respiratory-gated PET acquisitions during their scheduled staging examinations. Maximum, minimum, and average standardized uptake values (SUVs) and lesion size and volume were determined with and without respiratory gating. The results were then compared using the two-tailed Student's t test and the nonparametric Wilcoxon's test to assess the effects of respiratory gating on PET acquisitions.

RESULTS. Respiratory gating reduced the measured area of lung lesions by 15.5%, the axial dimension by 10.3%, and the volume by 44.5% (p = 0.014, p = 0.007, and p = 0.025, respectively). The lesion volumes in gated studies were closer to those assessed by standard CT (difference decreased by 126.6%, p = 0.025). Respiratory gating increased the measured maximum SUV by 22.4% and average SUV by 13.3% (p < 0.001 and p = 0.002).

CONCLUSION. Our findings suggest that the use of PET respiratory gating in PET/CT results in lesion volumes closer to those assessed by CT and improved measurements of tracer uptake for lesions in the lungs.

OBJECTIVE. The purpose of our study was to compare chest ultrasound and chest CT in children with complicated pneumonia and parapneumonic effusion.

MATERIALS AND METHODS. We retrospectively compared chest ultrasound and chest CT in 19 children (nine girls and 10 boys; age range, 8 months–17 years) admitted with complicated pneumonia and parapneumonic effusion between December 2006 and January 2009. Images were evaluated for effusion, loculation, fibrin strands, parenchymal consolidation, necrosis, and abscess. In the subset of patients who underwent surgical management, imaging findings were correlated with operative findings.

RESULTS. Eighteen of 19 patients had an effusion on both chest ultrasound and chest CT. The findings of effusion loculation as well as parenchymal consolidation and necrosis or abscess were similar between the two techniques. Chest ultrasound was better able to visualize fibrin strands within the effusions. Of the 14 patients who underwent video-assisted thoracoscopy, five had surgically proven parenchymal abscess or necrosis. Preoperatively, chest ultrasound was able to show parenchymal abscess or necrosis in four patients, whereas chest CT was able to show parenchymal abscess or necrosis in three.

CONCLUSION. In our series, chest ultrasound and chest CT were similar in their ability to detect loculated effusion and lung necrosis or abscess resulting from complicated pneumonia. Chest CT did not provide any additional clinically useful information that was not also seen on chest ultrasound. We suggest that the imaging workup of complicated pediatric pneumonia include chest radiography and chest ultrasound, reserving chest CT for cases in which the chest ultrasound is technically limited or discrepant with the clinical findings.

OBJECTIVE. Since the previous comprehensive radiology review on coagulation concepts that was done in 1990, many studies have been published in the medical and surgical literature that can guide the approach of a radiology practice. The purpose of this article is to provide an analysis of these works, updating the radiologist on proper use and interpretation of coagulation assessment tools, medications that modify the hemostatic system, and the use of transfusions prior to interventions.

CONCLUSION. The basic tools for coagulation assessment have not changed; however, results from subspecialty research have suggested ways in which the use of these tools can be modified and streamlined to safely reduce time and expense for the patient and the health care system.

OBJECTIVE. The objective of our study was to describe survival outcome in 124 patients with unresectable hepatocellular carcinoma treated with triple-drug transcatheter arterial chemoembolization (TACE) using doxorubicin, cisplatin, and mitomycin C using a standardized regimen.

MATERIALS AND METHODS. One hundred twenty-four patients underwent TACE using a standardized triple-drug regimen. Embolization was performed using subselective coaxial embolization technique. Fifty-six patients (group 1) received triple-drug TACE in conjunction with a nonpermanent embolic agent, microfibrillar collagen (Avitene), and 68 patients (group 2) had triple-drug TACE with a permanent embolic agent, Embosphere Microspheres.

RESULTS. Twenty-eight patients underwent liver transplantation after TACE, and survival in these patients was significantly longer than those who did not receive a transplant (p ≤ 0.001). The mean survival for the no-transplant group (n = 96) was longer in patients with Child-Pugh class A cirrhosis than in those with Child-Pugh class B cirrhosis (30.3 ± 2.92 [standard error] vs 11.6 ± 2.84 months, respectively; p < 0.001), in those with Okuda stage I versus stage II disease (31.4 ± 3.03 vs 17.4 ± 3.16 months; p = 0.002), and in those with a pre-TACE bilirubin level of less than 2.5 mg/dL (42.75 µmol/L; 28.3 ± 2.75 vs 13.2 ± 3.83 months; p = 0.007). Improved survival was seen in the no-transplant patients receiving TACE with the permanent embolic agent (group 2) than in those receiving TACE with the nonpermanent agent (group 1) out to 30 months (p = 0.002). Complications occurred in 16 patients (12.9%). The 30-day mortality was 2.4%.

