CT and 3-T MRI accurately identify T3c disease in colon cancer, which strongly predicts disease-free survival.

AIM: To compare the preoperative staging accuracy of computed tomography (CT) and 3-T magnetic resonance imaging (MRI) in colon cancer, and to investigate the prognostic significance of identified risk factors. MATERIALS AND METHODS: Fifty-eight patients undergoing primary resection of their colon cancer were prospectively recruited, with 53 patients included for final analysis. Accuracy of CT and MRI were compared for two readers, using postoperative histology as the reference standard. Patients were followed-up for a median of 39 months. Risk factors were compared by modality and reader in terms of metachronous metastases and disease-free survival (DFS), stratified for adjuvant chemotherapy. RESULTS: Accuracy for the identification of T3c+ disease was non-significantly greater on MRI (75% and 79%) than CT (70% and 77%). Differences in the accuracy of MRI and CT for identification of T3+ disease (MRI 75% and 57%, CT 72% and 66%) and N+ disease (MRI 62% and 63%, CT 62% and 56%) were also non-significant. Identification of extramural venous invasion (EMVI+) disease was significantly greater on MRI (75% and 75%) than CT (79% and 54%) for one reader (p=0.029). T3c+ disease at histopathology was the only risk factor that demonstrated a significant difference in rate of metachronous metastases (odds ratio [OR] 8.6, p=0.0044) and DFS stratified for adjuvant therapy (OR=4, p=0.048). CONCLUSION: T3c or greater disease is the strongest risk factor for predicting DFS in colon cancer, and is accurately identified on imaging. T3c+ disease may therefore be the best imaging entry criteria for trials of neoadjuvant treatment.

Relevance of magnetic resonance imaging-detected pelvic sidewall lymph node involvement in rectal cancer.

BACKGROUND: The significance of magnetic resonance imaging (MRI)-suspected pelvic sidewall (PSW) lymph node involvement in rectal cancer is uncertain. METHODS: Magnetic resonance images were reviewed retrospectively by specialist gastrointestinal radiologists for the presence of suspicious PSW nodes. Scans and outcome data were from patients with biopsy-proven rectal cancer and a minimum of 5 years' follow-up in the Magnetic Resonance Imaging and Rectal Cancer European Equivalence Study. Overall disease-free survival (DFS) was analysed using the Kaplan-Meier product-limit method and stratified according to preoperative therapy. Binary logistic regression was used to match patients for propensity of clinical and staging characteristics, and further survival analysis was carried out to determine associations between suspicious PSW nodes on MRI and survival outcomes. RESULTS: Of 325 patients, 38 (11·7 per cent) had MRI-identified suspicious PSW nodes on baseline scans. Such nodes were associated with poor outcomes. Five-year DFS was 42 and 70·7 per cent respectively for patients with, and without suspicious PSW nodes (P < 0·001). Among patients undergoing primary surgery, MRI-suspected PSW node involvement was associated with worse 5-year DFS (31 versus 76·3 per cent; P = 0·001), but the presence of suspicious nodes had no impact on survival among patients who received preoperative therapy. After propensity matching for clinical and tumour characteristics, the presence of suspicious PSW nodes on MRI was not an independent prognostic variable. CONCLUSION: Patients with suspicious PSW nodes on MRI had significantly worse DFS that appeared improved with the use of preoperative therapy. These nodes were associated with adverse features of the primary tumour and were not an independent prognostic factor.

Benefits of CT urography in patients presenting to the emergency department with suspected ureteric colic.

BACKGROUND: Ureteric colic is a common presentation in the emergency department and accounts for approximately 1% of all hospital admissions. Diagnosis depends on a typical history, clinical examination and the presence of haematuria. Intravenous urography has traditionally been used as the means of investigation, but over recent years this has been superseded by CT urography. This latter investigation gives potentially more information and may detect alternative or additional pathology which would otherwise be missed on intravenous urography. METHODS: 100 consecutive patients attending the emergency department with a provisional diagnosis of ureteric colic undergoing CT urography were studied to detect the incidence of alternative or incidental pathology. RESULTS: Stone disease was found in 58% of patients, with obstruction present in 43%. The most common site of obstruction was the vesicoureteric junction. Significant incidental or alternative pathology was found in 16% of patients. It was estimated that, in 12%, these findings would not have been detected by intravenous urography. CONCLUSION: The use of non-contrast CT urography is recommended in the initial investigation of patients with ureteric colic.

