Impact of body composition and physical strength changes during chemoradiotherapy on complications and survival after oesophagectomy.

BACKGROUND: The aim of this study was to assess body composition and physical strength changes during neoadjuvant chemoradiotherapy (nCRT) and assess their predictive value for (severe) postoperative complications and overall survival in patients who underwent oesophagectomy for oesophageal cancer. METHODS: Consecutive patients who underwent nCRT and oesophagectomy with curative intent in a tertiary referral center were included in the study. Perioperative data were collected in a prospectively maintained database. The CT images before and after nCRT were used to assess skeletal muscle index (SMI), subcutaneous fat index (SFI), and visceral fat index (VFI). To assess physical strength, handgrip strength (HGS) and the exercise capacity of the steep ramp test (SRT Wpeak) were acquired before and after nCRT. RESULTS: Between 2015 and 2020, 126 patients were included. SMI increased in female subgroups and decreased in male subgroups (35.38 to35.60 cm2/m2 for females, P value 0.048, 46.89 to 45.34 cm2/m2 for males, P value < 0.001). No significant changes in SFI, VFI, HGS, and SRT Wpeak were observed. No predictive value of changes in SMI, HGS, and SRT Wpeak was shown for (severe) postoperative complications and overall survival. CONCLUSIONS: A significant but minimal decrease in SMI during nCRT was observed for males only, it was not associated with postoperative complications or overall survival. Physical strength measurements did not decrease significantly over the course of nCRT. No associations with postoperative complications or overall survival were observed.

Deep learning body-composition analysis of clinically acquired CT-scans estimates creatinine excretion with high accuracy in patients and healthy individuals.

Assessment of daily creatinine production and excretion plays a crucial role in the estimation of renal function. Creatinine excretion is estimated by creatinine excretion equations and implicitly in eGFR equations like MDRD and CKD-EPI. These equations are however unreliable in patients with aberrant body composition. In this study we developed and validated equations estimating creatinine production using deep learning body-composition analysis of clinically acquired CT-scans. We retrospectively included patients in our center that received any CT-scan including the abdomen and had a 24-h urine collection within 2 weeks of the scan (n = 636). To validate the equations in healthy individuals, we included a kidney donor dataset (n = 287). We used a deep learning algorithm to segment muscle and fat at the 3rd lumbar vertebra, calculate surface areas and extract radiomics parameters. Two equations for CT-based estimate of RenAl FuncTion (CRAFT 1 including CT parameters, age, weight, and stature and CRAFT 2 excluding weight and stature) were developed and compared to the Cockcroft-Gault and the Ix equations. CRAFT1 and CRAFT 2 were both unbiased (MPE = 0.18 and 0.16 mmol/day, respectively) and accurate (RMSE = 2.68 and 2.78 mmol/day, respectively) in the patient dataset and were more accurate than the Ix (RMSE = 3.46 mmol/day) and Cockcroft-Gault equation (RMSE = 3.52 mmol/day). In healthy kidney donors, CRAFT 1 and CRAFT 2 remained unbiased (MPE = - 0.71 and - 0.73 mmol/day respectively) and accurate (RMSE = 1.86 and 1.97 mmol/day, respectively). Deep learning-based extraction of body-composition parameters from abdominal CT-scans can be used to reliably estimate creatinine production in both patients as well as healthy individuals. The presented algorithm can improve the estimation of renal function in patients who have recently had a CT scan. The proposed methods provide an improved estimation of renal function that is fully automatic and can be readily implemented in routine clinical practice.

[Are The Netherlands ready for personalized breast cancer screening? Abbreviated breast MRI and contrast-enhanced mammography for screening in women with dense breasts]. / Is Nederland klaar voor gepersonaliseerde borstkankerscreening?

One-size-fits-all breast cancer screening no longer reflects the current state of knowledge and technology. 8% of the participants in the Dutch Breastcancer Screening Program have extremely dense breasts, which is coupled to a strongly increased risk of breast cancer. In addition, for this group of approximately 80,000 women per year, mammography is only 60% sensitive. The DENSE trial showed that supplemental MRI after a negative mammogram reduced the number of interval cancers by more than 80%. The Dutch Health Council however subsequently recommended to consider contrast-enhanced mammography (CEM) as a screening tool. At the request of the Ministry of Health-Welfare and Sport, simultaneous research is being set up to study both CEM and the introduction of CEM and "accelerated" (abbreviated) MRI. This article explains the differences between the two techniques and discusses the role both could play in screening this large group of women when politicians give green light.