CONCLUSION. Patients with hepatocellular carcinoma who underwent triple-drug TACE followed by liver transplantation showed the longest survival. Patients who did not receive a transplant and were treated with triple-drug TACE with a permanent embolic agent showed longer survival to 30 months after TACE than those receiving a nonpermanent embolic agent.

OBJECTIVE. The objective of our study was to report and compare long-term results of percutaneous transluminal angioplasty and stenting of central venous obstruction in hemodialysis patients.

MATERIALS AND METHODS. Hemodialysis patients who underwent successful endovascular treatment of central venous obstruction were retrospectively evaluated. Stenotic lesions greater than 50% or inducing extremity swelling were subject to treatment. The primary treatment was angioplasty, and stent placement was accomplished in angioplasty-resistant obstructions. Angioplasty was the primary treatment of recurrence after stent placement. Additional stenting was reserved for angioplasty-resistant recurrences.

RESULTS. One hundred forty-seven veins in 126 patients (63 males, 63 females) between 15 and 82 years old primarily underwent 101 angioplasties and 46 stent placements. The mean follow-up was 22.1 ± 16.3 (SD) months. The average number of interventions per vein in the stent group (2.7 ± 2.4 interventions) was significantly higher than that in the angioplasty group (1.5 ± 1.0 interventions). Primary patency was significantly higher in the angioplasty group (mean, 24.5 ± 1.7 months) than that in the stent group (mean, 13.4 ± 2.0 months). Assisted primary patency of the angioplasty group (mean, 31.4 ± 2.0 months) and that of the stent group (mean, 31.0 ± 4.7 months) were equivalent. The overall mean primary patency was 21.1 ± 1.4 months, and the overall mean assisted primary patency was 31.7 ± 2.5 months. There were no significant differences in patency rates with regard to patient sex, the type of stent used, the vein or veins treated, or the type of lesions.

CONCLUSION. Endovascular treatment of central venous obstruction is a safe and effective procedure in hemodialysis patients. Stenting has a significantly lower primary patency rate than angioplasty but adds to the longevity of vein patency in angioplasty-resistant lesions; therefore, stent placement should be considered in angioplasty-resistant lesions.

OBJECTIVE. Currently, cardiac interventional radiology equipment has tended toward using flat-panel detectors (FPDs) instead of image intensifiers (IIs) because FPDs offer better imaging performance. However, the radiation dose from an FPD in cardiac interventional radiology is not clear. The purpose of our study was to measure the radiation doses during cineangiography and fluoroscopy of many cardiac radiology systems that use FPDs or IIs, in clinical settings.

MATERIALS AND METHODS. This study examined 20 radiology systems in 15 cardiac catheterization laboratories (11 used FPD and nine used II). The entrance surface doses with digital cineangiography and fluoroscopy were compared for the 20 systems using acrylic plates (20-cm thick) and a skin dose monitor.

RESULTS. For fluoroscopy, the average entrance surface doses of the 20-cm-thick acrylic plates were identical for FPD (average ± SD, 16.63 ± 7.89 mGy/min; range, 5.7–26.4 mGy/min; maximum/minimum, 4.63) and II (17.81 ± 12.52 mGy/min; range, 6.5–42.2 mGy/min; maximum/minimum, 6.49) (p = 0.799). For digital cineangiography, the average entrance surface dose of the 20-cm-thick acrylic plate was slightly lower with FPD (29.68 ± 16.40 mGy/10 s; range, 8.9–58.5 mGy/10 s; maximum/minimum, 6.57) than with II (38.50 ± 33.71 mGy/10 s; range, 15.2–117.1 mGy/10 s; maximum/minimum, 7.70), although the difference was not significant (p = 0.487).

CONCLUSION. We found that the average entrance doses of cineangiography and fluoroscopy in FPD systems were not significantly different from those in II systems. Hence, FPDs did not inherently reduce the radiation dose, although FPDs possess good detective quantum efficiency. Therefore, to reduce the radiation dose of cardiac interventional radiology systems, even FPD systems, practical measures are necessary.

OBJECTIVE. The objective of this study was to evaluate the effectiveness of CT-guided injection of 5% dextrose in water solution (D5W) into the retroperitoneum to displace organs adjacent to renal cell carcinoma.

