Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas: Comparison with Conventional Single-Shot Echo-Planar Imaging

ObjectiveTo investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI.ResultsOn qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm² and 2.81 ± 0.64 at b = 400 s/mm²), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm² and 3.15 ± 0.79 at b = 400 s/mm²), IQ score (8.51 ± 2.05 at b = 0 s/mm² and 8.79 ± 1.60 at b = 400 s/mm²), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm² and 2.56 ± 0.47 at b = 500 s/mm²; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm² and 2.89 ± 0.86 at b = 500 s/mm²; IQ score, 7.13 ± 1.83 at b = 0 s/mm² and 8.17 ± 1.31 at b = 500 s/mm²; clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm² (full FOV DWI, 2.41 ± 0.63) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas (1.061 × 10^-3 mm²/s ± 0.133 at reduced FOV and 1.079 × 10^-3 mm²/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10^-3 mm²/s ± 0.152 at reduced FOV and 1.004 × 10^-3 mm²/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10^-3 mm²/s ± 0.125 at reduced FOV and 1.218 × 10^-3 mm²/s ± 0.103 at full FOV) (p < 0.05).ConclusionReduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.     

Absolute myocardial flow quantification with 82Rb PET/CT: comparison of different software packages and methods

Purpose

In clinical cardiac ⁸²Rb PET, globally impaired coronary flow reserve (CFR) is a relevant marker for predicting short-term cardiovascular events. However, there are limited data on the impact of different software and methods for estimation of myocardial blood flow (MBF) and CFR. Our objective was to compare quantitative results obtained from previously validated software tools.

Methods

We retrospectively analyzed cardiac ⁸²Rb PET/CT data from 25 subjects (group 1, 62?±?11 years) with low-to-intermediate probability of coronary artery disease (CAD) and 26 patients (group 2, 57?±?10 years; P?=?0.07) with known CAD. Resting and vasodilator-stress MBF and CFR were derived using three software applications: (1) Corridor4DM (4DM) based on factor analysis (FA) and kinetic modeling, (2) 4DM based on region-of-interest (ROI) and kinetic modeling, (3) MunichHeart (MH), which uses a simplified ROI-based retention model approach, and (4) FlowQuant (FQ) based on ROI and compartmental modeling with constant distribution volume.

Results

Resting and stress MBF values (in milliliters per minute per gram) derived using the different methods were significantly different: using 4DM-FA, 4DM-ROI, FQ, and MH resting MBF values were 1.47?±?0.59, 1.16?±?0.51, 0.91?±?0.39, and 0.90?±?0.44, respectively (P?<?0.001), and stress MBF values were 3.05?±?1.66, 2.26?±?1.01, 1.90?±?0.82, and 1.83?±?0.81, respectively (P?<?0.001). However, there were no statistically significant differences among the CFR values (2.15?±?1.08, 2.05?±?0.83, 2.23?±?0.89, and 2.21?±?0.90, respectively; P?=?0.17). Regional MBF and CFR according to vascular territories showed similar results. Linear correlation coefficient for global CFR varied between 0.71 (MH vs. 4DM-ROI) and 0.90 (FQ vs. 4DM-ROI). Using a cut-off value of 2.0 for abnormal CFR, the agreement among the software programs ranged between 76 % (MH vs. FQ) and 90 % (FQ vs. 4DM-ROI). Interobserver agreement was in general excellent with all software packages.

Conclusion

Quantitative assessment of resting and stress MBF with ⁸²Rb PET is dependent on the software and methods used, whereas CFR appears to be more comparable. Follow-up and treatment assessment should be done with the same software and method.     