Proton MRS of cervical cancer at 7 T.

The differentiation grade of cervical cancer is histologically assessed by examining biopsies or surgical specimens. MRS is a highly sensitive technique that images tissue metabolism and can be used to increase the specificity of tissue characterization in a non-invasive manner. We aim to explore the feasibility of using in vivo 1 H-MRS at 7 T in women with cervical cancer to study tissue fatty acid composition. 10 women with histologically proven Stage IB1-IIB cervical cancer were scanned with a whole-body 7 T MR system with a multi-transmit system and an internal receive only monopole antenna. A STEAM sequence was used to obtain 1 H-MRS data. Fatty acid resonances were fitted with Lorentzian curves and the 2.1 ppm/1.3 ppm ratios were calculated. 1 H-MRS data showed fatty acid signals resonating at 2.1 ppm, 1.9 ppm, 1.5 ppm, 1.3 ppm and 0.9 ppm. Mean 2.1/1.3 ppm ratios were 0.019 ± 0.01, 0.021 ± 0.006, 0.12 ± 0.089 and 0.39 ± 0.27 for normal, Grade I, Grade II and Grade III groups respectively. Poorly differentiated tumor tissue (Grade III) showed elevated fatty acid ratios when compared with the well differentiated tumor (Grade I) or normal tissue. 1 H-MRS in cervical cancer at 7 T is feasible and individual fatty acid signals were detected. In addition, poorly differentiated tumors show more fatty acid unsaturation. The 2.1 ppm/1.3 ppm ratio has potential for tumor characterization in a non-invasive manner for uterine cervical cancer.

Reasons for (non)participation in supplemental population-based MRI breast screening for women with extremely dense breasts.

AIM: To determine the willingness of women with extremely dense breasts to undergo breast cancer screening with magnetic resonance imaging (MRI) in a research setting, and to examine reasons for women to participate or not. MATERIALS AND METHODS: Between 2011 and 2015, 8,061 women (50-75 years) were invited for supplemental MRI as part of the Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial (ClinicalTrials.gov Identifier: NCT01315015), after a negative screening mammography in the national population-based mammography screening programme. Demographics of participants and non-participants were compared. All invitees were asked to report reasons for (non)participation. Ethical approval was obtained. Participants provided written informed consent. RESULTS: Of the 8,061 invitees, 66% answered that they were interested, and 59% eventually participated. Participants were on average 54-years old (interquartile range: 51-59 years), comparable to women with extremely dense breasts in the population-based screening programme (55 years). Women with higher socio-economic status (SES) were more often interested in participation than women with lower SES (68% versus 59%, p<0.001). The most frequently stated reasons for non-participation were "MRI-related inconveniences and/or self-reported contraindications to MRI" (27%) and "anxiety regarding the result of supplemental screening" (21%). "Expected personal health benefit" (68%) and "contribution to science" (43%) were the most frequent reasons for participation. CONCLUSION: Of women invited for MRI because of extremely dense breasts, 59% participated. Common reasons for non-participation were "MRI-related inconveniences" and "anxiety regarding the result of supplemental screening". In case of future implementation, availability of precise evidence on benefits and harms might reduce this anxiety.

Preoperative indication for systemic therapy extended to patients with early-stage breast cancer using multiparametric 7-tesla breast MRI.

