A case report: septic shock due to (tropical) pyomyositis and multiple metastatic embolisms caused by Panton Valentine Leukocidin-positive methicillin-sensitive staphylococcus aureus in a 12-year-old boy.

CASE REPORT: A 12-year-old boy, of Congolese roots and without medical history, first presented to our Emergency Department 3 days after blunt trauma of the left ankle. The boy represented on two more occasions in the next 3 days due to ongoing pain. On the last occasion he presented with severe hypoglycaemia. He was diagnosed with severe septic shock, secondary to subperiosteal abscess formation / osteomyelitis of the ankle. The patient was transferred to the paediatric intensive care unit where appropriate medical care was provided, including broad-spectrum antibiotic therapy, high dose vasopressor / inotropic support, surgical debridement of abscesses and below-knee amputation. PANTON VALENTINE LEUKOCIDIN TOXIN AND PYOMYOSITIS TROPICALIS: The causative organism was a methicillin-susceptible S. aureus, which upon further identification was a carrier of the PVL (Panton Valentine leukocidin) toxin. This pathogen is responsible for severe musculoskeletal infections. In children these infections are often associated with more severe clinical course requiring a higher need for surgical intervention and longer hospital stay.Tropical pyomyositis is a disease caused by Staphylococcus aureus, often seen in tropical countries, and classically presented with muscle abscesses. Young males between the ages of 10-40 years old are the most susceptible, and often present with a history of blunt trauma. Treatment generally requires a combination of an anti-staphylococcal agent, and an anti-toxic agent blocking bacterial protein-synthesis of PVL. Source control by surgical debridement also plays a major role in the treatment of PVL-infection. Despite agressive treatment, mortality still varies from 0.5% to 2%.

Long-term outcome of pre- and perinatal management of congenital head and neck tumors and malformations.

INTRODUCTION: Congenital head and neck pathology may cause direct postnatal airway obstruction. Prenatal diagnosis facilitates safe delivery with pre- and perinatal airway assessment and management and Ex-Utero-Intrapartum-Treatment (EXIT) if necessary. Fetoscopic airway evaluation can optimize the selection of patients in need of an EXIT procedure. METHODS: Description of 11 consecutive fetuses, born with a potential airway obstruction between 1999 and 2011 and treated at the University Hospitals Leuven, with a long-term follow-up until 2018. An algorithm including fetoscopic airway evaluation is presented. RESULTS: In utero imaging revealed seven teratomas, one fourth branchial pouch cyst, one thymopharyngeal duct remnant, one lymphatic malformation and one laryngeal atresia. A multidisciplinary team could avoid EXIT in eight patients by ultrasonographic (n = 2) or fetoscopic (n = 6) documentation of accessible airways. Three patients needed an EXIT-to-airway-procedure. Neonatal surgery included tracheostomy during EXIT (n = 2) and resection of teratoma (n = 7) or branchiogenic pathology (n = 3). All patients do well at long-term (minimum 54 months) follow-up. CONCLUSIONS: Combining prenatal imaging and perinatal fetoscopy, EXIT-procedure and neonatal surgery yields an optimal long-term outcome in these complex patients. Fetoscopy can dramatically reduce the number of EXIT-procedures.

Congenital cytomegalovirus infection: contribution and best timing of prenatal MR imaging.

OBJECTIVE: To predict sensorineural hearing loss (SNHL) and neurological impairment in congenital cytomegalovirus (cCMV) infection using MR imaging and define the best timing in pregnancy for prenatal assessment. METHODS: In 121 patients with confirmed cCMV infection, brain features at MR imaging were respectively graded from 1 to 5: normal; isolated frontal/parieto-occipital hyperintensity; temporal periventricular hyperintensity; temporal/occipital cysts and/or intraventricular septa; migration disorders. Grading was correlated with postnatal SNHL and neurological impairment using regression analysis. In 51 fetuses with MR examinations at 26.9 and 33.0 weeks, the predictive value of SNHL and neurological impairment was compared using ROC curves. RESULTS: Postnatal follow-up showed SNHL in 18 infants and neurological impairment in 10. MR grading was predictive of SNHL and of neurological impairment (P < 0.001). In grade 1 or 2, none had SNHL and 1/74 had neurological impairment. The areas under ROC curves for prediction of postnatal SNHL and of neurological impairment from first and second MR examination were comparable. CONCLUSION: Our data suggest that in cCMV infection, prediction of SNHL and neurological impairment is feasible by fetal MR imaging with a high negative predictive value and can equally be done at 27 or 33 weeks of gestation. KEY POINTS: • In cCMV, isolated periventricular T2-weighted signal hyperintensity has a good postnatal prognosis. • In cCMV, SNHL and neurological impairment can be predicted at 27 or 33 weeks. • In cCMV, fetal MR has a high NPV in predicting SNHL. • In cCMV, fetal MR has a high NPV in predicting neurological impairment.

