Preoperative predictive factors for positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas: a retrospective study.

BACKGROUND: The clinical importance of positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas remains controversial. We evaluated the prognosis of these patients and the predictive preoperative risk factors for positive peritoneal cytology results. METHODS: We retrospectively reviewed patients who underwent curative-intent surgery at our institution between May 2010 and June 2020. Preoperative risk factors for positive peritoneal cytology results were identified using logistic regression analysis. A scoring model was constructed using the total number of significant independent predictors for positive peritoneal cytology results. RESULTS: Of 233 patients, 18 (7.7%) had positive peritoneal cytology results. The recurrence-free survival and cancer-specific survival were markedly worse in patients with positive peritoneal cytology results than in those with negative peritoneal cytology results (recurrence-free survival: 6.0 months vs. 16.6 months, p = 0.050; cancer-specific survival: 19.4 months vs. 47.5 months, p = 0.034). Tumor location (odds ratio: 3.760, 95% confidence interval: 1.099-11.818, p = 0.023), tumor size > 25 mm (odds ratio: 3.410, 95% confidence interval: 1.031-11.277, p = 0.046), preoperative serosal invasion (odds ratio: 5.193, 95% confidence interval: 1.099-24.531, p = 0.038), and preoperative carcinoembryonic antigen level > 5.6 ng/mL (odds ratio: 3.816, 95% confidence interval: 1.248-10.667, p = 0.019) were identified as significant independent predictive factors. Our predictive model's optimal cutoff and positive predictive values for positive peritoneal cytology results were 3 and 27.9%, respectively. CONCLUSIONS: The indications for curative-intent surgery should be considered carefully in patients with high-risk factors for positive peritoneal cytology results.

Initial experience of coaxial percutaneous liver biopsy with tract embolization using N-Butyl cyanoacrylate.

OBJECTIVE: Bleeding occurs after liver biopsy in up to 10.9% cases, and patients with impaired hemostasis or ascites are considered to have absolute or relative contraindications. N-butyl cyanoacrylate enables immediate hemostasis, even in lethal situations. Therefore, percutaneous liver biopsy combined with tract embolization using N-butyl cyanoacrylate is expected to enable safe biopsy, even in patients for whom conventional biopsy is contraindicated. Here we describe our initial experience with coaxial percutaneous biopsy with tract embolization using N-butyl cyanoacrylate. MATERIALS AND METHODS: Eighty-six patients who underwent tract embolization using N-butyl cyanoacrylate between October 2014 and July 2020, including 21 patients who had absolute or relative contraindications for liver biopsy, were retrospectively analyzed. Tract embolization using N-butyl cyanoacrylate comprised two steps: (1) liver biopsy with a biopsy needle inserted via a coaxial introducer needle and (2) embolization of the puncture route by injecting N-butyl cyanoacrylate via the coaxial needle. RESULTS: No complications occurred in any patient. The mean number of biopsies per patient was 3.30 (range, 1-7). Histologically adequate samples were acquired in all cases, and pathological diagnoses were obtained. The mean time required for tract embolization was 52.8 s (range, 6-132 s). The mean peak skin dose was 9.97 mGy (range, 2-68 mGy), which is far below the 3-Gy threshold dose for temporary erythema. CONCLUSIONS: This proposed technique may be a promising and straightforward alternative to improve the management of patients with severe liver disease by allowing safer biopsy, including patients for whom conventional liver biopsy is contraindicated.

Clinical characteristics and predictive factors of postoperative intra-abdominal abscess after distal pancreatectomy.