MATERIALS AND METHODS. An interventional radiology database was searched to identify the cases of patients who underwent CT-guided percutaneous radiofrequency ablation of biopsy-proven renal cell carcinoma in which D5W was injected into the retroperitoneal space to displace structures away from the targeted renal tumor. The number of organs displaced and the distance between the renal tumor and adjacent organs before and after displacement with D5W were assessed.

RESULTS. The cases of 135 patients with 139 biopsy-proven renal cell carcinomas who underwent 154 percutaneous CT-guided radiofrequency ablation procedures were found in the search. Thirty-one patients with 33 renal cell carcinomas underwent 36 ablation procedures after injection of D5W into the retroperitoneal space. Fifty-five organs were displaced away from renal cell carcinoma with this technique. The average distance between adjacent structures and renal cell carcinomas before displacement was 0.36 cm (range, 0.1–1.0 cm). The average distance between structures and adjacent renal cell carcinomas after displacement was 1.94 cm (range, 1.1–4.3 cm) (p < 0.0001). The average volume of D5W used to achieve organ displacement was 273.5 mL. No complications were associated with this technique.

CONCLUSION. CT-guided injection of D5W into the retroperitoneum is an effective method for displacing vital structures away from renal cell carcinoma.

OBJECTIVE. The purpose of this study was to assess the accuracy and short-term complication rate of ultrasound-guided fine-needle aspiration cytologic sampling of focal pancreatic lesions.

MATERIALS AND METHODS. We reviewed 545 consecutive ultrasound-guided fine-needle aspiration cytologic sampling procedures for focal pancreatic lesions from January 2004 through June 2008. The procedures were performed with a 20- or 21-gauge needle. The onsite cytopathologist evaluated the appropriateness of the sample and made a diagnosis. We reviewed the final diagnosis and the radiologic and medical records of all patients for onset of complications during or within 7 days of the procedure.

RESULTS. The study sample included 262 women and 283 men (mean age, 62 years; range, 25–86 years). The head or uncinate process of the pancreas was the location of 63.0% of the lesions, and 35.2% of the lesions were located in the body or tail of the pancreas. The site of 10 lesions (1.8%) was not specified. Sampling was diagnostic in 509 of the 545 cases (93.4%). Excluding the 36 nondiagnostic samples, ultrasound-guided fine-needle aspiration cytologic sampling had 99.4% sensitivity, 100% specificity, and 99.4% accuracy. In 537 of the 545 cases (98.5%), the procedure was uneventful. In two cases, abdominal fluid was found after the procedure that was not present before the procedure. Six patients experienced postprocedural pain without abnormal findings at subsequent imaging. No major complications occurred.

CONCLUSION. Ultrasound-guided cytologic sampling is safe and accurate for the diagnosis and planning of management of focal pancreatic lesions. With a cytologist on site, the rate of acquisition of samples adequate for diagnosis is high, reducing the need for patient recall.

OBJECTIVE. The purpose of this study was to review the use of an hourglass-shaped expanded polytetrafluoroethylene (ePTFE) stent-graft to reduce transjugular intrahepatic portosystemic shunts in patients with hepatic encephalopathy refractory to conventional medical therapy.

MATERIALS AND METHODS. From January 2000 through December 2008, 189 transjugular intrahepatic portosystemic shunt procedures were performed with self-expanding stent-grafts. After a mean period of 43.4 ± 57 weeks, hepatic encephalopathy developed in 12 patients and did not respond to conventional medical therapy with lactulose, nonabsorbable antibiotics, and a protein-restricted diet. In all cases, shunt reduction was performed with an hourglass-shaped balloon-expandable ePTFE stent-graft inserted into the original shunt.

RESULTS. Technically successful shunt reduction with an immediate increase in portosystemic gradient was achieved in all patients. Symptoms of hepatic encephalopathy disappeared a mean of 22.3 hours (range, 18–26 hours) after the procedure. After a mean follow-up period of 73.9 ± 61.88 weeks, no recurrence of hepatic encephalopathy was found. One patient (8.3%) needed dilation of the hourglass-shaped stent-graft after 37 weeks because of recurrence of ascites. At the end of the study, five patients (41.6%) were alive in good clinical condition. Four patients (33.3%) died of cardiovascular failure 1, 2, 24, and 96 weeks after the corrective procedure. Eight months after the reduction procedure, one patient (8.3%) underwent orthotopic liver transplantation, which resulted in clinical improvement. Two patients (16.6%) were lost to follow-up 15.6 and 46.8 weeks after the procedure.

CONCLUSION. Shunt reduction with an hourglass-shaped ePTFE balloon-expandable stent-graft seems effective in reducing shunt flow and rapidly improving the patient's clinical condition. With this technique, shunt diameter can be modified on the basis of the patient's clinical condition.