Ischemic Strangulation of a Giant Epiploic Appendage through an Omental Defect: a Case Report.

We report a rare case of an epiploic appendage twisted through an omental defect, resulting in an epiploic appendagitis at a distance to the colonic wall. The 59-year-old women complained of low abdominal pain and alguria, progressively increasing following a total colonoscopy 4 days earlier.

High-Resolution (1)H NMR Spectroscopy Discriminates Amniotic Fluid of Fetuses with Congenital Diaphragmatic Hernia from Healthy Controls.

Lung hypoplasia in congenital diaphragmatic hernia (CDH) is a life-threatening birth defect. Severe cases can be offered tracheal occlusion to boost prenatal lung development, although defining those to benefit remains challenging. Metabonomics of (1)H NMR spectra collected from amniotic fluid (AF) can identify general changes in diseased versus healthy fetuses. AF embodies lung secretions and hence might contain pulmonary next to general markers of disease in CDH fetuses. AF from 81 healthy and 22 CDH fetuses was collected. NMR spectroscopy was performed at 400 MHz to compare AF from fetuses with CDH against controls. Several advanced feature extraction methods based on statistical tests that explore spectral variability, similarity, and dissimilarity were applied and compared. This resulted in the identification of 30 spectral regions, which accounted for 80% variability between CDH and controls. Combination with automated classification discriminates AF from CDH versus healthy fetuses with up to 92% accuracy. Within the identified spectral regions, isoleucine, leucine, valine, pyruvate, GABA, glutamate, glutamine, citrate, creatine, creatinine, taurine, and glucose were the most concentrated metabolites. As the metabolite pattern of AF changes with fetal development, we have excluded metabolites with a high age-related variability and repeated the analysis with 12 spectral regions, which has resulted in similar classification accuracy. From this analysis, it was possible to distinguish between AF from CDH fetuses versus healthy controls independent of gestational age.

In vivo evidence by magnetic resonance volumetry of a gestational age dependent response to tracheal occlusion for congenital diaphragmatic hernia.

OBJECTIVE: We aimed to assess in vivo changes in lung and liver volumes in fetuses with isolated congenital diaphragmatic hernia, either expectantly managed or treated in utero. METHOD: This is a secondary analysis of prospectively collected data at two fetal therapy centers. We used archived magnetic resonance images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second magnetic resonance prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio. We calculated changes in volume as compared with the initial measurement and its rate as a function of gestational age (GA) at occlusion. RESULTS: The liver-to-thoracic volume ratio did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion, the measured increase in volume was 2.6 times larger with balloon in place as compared with that after its removal. GA at tracheal occlusion was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5% per week by 35 to 45 days after occlusion. CONCLUSIONS: Tracheal occlusion induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion.

Termination of pregnancy for renal malformations.