Reoperation, myocardial infarction and mortality after transurethral and open prostatectomy: a nation-wide, long-term analysis of 23,123 cases

OBJECTIVE: To analyse long-term rates of reoperation, myocardial infarction and mortality after transurethral (TURP) and open prostatectomy (open PE) in a nation-wide analysis. MATERIAL AND METHODS: Patients who underwent TURP (n=20,671) or open PE (n=2452) in Austria between 1992 and 1996 entered this study and were followed for up to 8 years. Actuarial cumulative incidences of reoperation (TURP, urethrotomy, bladder neck incision), myocardial infarction and death after 1, 5 and 8 years were calculated. Data were provided by the Austrian Health Institute (OBIG). RESULTS: Actuarial cumulative incidences of a secondary TURP after primary TURP at 1, 5 and 8 years were 2.9%, 5.8% and 7.4%; the respective numbers after open PE 1.0%, 2.7% and 3.4%. The overall incidence of a secondary endourological procedure (TURP, urethrotomy, bladder neck incision) within 8 years was 14.7% after TURP and 9.5% after open PE. The 8 years incidence of myocardial infarction was identical after TURP (4.8%) and open PE (4.9%). In parallel, mortality rates at 90 days (TURP: 0.7%; open PE: 0.9%), one year (2.8% vs. 2.7%), 5 years (12.7% vs. 11.8%) and 8 years (20% vs. 20.9%) was identical after TURP and open PE. CONCLUSIONS: This large-scale, contemporary, nation-wide analysis confirms the higher reoperation rate after TURP compared to open PE. We observed no excess risk of myocardial infarction or death after TURP compared to open PE.     

Risk stratification with cardiac troponin I in patients undergoing elective coronary artery bypass surgery.

OBJECTIVE: Cardiac troponin I (cTnI) is a highly sensitive and specific marker for postoperative prediction of patients outcome after coronary artery bypass surgery (CABG). Whether preoperatively elevated cTnI levels similarly predict the outcome in patients scheduled for elective CABG is currently unknown. METHODS: Therefore, a possible correlation between preoperative cTnI levels and perioperative major adverse events and in-hospital mortality after CABG was investigated. CTnI was measured within 24h before surgery in 1405 out of 3124 consecutive elective CABG patients. Out of these patients, 1178 had a preoperative cTnI level below 0.1ng/ml (group 1), 163 patients had a cTnI level between 0.11 and 1.5ng/ml (group 2), and 64 patients had a cTnI level above 1.5ng/ml (group 3). CTnI levels, electrocardiograms, clinical data, adverse events and in-hospital mortality were recorded prospectively. Patients with ST-elevation myocardial infarction less than 7 days before surgery were excluded from the study. RESULTS: Perioperative myocardial infarction (PMI) occurred in 69/1178 patients (5.9%) in group 1, 14/163 patients (8.6%; odds ratio (OR) 1.5, 95% confidence interval (CI): 0.8-2.8) in group 2, and 11/64 patients (17.2%; OR 3.3, CI: 1.6-7.0) in group 3 (overall: P<0.001, Cochran-Armitage trend test). Low cardiac output syndrome (LCOS) occurred in 19/1178 patients (1.6%), 9/163 (5.5%; OR 3.6, CI: 1.5-8.5), and 7/64 patients (10.9%; OR 7.5, CI: 2.7-19.8) (overall: P<0.001, group 1 vs. group 2: P<0.002), respectively. In-hospital mortality was 1.7% in group 1 and 3.1% in group 2, but 6.3% (OR 3.9, CI: 1.1-12.5) in group 3 (overall: P<0.01, group 1 vs. group 2: P=NS). Intensive care and hospital stay were significantly longer in group 3 compared to groups 1 and 2. Univariate and multivariate logistic regression analysis confirmed the statistically significant relationship between cTnI and PMI, LCOS and in-hospital mortality, respectively (P<0.001). CONCLUSIONS: Risk stratification by measurement of cTnI levels within 24h before elective CABG clearly identifies a subgroup of patients with increased risk for postoperative adverse outcome and in-hospital mortality.     