PURPOSE: The postoperative mortality rate of distal pancreatectomy is lower than that of pancreaticoduodenectomy, although persistent complications may occur after distal pancreatectomy. Fluid collection (FC) is frequently observed after distal pancreatectomy; however, FC may occasionally progress to postoperative intra-abdominal abscess (PIAA), which requires conservative or progressive interventional treatment. This study aimed to compare the status between patients with or without PIAA, identify predictive factors for PIAA and clinically relevant postoperative pancreatic fistula, and investigate the clinical characteristics of patients with PIAA with interventional drainage. METHODS: We retrospectively reviewed data of patients who underwent distal pancreatectomy between January 2012 and December 2019 at two high-volume centers, where hepatobiliary-pancreatic surgeries were performed by expert specialist surgeons. Logistic regression analysis was performed to determine the predictive factors for PIAA. RESULTS: Overall, 242 patients were analyzed, among whom 49 (20.2%) had PIAA. The median postoperative period of PIAA formation was 9 (range: 3-49) days. Among the 49 patients with PIAA, 25 (51.0%) underwent percutaneous ultrasound, computed tomography, or endoscopic ultrasound-guided interventions for PIAA. In the univariate analysis, preoperative indices representing abdominal fat mass (i.e., body mass index, subcutaneous fat area, and visceral fat area) were identified as predictive factors for PIAA; in the multivariate analysis, C-reactive protein (CRP) level (continuous variable) on postoperative day (POD) 3 (odds ratio: 1.189, 95.0% confidence interval: 1.111 - 1.274; P < 0.001) was the only independent and significant predictive factor for PIAA. CONCLUSIONS: CRP level on POD 3 was an independent and significant predictive factor for PIAA after distal pancreatectomy.

Comparison of Foaming Properties Between the Shirasu Porous Glass Membrane Device and Tessari's Three-way Stopcock Technique for Polidocanol and Ethanolamine Oleate Foam Production: A Benchtop Study.

PURPOSE: To compare the characteristics of polidocanol (POL) and ethanolamine oleate (EO) sclerosing foams produced by a Shirasu porous glass membrane (SPGM) device with those made using a 3-way stopcock (3WSC). MATERIALS AND METHODS: Foam half-life times were measured in an ex-vivo benchtop study. Computed tomography (CT) images of each foam were obtained over the time course, and a CT texture analysis was conducted. The bubble size in each foam was measured by an optical microscope. RESULTS: Median foam half-life times were longer in the SPGM group than in the 3WSC group (POL: 198 vs 166 s, P = .02; EO: 640 vs 391 s, P < .01). In the CT texture analysis, median standard deviation (SD) and entropy (randomness) were lower, and median energy (uniformity) and gray-level cooccurrence matrix (GLCM) homogeneity were higher in the SPGM group than in the 3WSC group (POL SD: at 30 s and 50-300 s; POL entropy: at 0-60 s; EO SD: at 0-600 s; EO entropy: at 0-460 s; POL energy: at 0-40 s; POL GLCM homogeneity: at 0-250 s; EO energy: at 0-360 s; EO GLCM homogeneity: at 0-480 s; all P < .05). Median bubble diameters in the SPGM group and in the 3WSC group were 69 and 83 µm (P < .01), respectively, in the POL foam; and 36 and 36 µm (P = .45), respectively, in the EO foam. CONCLUSIONS: POL and EO foams had greater uniformity and longer foam half-life time when prepared with an SPGM device than with a 3WSC.

Quantitative analysis of the anatomical changes in the scalp and hair follicles in androgenetic alopecia using magnetic resonance imaging.

BACKGROUND: Although the structural changes of the scalp in androgenetic alopecia (AGA) have been reported, these changes have been poorly understood. It is expected that modern MRI would visualize the scalp anatomy in vivo. This study aimed to explore whether AGA causes (a) changes in the thickness of the scalp, (b) anatomical changes in the hair follicles, and (c) changes in the signal intensity of MRI. MATERIALS AND METHODS: Twenty-seven volunteers underwent MRI for hair and scalp (MRH) and were categorized into two according to the Hamilton-Norwood Scale: the "AGA group" and the "normal group." Two radiologists analyzed the thickness and signal intensity of the scalp, and the depth of hair follicles. These measurements were compared between the two groups. RESULTS: The thickness of the hypodermis and the entire scalp was significantly thinner in the AGA group than in the control group. The AGA group had significantly shallower depth of hair follicles and relative depth of the hair follicles to that of the entire scalp than the normal group. The hypodermis showed higher signal intensity in the AGA group than the normal group. CONCLUSION: MRH allowed noninvasive visualization of the scalp anatomy and demonstrated the thinner nature of the entire scalp and hypodermis, along with the shallower depth of the hair follicles in the AGA group in comparison to the normal group. Additionally, MRH demonstrated the increased MR signal intensity in the scalp associated with AGA. MRH may be a promising new method for quantitative and objective analyses of AGA.

The use of magnetic resonance imaging to predict placenta previa with placenta accreta spectrum.