BACKGROUND: We studied the correlation between prenatal diagnosis and postmortem investigations in pregnancies terminated for renal malformations. METHODS: Over a 5-year period, 77 cases of termination of pregnancy (TOP) for renal malformations were reviewed. Chromosomal anomalies (n = 9) and cases without conventional or virtual autopsy were excluded (n = 15). In 53 cases, prenatal ultrasound diagnosis and conventional autopsy findings were compared. In addition, we compared the accuracy of conventional and virtual autopsy findings in 17 cases. RESULTS: Full agreement was observed in 60.4% (32/53) of cases. In 26.4% (14/53) of the cases, the presence of additional malformations did not alter the final diagnosis. However, in 11.3% (6/53) the final diagnosis was adjusted because of major additional findings. One case showed a total disagreement. Conventional and virtual autopsy were in full agreement in 52.9% (9/17). Postmortem magnetic resonance imaging (MRI) description and detection of malformations was less complete and failed to correctly diagnose 5/17 cases (29.4%). In 17.6% (3/17) of the cases, postmortem MRI revealed malformations not confirmed by conventional autopsy. CONCLUSIONS: A high correlation between prenatal ultrasound and postmortem investigations was observed. Conventional autopsy remains the gold standard to reveal additional major and minor malformations, leading to a correct final diagnosis. The added value of virtual necropsy for renal pathology was limited.

Three-dimensional analysis of implanted magnetic-resonance-visible meshes.

OBJECTIVE: Our primary objective was to develop relevant algorithms for quantification of mesh position and 3D shape in magnetic resonance (MR) images. METHODS: In this proof-of-principle study, one patient with severe anterior vaginal wall prolapse was implanted with an MR-visible mesh. High-resolution MR images of the pelvis were acquired 6 weeks and 8 months postsurgery. 3D models were created using semiautomatic segmentation techniques. Conformational changes were recorded quantitatively using part-comparison analysis. An ellipticity measure is proposed to record longitudinal conformational changes in the mesh arms. The surface that is the effective reinforcement provided by the mesh is calculated using a novel methodology. The area of this surface is the effective support area (ESA). RESULTS: MR-visible mesh was clearly outlined in the images, which allowed us to longitudinally quantify mesh configuration between 6 weeks and 8 months after implantation. No significant changes were found in mesh position, effective support area, conformation of the mesh's main body, and arm length during the period of observation. Ellipticity profiles show longitudinal conformational changes in posterior arms. CONCLUSIONS: This paper proposes novel methodologies for a systematic 3D assessment of the position and morphology of MR-visible meshes. A novel semiautomatic tool was developed to calculate the effective area of support provided by the mesh, a potentially clinically important parameter.

Incidence of bowel wall oedema on computed tomography exams and association with diarrhoea in renal cell carcinoma patients treated with sunitinib.

OBJECTIVES: The purpose of this study was to retrospectively assess the incidence of bowel wall oedema on computed tomography (CT) in patients with renal cell carcinoma (RCC) treated with sunitinib, and to investigate its association with diarrhoea. METHODS: We conducted a retrospective analysis of all RCC patients treated with sunitinib at our hospital between December 2005 and December 2011. The presence or absence of bowel wall oedema on these CT examinations was scored. The presence of diarrhoea preceding, during, or after sunitinib treatment was identified from the patient files and retrospectively graded. RESULTS: For 54 of 87 patients, bowel wall oedema was present on at least one CT examination. Of these 54 patients, the right-sided colonic segment was affected in 87%. Diarrhoea was the most common reported adverse event during treatment, with 58 patients (67%) having grade 1/2 diarrhoea and 9 patients (10%) having grade 3. There was a statistically significant correlation between the incidence of CT-scored bowel oedema and diarrhoea during sunitinib treatment (P = 0.004). CONCLUSIONS: This study shows a very high incidence of bowel wall oedema and a strong correlation between the incidence of bowel wall oedema and diarrhoea in patients treated with sunitinib. KEY POINTS: • Sunitinib is routinely used in patients with advanced renal cell carcinoma. • Diarrhoea is the most common reported adverse event during sunitinib treatment. • Incidence of bowel oedema and diarrhoea during sunitinib treatment is correlated. • Radiologists should avoid misinterpretation of bowel oedema as infectious colitis.

Mesh contraction: in vivo documentation of changes in apparent surface area utilizing meshes visible on magnetic resonance imaging in the rabbit abdominal wall model.

