Assessment of remaining tumour involved lymph nodes with MRI in patients with complete luminal response after neoadjuvant treatment of rectal cancer.

OBJECTIVE: To assess the accuracy of MRI to predict remaining lymph node metastases in patients with complete pathological luminal response (ypT0) after neoadjuvant therapy. METHODS: Data from a national registry were used. 19 patients with histopathologically remaining lymph node metastases (ypT0N+) were identified. Another 19 patients without lymph node metastases (ypT0N0) were used as matched controls. Two radiologists blinded to all patient information evaluated staging and restaging MRI that was compared to histopathological findings of the resected specimen. RESULTS: The average size of the largest lymph node on restaging MRI was significantly larger (4.5 mm) in the ypT0N+ group than in the ypT0N0 group (2.6 mm) (p = 0.04). Presence of ypN+ was correctly predicted by MRI in 7 of 19 patients. In patients without lymph node metastases (ypT0N0), these were correctly classified by MRI in 16 of 19 patients. All patients who had MR-identified lymph nodes larger than 8 mm at restaging were ypTN+. The sensitivity, specificity, positive predictive value and negative for prediction of remaining lymph node metastasis with MRI were 37, 84, 70 and 57%. CONCLUSION: In patients with ypT0 in rectal cancer after neoadjuvant treatment, remaining regional lymph node metastases cannot safely be predicted by restaging MRI alone using presently known criteria. Presence of a lymph node over 8 mm on restaging MRI strongly indicates yPN+. Advances in knowledge: This is one of the first studies on MRI lymph node assessment after chemo-radiotherapy (CRT) in luminal complete response.

Assessment and diagnostic accuracy of lymph node status to predict stage III colon cancer using computed tomography.

BACKGROUND: To study different imaging criteria for prediction of lymph node metastases (Stage III disease) in colon cancer using CT. METHODS: In a retrospective setting, 483 consecutive patients with histology proven colon cancer underwent elective primary resection during 2008-2011, a cohort of 119 patients were included. Contrast enhanced CT examinations, in portal-venous phase, were reviewed with assessment of the number of lymph nodes, their anatomical distribution, size, size ratio, internal heterogeneity, presence of irregular outer border and attenuation values. Sensitivity, specificity, PPV and NPV for each studied criteria for prediction of stage III disease was calculated. RESULTS: According to histopathology 80 patients were stage I-II and 39 were stage III. Of the studied CT-criteria for lymph node metastases per patient, internal heterogeneity in at least one lymph node resulted in the best performance with sensitivity, specificity, PPV and NPV of 79, 84, 70 and 89%, Odds ratio (OR) 20. Presence of irregular outer border resulted in a sensitivity, specificity, PPV and NPV of 59, 81, 61 and 82%, OR 6.2. If both internal heterogeneity and/or irregular outer border was used as a criterion this resulted in a sensitivity, specificity, PPV and NPV of 85, 75, 62 and 91%, OR 16.5. None of the size criteria used were predictive for stage III disease. CONCLUSIONS: When performing preoperative CT in patients with colon cancer, the imaging criteria that allow best prediction of stage III disease on CT are either presence of at least one lymph node with internal heterogeneity or internal heterogeneity and/or irregular outer border. These criteria have to be validated in a prospective study.

Accurate prediction tools in prostate cancer require consistent assessment of included variables.

OBJECTIVE: The aim of this study was to create a preoperative prediction model predicting extraprostatic tumour growth in men with clinically organ-confined disease from a prospectively collected Swedish cohort. MATERIALS AND METHODS: The study used data from 3386 men in the prospective multi-centre Laparoscopic Prostatectomy Robot Open (LAPPRO) trial, with 14 participating urological departments. External validation was performed using a cohort of 634 men from the largest study centre with patients who underwent surgery before and after the inclusion period of the LAPPRO study. External validation of the updated Partin table was used for comparison. The prediction models were created by multivariable logistic regression. Nomogram prediction performance, internal, internal-external and external validation are presented as the area under the receiver operating characteristic curve (AUC). RESULTS: The nomogram reached a prediction performance with an AUC of 0.741, with internal and external validation of 0.738 and 0.698, respectively. Internal-external validation showed great divergence between centres, with AUCs ranging from 0.476 to 0.892, indicating inconsistencies in pathological staging or one or more of the included variables in the regression model. When including centre as a variable in the multivariable model it was significantly associated with the outcome of pT3 (p < 0.001). AUC for external validation of the Partin table was 0.694. CONCLUSIONS: Accurate prediction tools in prostate cancer require consistent assessment of included variables, and local validation is needed before the use of such tools in clinical practice.