INTRODUCTION: Massive hemorrhage due to placenta previa with placenta accreta spectrum is associated with high maternal mortality and morbidity. Therefore, accurate prediction of placenta previa with placenta accreta spectrum is essential; magnetic resonance imaging (MRI) is a useful tool for this purpose. This study investigated novel predictors of anterior and posterior placenta previa with placenta accreta spectrum using MRI. MATERIAL AND METHODS: This was a retrospective study at a tertiary obstetrics hospital in Japan. The singleton patients with placenta previa who were scanned with MRI prenatally and had a cesarean section at our institution between 2007 and 2018 were included. The prediction of anterior and posterior placenta previa with placenta accreta spectrum was evaluated using four MRI findings: heterogeneous signals in the placenta, dark T2-weighted intraplacental bands, myometrial thinning or interruption, and focal uterine bulging. The prediction of posterior placenta previa with placenta accreta spectrum was performed using the quantification of cervical varicosities, which were defined as the ratio of the distance between the minimum distance from the most dorsal cervical varicosities (a) to the deciduous and amniotic placenta (b) on a sagittal image. RESULTS: Among 202 patients, 14 (6.9%) patients were pathologically diagnosed as having placenta accreta spectrum. Further, 38 (18.8%) patients had anterior placenta previa and 164 (81.2%) patients had posterior placenta previa. When anterior placenta previa with placenta accreta spectrum was predicted using at least one of the four MRI findings, the sensitivity and specificity of the anterior placenta previa with placenta accreta spectrum were 87.5% and 86.7%, respectively. In contrast, the sensitivity and specificity of posterior placenta previa with placenta accreta spectrum were 42.9% and 96.2%, respectively. But when the A/B ratio was set at 0.20, the sensitivity and specificity of the prediction for posterior placenta previa with placenta accreta spectrum using cervical varicosities were 100.0% and 89.2%, respectively. CONCLUSIONS: The findings of MRI to predict the anterior placenta previa with placenta accreta spectrum were different from posterior placenta previa. The cervical varicosities may be useful in predicting posterior placenta previa with placenta accreta spectrum.

The benefits of extrinsic ligament release for potentially hemodynamically unstable pancreaticoduodenal arcade aneurysm with median arcuate ligament syndrome: a case report.

BACKGROUND: A pancreaticoduodenal artery aneurysm (PDAA) occurring in close association with median arcuate ligament syndrome (MALS) is rare. A surgical procedure, such as median arcuate ligament (MAL) release, should be considered in such cases, but the operative criteria remain unknown. In this study, we reported an extremely rare case of PDAA with periarteritis nodosa (PAN) and MALS. CASE PRESENTATION: A 60-year-old man was transferred to our department with sudden onset of abdominal pain. We initially diagnosed his condition as a PDAA rupture with MALS based on enhanced computed tomography (CT). We promptly performed transcatheter arterial embolization (TAE) of PDAA, and the angiogram showed stagnant contrast agent in the celiac trunk, indicating total celiac artery occlusion. Follow-up enhanced CT three weeks after the first TAE clearly demonstrated newly formed, multiple aneurysms in the pancreaticoduodenal arcade and the hepatic artery. These findings indicated a systemic disorder, such as PAN or segmental arterial mediolysis, as the underlying cause. Therefore, we started corticosteroid therapy and performed diagnostic angiography to clarify the celiac artery's patency. Contrary to the initial angiography, the second angiography showed sustained blood flow in the celiac artery. Nevertheless, we performed both extrinsic MAL release and consecutive TAE because of the risk of multiple aneurysms rupturing due to an uncontrolled systemic disorder and consequent hepatic ischemia. The patient had no episode of recurrence until one year of follow-up. CONCLUSIONS: It is important to evaluate risk for hemodynamically unstable events to decide the best treatment strategy for MALS.

Diffusion-weighted imaging of prostate cancer using a statistical model based on the gamma distribution.