INTRODUCTION AND HYPOTHESIS: Our aim was to analyze the apparent contraction of meshes in vivo after abdominal wall reconstruction and evaluate histological and biomechanical properties after explantation. METHODS: Nine New Zealand female rabbits underwent repair of two full-thickness 25 × 30-mm midline defects in the upper and lower parts of the abdomen. These were primarily overlaid by 35 × 40-mm implants of a polyvinylidene fluoride (PVDF) DynaMesh (n = 6) or polypropylene meshes Ultrapro (n = 6) and Marlex (n = 6). Edges of the meshes were secured with iron(II,III) oxide (Fe(3)O(4))-loaded PVDF sutures. Magnetic resonance images (MRIs) were taken at days 2, 30 and 90 after implantation. The perimeter of the mesh was traced using a 3D spline curve. The apparent surface area or the area within the PVDF sutures was compared with the initial size using the one-sample t test. A two-way repeat analysis of variance (ANOVA) was used to compare the apparent surface area over time and between groups. RESULTS: PVDF meshes and sutures with Fe(3)O(4) could be well visualized on MRI. DynaMesh and Marlex each had a 17 % decrease in apparent surface area by day 2 (p < 0.001 and p = 0.001), respectively, which persisted after day 90. Whereas there was a decrease in apparent surface area in Ultrapro, it did not reach significance until day 90 (p = 0.01). Overall, the apparent surface area decreased 21 % in all meshes by day 90. No differences in histological or biomechanical properties were observed at day 90. CONCLUSIONS: There was a reduction in the apparent surface area between implantation and day 2, indicating that most mesh deformation occurs prior to tissue in-growth.

Fetal heart pathology on postmortem 3-T magnetic resonance imaging.

INTRODUCTION: Postmortem magnetic resonance imaging (pmMRI) is increasingly used in perinatology, typically as an alternative or complement to conventional necropsy for central nervous system anomalies. Overall, it provides reliable information on structural malformations but was shown to be of limited use in examining the fetal heart. OBJECTIVE: We aimed to assess the fetal heart on 3-T pmMRI in a consecutive series of fetuses with structural congenital heart defects (CHD) and to determine diagnostic evaluation limits in case of CHD. METHODS: A single-center database was retrospectively reviewed. Only fetuses having CHD of functional significance were included. Fetal cardiac anatomy was assessed on T2-weighted 3D multiplanar reconstructed images acquired using isovolumetric voxel size (0.3-0.8 mm(3) ), which allows to visualize cardiac structures in situ in multiple fetal body planes. Cardiac pathology was classified into complex and isolated CHD. On the basis of clinically relevant findings, pmMRI was considered either diagnostic or not diagnostic. RESULTS: A total of 24 fetuses were included in this study. The median gestational age was 22 weeks and 2 days (range 12w5d-34w6d). The median delay between delivery of the fetus and MR was 6 h and 30 min (range 1 h and 30 min-19 h). PmMRI was diagnostic for 12 out of 13 (92.3%) complex CHD and for 6 out of 11 (54.5%) isolated CHD. In case of valvular malformation, a tentative diagnosis was reached in 7/11 cases (64%) on the basis of indirect features. CONCLUSIONS: Postmortem MRI is a valid diagnostic tool for CHD in fetuses beyond 16 weeks up to term.

A pictorial essay on fetal rabbit anatomy using micro-ultrasound and magnetic resonance imaging.

INTRODUCTION: With this pictorial essay, we aimed to provide gestational age specific reference ranges of relevant fetal structures using micro-ultrasound, as well as its correlation with postmortem MRI and whole body sections. MATERIAL AND METHODS: Time-mated pregnant rabbits (n = 24) were assessed once at various gestational ages in the second half of pregnancy (15, 17, 21 to 23, 25 to 28, and 30 to 31 days; term = 31 days). We obtained biometric data, together with Doppler flow patterns in the ductus venosus, umbilical artery and umbilical vein. After euthanasia, micro-ultrasound images were compared with images obtained by 9.4 Tesla MRI and whole body paraffin sections at 15, 23, 26, and 28 days. RESULTS: We constructed biometric normative curves, which showed a significant correlation with gestational age. The pulsatility index (PI) in the umbilical artery decreased with gestation (PI = 5.746-0.2969(GA) + 0.004931(GA)(2) ; R(2) = 0.30), whereas pulsatility index for veins (PIV) in the ductus venosus remained constant (median PIV = 0.82 (0.60-1.12)). In this report, we provide an anatomical atlas of fetal thoracic development using both micro-ultrasound and MRI. CONCLUSION: We describe anatomical fetal leporine development as can be visualized by micro-ultrasound and MR imaging. The reported reference ranges may be useful for researchers using the fetal rabbit model.

