MC3DU-Net: a multisequence cascaded pipeline for the detection and segmentation of pancreatic cysts in MRI.

PURPOSE: Radiological detection and follow-up of pancreatic cysts in multisequence MRI studies are required to assess the likelihood of their malignancy and to determine their treatment. The evaluation requires expertise and has not been automated. This paper presents MC3DU-Net, a novel multisequence cascaded pipeline for the detection and segmentation of pancreatic cysts in MRI studies consisting of coronal MRCP and axial TSE MRI sequences. METHODS: MC3DU-Net leverages the information in both sequences by computing a pancreas Region of Interest (ROI) segmentation in the TSE MRI scan, transferring it to MRCP scan, and then detecting and segmenting the cysts in the ROI of the MRCP scan. Both the voxel-level ROI of the pancreas and the segmentation of the cysts are performed with 3D U-Nets trained with Hard Negative Patch Mining, a new technique for class imbalance correction and for the reduction in false positives. RESULTS: MC3DU-Net was evaluated on a dataset of 158 MRI patient studies with a training/validation/testing split of 118/17/23. Ground truth segmentations of a total of 840 cysts were manually obtained by expert clinicians. MC3DU-Net achieves a mean recall of 0.80 ± 0.19, a mean precision of 0.75 ± 0.26, a mean Dice score of 0.80 ± 0.19 and a mean ASSD of 0.60 ± 0.53 for pancreatic cysts of diameter > 5 mm, which is the clinically relevant endpoint. CONCLUSION: MC3DU-Net is the first fully automatic method for detection and segmentation of pancreatic cysts in MRI. Automatic detection and segmentation of pancreatic cysts in MRI can be performed accurately and reliably. It may provide a method for precise disease evaluation and may serve as a second expert reader.

Real-time influence of intracellular acidification and Na+ /H+ exchanger inhibition on in-cell pyruvate metabolism in the perfused mouse heart: A 31 P-NMR and hyperpolarized 13 C-NMR study.

Disruption of acid-base balance is linked to various diseases and conditions. In the heart, intracellular acidification is associated with heart failure, maladaptive cardiac hypertrophy, and myocardial ischemia. Previously, we have reported that the ratio of the in-cell lactate dehydrogenase (LDH) to pyruvate dehydrogenase (PDH) activities is correlated with cardiac pH. To further characterize the basis for this correlation, these in-cell activities were investigated under induced intracellular acidification without and with Na+ /H+ exchanger (NHE1) inhibition by zoniporide. Male mouse hearts (n = 30) were isolated and perfused retrogradely. Intracellular acidification was performed in two ways: (1) with the NH4 Cl prepulse methodology; and (2) by combining the NH4 Cl prepulse with zoniporide. 31 P NMR spectroscopy was used to determine the intracellular cardiac pH and to quantify the adenosine triphosphate and phosphocreatine content. Hyperpolarized [1-13 C]pyruvate was obtained using dissolution dynamic nuclear polarization. 13 C NMR spectroscopy was used to monitor hyperpolarized [1-13 C]pyruvate metabolism and determine enzyme activities in real time at a temporal resolution of a few seconds using the product-selective saturating excitation approach. The intracellular acidification induced by the NH4 Cl prepulse led to reduced LDH and PDH activities (-16% and -39%, respectively). This finding is in line with previous evidence of reduced myocardial contraction and therefore reduced metabolic activity upon intracellular acidification. Concomitantly, the LDH/PDH activity ratio increased with the reduction in pH, as previously reported. Combining the NH4 Cl prepulse with zoniporide led to a greater reduction in LDH activity (-29%) and to increased PDH activity (+40%). These changes resulted in a surprising decrease in the LDH/PDH ratio, as opposed to previous predictions. Zoniporide alone (without intracellular acidification) did not change these enzyme activities. A possible explanation for the enzymatic changes observed during the combination of the NH4 Cl prepulse and NHE1 inhibition may be related to mitochondrial NHE1 inhibition, which likely negates the mitochondrial matrix acidification. This effect, combined with the increased acidity in the cytosol, would result in an enhanced H+ gradient across the mitochondrial membrane and a temporarily higher pyruvate transport into the mitochondria, thereby increasing the PDH activity at the expense of the cytosolic LDH activity. These findings demonstrate the complexity of in-cell cardiac metabolism and its dependence on intracellular acidification. This study demonstrates the capabilities and limitations of hyperpolarized [1-13 C]pyruvate in the characterization of intracellular acidification as regards cardiac pathologies.