PURPOSE: To assess the adequacy of a statistical model based on the gamma distribution for diffusion signal decays of prostate cancer (PCa) using b-values ranging up to 2000 sec/mm(2) , and to evaluate the differences in gamma model parameters for PCa, benign prostatic hyperplasia (BPH), and peripheral zone (PZ). MATERIALS AND METHODS: Twenty-six patients with histologically proven PCa underwent diffusion-weighted magnetic resonance imaging using five b-values (0, 500, 1000, 1500, 2000 sec/mm(2) ). The acquired signal decay curves were fit with both gamma and truncated Gaussian models and a statistical comparison between the two fits was performed. The acquired parameters using the gamma model (mean, standard deviation, the area fraction for D < 1.0 mm(2) /s [Frac<1.0], the area fraction of D > 3.0 mm(2) /s [Frac>3.0]) were compared between PCa, BPH, and PZ. RESULTS: The gamma model provided a statistically improved fit over the truncated Gaussian model in PCa. The mean and the standard deviation were significantly lower in PCa than in BPH and PZ (P < 0.01). Frac<1.0 was significantly higher in PCa than in BPH and PZ, and Frac>3.0 was significantly lower in PCa than in BPH and PZ (P < 0.01). CONCLUSION: A statistical model based on the gamma distribution proved suitable for describing diffusion signal decay curves of PCa. This approach may provide better correlation between diffusion signal decay and histological information in the prostate gland.

Anterior Prostate Cancer: Diagnostic Performance of T2-Weighted MRI and an Apparent Diffusion Coefficient Map.

OBJECTIVE: Diagnosis of anterior prostate cancer is challenging. The purpose of this study was to evaluate the diagnostic performance of T2-weighted imaging and an apparent diffusion coefficient (ADC) map in the detection of anterior prostate cancer and to compare that with the diagnostic performance in the detection of posterior prostate cancer. MATERIALS AND METHODS: We retrospectively reviewed the records of 87 patients who underwent 3-T MRI that included T2-weighted imaging and diffusion-weighted imaging before radical prostatectomy. The prostate gland was divided into anterior and posterior segments, and the radiologists interpreted two protocols (T2-weighted imaging alone vs T2-weighted imaging and an ADC map) and sorted the confidence levels for the presence of prostate cancer into five grades. ROC analysis was performed to evaluate the diagnostic performance of each protocol for the detection of anterior and posterior prostate cancers. We also assessed the relative fractions of sensitivity and specificity between anterior and posterior prostate cancers. Additionally, the ADCs of noncancerous anterior fibromuscular stroma were measured and compared with the ADCs of anterior prostate cancers. RESULTS: The AUCs with T2-weighted imaging alone and with T2-weighted imaging and an ADC map were 0.75 and 0.88 for anterior prostate cancer, respectively, and were 0.70 and 0.81 for posterior prostate cancer. The sensitivity for detecting anterior prostate cancer was 90% and was significantly higher than that for detecting posterior prostate cancer in the protocol using T2-weighted imaging and an ADC map (p = 0.003) when scores of 3-5 were considered as positive for prostate cancer. The ADC was significantly lower in anterior prostate cancer (mean, 0.80 × 10(-3) mm(2)/s) than in noncancerous anterior fibromuscular stroma (1.13 × 10(-3) mm(2)/s) (p < 0.001). CONCLUSION: The protocol using T2-weighted imaging and an ADC map showed higher accuracy for the detection of anterior prostate cancer than for the detection of posterior prostate cancer.

Pregnant woman with non-comatose autoimmune acute liver failure in the second trimester rescued using medical therapy: A case report.

We present the case of a 25-year-old woman at 16 weeks of gestation who presented with non-comatose autoimmune acute liver failure and was at high risk of developing fulminant hepatitis. Predictive formulas indicated a high probability of developing fulminant hepatitis. Unenhanced computed tomography showed marked hepatic atrophy and broadly heterogeneous hypoattenuating areas. The course of her illness was subacute, and the etiology of liver injury was unclear. Considering all of the above, we predicted a poor prognosis. Plasma exchange (PE) and continuous hemodiafiltration (CHDF) therapy were initiated just after admission. A few days after admission, a high titer (×80) of antinuclear antibody was noted. Because autoimmune hepatitis (AIH) was considered a cause of liver failure, treatment with moderate prednisolone (30 mg/day) doses was administrated, with careful consideration of her pregnancy. Thereafter, her laboratory findings and clinical course gradually improved without the need for liver transplantation. A liver biopsy at 18 days after admission indicated a diagnosis of AIH. She continued the pregnancy and delivered a healthy baby without any complications. Eventually, prednisolone doses were decreased to 10 mg, after which her liver function worsened. The second liver biopsy also indicated a diagnosis of AIH. Accordingly, low-dose prednisolone and azathioprine doses (50 mg/day) were administrated to recover her liver function, after which her liver function regained normalcy. This case illustrates that a pregnant woman with non-comatose autoimmune acute liver failure in the first or second trimester of pregnancy and her fetus can be rescued by PE/CHDF therapy and safe moderate doses of prednisolone.