Calculation of membrane tension in selected sections of the pelvic floor.

INTRODUCTION AND HYPOTHESIS: A mathematical model to estimate membrane tensions (Mt) at the urogenital hiatus and midpelvis in patients with and without prolapse is proposed. For that purpose the complex structures of the pelvic floor were simplified and, based on assumptions concerning geometry and loading conditions, Laplace's law was used to calculate Mt. The pelvic cavity is represented by an ellipsoid in which the midpelvic and hiatal sections are described by an ellipse. The downwards forces within the pelvis (F(in)) are in equilibrium with the support forces within its walls (F(w)). F(in) is the abdominal pressure (PABD) multiplied by the area A of the ellipse. The force inside the tissues (F(w)) is distributed along the circumference of the ellipse C. The Mt can be approximated as Mt = (PABD.A)/C (N/m). Mt-α accounts for the angle α which describes tissue orientation with respect to the anatomical section and is calculated as Mt-α = Mt/sin(α). METHODS: We conducted a retrospective study on archived magnetic resonance imaging scans (n = 20) and ultrasound images in patients with (n = 50) or without prolapse (n = 50) and measured actual geometrical variables. PABD was measured in patients with and without prolapse (n = 20). RESULTS: Mt at the urogenital hiatus at rest is 0.35 N/cm. They significantly increase with the Valsalva manoeuvre, by a factor of 2.3 (without prolapse) to 3.6 (with prolapse). CONCLUSIONS: Calculated Mt are much lower than what is reported for the abdominal cavity. Prolapse patients have significantly larger Mt, which during the Valsalva manoeuvre increase more than in healthy subjects.

Intrarenal resistive index after renal transplantation.

BACKGROUND: The intrarenal resistive index is routinely measured in many renal-transplantation centers for assessment of renal-allograft status, although the value of the resistive index remains unclear. METHODS: In a single-center, prospective study involving 321 renal-allograft recipients, we measured the resistive index at baseline, at the time of protocol-specified renal-allograft biopsies (3, 12, and 24 months after transplantation), and at the time of biopsies performed because of graft dysfunction. A total of 1124 renal-allograft resistive-index measurements were included in the analysis. All patients were followed for at least 4.5 years after transplantation. RESULTS: Allograft recipients with a resistive index of at least 0.80 had higher mortality than those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 5.20 [95% confidence interval {CI}, 2.14 to 12.64; P<0.001]; 3.46 [95% CI, 1.39 to 8.56; P=0.007]; and 4.12 [95% CI, 1.26 to 13.45; P=0.02], respectively). The need for dialysis did not differ significantly between patients with a resistive index of at least 0.80 and those with a resistive index of less than 0.80 at 3, 12, and 24 months after transplantation (hazard ratio, 1.95 [95% CI, 0.39 to 9.82; P=0.42]; 0.44 [95% CI, 0.05 to 3.72; P=0.45]; and 1.34 [95% CI, 0.20 to 8.82; P=0.76], respectively). At protocol-specified biopsy time points, the resistive index was not associated with renal-allograft histologic features. Older recipient age was the strongest determinant of a higher resistive index (P<0.001). At the time of biopsies performed because of graft dysfunction, antibody-mediated rejection or acute tubular necrosis, as compared with normal biopsy results, was associated with a higher resistive index (0.87 ± 0.12 vs. 0.78 ± 0.14 [P=0.05], and 0.86 ± 0.09 vs. 0.78 ± 0.14 [P=0.007], respectively). CONCLUSIONS: The resistive index, routinely measured at predefined time points after transplantation, reflects characteristics of the recipient but not those of the graft. (ClinicalTrials.gov number, NCT01879124 .).

18F-MK-9470 PET imaging of the type 1 cannabinoid receptor in prostate carcinoma: a pilot study.