Focal Irreversible Electroporation for Localized Prostate Cancer - Oncological and Safety Outcomes Using mpMRI and Transperineal Biopsy Follow-Up.

Introduction: Irreversible electroporation (IRE) technology for prostate cancer (PC) generates consecutive electrical pulses between pairs of electrodes which move through tumorous cells, irreversibly perforate their membranes and eventually lead to cell death, while avoiding tissue thermal effect. The technique is used for primary focal lesions as well as for focal salvage cases. This series reports short term oncological control, quality of life and safety results. Methods: Retrospective data were collected from 45 consecutive cases of primary (N=38) and salvage (N=7) PC patients treated with IRE. All patients had transperineal MRI/US fusion biopsy and PET-PSMA scan prior to treatment, to verify single lesion. Transperineal Nano-Knife IRE system was used in day-care theatre. Patients had 6 months mpMRI, blood PSA and 1 year confirmatory biopsy following procedure. Quality of life was recorded during the first year. Results: Median primary subgroup analysis (N=38): age 69 years, initial PSA 5.6 ng/dL, lesion size 0.8 mL and ISUP Group 2 (1-3). Median salvage subgroup analysis (N=7): age 76 years, initial PSA 11.9 ng/dL, lesion size 2.0 mL and ISUP Group 4 (1-5). Median catheter time 5 (3-7) days. No Clavien-Dindo>1 complications were reported nor re-admissions, incontinence, strictures or fistulas. 5% of patients were given PDE-5i drugs. Primary group PSA dropped by 39%, mpMRI clearance in 84%, out-field new lesion in 12%, in-field lesion in 4%. Biopsy at 1 year: 4 patients had out-field clinically significant PC, thus 3 had re-IRE and 1 had radiation therapy. Salvage subgroup MRI clearance was 60%, and 52% remained on active surveillance by 1 year. Conclusion: IRE treatment for focal PC is safe for primary and salvage cases, if done by a meticulously skilled and trained team, and under strict protocols. The short term oncological results are promising especially for primary lesions. Long term oncological results will be published over time.

Existing Scores Fail to Predict Bowel Ischemia in Patients With Adhesive Small Bowel Obstruction.

INTRODUCTION: Early recognition of bowel ischemia is critical in patients suffering from acute adhesive small bowel obstruction (ASBO). Recent studies attempted to propose a score combining clinical and radiological factors to predict the risk of bowel ischemia in patients with ASBO. This study aimed to compare and validate the existing clinical scores with a cohort of surgical patients. METHODS: We conducted a retrospective study including all ASBO cases admitted to our institution between January 1, 2005 and December 31, 2019. Based on three existing clinical scores, we calculated the risk of bowel ischemia for each patient. We then divided the cohort into groups based on the risk for bowel ischemia. For each risk-based category, the proportion of patients who underwent surgical resection and were found to have evidence of ischemic bowel was calculated. RESULTS: A total of 160 patients presenting with 217 episodes of acute ASBO were included. One hundred seventy-one (78.8%) cases were managed nonoperatively while 46 cases (21.2%) required surgery. Sixteen patients (7.3%) were eventually found to have ischemic bowel while 13 required small bowel resection (5.9%). All three clinical scores showed correlation between the calculated risk of ischemia and the intraoperative finding of ischemia. However, all three scores overestimated ischemia rates in the high-risk groups, yielding a PPV of 8.3%-28.5% and a NPV of 93.3%-94.7%. CONCLUSIONS: Current clinical scores for predicting bowel ischemia in patients with ASBO are of high value in ruling out ischemia, yet are of extremely low sensitivity, warranting an overly aggressive and unnecessary surgical approach.

The Liver Tumor Segmentation Benchmark (LiTS).