Transarterial embolization for pediatric hepatocellular carcinoma with cardiac cirrhosis.

We describe the case of a 15-year-old boy with a history of Fontan operation and multiple intrahepatic tumors. Computed tomography showed multiple hepatic nodules with arterial enhancement. Because hepatocellular carcinoma (HCC) was not detected on biopsies and tumor markers were normal, progress was monitored on imaging. One hepatic tumor increased greatly in size during follow up. At 15 years of age, tumor markers rose rapidly, and he had upper abdominal swelling. Therefore, transarterial embolization (TAE) was performed for the largest tumor, suspected to be a HCC due to cardiac cirrhosis. This tumor had not increased at follow up 4 months later. The patient died from hepatic failure at the age of 17 years, and HCC was diagnosed at autopsy. Although pediatric HCC is rare, its incidence is likely to increase. TAE, with or without anticancer agents, is a therapeutic option for unresectable pediatric HCC, as it is for adult HCC.

Diffusion kurtosis imaging study of prostate cancer: preliminary findings.

PURPOSE: To evaluate the differences in parameters of diffusion kurtosis imaging (DKI) between prostate cancer, benign prostatic hyperplasia (BPH), and benign peripheral zone (PZ). MATERIALS AND METHODS: Twenty-four foci of prostate cancer, 41 BPH nodules (14 stromal and 27 nonstromal hyperplasia), and 20 benign PZ from 20 patients who underwent radical prostatectomy were investigated. Diffusion-weighted imaging (DWI) was performed using 11 b-values (0-1500 s/mm(2) ). DKI model relates DWI signal decay to parameters that reflect non-Gaussian diffusion coefficient (D) and deviations from normal distribution (K). A mixed model analysis of variance and receiver operating characteristic (ROC) analyses were performed to assess the statistical significance of the metrics of DKI and apparent diffusion coefficient (ADC). RESULTS: K was significantly higher in prostate cancer and stromal BPH than in benign PZ (1.19 ± 0.24 and 0.99 ± 0.28 versus 0.63 ± 0.23, P < 0.001 and P < 0.001, respectively). K showed a trend toward higher levels in prostate cancer than in stromal BPH (1.19 ± 0.24 versus 0.99 ± 0.28, P = 0.051). On the ROC analyses, a significant difference in area under the curve was not observed between K and ADC, however, K showed the highest sensitivity among three parameters. CONCLUSION: DKI may contribute to the imaging diagnosis of prostate cancer, especially in the differential diagnosis of prostate cancer and BPH.

A Versatile MR Elastography Research Tool with a Modified Motion Signal-to-noise Ratio Approach.

PURPOSE: This study aimed to facilitate research progress in MR elastography (MRE) by providing a versatile and convenient application for MRE reconstruction, namely the MRE research tool (MRE-rTool). It can be used for a series of MRE image analyses, including phase unwrapping, arbitrary bandpass and directional filtering, noise assessment of the wave propagation image (motion SNR), and reconstruction of the elastogram in both 2D and 3D MRE acquisitions. To reinforce the versatility of MRE-rTool, the conventional method of motion SNR was modified into a new method that reflects the effects of image filtering. METHODS: MRE tests of the phantom and liver were performed using different estimation algorithms for stiffness value (algebraic inversion of the differential equation [AIDE], local frequency estimation [LFE] in MRE-rTool, and multimodel direct inversion [MMDI] in clinical reconstruction) and acquiring dimensions (2D and 3D acquisitions). This study also tested the accuracy of masking low SNR regions using modified and conventional motion SNR under various mechanical vibration powers. RESULTS: The stiffness values estimated using AIDE/LFE in MRE-rTool were comparable to that of MMDI (phantom, 3.71 ± 0.74, 3.60 ± 0.32, and 3.60 ± 0.54 kPa in AIDE, LFE, and MMDI; liver, 2.26 ± 0.31, 2.74 ± 0.16, and 2.21 ± 0.26 kPa in AIDE, LFE, and MMDI). The stiffness value in 3D acquisition was independent of the direction of the motion-encoding gradient and was more accurate than that of 2D acquisition. The masking of low SNR regions using the modified motion SNR worked better than that in the conventional motion SNR for each vibration power, especially when using a directional filter. CONCLUSION: The performance of MRE-rTool on test data reached the level required in clinical MRE studies. MRE-rTool has the potential to facilitate MRE research, contribute to the future development of MRE, and has been freely released online.