PURPOSE: To establish a preoperative decision model for accurate indication of systemic therapy in early-stage breast cancer using multiparametric MRI at 7-tesla field strength. MATERIALS AND METHODS: Patients eligible for breast-conserving therapy were consecutively included. Patients underwent conventional diagnostic workup and one preoperative multiparametric 7-tesla breast MRI. The postoperative (gold standard) indication for systemic therapy was established from resected tumor and lymph-node tissue, based on 10-year risk-estimates of breast cancer mortality and relapse using Adjuvant! Online. Preoperative indication was estimated using similar guidelines, but from conventional diagnostic workup. Agreement was established between preoperative and postoperative indication, and MRI-characteristics used to improve agreement. MRI-characteristics included phospomonoester/phosphodiester (PME/PDE) ratio on 31-phosphorus spectroscopy (31P-MRS), apparent diffusion coefficients on diffusion-weighted imaging, and tumor size on dynamic contrast-enhanced (DCE)-MRI. A decision model was built to estimate the postoperative indication from preoperatively available data. RESULTS: We included 46 women (age: 43-74yrs) with 48 invasive carcinomas. Postoperatively, 20 patients (43%) had positive, and 26 patients (57%) negative indication for systemic therapy. Using conventional workup, positive preoperative indication agreed excellently with positive postoperative indication (N = 8/8; 100%). Negative preoperative indication was correct in only 26/38 (68%) patients. However, 31P-MRS score (p = 0.030) and tumor size (p = 0.002) were associated with the postoperative indication. The decision model shows that negative indication is correct in 21/22 (96%) patients when exempting tumors larger than 2.0cm on DCE-MRI or with PME>PDE ratios at 31P-MRS. CONCLUSIONS: Preoperatively, positive indication for systemic therapy is highly accurate. Negative indication is highly accurate (96%) for tumors sized ≤2,0cm on DCE-MRI and with PME≤PDE ratios on 31P-MRS.

Evaluation of motion correction for clinical dynamic contrast enhanced MRI of the liver.

Motion correction of 4D dynamic contrast enhanced MRI (DCE-MRI) series is required for diagnostic evaluation of liver lesions. The registration, however, is a challenging task, owing to rapid changes in image appearance. In this study, two different registration approaches are compared; a conventional pairwise method applying mutual information as metric and a groupwise method applying a principal component analysis based metric, introduced by Huizinga et al (2016). The pairwise method transforms the individual 3D images one by one to a reference image, whereas the groupwise registration method computes the metric on all the images simultaneously, exploiting the temporal information, and transforms all 3D images to a common space. The performance of the two registration methods was evaluated using 70 clinical 4D DCE-MRI series with the focus on the liver. The evaluation was based on the smoothness of the time intensity curves in lesions, lesion volume change after deformation and the smoothness of spatial deformation. Furthermore, the visual quality of subtraction images (pre-contrast image subtracted from the post contrast images) before and after registration was rated by two observers. Both registration methods improved the alignment of the DCE-MRI images in comparison to the non-corrected series. Furthermore, the groupwise method achieved better temporal alignment with smoother spatial deformations than the pairwise method. The quality of the subtraction images was graded satisfactory in 32% of the cases without registration and in 77% and 80% of the cases after pairwise and groupwise registration, respectively. In conclusion, the groupwise registration method outperforms the pairwise registration method and achieves clinically satisfying results. Registration leads to improved subtraction images.

Boosting the SNR by adding a receive-only endorectal monopole to an external antenna array for high-resolution, T2 -weighted imaging of early-stage cervical cancer with 7-T MRI.

The aim of this study was to investigate the signal-to-noise ratio (SNR) gain in early-stage cervical cancer at ultrahigh-field MRI (e.g. 7 T) using a combination of multiple external antennas and a single endorectal antenna. In particular, we used an endorectal monopole antenna to increase the SNR in cervical magnetic resonance imaging (MRI). This should allow high-resolution, T2 -weighted imaging and magnetic resonance spectroscopy (MRS) for metabolic staging, which could facilitate the local tumor status assessment. In a prospective feasibility study, five healthy female volunteers and six patients with histologically proven stage IB1-IIB cervical cancer were scanned at 7 T. We used seven external fractionated dipole antennas for transmit-receive (transceive) and an endorectally placed monopole antenna for reception only. A region of interest, containing both normal cervix and tumor tissue, was selected for the SNR measurement. Separated signal and noise measurements were obtained in the region of the cervix for each element and in the near field of the monopole antenna (radius < 30 mm) to calculate the SNR gain of the endorectal antenna in each patient. We obtained high-resolution, T2 -weighted images with a voxel size of 0.7 × 0.8 × 3.0 mm3 . In four cases with optimal placement of the endorectal antenna (verified on the T2 -weighted images), a mean gain of 2.2 in SNR was obtained at the overall cervix and tumor tissue area. Within a radius of 30 mm from the monopole antenna, a mean SNR gain of 3.7 was achieved in the four optimal cases. Overlap between the two different regions of the SNR calculations was around 24%. We have demonstrated that the use of an endorectal monopole antenna substantially increases the SNR of 7-T MRI at the cervical anatomy. Combined with the intrinsically high SNR of ultrahigh-field MRI, this gain may be employed to obtain metabolic information using MRS and to enhance spatial resolutions to assess tumor invasion.