In this work, we report the set-up and results of the Liver Tumor Segmentation Benchmark (LiTS), which was organized in conjunction with the IEEE International Symposium on Biomedical Imaging (ISBI) 2017 and the International Conferences on Medical Image Computing and Computer-Assisted Intervention (MICCAI) 2017 and 2018. The image dataset is diverse and contains primary and secondary tumors with varied sizes and appearances with various lesion-to-background levels (hyper-/hypo-dense), created in collaboration with seven hospitals and research institutions. Seventy-five submitted liver and liver tumor segmentation algorithms were trained on a set of 131 computed tomography (CT) volumes and were tested on 70 unseen test images acquired from different patients. We found that not a single algorithm performed best for both liver and liver tumors in the three events. The best liver segmentation algorithm achieved a Dice score of 0.963, whereas, for tumor segmentation, the best algorithms achieved Dices scores of 0.674 (ISBI 2017), 0.702 (MICCAI 2017), and 0.739 (MICCAI 2018). Retrospectively, we performed additional analysis on liver tumor detection and revealed that not all top-performing segmentation algorithms worked well for tumor detection. The best liver tumor detection method achieved a lesion-wise recall of 0.458 (ISBI 2017), 0.515 (MICCAI 2017), and 0.554 (MICCAI 2018), indicating the need for further research. LiTS remains an active benchmark and resource for research, e.g., contributing the liver-related segmentation tasks in http://medicaldecathlon.com/. In addition, both data and online evaluation are accessible via https://competitions.codalab.org/competitions/17094.

The effect of atrophied pancreas as shown in the preoperative imaging on the leakage rate after pancreaticoduodenectomy.

Backgrounds/Aims: The soft texture of the pancreas parenchyma may influence the incidence of pancreatic leakage after pancreaticoduodenectomy (PD). One possible method to assess pancreatic texture and atrophy, is via computed tomography (CT) scan of the abdomen. The purpose of our study was to evaluate the relation between the preoperative CT scan and the incidence of pancreatic fistula after PD. Methods: A retrospective single-center study including patients who underwent PD for a benign and malignant tumor of the periampullary region between the years 2000 and 2016. Demographic and imaging data were analysed and a correlation with the post-operative leak was evaluated. Results: Pancreatic leak was documented in 34 out of 154 (22.1%) patients. All the leakage cases occurred in the preserved pancreas group (33.1% of the total preserved pancreas group alone). No leak was documented in the atrophic pancreas group. This difference between the two groups was found to be statistically significant (p ≤ 0.00001). Conclusions: Atrophic pancreas in the preoperative CT scan may be protective against leakage after PD. These findings may help the surgeon to risk stratify patients accordingly. In addition, the findings suggest that patients with a preserved pancreas may require more protective methods to prevent leakage.

Characterization and Evaluation of Injectable Biodegradable Polymer Multimodality Radiologic Markers in an In Vivo Murine Model.

Biodegradable polymer clips as multidimensional soft tissue biopsy markers were developed with better biocompatibility and imaging features. Unlike the commercially available metallic biopsy markers, the developed polymer clips are temporary implants with similar efficacies as metal markers in imaging and detection and get absorbed within the body with time. Herein, we evaluate the degradation rate of three resorbable polymer-based marker compounds in an in vivo murine model. Three polymers, abbreviated as Polymer A (PLGA poly(lactic-co-glycolic acid)50:50), Polymer B (PLGA (poly(lactic-co-glycolic acid)) 75:25), and Polymer C (polycaprolactone (PCL)), mixed with 20% lipiodol and 0.2% iron oxide and a control polymer were implanted into nine mice, followed by CT and MRI imaging. Images were evaluated for conspicuity. Specimens were examined for tissue analysis of iodine and iron contents. Significant differences in polymer resorption and visualization on CT were noted, particularly at 8 weeks (p < 0.027). Polymers A, B, and C were visible by CT at 4, 6, and 8 weeks, respectively. All marker locations were detected on MRI (T1 and SWI) after 24 weeks, with tattooing of the surrounding soft tissue by iron deposits. CT and MR visible polymer markers can be constructed to possess variable resorption, with stability ranging between 4 and 14 weeks post placement, making this approach suitable for distinct clinical scenarios with varying time points.

Accumulation of 3-aminopropylphosphonate in the ex vivo brain observed by phosphorus-31 nuclear magnetic resonance.