Patients' experience of outsourcing and care related to magnetic resonance examinations.

BACKGROUND: Outsourcing radiological examinations from public university hospitals affects the patient, who has to attend a different clinic or hospital for the radiological examination. We currently have a limited understanding of how patients view outsourcing and their care related to MR examinations. AIM: To examine the experiences of patients who are sent to private radiology units when their referrals for MR examinations are outsourced from a university hospital, as well as to explore factors which influence patient satisfaction regarding the quality of care related to the MR examination. METHODS: A group of patients (n = 160) referred for MR examinations and either examined at a university hospital or at an external private unit were interviewed. The interview was designed as a verbal questionnaire. Data were analyzed using Student's t test, analysis of variance (ANOVA), and Pearson's correlation. RESULTS: Sixty-nine percent of the patients could neither choose nor influence the location at which they were examined. For those who could, aspects that influenced the patient's choice of radiology department were: short waiting time 79% (127/160), ease of traveling to the radiology department 68% (110/160), and short distance to their home or work 58% (93/160). For 40% (60/160) of the patients, a short time in the waiting room was related to a positive experience of the MR examination. CONCLUSION: If patients were informed about outsourcing and could also choose where to have their examination, key factors contributing to patient satisfaction could be met even when MR examinations are outsourced.

Preoperative magnetic resonance imaging assessment of circumferential resection margin predicts disease-free survival and local recurrence: 5-year follow-up results of the MERCURY study.

PURPOSE: The prognostic relevance of preoperative high-resolution magnetic resonance imaging (MRI) assessment of circumferential resection margin (CRM) involvement is unknown. This follow-up study of 374 patients with rectal cancer reports the relationship between preoperative MRI assessment of CRM staging, American Joint Committee on Cancer (AJCC) TNM stage, and clinical variables with overall survival (OS), disease-free survival (DFS), and time to local recurrence (LR). PATIENTS AND METHODS: Patients underwent protocol high-resolution pelvic MRI. Tumor distance to the mesorectal fascia of ≤ 1 mm was recorded as an MRI-involved CRM. A Cox proportional hazards model was used in multivariate analysis to determine the relationship of MRI assessment of CRM to survivorship after adjusting for preoperative covariates. RESULTS: Surviving patients were followed for a median of 62 months. The 5-year OS was 62.2% in patients with MRI-clear CRM compared with 42.2% in patients with MRI-involved CRM with a hazard ratio (HR) of 1.97 (95% CI, 1.27 to 3.04; P < .01). The 5-year DFS was 67.2% (95% CI, 61.4% to 73%) for MRI-clear CRM compared with 47.3% (95% CI, 33.7% to 60.9%) for MRI-involved CRM with an HR of 1.65 (95% CI, 1.01 to 2.69; P < .05). Local recurrence HR for MRI-involved CRM was 3.50 (95% CI, 1.53 to 8.00; P < .05). MRI-involved CRM was the only preoperative staging parameter that remained significant for OS, DFS, and LR on multivariate analysis. CONCLUSION: High-resolution MRI preoperative assessment of CRM status is superior to AJCC TNM-based criteria for assessing risk of LR, DFS, and OS. Furthermore, MRI CRM involvement is significantly associated with distant metastatic disease; therefore, colorectal cancer teams could intensify treatment and follow-up accordingly to improve survival outcomes.

Dynamic gadoxetate-enhanced MRI for the assessment of total and segmental liver function and volume in primary sclerosing cholangitis.

PURPOSE: To evaluate dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) for the assessment of global and segmental liver volume and function in patients with primary sclerosing cholangitis (PSC), and to explore the heterogeneous distribution of liver function in this patient group. MATERIALS AND METHODS: Twelve patients with primary sclerosing cholangitis (PSC) and 20 healthy volunteers were examined using DHCE-MRI with Gd-EOB-DTPA. Segmental and total liver volume were calculated, and functional parameters (hepatic extraction fraction [HEF], input relative blood-flow [irBF], and mean transit time [MTT]) were calculated in each liver voxel using deconvolutional analysis. In each study subject, and incongruence score (IS) was constructed to describe the mismatch between segmental function and volume. Among patients, the liver function parameters were correlated to bile duct obstruction and to established scoring models for liver disease. RESULTS: Liver function was significantly more heterogeneously distributed in the patient group (IS 1.0 versus 0.4). There were significant correlations between biliary obstruction and segmental functional parameters (HEF rho -0.24; irBF rho -0.45), and the Mayo risk score correlated significantly with the total liver extraction capacity of Gd-EOB-DTPA (rho -0.85). CONCLUSION: The study demonstrates a new method to quantify total and segmental liver function using DHCE-MRI in patients with PSC.