The influence of displacement on shoulder function in patients with minimally displaced fractures of the greater tuberosity

INTRODUCTION: There is little outcome data on functional results after non-operative treatment of greater tuberosity fractures, and no clear evidence in minimally displaced (1-5 mm) fractures of the greater tuberosity showing that the results of non-operative treatments are good enough. This study assesses the relationship between degree of displacement in non-operatively treated patients and shoulder function. MATERIALS AND METHODS: We evaluated the radiographs and function in 135 patients after non-operative treatment of minimally displaced (1-5 mm) fractures of the greater tuberosity at a mean time of 3.7 years (2-20 years) after injury. Shoulder function was assessed using the Vienna Shoulder Score (VSS), the Constant Score (CS) and the UCLA-Score. RESULTS: 97% of the evaluated patients had good or excellent results. Patients with a displacement of more than 3 mm had slightly worse results compared to those with less displacement, but this was not statistically significant. Female patients had significantly better results than male patients, and patients in the eighth and ninth decade had significantly worse results compared to younger patients. CONCLUSION: We recommend non-operative treatment in all patients with minimally displaced fractures of the greater tuberosity, as most obtain very good results. The best results followed treatment with Gilchrist bandages or Mitella slings for 3 weeks, followed by intensive rehabilitation.     

Carnosine as a protective factor in diabetic nephropathy: association with a leucine repeat of the carnosinase gene CNDP1

The risk of diabetic nephropathy is partially genetically determined. Diabetic nephropathy is linked to a gene locus on chromosome 18q22.3-q23. We aimed to identify the causative gene on chromosome 18 and to study the mechanism by which the product of this gene could be involved in the development of diabetic nephropathy. DNA polymorphisms were determined in 135 case (diabetic nephropathy) and 107 control (diabetes without nephropathy) subjects. The effect of carnosine on the production of extracellular matrix components and transforming growth factor-beta (TGF-beta) after exposure to 5 and 25 mmol/l d-glucose was studied in cultured human podocytes and mesangial cells, respectively. A trinucleotide repeat in exon 2 of the CNDP1 gene, coding for a leucine repeat in the leader peptide of the carnosinase-1 precursor, was associated with nephropathy. The shortest allelic form (CNDP1 Mannheim) was more common in the absence of nephropathy (P = 0.0028, odds ratio 2.56 [95% CI 1.36-4.84]) and was associated with lower serum carnosinase levels. Carnosine inhibited the increased production of fibronectin and collagen type VI in podocytes and the increased production of TGF-beta in mesangial cells induced by 25 mmol/l glucose. Diabetic patients with the CNDP1 Mannheim variant are less susceptible for nephropathy. Carnosine protects against the adverse effects of high glucose levels on renal cells.     

Effects of smoking on renal function in patients with type 1 and type 2 diabetes mellitus.

BACKGROUND: Smoking increases the risk of end-stage renal failure in patients with primary renal disease. Whether and to what extent smoking affects the kidneys in diabetic patients with normal renal function and variable degrees of proteinuria has not been fully studied. METHODS: We followed 185 patients with type 1 or 2 diabetes mellitus and with or without signs of overt renal disease for at least 3 years, median 5.1 (3-6.8) years. Each patient had a baseline visit and at least four follow-up visits (average 4.8+/-0.3). Cases were patients who were smoking (n = 44) at the time the survey was started. Controls were patients who had never smoked (n = 141). Glomerular filtration rate (GFR) was estimated using the MDRD formula. Multiple logistic regression was used to correct for confounding factors. RESULTS: At baseline, smokers were younger (47+/-14 vs 54+/-16 years, P < 0.01), and had a lower GFR (95+/-26 ml/min) than non-smokers (107+/-33 ml/min, P < 0.05). Mean GFR remained constant during follow-up in non-smokers (106+/-31 ml/min), but decreased significantly in smokers (83+/-22 ml/min, P < 0.0001), and this relationship persisted when adjusted for retinopathy, glycaemic control, age, body habitus, ACE-inhibitor treatment, blood pressure control or severity of proteinuria. The effect of smoking on GFR decline was stronger in patients with type 1 diabetes or male gender. CONCLUSIONS: Cigarette smoking causes a decrease in GFR in diabetic patients with normal or near-normal renal function, independent of confounding factors including severity of proteinuria. The latter finding suggests a mechanism independent of glomerular damage.     

Pelvic tilt compensates for increased acetabular anteversion

Purpose

Pelvic tilt determines functional orientation of the acetabulum. In this study, we investigated the interaction of pelvic tilt and functional acetabular anteversion (AA) in supine position.