3-aminopropylphosphonate (3-APP) is known for its use as an exogenous indicator of extracellular volume and pH in phosphorus-31 nuclear magnetic resonance (31 P NMR) studies. We used 3-APP for estimating the extracellular volume in NMR studies of several ex vivo preparations including retrograde perfused mouse heart (n = 4), mouse liver slices (n = 2), xenograft breast cancer tumors (n = 7, MCF7), and rat brain slices (n = 4). In the former three preparations, the 3-APP signal was stable in lineshape and intensity for hours and the chemical shift of the signal in the presence of the biological sample was the same as in the perfusion medium without the biological sample. However, in studies of brain slices, the 3-APP signal appeared split into two, with an upfield component (0.7 ± 0.1 ppm to the left) increasing with time and showing a wider linewidth (66.7 ± 12.6 vs. 39.1 ± 7.6 Hz, the latter is of the perfusion medium signal). This finding suggests that 3-APP inadvertently accumulated in brain slices, most likely as a membrane bound form. This observation limits the use of 3-APP as an inert biochemical indicator in brain preparations and should be taken into account when using 3-APP in vivo.

Randomised clinical trial: A phase 2 double-blind study of namodenoson in non-alcoholic fatty liver disease and steatohepatitis.

BACKGROUND: Namodenoson, an A3 adenosine receptor (A3AR) agonist, improved liver function/pathology in non-alcoholic steatohepatitis (NASH) preclinical models. AIM: To evaluate the efficacy and safety of namodenoson for the treatment of non-alcoholic fatty liver disease (NAFLD) with or without NASH METHODS: This phase 2 study included 60 patients with NAFLD (ALT ≥60 IU/L) who were randomised (1:1:1) to oral namodenoson 12.5 mg b.d. (n = 21), 25 mg b.d. (n = 19), or placebo (n = 20) for 12 weeks (total follow-up: 16 weeks). The main efficacy endpoint involved serum ALT after 12 weeks of treatment. RESULTS: Serum ALT decreased over time with namodenoson in a dose-dependent manner. The difference between change from baseline (CFB) for ALT in the namodenoson 25 mg b.d. arm vs placebo trended towards significance at 12 weeks (P = 0.066). Serum AST levels also decreased with namodenoson in a dose-dependent manner; at 12 weeks, the CFB for 25 mg b.d. vs placebo was significant (P = 0.03). At Week 12, 31.6% in the namodenoson 25 mg b.d. arm and 20.0% in the placebo arm achieved ALT normalisation (P = 0.405). At week 16, the respective rates were 36.8% and 10.0% (P = 0.038). A3AR expression levels were stable over time across study arms. Both doses of namodenoson were well tolerated with no drug-emergent severe adverse events, drug-drug interactions, hepatotoxicity, or deaths. Three adverse events were considered possibly related to study treatment: myalgia (12.5 mg b.d. arm), muscular weakness (25 mg b.d. arm), and headache (25 mg b.d. arm). CONCLUSION: A3AR is a valid target; namodenoson 25 mg b.d. was safe and demonstrated efficacy signals (ClinicalTrials.gov #NCT02927314).

Dual energy CT in acute appendicitis: value of low mono-energy.

OBJECTIVES: To assess the potential role of low monoenergetic images in the evaluation of acute appendicitis. METHODS: A retrospective study of 42 patients with pathology proven acute appendicitis underwent contrast-enhanced-CT conducted on a single-source-DECT before surgery. Attenuation, SNR, and CNR were calculated on both monoenergetic and conventional images and compared to 24 abdominal CT-scans with normal appendix. Representative conventional and monoenergetic images were randomized and presented side-by-side to three abdominal radiologists to determine preferred images for detecting inflammation. Additionally, six individual acute inflammatory characteristics were graded on a 1-5 scale to determine factors contributing to differences between conventional and monoenergetic images by 2 abdominal radiologists. Paired t-tests, Wilcoxon and McNemar tests, and intra-observer error statistics were performed. RESULTS: For the inflamed appendixes monoenergetic images had overall increased attenuation (average ratio 1.7; P < 0.05), signal-to-noise-ratio (6.7 ± 3.1 vs 4.2 ± 1.6; P < 0.001) and contrast-to-noise-ratio (12.1 ± 3 vs 9 ± 2.1; P < 0.001). Moreover, this increase was not found in normal appendixes (P < 0.001 vs p = 0.28-0.44). Subjectively, radiologists showed significant preferences towards monoenergetic images (P < 0.001), with inter-reader agreement of 0.84. Two parameters, diffuse bowel wall and mucosal enhancement, received significantly higher scores on monoenergetic images (average 4.3 vs. 3.0; P < 0.001 and 2.8 vs. 2.3 P < 0.03 respectively, with interobserver agreements of 62% and 52%). CONCLUSION: Increased bowel wall conspicuity from enhanced attenuation, SNR, and CNR on low monenergetic CT images results in a significant preference by radiologists for these images when assessing acute inflamed appendixes. Thus, close inspection of low monoenergetic images may improve the visualization of acute inflammatory bowel processes.