Effects of outsourcing magnetic resonance examinations from a public university hospital to a private agent.

BACKGROUND: Sometimes the measures taken to make a radiology department more effective, such as prioritizing the workload and keeping equipment running for as many hours as staffing permits, are not enough. In such cases, outsourcing radiological examinations is a potential solution for reducing waiting times. PURPOSE: To investigate differences in waiting time, quality and costs between magnetic resonance (MR) examinations performed in a university hospital and examinations outsourced to private service. MATERIAL AND METHODS: We retrospectively selected a group of consecutive, outsourced MR examinations (n=97) and a control group of in-house MR examinations, matched for type of examination. In each group there were referrals that had a specified preferred timeframe for completion. We measured the percentage of cases in which this timeframe was met and if it was not met, how many days exceeded the preferred time. In referrals without a specified preferred timeframe, we also calculated the waiting time. Quality standards were measured by the percentage of examinations that had to be re-done and re-assessed. Finally, we calculated the cumulative costs, taking into account the costs for re-doing and re-assessing examinations. RESULTS: There was no statistically significant difference between the groups, in either the number of examinations that were not performed within the preferred time or the number of days that exceeded the preferred timeframe. For referrals without a preferred timeframe, the waiting time was shorter for outsourced examinations than those not outsourced. There were no differences in the number of examinations that had to be re-done, but more examinations needed to be re-assessed in the outsourced group than in the in-house group. The calculated costs for outsourced examinations were lower than the costs for internally performed examinations. CONCLUSION: Outsourcing magnetic resonance examinations may be an effective way of reducing a radiology department's workload. Ways in which to reduce the additional costs incurred for re-assessment of outsourced examinations must be investigated further.

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI.

OBJECTIVES: Gd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified. METHODS: Gd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (C(max) , T(max) and T(1/2) ), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM). RESULTS: Although the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child-Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child-Pugh scores. CONCLUSIONS: Dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels.

Assessment of hepatic extraction fraction and input relative blood flow using dynamic hepatocyte-specific contrast-enhanced MRI.

PURPOSE: To assess the feasibility to use dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) as an imaging-based liver function test, and to compare two methods for deconvolutional analysis (DA) in healthy human subjects. MATERIALS AND METHODS: T(1)-weighted DHCE-MRI with the hepatocyte-specific contrast medium Gd-EOB-DTPA was performed in 20 healthy volunteers. DA was performed using truncated singular value decomposition (TSVD) and Fourier analysis with an appended tail (FA+Tail). Hepatic extraction fraction (HEF) and input relative blood flow (irBF) were calculated for each liver segment. A computer simulation comparing the standard deviation (SD) of TSVD and FA+tail at different levels of signal-to-noise (SNR) ratio was performed. The results obtained were compared using descriptive statistics, the Wilcoxon matched pairs test and the variance ratio test. RESULTS: Median HEF was 0.201 and 0.205 using TSVD and FA+tail, respectively (P = 0.086). The corresponding results for irBF was 0.240 and 0.239 (P = 0.51). TSVD yielded a smaller SD, although the difference was not significant (P = 0.068 for HEF and P = 0.84 for irBF). The computer simulation showed that TSVD is more stable than FA+tail at most levels of SNR. CONCLUSION: DHCE-MRI with Gd-EOB-DTPA enables the calculation of HEF and irBF. We regard these parameters as being markers of hepatic parenchymal function.

Significance of mesorectal volume in staging of rectal cancer with magnetic resonance imaging and the assessment of involvement of the mesorectal fascia.