The time to progression ratio: a new individualized volumetric parameter for the early detection of clinical benefit of targeted therapies.

BACKGROUND: Early signs of efficacy are critical in drug development. Response Evaluation Criteria in Solid Tumors (RECIST) are commonly used to determine the efficacy of anti-cancer therapy in clinical trials. RECIST, however, emphasizes the value of tumor shrinkage, while many targeted agents induce prolonged tumor growth arrest. This limits its use for the detection of treatment efficacy for these more cytostatic regimens. Therefore, we designed an individualized variant of a time to progression (TTP) end point based on prospective volumetric measurements and an intra-patient control, the TTP ratio. PATIENTS AND METHODS: Patients with any metastatic malignancy, without regular treatment options, were treated with the mTOR inhibitor everolimus. Treatment response was determined using both RECIST and the TTP ratio. The TTP ratio was defined as the volumetric pretreatment TTP divided by the volumetric on-treatment TTP. A patient was classified as a responder if the TTP ratio was <0.7. Consistency and reproducibility of volumetric measurements were determined. RESULTS: Seventy-three patients were included of whom 59 started treatment. A TTP ratio could be established in 73% (n = 43) of the treated patients. The inter-observer agreement for volumetric progression was 0.78 (95% confidence interval 0.70-0.87) (Krippendorff's α-coefficient). According to RECIST, 35 patients (59%) had stable disease (SD) and 1 patient demonstrated a partial response (PR), whereas only 21 patients (36%) met the prespecified criteria for treatment efficacy according to the TTP ratio. Treatment response according to both the TTP ratio and RECIST (SD + PR) correlated with overall survival (OS) [P(log-rank) < 0.001]. The TTP ratio, however, was also able to differentiate which patients had a better OS within the RECIST SD group [P(log-rank) = 0.0496]. CONCLUSION: The TTP ratio had a high inter-observer agreement, correlated with OS and identified which patients within the RECIST SD group had a longer OS. CLINICALTRIALSGOV IDENTIFIER: NCT01566279.

(31)P magnetic resonance spectroscopy of the breast and the influence of the menstrual cycle.

Phosphorus metabolite ratios are potential biomarkers in breast cancer diagnosis and treatment monitoring. Our purpose was to investigate the metabolite ratios phosphomonoester to phosphodiester, phosphoethanolamine (PE) to glycerophosphoethanolamine (GPE), and phosphocholine (PC) to glycerophosphocholine (GPC) in glandular breast tissue, and the potential effect of the menstrual cycle, using (31)P magnetic resonance spectroscopy (MRS) at 7T. Seven women with regular menstrual cycles each underwent four examinations using a 3D (31)P multi-echo magnetic resonance spectroscopic imaging sequence. Peak integrals were assessed using IDL and JMRUI software. First, T2 relaxation times were calculated using multi-echo data pooled across subjects and time points. Subsequent, metabolite ratios were calculated for each phase of the menstrual cycle using the calculated T2 values to account for when combining the free induction decay and all five echoes. The metabolite ratios were calculated both on group level and individually. T2 decay fits resulted in a T2 relaxation time for PE of 154 ms (95 % CI 144-164), for PC of 173 ms (95 % CI 148-205), for Pi of 188 ms (95 % CI 182-193), for GPE of 48 ms (95 % CI 44-53), and for GPC of 23 ms (95 % CI 21-26). The metabolite ratios analyzed on group level showed negligible variation throughout the menstrual cycle. Individual results did show an apparent intra-individual variation; however, not significant due to the measurements' uncertainty. To conclude, phospholipids in glandular tissue as measured with (31)P MRS at 7 T are not significantly affected by the menstrual cycle.

3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography.