Psoas Attenuation and Mortality of Elderly Patients Undergoing Nontraumatic Emergency Laparotomy.

BACKGROUND: Emergency laparotomy (EL) is an increasingly common procedure in the elderly. Factors associated with mortality in the subpopulation of frail patients have not been thoroughly investigated. Sarcopenia has been investigated as a surrogate for frailty and poor prognosis. Our primary aim was to evaluate the association between easily measured sarcopenia parameters and 30-day postoperative mortality in elderly patients undergoing EL. Length of stay (LOS) and admission to an intensive care unit were secondary end points. METHODS: We conducted a retrospective cohort study, over a 5-year period, of patients aged 65 y and older who underwent EL at a tertiary university hospital. Sarcopenia was evaluated on admission computed tomography scan by two methods, first by psoas muscle attenuation and second by the product of perpendicular cross-sectional diameters (PCSDs). The lowest quartile of PCSDs and attenuation were defined as sarcopenic and compared with the rest of the cohort. Attenuation was stratified for the use of contrast enhancement. Multivariant logistic regression was performed to determine independent risk factors. RESULTS: During the study period, 403 patients, older than 65 y, underwent EL. Of these, 283 fit the inclusion criteria and 65 (23%) patients died within 30 d of surgery. On bivariate analysis, psoas muscle attenuation, but not PCSDs, was found to be associated with 30-day mortality (OR = 2.43, 95% CI = 1.34-4.38, P = 0.003) and longer LOS (35.7 d versus 22.2 d, Δd 13.5, 95% CI = 6.4-20.7, P < 0.001). In a multivariate analysis, psoas muscle attenuation, but not PCSDs, was an independent risk factor for 30-day postoperative mortality (OR = 2.35, 95% CI = 1.16-4.76, P = 0.017) and longer LOS (Δd = 14.4, 95% CI = 7.7-21.0, P < 0.001). Neither of the sarcopenia parameters was associated with increased admission to an intensive care unit. DISCUSSION: Psoas muscle attenuation is an independent risk factor for 30-day postoperative mortality and LOS after EL in the elderly population. This measurement can inform clinicians about the operative risk and hospital resource utilization.

Long-term outcomes in MEN-1 patients with pancreatic neuroendocrine neoplasms: an Israeli specialist center experience.

PURPOSE: The decreased life expectancy of MEN-1 patients is mainly related to pancreatic neuroendocrine tumors (pNETs). At best, limited data is available on the natural history of MEN-1-associated pNETs, as these tumors are rare and have a wide range of biologic behavior. Our study aims to explore the clinical course of patients with MEN-1-associated pNETs and the long-term outcomes. METHODS: This longitudinal study was conducted on the MEN-1 cohort treated at our referral center over a 22-year period (1996-2018). Relevant clinical data were retrospectively analysed. RESULTS: Among the 33 MEN-1 patients included in our study, pNETs were identified in 21 subjects with a penetrance of 48% by the age of 50. Non-functioning and functioning pNETs were diagnosed in sixteen (76%) and five (24%) patients, respectively. Two-thirds of the patients had multifocal tumors. The median number of pancreatic macroscopic lesions per individual was 4.0 ± 3.9 (range 1-8) with a mean size of 1.3 ± 2.1 cm (range 0.5-10). The metastatic rate according to the dominant pNET lesion reached 100%, 62% and 6% for tumors sized > 4 cm, 2.1-4 cm, and 1-2 cm, respectively. Over the study period, one or more therapeutic interventions for pNETs were required in 20 out of the 21 patients. pNET-related metastatic complication was the main cause of death within this MEN-1 cohort. The overall survival rate for the pNETs patients was 86% during a mean follow-up period of 8.0 ± 4.6 years. CONCLUSIONS: In our MEN-1 cohort, non-functioning pNETs were the most frequent type of pancreaticoduodenal tumor, and the tumor size correlated with the risks of metastasis and death. Increased awareness, early diagnosis, and a multidisciplinary approach may improve the associated morbidity and mortality in these patients.