Silica wool filtration (SIFT) assay: a simple system to estimate the percentage of acrosome-reacted sperm.

OBJECTIVE: To develop a simple assay using the silica wool filtration (SIFT) procedure to estimate percentage of acrosome-reacted (AR) sperm. SETTING: Private andrology laboratory. MATERIALS AND METHODS: Capacitated sperm processed by the SIFT procedure to remove nonviable sperm and those with broken membrane were acrosome reacted by induction with a calcium ionophore. Following the acrosome reaction, the sample was processed by the SIFT procedure. Sperm concentration and acrosomal status were also determined before and after the SIFT procedure. RESULTS: The SIFT procedure prevented AR sperm from filtering (mean +/- SD, 22.2 +/- 1.9 vs. 9.8 +/- 4.9%). The mean percent of sperm retained in the filter (SIFT assay: 61.8 +/- 21.5%) was significantly higher than the percent of AR sperm estimated by a staining technique (26.4 +/- 7.3%), but they were significantly correlated (r = .34) with each other. The filtration of capacitated sperm prior to induction of the acrosome reaction eliminated, or at least minimized, the possibility of falsely increasing the percent of AR sperm estimated by the SIFT assay. The higher estimate obtained by SIFT assay, therefore, suggests that it may be estimating sperm at various stages that are undergoing the acrosome reaction. CONCLUSION: The findings suggest that the SIFT assay could be used to estimate the percentage of AR spermatozoa.

Perfusion CT to assess angiogenesis in colon cancer: technical limitations and practical challenges.

OBJECTIVE: Perfusion CT may have the potential to quantify the degree of angiogenesis of solid tumours in vivo. This study aims to identify the practical and technical challenges inherent to the technique, and evaluate its feasibility in colorectal tumours. METHODS: 51 patients from 2 institutions prospectively underwent a single perfusion CT on 2 different multidetector scanners. The patients were advised to breath-hold as long as possible, followed by shallow breathing, and were given intravenous buscopan to reduce movement. Numerous steps were explored to identify the challenges. RESULTS: 43 patients successfully completed the perfusion CT as per protocol. Inability to detect the tumour (n=3), misplacement of dynamic sequence co-ordinates (n=2), failure of contrast injection (n=2) and displacement of tumour (n=1) were the reasons for failure. In 14 cases excessive respiratory motion displaced the tumour out of the scanning field along the temporal sequence, leading to erroneous data capture. In nine patients, minor displacements of the tumour were corrected by repositioning the region of interest (ROI) to its original position after reviewing each dynamic sequence slice. In 20 patients the tumour was stable, and data captured from the ROI were representative, and could have been analysed by commercially available Body Tumor Perfusion 3.0® software (GE Healthcare, Waukesha, WI). Hence all data were manually analysed by MATLAB® processing software (MathWorks, Cambridge, UK). CONCLUSION: Perfusion CT in tumours susceptible to motion during acquisition makes accurate data capture challenging and requires meticulous attention to detail. Motion correction software is essential if perfusion CT is to be used routinely in colorectal cancer.

Imaging features of aggressive angiomyxoma.

AIM: To describe the imaging features of aggressive angiomyxoma in a rare benign mesenchymal tumour most frequently arising from the perineum in young female patients. MATERIALS AND METHODS: We reviewed the computed tomography (CT) and magnetic resonance (MR) imaging features of patients with aggressive angiomyxoma who were referred to our hospital. The imaging features were correlated with clinical information and pathology in all patients. RESULTS: Four CT and five MR studies were available for five patients (all women, mean age 39, range 24-55). Three patients had recurrent tumour at follow-up. CT and MR imaging demonstrated a well-defined mass-displacing adjacent structures. The tumour was of low attenuation relative to muscle on CT. On MR, the tumour was isointense relative to muscle on T1-weighted image, hyperintense on T2-weighted image and enhanced avidly after gadolinium contrast with a characteristic "swirled" internal pattern. MR imaging demonstrates the extent of the tumour and its relation to the pelvic floor. Recurrent tumour has a similar appearance to the primary lesion. CONCLUSION: The MR appearances of aggressive angiomyxomas are characteristic, and the diagnosis should be considered in any young woman presenting with a well-defined mass arising from the perineum.