OBJECTIVE: To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography. METHODS: Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3­5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound. RESULTS: At pathology, 40/123 (33%) lesions proved malignant; 28 (70%) DCIS and 12 (30%) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79% (observer 1) and 86% (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95% CI 0.56­0.79) to 0.79 (95% CI 0.70­0.88, observer 1) and to 0.80 (95% CI 0.71­0.89, observer 2), respectively. CONCLUSIONS: 3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography. KEY POINTS: • 3-T MRI is increasingly used for breast imaging in clinical practice. • On 3-T breast MRI up to 86% of DCIS lesions are detected. • 3-T MRI increases the diagnostic value in patients with mammographically detected microcalcifications.

CT, MRI and laparoscopy findings of a retroperitoneally herniated ovary causing acute abdominal pain.

We report a case of a young woman presenting with abdominal pain due to a rare and recurrent herniation of the ovary, to a retroperitoneal location lateral to the external iliac artery and directly dorsal to the iliopsoas muscle. Correlation between computed tomography, magnetic resonance imaging and laparoscopy is presented. The patient's complaints subsided after right oophoropexy. When aware, this diagnosis is easy to make and may allow symptomatic patients to be treated with laparoscopic oophoropexy.

Adiabatic multi-echo ³¹P spectroscopic imaging (AMESING) at 7 T for the measurement of transverse relaxation times and regaining of sensitivity in tissues with short T2 values.

An adiabatic multi-echo spectroscopic imaging (AMESING) sequence, used for (31) P MRSI, with spherical k-space sampling and compensated phase-encoding gradients, was implemented on a whole-body 7-T MR system. One free induction decay (FID) and up to five symmetric echoes can be acquired with this sequence. In tissues with low T2 and high T2 , this can theoretically lead to a potential maximum signal-to-noise ratio (SNR) increase of almost a factor of three, compared with a conventional FID acquisition with Ernst-angle excitation. However, with T2 values being, in practice, ≤400 ms, a maximum enhancement of approximately two compared with low flip Ernst-angle excitation should be feasible. The multi-echo sequence enables the determination of localized T2 values, and was validated with (31) P three-dimensional MRSI on the calf muscle and breast of a healthy volunteer, and subsequently applied in a patient with breast cancer. The T2 values of phosphocreatine, phosphodiesters (PDE) and inorganic phosphate in calf muscle were 193 ± 5 ms, 375 ± 44 ms and 96 ± 10 ms, respectively, and the apparent T2 value of γ-ATP was 25 ± 6 ms. A T2 value of 136 ± 15 ms for inorganic phosphate was measured in glandular breast tissue of a healthy volunteer. The T2 values of phosphomonoesters (PME) and PDE in breast cancer tissue (ductulolobular carcinoma) ranged between 170 and 210 ms, and the PME to PDE ratios were calculated to be phosphoethanolamine/glycerophosphoethanolamine = 2.7, phosphocholine/glycerophosphocholine = 1.8 and PME/PDE = 2.3. Considering the relatively short T2 values of the metabolites in breast tissue at 7 T, the echo spacing can be short without compromising spectral resolution, whilst maximizing the sensitivity.

Radioactive seed localization for non-palpable breast cancer.

BACKGROUND: Radioactive seed localization (RSL) is an alternative to wire localization for guiding surgical excision of non-palpable breast cancer. This review provides an overview of the available evidence on the accuracy of RSL in patients undergoing breast-conserving surgery. METHODS: PubMed, Embase and the Cochrane Library were searched systematically in January 2012 for studies that addressed localization of non-palpable breast cancer using an iodine-125-labelled seed. Studies were deemed eligible if they reported on the proportion of patients with tumour-positive margins after RSL, the proportion of patients needing re-excision after RSL, and procedural complications. RESULTS: Six studies reported data on RSL in 1611 patients with non-palpable breast lesions. Overall complete resection rates ranged from 73 to 96.7 per cent. Three studies included over 300 patients, and complete resection rates in these studies varied between 89.5 and 96.7 per cent. The risk of seed migration and failure of seed placement ranged from 0 to 0.6 per cent and 0 to 7.2 per cent respectively. CONCLUSION: Available scientific evidence suggests that RSL is a safe and accurate technique for localization of non-palpable breast lesions.