Hyperpolarized product selective saturating-excitations for determination of changes in metabolic reaction rates in real-time.

Investigation of hyperpolarized substrate metabolism has been showing utility in real-time determination of in-cell and in vivo enzymatic activities. Intracellular reaction rates may vary during the course of a measurement, even on the very short time scales of visibility on hyperpolarized MR, due to many factors such as the availability of the substrate and co-factors in the intracellular space. Despite this potential variation, the kinetic analysis of hyperpolarized signals typically assumes that the same rate constant (and in many cases, the same rate) applies throughout the course of the reaction as observed via the build-up and decay of the hyperpolarized signals. We demonstrate here an acquisition approach that can null the need for such an assumption and enable the detection of instantaneous changes in the rate of the reaction during an ex vivo hyperpolarized investigation, (i.e. in the course of the decay of one hyperpolarized substrate dose administered to a viable tissue sample ex vivo). This approach utilizes hyperpolarized product selective saturating-excitation pulses. Similar pulses have been previously utilized in vivo for spectroscopic imaging. However, we show here favorable consequences to kinetic rate determinations in the preparations used. We implement this acquisition strategy for studies on perfused tissue slices and develop a theory that explains why this particular approach enables the determination of changes in enzymatic rates that are monitored via the chemical conversions of hyperpolarized substrates. Real-time changes in intracellular reaction rates are demonstrated in perfused brain, liver, and xenograft breast cancer tissue slices and provide another potential differentiation parameter for tissue characterization.

Clinical and Radiologic Characteristics of Intra-Abdominal Fistulizing Crohn's Disease.

BACKGROUND: Few studies describe the radiological and laboratory characteristics of patients with Crohn's disease (CD) with intra-abdominal fistulae. OBJECTIVES: We aimed to describe a cohort of CD patients with intra-abdominal fistulae and determine characteristics associated with complex fistulae. METHODS: Data were gathered from medical records and imaging studies of patients. Evaluation included type of fistula, number of fistulae, and radiological characteristics. RESULTS: A total of 205 fistulae in 132 patients were identified with an average patient age of 31 (±12) years. The average time from CD diagnosis to fistula development was 7 years. The most common type of fistula was entero-enteric (53%). Patients with an extra-intestinal fistula presented with an average of 1.96 fistulae, compared with an average of 1.28 fistulae for those with a fistula limited to the bowel (p =0.01). Except for the number of fistula no other significant differences were observed in radiological characteristics of patients who were diagnosed with a fistula at time of CD diagnosis compared to those diagnosed with a fistula later. CONCLUSIONS: The most common CD-associated intra-abdominal fistulae are entero-enteric and entero-colonic fistulae. An extra-intestinal fistula and diagnosis of a fistula subsequent to diagnosis of CD were associated with an increased number of fistulae per patient.

VHL-Related Neuroendocrine Neoplasms And Beyond: An Israeli Specialized Center Real-Life Report.

OBJECTIVE: Von Hippel-Lindau (VHL) syndrome is a rare and complex disease. In 1996, we described a 3 generation VHL 2A kindred with 11 mutation carriers. We aim to share our experience regarding the long-term follow-up of this family and the management of all our other VHL patients focusing on frequently encountered neuroendocrine neoplasms: pheochromocytoma/paraganglioma and pancreatic neuroendocrine neoplasms (PNEN). METHODS: All VHL patients in follow-up at our tertiary center from 1980 to 2019 were identified. Clinical, laboratory, imaging, and therapeutic characteristics were retrospectively analyzed. RESULTS: We identified 32 VHL patients in 16 different families, 7/16 were classified as VHL 2 subtype. In the previously described family, the 4 initially asymptomatic carriers developed a neuroendocrine tumor; 7 new children were born, 3 of them being mutation carriers; 2 patients died, 1 due to metastatic PNEN-related liver failure. Pheochromocytoma was frequent (22/32), bilateral (13/22;59%), often diagnosed in early childhood when active screening was timely performed, associated with paraganglioma in 5/22, rarely malignant (1/22), and recurred after surgery in some cases after more than 20 years. PNEN occurred in 8/32 patients (25%), and was metastatic in 3 patients. Surgery and palliative therapy allowed relatively satisfactory outcomes. Severe disabling morbidities due to central-nervous system and ophthalmologic hemangiomas, and other rare tumors as chondrosarcoma in 2 patients and polycythemia in 1 patient were observed. CONCLUSION: A multidisciplinary approach and long-term follow-up is mandatory in VHL patients to manage the multiple debilitating morbidities and delay mortality in these complex patients.