Computed Tomography-guided Drainage with Modified Trocar Technique Using a Drainaway Drainage Kit.

Purpose: Image-guided percutaneous drainage for abscesses is known as a safe and effective treatment. The computed tomography-guided percutaneous drainage kit Drainaway (SB Kawasumi Co., Ltd.), developed on the basis of a modified trocar method, has made it possible to complete the procedure only under computed tomography guidance without radiographic fluoroscopy. This study investigated the feasibility and safety of Drainaway for abscess drainage. Material and Methods: In this retrospective observational study, 28 procedures in 27 patients (18 men and 9 women; age 67.0 ± 12.3 years) who underwent computed tomography-guided drainage using Drainaway between March and December 2021 at seven affiliated hospitals were analyzed. Patients with symptomatic, puncturable on computed tomography and refractory abscesses were included. Technical success (successful drainage with computed tomography alone), primary clinical success (successful drainage with Drainaway alone), secondary clinical success (avoidance of surgery), and complications were evaluated. Results: The sites of the abscesses were the intraperitoneal, retroperitoneal, and thoracic cavities in 19, 5, and 2 patients, respectively, and subcutaneous tissue in 1 patient. The mean size of the abscesses was 7.1 ± 3.4 cm. The technical success rate was 96.4%; the ligament of the puncture route could not be penetrated in one case. The primary clinical success rate was 77.8%, whereas the secondary clinical success rate of catheter upsizing or replacement was 96.3%. Complications included one case of biliary pleurisy that required drainage. Conclusions: Drainaway is a useful device that allows abscess drainage using only computed tomography guidance without radiographic fluoroscopy.

An intravoxel incoherent motion diffusion-weighted imaging study of prostate cancer.

OBJECTIVE: The purpose of this study is to investigate whether the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters are different between prostate cancer, benign prostatic hyperplasia (BPH), and healthy peripheral zone (PZ). MATERIALS AND METHODS: Detailed diffusion measurements of 26 patients with histologically proven prostate cancer have been made in this retrospective study. Trace IVIM DWI was performed using 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 1000 s/mm2). Biexponential fits were applied to diffusion decay curves to calculate molecular diffusion coefficient, perfusion-related diffusion coefficient, and perfusion fraction on the basis of the IVIM model. Decay curves were also fit with monoexponential decay functions, and a statistical comparison between mono- and biexponential fits was performed. Paired t tests were performed to evaluate the statistical significance of the parameters of IVIM DWI and apparent diffusion coefficient (ADC) between prostate cancer, BPH, and PZ. RESULTS: The chi-square values of biexponential fits were smaller than those from monoexponential fits in all cases. Biexponential functions provided statistically improved fits over monoexponential functions in 81% of cases. The ADC, molecular diffusion coefficient, and perfusion fraction in prostate cancer were significantly lower than those found in the PZ; however, perfusion fractions in prostate cancer and BPH were not significantly different. There were no significant differences in the prostate cancer, BPH, and PZ for the perfusion-related diffusion coefficient, which had large SDs. CONCLUSION: IVIM DWI parameters are significantly different between prostate cancer and PZ. IVIM DWI may offer additional information for tissue characterization in the prostate gland.

Comprehensive comparative study of computed tomography-based estimates of split renal function for potential renal donors: modified ellipsoid method and other CT-based methods.

OBJECTIVE: To investigate a new modified computed tomographic (CT) ellipsoid method of split renal function and to compare results from this method with other CT-derived metrics. METHODS: Thirty-eight potential renal donors with both CT and nuclear renography were retrospectively evaluated for estimated split function using 6 CT methods to determine accuracy. For the CT methods, correlation, reproducibility, ease in image post-processing, and the ability of CT-derived methods to determine the dominant kidney before renal transplantation were evaluated using a nuclear renography reference standard. RESULTS: Four of the 6 CT methods (split renal volume, modified ellipsoid method, parenchymal area, attenuation capacity) showed similar strong correlation (r = 0.84-0.79). Bland-Altman analysis revealed similar performance in differences (SDs <3.0%) between those CT measures and reference standard, as well as good interobserver agreement for the modified ellipsoid and parenchymal area methods. The technically simpler methods had inferior performance. Post-processing time for the modified ellipsoid method was significantly shorter than semiautomated split renal volume or parenchymal area method (P < 0.01). Each CT-based method showed excellent agreement (100% or 97.4%) with renography regarding the determination of dominant kidney. CONCLUSIONS: Excellent correlation with nuclear split renal function supports the use of CT alone for the imaging assessment for many potential renal donors, including the decision of which kidney to harvest. Among the CT-based methods, the modified ellipsoid method can be performed rapidly with high accuracy and reproducibility.