Added value of FDG-PET imaging in the diagnostic workup for yttrium-90 radioembolisation in patients with colorectal cancer liver metastases.

OBJECTIVE: Yttrium-90 radioembolisation (Y90-RE) is recommended for unresectable, chemorefractory liver-dominant disease; however, the incidence of extrahepatic disease (EHD) is high. FDG-PET may have additional value to CT in demonstrating EHD. Our aim was to evaluate the added diagnostic value of FDG-PET to abdominal CT and study the influence of FDG-PET findings on treatment decisions. METHODS: All consecutive patients with colorectal cancer liver metastases (CRCLM) referred for Y90-RE were included. Patients who underwent both CT and FDG-PET in the diagnostic workup were selected. Imaging reports were scrutinised for documented sites of EHD, and changes of management due to FDG-PET findings were determined. RESULTS: A total of 42 patients were included. Findings on CT and FDG-PET matched in 20 patients (no EHD, n = 15; identical EHD, n = 5). In 4 patients, lesions detected on CT were not FDG-avid, and in 18 patients, FDG-PET showed more lesions than CT (P < 0.05). In 7/42 patients (17 %) a change of management was made based on the additional FDG-PET findings, i.e. exclusion from Y90-RE treatment (n = 6) and change in treatment plan (whole liver rather than segmental treatment, n = 1). CONCLUSIONS: In patients with CRCLM referred for Y90-RE, FDG-PET showed significantly more EHD and led to a considerable change of management.

Focal nodular hyperplasia: hepatobiliary enhancement patterns on gadoxetic-acid contrast-enhanced MRI.

OBJECTIVES: To assess the range of hepatobiliary enhancement patterns of focal nodular hyperplasia (FNH) after gadoxetic-acid injection, and to correlate these patterns to specific histological features. MATERIALS AND METHODS: FNH lesions, imaged with Gadoxetic-acid-enhanced MRI, with either typical imaging findings on T1, T2 and dynamic-enhanced sequences or histologically proven, were evaluated for hepatobiliary enhancement patterns and categorized as homogeneously hyperintense, inhomogeneously hyperintense, iso-intense, or hypo-intense-with-ring. Available histological specimens of FNHs (surgical resection or histological biopsy), were re-evaluated to correlate histological features with observed enhancement patterns. RESULTS: 26 FNHs in 20 patients were included; histology was available in six lesions (four resections, two biopsies). The following distribution of enhancement patterns was observed: 10/26 homogeneously hyperintense, 4/26 inhomogeneously hyperintense, 5/26 iso-intense, 6/26 hypointense-with-ring, and 1/26 hypointense, but without enhancing ring. The following histological features associated with gadoxetic-acid uptake were identified: number and type of bile-ducts (pre-existent bile-ducts, proliferation, and metaplasia), extent of fibrosis, the presence of inflammation and extent of vascular proliferation. CONCLUSION: FNH lesions can be categorized into different hepatobiliary enhancement patterns on Gadoxetic-acid-enhanced MRI, which appear to be associated with histological differences in number and type of bile-ducts, and varying the presence of fibrous tissue, inflammation, and vascularization.

The value of 3.0Tesla diffusion-weighted MRI for pelvic nodal staging in patients with early stage cervical cancer.

OBJECTIVE: The purpose of this study is to investigate the diagnostic accuracy of 3.0Tesla (3T) diffusion-weighted magnetic resonance imaging (MRI) in addition to conventional MRI for the detection of lymphadenopathy in patients with early stage cervical cancer compared to histopathological evaluation of the systematically removed pelvic lymph nodes as reference standard. METHODS: 68 fédération internationale de gynécologie obstétrique (FIGO) stage Ia2 to IIb cervical cancer patients were included. Sensitivity and specificity rates for two experienced observers were computed for the detection of lymphatic metastasis. Reproducibility of conventional MRI was tested by kappa statistics. The variables included in the analysis were: size of the long axis, short axis, ratio short to long axis and apparent diffusion coefficient (ADC). RESULTS: Nine patients had 15 positive pelvic nodes at histopathological examination. The sensitivity and specificity of lymphatic metastasis detection by predefined conventional MRI characteristics was 33% (95% Confidence Interval (CI) 3-64) and 83% (95% CI 74-93) on patient level, and 33% (95% CI 7-60) and 97% (95% CI 95-99) on regional level respectively for observer 1. For observer 2 the sensitivity was 33% (95% CI 3-64) and the specificity 93% (95% CI 87-100) on patient level, and 25% (95% CI 1-50) and 98% (95% CI 97-100) on regional level, respectively. The kappa-value for reproducibility of metastasis detection on regional level was 0.50. The short axis diameter showed the highest diagnostic accuracy (area under the curve (AUC)=0.81 95% CI 0.70-0.91); ADC did not improve diagnostic accuracy (AUC=0.83 95% CI 0.73-0.93). CONCLUSIONS: Diffusion-weighted MRI did not result in additional diagnostic value compared to conventional MRI.