BACKGROUND: Preclinical and histological data show overexpression of the type 1 cannabinoid receptor (CB1R) in prostate carcinoma (PCa). In a prospective study, the feasibility of 18F-MK-9470 positron emission tomography (PET) imaging in patients with primary and metastatic PCa was evaluated. METHODS: Eight patients were included and underwent 18F-MK-9470 PET/CT imaging. For five patients with primary PCa, dynamic PET/CT imaging was performed over three acquisition intervals (0 to 30, 60 to 90 and 120 to 150 min post-injection). In malignant and benign prostate tissue regions, time activity curves of the mean standardized uptake value (SUVmean) were determined as well as the corresponding area under the curve to compare 18F-MK-9470 uptake over time. Muscle uptake of 18F-MK-9470 was used as reference for non-specific binding. Magnetic resonance imaging (MRI) was used as anatomical reference and for delineating intraprostatic tumours. Histological and immunohistochemical (IHC) examination was performed on the whole-mount histopathology sections of four patients who underwent radical prostatectomy to assess the MRI-based tumour versus benign tissue classification. For three patients with proven advanced metastatic disease, two static PET/CTs were performed 1 and 3 h post-injection. 18F-MK-9470 uptake was evaluated in bone lesions of metastatic PCa by comparing SUVmean values of metastases with these of the contralateral bone tissue. RESULTS: 18F-MK-9470 uptake was significantly higher in benign and malignant prostate tissue compared to muscle, but it did not differ between both prostate tissue compartments. IHC findings of corresponding prostatic histopathological sections indicated weak CB1R expression in locally confined PCa, which was not visualized with 18F-MK-9470 PET. Metastases in the axial skeleton could not be detected while some metastases in the appendicular skeleton showed higher 18F-MK-9470 uptake as compared to the uptake in contralateral normal bone. CONCLUSIONS: 18F-MK-9470 PET could not detect local PCa or bone metastases in the axial skeleton but was able to visualize metastases in the appendicular skeleton. Based on these pilot observations, it seems unlikely that CB1R PET will play a significant role in the evaluation of PCa.

Postmortem high-resolution fetal magnetic resonance imaging in three cases of lower urinary tract obstruction.

In this manuscript we report 3 cases of severe lower urinary tract obstruction diagnosed before 20 weeks of pregnancy. All cases had a very similar prenatal presentation with a megacystis, bilateral hydro-ureteronephrosis and increased echogenicity of the kidneys. High-resolution postmortem magnetic resonance imaging (MRI), following termination of pregnancy, enabled accurate investigation of the underlying cause of the urinary tract obstruction, by depicting the presence of an urethral valve, urethral atresia and cloacal dysgenesis. Postmortem fetal MRI provides high anatomical detail and is very suitable to investigate congenital anomalies of the lower urinary tract. In case (timely or consented) conventional autopsy is not possible, MRI is an excellent alternative.

A morphometric study of the human fetal heart on post-mortem 3-tesla magnetic resonance imaging.

OBJECTIVE: To report on the feasibility of assessing cardiac structures on post-mortem 3-tesla MRI (pmMRI) and to provide morphometric data in fetuses without cardiac abnormalities. METHODS: Retrospective single center study on 3T pmMRI of 39 consecutive fetuses without cardiac abnormalities (13-38 weeks of gestation). Fetal cardiac anatomy was assessed and measurements of cardiac structures were performed on T2-weighted 3D multiplanar reconstructed images. Linear regression analysis was performed to examine changes of cardiac dimensions during gestation. RESULTS: The four-chamber view of the fetal heart could be obtained and the measurements of cardiac chambers and ventricular walls could be performed in all 39 cases. The aorta and the pulmonary artery were visualized and their diameters were measured in 38 (97.4%) fetuses, ductus arteriosus in 32 (82%). All measurements showed strong linear correlation with gestational age. The relationship of the diameters of the pulmonary artery, aorta, and ductus arteriosus remained constant over pregnancy. All these observations are consistent with what is known from prenatal ultrasound. CONCLUSIONS: The present study proves the feasibility of visualizing normal cardiac structures on 3-tesla pmMRI in fetuses beyond 14 weeks. We provide morphometric data that may enable diagnostic evaluation of cardiac abnormalities on pmMRI.