The aim was to study the influence of mesorectal volume, as estimated by magnetic resonance imaging (MRI), that is to be removed during total mesorectal excision (TME), on the accuracy of the first preoperative MRI of rectal cancer compared to histopathology, and its correlation to locoregional prognostic factors. A total of 267 rectal cancer patients from a multinational study (MERCURY or MRI equivalence study) had their mesorectal volume retrospectively estimated by researchers without knowledge of the assessments made by the radiologist or the pathologist. The evaluations made by the pathologist and the radiologist were then compared, including T- and N-staging, assessment of extent of extramural tumor invasion (the largest portion of the tumor beyond the muscularis propria or EMI) and distance to mesorectal fascia; the discrepancies in the results were correlated to the mesorectal volume. T- or N-staging accuracy by MRI and the difference between the EMI as measured by the pathologist and the radiologist were not dependent on individual mesorectal volume. There was no correlation between assessment of involvement of mesorectal fascia or local neighboring organs by MRI and histopathology with mesorectal volume. Mesorectal volume does not affect locoregional prognostic factors or the accuracy of local staging of rectal cancer.

The mesorectum: morphometric assessment with magnetic resonance imaging.

The purpose of the present study was to assess the size and configuration of the perirectal fatty tissues using magnetic resonance imaging, including the volume occupied by the rectum itself, and to establish a simple method by which such analysis could be derived. Included in the study were 25 consecutive patients without any large pelvic tumor (diameter of potential pelvic tumor less than 3 cm in any plane) referred for high-resolution pelvic MR imaging. The volume and cross-sectional parameters based on the amount of mesorectum to different sides of the rectum, and the total area occupied, including the rectum, were retrospectively measured using a transaxial three-dimensional T1-weighted gradient-echo sequence. The mesorectum, including the rectum within, occupied an axial area ranging from 320 to 5992 mm(2), and a total volume of 54-323 ml. There was a good correlation between anteroposterior diameter of the perirectal fat at 4 cm below S1-2 and the left-to-right diameter 7 cm below S1-2, and the total volume. Furthermore, the form of mesorectal tissue differed significantly between male and female subjects. In male subjects, measurements in the anteroposterior dimension accurately reflected the volume of mesorectal tissue, while in women, assessment of both the anteroposterior and the size parameters of the mesorectum from the left to right were required for the best evaluation of the volume of mesorectal tissue. The amount of fat posterior to the rectum was significantly more in men than in women, with or without consideration of length of the pelvis. Finally, the contour of the mesorectal fascia was subject to impression by other nearby visceral organs. There is a great individual variation in the amount of mesorectal fat, and in morphometric parameters between the two sexes. The morphological variations of the mesorectum can be assessed by magnetic resonance imaging using a formula based on two simple measurements of the anteroposterior and left-to-right dimensions.

[Deep venous thrombosis of the lower extremity. Ultrasonography should replace phlebography as first line diagnostic imaging]. / Djup ventrombos i nedre extremiteten. Ultraljud bör ersätta flebografi som första bildgivande undersökning.

In Sweden, there is a widespread use of ascending venography for the diagnosis of deep vein thrombosis of the lower extremities (LEDVT) instead of ultrasonography. The main reason for this is the inferiority of US in diagnosing LEDVT in the calf veins. In order to indirectly estimate the magnitude of this inadequacy, we reviewed all of the cases of attempts to perform venograms at our center during a four-month period. The results showed that only 4-5 per cent of requested and successful venograms were able to show signs of LEDVT in the calf veins (distal LEDVT). With regards to these results and a recent report by SBU (Swedish Council on Technology Assessment in Health Care), we believe that US with compression technique and Doppler should be considered as a replacement for venography of the lower extremities as the first line of diagnostic imaging modality.

Cost-effectiveness of reduction mammaplasty.

OBJECTIVES: The purpose of this study is to provide a comparison of the benefits of reduction mammaplasty (RM) for women with heavy breasts often termed macromastia or breast hypertrophy (BH) surgery. The rationale is to provide information to allow decision-makers to make judgments about the cost-effectiveness of this intervention and make comparisons with other interventions which are commonly undertaken within publicly financed health-care systems. METHODS: Data from a previous outcomes study in Sweden is re-analyzed to derive quality of life measures, from which a mean level of benefit outcome is derived and a cost per quality-adjusted life year is calculated (cost per QALY). RESULTS: The low Cost per QALY suggests that reduction mammaplasty is cost-effective when compared with other treatments which are commonly undertaken. CONCLUSIONS: The authors suggest that the evidence in favor of funding reduction mammaplasty is strong and that decision-makers review their policy in light of this new evidence.