MR liver imaging with Gd-EOB-DTPA: a delay time of 10 minutes is sufficient for lesion characterisation.

OBJECTIVES: To assess whether, in patients with normal liver function, a hepatobiliary delay time of 10 min after Gd-EOB-DTPA injection is sufficient for lesion characterisation. METHODS: In 42 consecutive patients with suspected focal liver lesions, dynamic MRI was performed after intravenous Gd-EOB-DTPA, followed by hepatobiliary phases at 5, 10 and 20 min. The following items were assessed at each hepatobiliary phase: parenchymal enhancement, contrast agent excretion in bile ducts, lesion enhancement characteristics (hypo-, iso-, or hyperintensity, rim enhancement, central non-enhancement), and contrast- and signal-to-noise ratios, separately for hypo- and hyperintense lesions. RESULTS: Following enhancement, parenchymal signal intensity increased significantly up to 10 min (86.3%, P < 0.001), and subsequently stabilised (86.5% after 20 min, P = 0.223). Biliary contrast agent excretion was first observed in 2, 32 and 5 patients after 5, 10 and 20 min respectively. Hepatobiliary lesion enhancement characteristics observed after 5 min persisted during later hepatobiliary phases. CNR and SNR ratios increased significantly (P < 0.05) up to 10 min after enhancement without further increase at 20 min, in hypo- and hyperintense lesions. CONCLUSIONS: If lesion characterisation is the primary reason for performing MRI, a hepatobiliary delay time of 10 min after Gd-EOB-DTPA injection is sufficient in patients with normal liver function. KEY POINTS : • Magnetic resonance imaging is now a first line of investigation of the liver. • Optimal CNR and SNR are achieved 10 min after Gd-EOB-DTPA injection. • Typical enhancement characteristics are observed early and do not change. • Ten-minute hepatobiliary delay is sufficient for characterisation of focal liver lesions.

Characterization of ex vivo healthy human axillary lymph nodes with high resolution 7 Tesla MRI.

OBJECTIVE: To characterize ex vivo healthy human axillary lymph nodes on 7 Tesla MRI and to correlate the findings with pathological analysis as a first step towards non-invasive staging of breast cancer patients in the future. METHODS: Four axillary lymph node dissection (ALND) specimens from 2 autopsy patients, who had no cancer, were examined on a clinical 7 Tesla MRI system. For morphological analysis a 3D T1-weighted fat-suppressed fast-field-echo [isotropic resolution 180 µm] was acquired. For quantitative analyses 2D T1-, 3D T2-, T2*- and diffusion-weighted images were acquired. The ALNDs were mapped and stained for precise correlation of MRI to pathology. Nodes were sliced in 3 µm sections, Haematoxylin & Eosin stained, and examined by an experienced pathologist. RESULTS: MRI detected all 45 nodes and 6 additional nodes that were not detected at pathological analysis. B-cell follicles, efferent- and afferent lymph vessels and blood vessels were identified. Mean T1, T2, T2*, ADC values (± standard deviation) were 944 ± 113 ms, 32 ± 2 ms, 16 ± 2 ms, 0.39 ± 0.09·10⁻³ mm²/s, respectively. CONCLUSIONS: 7 Tesla MRI of ex vivo human axillary lymph nodes correlated well with pathology. MRI detected all nodes present in the specimens and allowed visualization of fine structural detail. Pathology-correlated quantitative MRI data are presented.