In search of a genetic explanation for LDLc variability in an FH family: common SNPs and a rare mutation in MTTP explain only part of LDL variability in an FH family.

We previously identified a highly consanguineous familial hypercholesterolemia (FH) family demonstrating segregation of the JD Bari mutation in the LDL receptor as well as a putative cholesterol-lowering trait. We aimed to identify genes related to the latter effect. LDL cholesterol (LDLc) values were normalized for FH affectation status, age, and gender. Using genome-wide SNP data, we examined whether known SNPs gleaned from a genome-wide association study could explain the variation observed in LDLc. Four individuals with markedly reduced LDL levels underwent whole exome sequencing. After prioritizing all potential mutations, we identified the most promising candidate genes and tested them for segregation with the lowering trait. We transfected a plasmid carrying the top candidate mutation, microsomal triglyceride transfer protein (MTTP) R634C, into COS-7 cells to test enzymatic activity. The SNP score explained 3% of the observed variability. MTTP R634C showed reduced activity (49.1 nmol/ml) compared with the WT allele (185.8 nmol/ml) (P = 0.0012) and was marginally associated with reduced LDLc in FH patients (P = 0.05). Phenotypic variability in a FH pedigree can only partially be explained by a combination of common SNPs and a rare mutation and a rare variant in the MTTP gene. LDLc variability in FH patients may have nongenetic causes.

In-cell determination of Lactate Dehydrogenase Activity in a Luminal Breast Cancer Model ⁻ ex vivo Investigation of Excised Xenograft Tumor Slices Using dDNP Hyperpolarized [1-13C]pyruvate.

[1-13C]pyruvate, the most widely used compound in dissolution-dynamic nuclear polarization (dDNP) magnetic resonance (MR), enables the visualization of lactate dehydrogenase (LDH) activity. This activity had been demonstrated in a wide variety of cancer models, ranging from cultured cells, to xenograft models, to human tumors in situ. Here we quantified the LDH activity in precision cut tumor slices (PCTS) of breast cancer xenografts. The Michigan Cancer Foundation-7 (MCF7) cell-line was chosen as a model for the luminal breast cancer type which is hormone responsive and is highly prevalent. The LDH activity, which was manifested as [1-13C]lactate production in the tumor slices, ranged between 3.8 and 6.1 nmole/nmole adenosine tri-phosphate (ATP) in 1 min (average 4.6 ± 1.0) on three different experimental set-ups consisting of arrested vs. continuous perfusion and non-selective and selective RF pulsation schemes and combinations thereof. This rate was converted to an expected LDH activity in a mass ranging between 3.3 and 5.2 µmole/g in 1 min, using the ATP level of these tumors. This indicated the likely utility of this approach in clinical dDNP of the human breast and may be useful as guidance for treatment response assessment in a large number of tumor types and therapies ex vivo.

Real-time ALT and LDH activities determined in viable precision-cut mouse liver slices using hyperpolarized [1-13 C]pyruvate-Implications for studies on biopsied liver tissues.

Precision-cut liver slices (PCLS) are widely used in liver research as they provide a liver model with all liver cell types in their natural architecture. The purpose of this study was to demonstrate the use of PCLS for hyperpolarized metabolic investigation in a mouse model, for potential future application in liver biopsy cores. Fresh normal liver was harvested from six mice. 500 µm PCLS were prepared and placed in a 10 mm NMR tube in an NMR spectrometer and perfused continuously. 31 P spectra were acquired to evaluate the presence of adenosine triphosphate (ATP) and validate viability in all samples. Hyperpolarized [1-13 C]pyruvate was flushed into the NMR tube in the spectrometer. Consecutive 13 C NMR spectra were acquired immediately after the injection using both non-selective (five injections, two livers) and selective RF excitation (six injections, three livers). The 31 P spectra showed the characteristic signals of ATP, confirming the viability of the PCLS for more than 2.5 h in the spectrometer. After each of the [1-13 C]pyruvate injections, both [1-13 C]lactate and [1-13 C]alanine signals were detected. Selective RF excitation aimed at both [1-13 C]lactate and [1-13 C]alanine enabled better visualization and quantification of the metabolic activity. Using this acquisition approach only the newly formed metabolites are observed upon excitation, and their intensities relative to those of hyperpolarized pyruvate enable quantification of metabolite production rates. This rate of lactate and alanine production appeared to be constant throughout the measurement time, with alanine production about 2.3 times higher than lactate. In summary, the viability of PCLS in an NMR spectrometer was demonstrated and hyperpolarized [1-13 C]pyruvate metabolism was recorded. This study opens up the possibility of evaluating alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities in human liver biopsies, while preserving the tissue architecture and viability. In healthy, well-perfused liver slices the ratio of ALT to LDH activity is about 2.3.