Methods

Pelvic tilt and AA of 138 individuals were measured by computed tomography (CT). AA was calculated in relation to the anterior pelvic plane (APP) and relative to the table plane. We analysed these parameters for gender-specific and age-related differences.

Results

The mean pelvic tilt was -0.1?±?5.5°. Pelvic sagittal rotation displayed no gender nor age related differences. Females showed higher angles of AA compared with males (20.0° vs 17.2°, p?<?0.001; AA relative to the APP). Anterior tilting of the pelvis positively correlated with AA and individuals with high AA had a higher anterior pelvic tilt compared with those with low AA (p?<?0.0001; AA relative to the APP).

Conclusions

AA has to be calculated regarding pelvic sagittal rotation for correct acetabular orientation. Pelvic tilt is dependent on acetabular orientation and compensates for increased AA.

     

Head‐locking durability of fixed and variable angle locking screws under repetitive loading

Polyaxial locking screws are increasingly applied in fracture fixation. To investigate the durability of the head‐locking mechanism, the removal torque of variable angle (VA) and fixed angle (FA) stainless steel and titanium locking screws was investigated without and after a cyclic loading test. Stainless steel (St) and titanium (Ti) 2.4 mm orthogonally inserted FA screws and 2.4 mm VA screws inserted in different inclinations (0°–15°) (n = 6 per group) were locked at 0.8 Nm. Removal torque was determined without (W) and after (A) cyclic loading (sinusoidal load, 5 Hz, constant amplitude of 25 N, up to 10′000 cycles, or failure). Significant differences in‐between the groups were detected by Student's t‐test (p < 0.05). Except VA Ti in 0deg and FA, all groups exhibited a drop in removal torque below the insertion torque without and after cyclic testing. The removal torque was (St: FA W:0.81 Nm ± 0.04 A:0.72Nm ± 0.04; VA0deg W:0.73 Nm ± 0.04 A:0.65 Nm ± 0.05; VA15deg W:0.51 Nm ± 0.05 A:0.50 Nm ± 0.08; Ti: FA W:0.82 Nm ± 0.03 A:0.70 Nm ± 0.04; VA0deg W:0.80 Nm ± 0.02 A:0.72 Nm ± 0.05; VA15deg W:0.55 Nm ± 0.03 A:0.54 Nm ± 0.06). In all groups, the removal torque after cyclic testing did not drop below 16% of the removal torque without cyclic testing. No head loosening was observed after cyclic testing. Stainless steel and titanium 2.4 mm fixed and variable angle locking screws provide a stable and lasting head‐locking mechanism. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:949–952, 2016.     

18F-FDG-PET/CT to Select Patients with Peritoneal Carcinomatosis for Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Background

Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with significantly longer survival in patients with peritoneal carcinomatosis (PC). So far, no morphological imaging method has proven to accurately assess the intra-abdominal tumor spread. This study was designed to predict tumor load in patients with PC using dual-modality ¹⁸FDG-PET/CT and to compare the results with those of PET and CT alone by correlating imaging findings with intraoperative staging.

Methods

Twenty-two patients with PC from gastrointestinal (n = 13), ovarian cancer (n = 8), and mesothelioma (n = 1) underwent contrast-enhanced ¹⁸FDG-PET/CT before surgery and HIPEC. In a retrospective analysis PET, CT, and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the Peritoneal Cancer Index (PCI). Imaging results were correlated with the intraoperative PCI using Pearson’s correlation coefficient and linear regression analysis.

Results

There was a strong correlation between the PCI obtained with PET/CT and the surgical PCI with respect to the total score (r = 0.951) as well as in the regional analysis (small bowel, r = 0.838; other, r = 0.703). The correlation was slightly lower for CT alone (total score, r = 0.919; small bowel, r = 0.754; other, r = 0.666) and significantly lower (p = 0.002) for PET alone (total score, r = 0.793; small bowel, r = 0.553, other, 0.507).

Conclusions

Contrast-enhanced CT is superior compared with PET alone to predict the extent of PC. In our patient group, the combination of both modalities (contrast enhanced PET/CT) yielded the best results and proved to be a useful tool for selecting candidates for peritonectomy and HIPEC.