Katrijn Michielsen

Prenatal Anatomical Imaging in Fetuses with Congenital Diaphragmatic Hernia

The role of prenatal ultrasound and magnetic resonance imaging in the diagnosis and management of congenital diaphragmatic hernia (CDH) is reviewed. Topics include morphologic imaging and vascular assessment of the developing lung, the value of imaging parameters as prognostic predictors in CDH and the role of imaging following percutaneous fetoscopic endoluminal tracheal occlusion.

Chemoembolization for Hepatocellular Carcinoma: 1-Month Response Determined with Apparent Diffusion Coefficient Is an Independent Predictor of Outcome

PURPOSE To evaluate the predictive utility of apparent diffusion coefficient (ADC) changes at diffusion-weighted (DW) magnetic resonance (MR) imaging 1 month after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) compared with the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, European Association for the Study of the Liver (EASL) criteria, and modified RECIST (mRECIST). MATERIALS AND METHODS Institutional review board approval and informed consent were obtained for this prospective study. Thirty-eight patients with inoperable HCC underwent 1.5-T MR imaging, including DW imaging, before and 1 month after TACE. Responses 1 month after TACE were assessed with the ADC change relative to baseline (ADC ratio), RECIST, EASL criteria, and mRECIST. Eight patients underwent transplantation 4 months after TACE, allowing the association between response and histopathologic necrosis ratio to be determined. In 30 patients, Kaplan-Meier and log-rank tests were used to correlate the response variables with progression-free and overall survival. RESULTS Median progression-free survival (PFS) was 5 months, and overall survival was 17.5 months. Survival analyses showed significant effects of pretreatment α-fetoprotein level (P = .03) and ADC ratio (P < .0001) on PFS and substantial effects of mRECIST, RECIST, and EASL criteria (.05 < P < .1). ADC ratio was a significant predictor of 5-month PFS (P < .001), with an accuracy of 93.3% compared with 53.3% with mRECIST and EASL criteria and 66.7% with RECIST. No response variables correlated with overall survival. Only the ADC ratio was significantly associated with histopathologic tumor necrosis (P = .03). CONCLUSION The ADC ratio 1 month after TACE was an independent predictor of PFS, which showed stronger association with tumor response than did RECIST, EASL criteria, or mRECIST.

MR volumetry of the normal fetal kidney: reference values.

The aim of this study is to provide reference values for normal fetal kidney growth based on magnetic resonance (MR) volumetry. Differences in side and gender will be investigated.

Fetal cerebral blood flow velocities in congenital diaphragmatic hernia

Left ventricular cardiac output is decreased in fetuses with congenital diaphragmatic hernia (CDH). Our aim was to assess whether this alters cerebral perfusion or growth @ in utero.

Whole-body diffusion-weighted MRI for staging of women with cancer during pregnancy: a pilot study.

Methods Twenty patients diagnosed with cancer during pregnancy underwent WB-DWI additional to conventional imaging in this prospective single centre study. Reproducibility of WB-DWI between 2 readers was evaluated using Cohen’s statistics and accuracy was compared to conventional imaging for assessing primary tumour site, nodal metastases and visceral metastases. Histopathology after surgery or biopsy was the primary reference standard.

Feasibility of whole-body diffusion-weighted MRI for detection of primary tumour, nodal and distant metastases in women with cancer during pregnancy: a pilot study