Patient-specific and global convolutional neural networks for robust automatic liver tumor delineation in follow-up CT studies.

Radiological longitudinal follow-up of tumors in CT scans is essential for disease assessment and liver tumor therapy. Currently, most tumor size measurements follow the RECIST guidelines, which can be off by as much as 50%. True volumetric measurements are more accurate but require manual delineation, which is time-consuming and user-dependent. We present a convolutional neural networks (CNN) based method for robust automatic liver tumor delineation in longitudinal CT studies that uses both global and patient specific CNNs trained on a small database of delineated images. The inputs are the baseline scan and the tumor delineation, a follow-up scan, and a liver tumor global CNN voxel classifier built from radiologist-validated liver tumor delineations. The outputs are the tumor delineations in the follow-up CT scan. The baseline scan tumor delineation serves as a high-quality prior for the tumor characterization in the follow-up scans. It is used to evaluate the global CNN performance on the new case and to reliably predict failures of the global CNN on the follow-up scan. High-scoring cases are segmented with a global CNN; low-scoring cases, which are predicted to be failures of the global CNN, are segmented with a patient-specific CNN built from the baseline scan. Our experimental results on 222 tumors from 31 patients yield an average overlap error of 17% (std = 11.2) and surface distance of 2.1 mm (std = 1.8), far better than stand-alone segmentation. Importantly, the robustness of our method improved from 67% for stand-alone global CNN segmentation to 100%. Unlike other medical imaging deep learning approaches, which require large annotated training datasets, our method exploits the follow-up framework to yield accurate tumor tracking and failure detection and correction with a small training dataset. Graphical abstract Flow diagram of the proposed method. In the offline mode (orange), a global CNN is trained as a voxel classifier to segment liver tumor as in [31]. The online mode (blue) is used for each new case. The input is baseline scan with delineation and the follow-up CT scan to be segmented. The main novelty is the ability to predict failures by trying the system on the baseline scan and the ability to correct them using the patient-specific CNN.

Extrahepatic metastasis risk of hepatocellular carcinoma based on α-fetoprotein and tumor staging parameters at cross-sectional imaging.

BACKGROUND: Extrahepatic metastases have important implications in the clinical management of hepatocellular carcinoma (HCC). The purpose of this study was to validate tumor staging parameters and serum AFP as risk factors of HCC metastasis. PATIENTS AND METHODS: In this retrospective case-control study, patients with a new diagnosis of HCC (N=236), median age 57 years (range 28-89 years), and male-to-female ratio of 183/53 were divided into a "no-met" group (N=101) without extrahepatic metastasis or a "met" group with extrahepatic metastases (N=135). Metastasis risk factors based on tumor staging parameters (size, number, infiltration, and vascular invasion) and serum AFP level were calculated as odds ratio (OR). Sensitivities of the risk factors as metastasis screening tests were also calculated. RESULTS: AFP >400 µg/mL, index tumor size >5 cm, and vascular invasion individually had strong association with metastasis, with OR (95% confidence interval) of 11.5 (5.9-22.1), 17.7 (9.0-34.8), and 18.9 (8.2-43.9), respectively, but with moderate sensitivities as metastasis screening tests, with 71.9% (65.7-77.3), 75.6% (69.6-80.7), and 58.5% (52.1-64.7), respectively. Composite multiparametric criteria, eg, a logical union of 1) tumor size outside of Milan criteria, 2) AFP threshold >35 µg/mL, and 3) vascular invasion, had excellent OR up to 55.6 (13.0-237.1) with screening sensitivity 98.5% (95.8-99.6). CONCLUSION: Serum AFP, tumor size, and vascular invasion are strongly associated with extrahepatic metastasis of HCC, especially when combined into a multiparametric metastasis prediction criterion.