Craniofacial principles in face transplantation.

BACKGROUND: Face transplantation allows the reconstruction of the previously nonreconstructible injury. Anthropometric landmarks are fixated to corresponding cephalometric landmarks to restore function and appearance, with emphasis on phonation, mastication, and functional upper airway. Currently, only a few face transplantations have been performed worldwide. A portion of these reconstructions involves combinations of hard and soft tissues of the midface. METHODS: Craniofacial and orthognathic considerations should be emphasized for functional effect in the planning and execution of face transplants that include both bone and soft tissue elements. These steps are taken to restore normal anatomy by fixating the midface into proper relationship with the skull base. Traditional orthognathic planning, using cephalometric parameters, often involves a line through sella and nasion as a reference for the skull base. Intraoperatively though, without a cephalograph, the sella-nasion plane is not accessible as a reference point. RESULTS: Postoperative analysis of our first face transplant recipient revealed that the Frankfort horizontal plane can alternatively serve as an accessible skull base reference point to guide the positioning of the midface. We have developed a technique to ensure fixation of the midface donor allograft in a proper functional relationship with the skull base, within 1 SD of Bolton normative data. CONCLUSIONS: "Reverse craniofacial planning" allows for precise fixation of the hard tissue components of the face transplant in relation to the skull base, as opposed to a "best fit" approach. We believe that this relationship results in the most anatomical restoration of occlusion, speech, and airway function.

A novel technique for automating stiffness measurement and emphasizing the main wave: Coherent-wave auto-selection (CHASE).

This study aims to develop and assess a new automated processing technique in MR elastography (MRE), namely coherent-wave auto-selection (CHASE). CHASE enables automatic selection of the region of interest (ROI) for stiffness measurement by extraction of the coherent wave region (CHASE ROI), and it improves the reconstruction of stiffness by a directional filter oriented along the main wave in each pixel (CHASE filtering). In this study, MRE of a phantom and of the liver of four healthy volunteers was performed. To investigate the potential of CHASE, this study assessed the CHASE according to three indices through the phantom study: 1) agreement on the ROI settings between CHASE and expert observers, 2) noise dependency, and 3) effect of the CHASE on stiffness variability within the CHASE ROI. The agreements on the ROI settings were analyzed by Cohen's kappa coefficient (κ). The noise dependency was analyzed by the mean absolute percentage errors (MAPEs) within the ROI between low (20%-80% amplitudes) and high vibration amplitudes (100% amplitude). The stiffness variability was assessed by standard deviation (SD) within the ROI. In the volunteer study, agreements on the ROI settings (or stiffness value) and stiffness variability within the CHASE ROI were assessed using κ-value (or intraclass correlation coefficient: ICC) and coefficient of variation, respectively. The results showed close agreement on the ROI settings and stiffness (κ-value: greater than 0.61 in both the phantom and volunteer studies, ICC: 0.97 in the volunteer study). The MAPEs within the CHASE ROI were much smaller than those in the whole region of the phantom (CHASE ROI vs. the whole region at 20% amplitude: 10.3% vs. 50.8%). Moreover, in both the phantom and volunteer studies, the stiffness variation within the CHASE ROI was smaller in the elastogram processed with CHASE filtering than in the unprocessed one. Our results demonstrated that the CHASE has high robustness against noise and the potential to provide ROI settings for stiffness measurement comparable to expert observers, as well as improve the reconstruction of stiffness.

Lower limb lymphedema staging based on magnetic resonance lymphangiography.

OBJECTIVE: Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings? METHODS: Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema. RESULTS: DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10-3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10-5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P < .05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P < .05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P < .01) and the duration of lymphedema (r = 0.57, P < .01). CONCLUSIONS: MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.