Prenatal diagnosis of MPPH syndrome.

We report the prenatal sonographic detection of a fetus with megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly. Only 14 patients have been reported in the literature so far, all but one were diagnosed postnatally. The polymicrogyria in the frontoparietal lobe was confirmed by prenatal magnetic resonance imaging. Additionally, a hypoplastic thymus as seen in a 22q11 deletion was present. Although polymicrogyria along with pre-axial polydactyly has been described in 22q11 deletion, the diagnosis of Di George syndrome was ruled out. The etiology of megalencephaly, polymicrogyria, postaxial polydactyly and hydrocephaly has not been revealed yet. A dominant as well as recessive inheritance has been suggested.

Tumour-related imaging parameters predicting the percentage of preserved normal renal parenchyma following nephron sparing surgery: a retrospective study.

OBJECTIVES: To examine pre-operative imaging parameters that predict the residual amount of healthy renal parenchyma after nephron sparing surgery (NSS) for renal tumours, as this can help stratify patients towards the optimal surgical choice. METHODS: Ninety-eight patients with the diagnosis of a solitary unilateral renal tumour and with pre- and post-operative imaging were included in this retrospective study. Imaging, patient and surgical parameters were acquired and their correlation to the percentage decrease of healthy renal parenchyma following surgery was statistically examined to find the most significant predictor of nephron sparing. RESULTS: Loss of healthy renal parenchyma was highest in patients with renal sinus tumour involvement (P = 0.003) and anterior tumours (P = 0.006), but not significantly correlated with medial/lateral location (P = 0.940) or exophytic/endophytic tumour growth (P = 0.244). The correlation of tumour size with the percentage of parenchymal sparing did not quite reach statistical significance (P = 0.053), but involvement of the urinary collecting system (P = 0.008) was a very good predictor of complications. Loss of healthy renal parenchyma was higher in patients with high-grade surgical complications (P = 0.001). CONCLUSIONS: Several pre-operative parameters correlate to percentage nephron sparing after NSS. Anterior tumour location and renal sinus involvement proved to be the best predictors of loss of healthy renal parenchyma.

Correlation of free-response and receiver-operating-characteristic area-under-the-curve estimates: results from independently conducted FROC∕ROC studies in mammography.

PURPOSE: From independently conducted free-response receiver operating characteristic (FROC) and receiver operating characteristic (ROC) experiments, to study fixed-reader associations between three estimators: the area under the alternative FROC (AFROC) curve computed from FROC data, the area under the ROC curve computed from FROC highest rating data, and the area under the ROC curve computed from confidence-of-disease ratings. METHODS: Two hundred mammograms, 100 of which were abnormal, were processed by two image-processing algorithms and interpreted by four radiologists under the FROC paradigm. From the FROC data, inferred-ROC data were derived, using the highest rating assumption. Eighteen months afterwards, the images were interpreted by the same radiologists under the conventional ROC paradigm; conventional-ROC data (in contrast to inferred-ROC data) were obtained. FROC and ROC (inferred, conventional) data were analyzed using the nonparametric area-under-the-curve (AUC), (AFROC and ROC curve, respectively). Pearson correlation was used to quantify the degree of association between the modality-specific AUC indices and standard errors were computed using the bootstrap-after-bootstrap method. The magnitude of the correlations was assessed by comparison with computed Obuchowski-Rockette fixed reader correlations. RESULTS: Average Pearson correlations (with 95% confidence intervals in square brackets) were: Corr(FROC, inferred ROC) = 0.76[0.64, 0.84] > Corr(inferred ROC, conventional ROC) = 0.40[0.18, 0.58] > Corr (FROC, conventional ROC) = 0.32[0.16, 0.46]. CONCLUSIONS: Correlation between FROC and inferred-ROC data AUC estimates was high. Correlation between inferred- and conventional-ROC AUC was similar to the correlation between two modalities for a single reader using one estimation method, suggesting that the highest rating assumption might be questionable.