ObjectivesTo evaluate the feasibility of whole-body diffusion-weighted MRI (WB-DWI/MRI) for detecting primary tumour, nodal and distant metastases in pregnant women with cancer.MethodsTwenty pregnant patients underwent WB-DWI/MRI in additional to conventional imaging. Reproducibility of WB-DWI/MRI between two readers was evaluated using Cohen’s κ statistics and accuracy was compared to conventional imaging for assessing primary tumour site, nodal and visceral metastases.ResultsBoth WB-DWI/MRI readers showed good–very good agreement for lesion detection (primary lesions: κ=1; lymph nodes: κ=0.89; distant metastases: κ=0.61). Eight (40 %) patients were upstaged after WB-DWI/MRI. For nodal metastases, WB-DWI/MRI showed 100 % (95 % CI: 83.2–100) sensitivity for both readers with specificity of 99.4 % (96.9–100) and 100 % (80.5–100) for readers 1 and 2, respectively. For distant metastases, WB-DWI/MRI showed 66.7 % (9.4–99.2) and 100 % (29.2–100) sensitivity and specificity of 94.1 % (71.3–99.9) and 100 % (80.5–100) for readers 1 and 2, respectively. Conventional imaging showed sensitivity of 50 % (27.2-72.8) and 33.3 % (0.8–90.6); specificity of 100 % (98–100) and 100 % (80.5–100), for nodal and distant metastases respectively.ConclusionsWB-DWI/MRI is feasible for single-step non-invasive staging of cancer during pregnancy with additional value for conventional imaging procedures.Key points• In our study, WB-DWI/MRI was more accurate than conventional imaging during pregnancy.• WB-DWI/MRI improves diagnostic assessment of patients with cancer during pregnancy.• Accurate imaging and oncologic staging improves treatment and outcome.

Value of pretreatment MRI determined parameters for predicting outcome after radio-frequency ablation of hepatocellular carcinoma

Methods Thirty-seven patients with HCC treated by RFA were evaluated. Lesion number, size and segmental location, T2-weighted (w), arterial, portal-venous and venous contrast-phase, b600 diffusion-w imaging (DWI) and delayed phase contrast-enhanced imaging pattern were assessed at MRI. The separate imaging patterns as well as pretreatment clinical variables were correlated with outcome (disease free survival longer or shorter than 1 year) using a chi-square test with multiple variables and Mann-Whitney U test respectively. Pretreatment clinical variables and imaging parameters were correlated with Keratin 19 and microvascular invasion status at the biopsy during RFA.

Tumour characterisation, staging and operability assessment in ovarian carcinoma: whole body diffusion-weighted MRI versus CT

Methods One-hundred-sixty-six patients suspected for ovarian carcinoma underwent 3T WB-DWI/MRI using 2 b-values (b=0-1000 s/mm), T2-weighted and contrast-enhanced T1-weighted sequences in addition to contrast-enhanced CT. WB-DWI/MRI and CT were independently and blindly evaluated and correlated with pathological findings at surgery as reference standard. Superiority was assessed using two-tailed McNemar tests for following parameters: characterisation of the malignant nature and primary origin of the ovarian mass, assessment of disease extent according to FIGO stage and prediction of R0-resection according to predefined operability criteria. Inter observer agreement for WB-DWI/MRI and CT was determined using Cohen’s kappa statistics.

Pre-treatment ADC histogram-analysis at whole body diffusion-weighted MRI predicts disease free survival in ovarian cancer.

Methods Institutional review board approval and informed consent were obtained for this prospective study. Forty-four women diagnosed with FIGO stage III or IV ovarian carcinoma underwent 3-Tesla WB-DWI/MRI using 2 b-values (b=0-1000 s/mm), T2-weighted and contrast-enhanced T1-weighted sequences prior to treatment. The primary tumour was delineated using semi-automated software and was analysed by using an ADC histogram approach: mean and median ADC, standard deviation (SD), coefficient of variation (CoV, SD/mean), kurtosis and skewness were calculated. Kaplan-Meier with log-rank statistics were used to correlate baseline ADC parameters to disease free survival (DFS). Effects of confounding patientsand tumour-related factors were taken into consideration using Cox proportional hazard model.

Whole-body diffusion-weighted MRI versus CT for detection, restaging and operability assessment of recurrent ovarian carcinoma

Methods Fifty-one women suspected for recurrent ovarian cancer underwent 3-Tesla WB-DWI/MRI using 2 b-values (b=0-1000 s/mm2), T2and contrast T1-weighted sequences in addition to CT. WB-DWI/MRI and CT were compared for per-patient detection of recurrence, per-site detection of disease extent including peritoneal, serosal, retroperitoneal, periportal and distant metastases and for detecting disease extent according to institutional operability criteria. Imaging findings were correlated with surgical/pathological findings or imaging follow-up for at least 6 months.