The added role of MR imaging in treatment stratification of patients with gynecologic malignancies: what the radiologist needs to know.

Many treatment options are available to patients with endometrial, cervical, or ovarian cancer. Magnetic resonance (MR) imaging plays an important role in the patient journey from the initial evaluation of the extent of the disease to appropriate treatment selection and follow-up. The purpose of this review is to highlight the added role of MR imaging in the treatment stratification and overall care of patients with endometrial, cervical, or ovarian cancer. Several MR imaging techniques used in evaluation of patients with gynecologic malignancies are described, including both anatomic MR imaging sequences (T1- and T2-weighted sequences) and pulse sequences that characterize tissue on the basis of physiologic features (diffusion-weighted MR imaging), dynamic contrast agent-enhanced MR imaging, and MR spectroscopy. MR imaging findings corresponding to the 2009 revised International Federation of Gynecology and Obstetrics staging of gynecologic malignancies are also described in detail, highlighting possible pearls and pitfalls of staging. With the growing role of the radiologist as a core member of the multidisciplinary treatment planning team, it is crucial for imagers to recognize that MR imaging has become central in tailoring treatment options and therapy in patients with gynecologic malignancies.

The revised FIGO staging system for uterine malignancies: implications for MR imaging.

Cancers of the uterine corpus and cervix are the most common gynecologic malignancies worldwide. The International Federation of Gynecology and Obstetrics (FIGO) staging system was first established in 1958, when it was recognized that the recurrence rate and patient outcomes were directly related to the degree of tumor spread at the patient's initial presentation. Changes in understanding of tumor biology led to a recent update in the FIGO staging system that reflects the variation in treatment strategies between endometrial and cervical cancer. Patients with endometrial cancer are primarily treated with hysterectomy; thus, staging is done at surgery and histologic analysis. Magnetic resonance (MR) imaging may accurately depict the extent of endometrial cancer at diagnosis and, in conjunction with the tumor grade and histologic subtype, help stratify risk, which determines the therapeutic course. Cervical carcinoma is staged at clinical examination because many tumors are inoperable at the time of patient presentation. Preoperative MR imaging criteria are not formally included in the revised FIGO staging system because cervical carcinoma is most prevalent in developing countries, where imaging resources are limited. However, MR imaging is highly sensitive and specific for depicting important prognostic factors and, when available, is recommended as an adjunct to clinical examination. The MR imaging findings of uterine carcinoma should be discussed in a multidisciplinary setting in conjunction with clinical and histologic findings, an approach that provides accurate staging and risk stratification and allows for individualized treatment.

Magnetization transfer imaging of ovarian cancer: initial experiences of correlation with tissue cellularity and changes following neoadjuvant chemotherapy.

Objectives: To investigate the relationship between magnetization transfer (MT) imaging and tissue macromolecules in high-grade serous ovarian cancer (HGSOC) and whether MT ratio (MTR) changes following neoadjuvant chemotherapy (NACT). Methods: This was a prospective observational study. 12 HGSOC patients were imaged before treatment. MTR was compared to quantified tissue histology and immunohistochemistry. For a subset of patients (n = 5), MT imaging was repeated after NACT. The Shapiro-Wilk test was used to assess for normality of data and Spearman's rank-order or Pearson's correlation tests were then used to compare MTR with tissue quantifications. The Wilcoxon signed-rank test was used to assess for changes in MTR after treatment. Results: Treatment-naïve tumour MTR was 21.9 ± 3.1% (mean ± S.D.). MTR had a positive correlation with cellularity, rho = 0.56 (p < 0.05) and a negative correlation with tumour volume, ρ = -0.72 (p = 0.01). MTR did not correlate with the extracellular proteins, collagen IV or laminin (p = 0.40 and p = 0.90). For those patients imaged before and after NACT, an increase in MTR was observed in each case with mean MTR 20.6 ± 3.1% (median 21.1) pre-treatment and 25.6 ± 3.4% (median 26.5) post-treatment (p = 0.06). Conclusion: In treatment-naïve HGSOC, MTR is associated with cellularity, possibly reflecting intracellular macromolecular concentration. MT may also detect the HGSOC response to NACT, however larger studies are required to validate this finding. Advances in knowledge: MTR in HGSOC is influenced by cellularity. This may be applied to assess for cell changes following treatment.

What is the significance of solitary bony abnormalities on bone scintigrams of children with malignancy?

This investigation was undertaken to evaluate the significance of solitary bony abnormalities on bone scintigrams of children with known or suspected malignancy. A total of 215 bone scans were performed in 183 children in order to look for possible metastasis over a 10-year period. Forty-nine scans (22.8%) were found to have single lesions, of which 18 were due to uptake at the primary site and were excluded from further consideration. Of the remaining 31 lesions, 13 (41.9%) were confirmed as metastases, 17 lesions were proved to be benign, and 1 indeterminate. Solitary hot spots in children with known or suspected malignancy are common and therefore have to be taken seriously due to their higher malignant potential.

Image-guided biopsy in patients with suspected ovarian carcinoma: a safe and effective technique?

In patients with suspected advanced ovarian carcinoma, a precise histological diagnosis is required before commencing neo-adjuvant chemotherapy. This study aims to determine the diagnostic accuracy and complication rate of percutaneous biopsies performed under ultrasound or computed tomography guidance. Between 2002 to 2007, 60 consecutive image-guided percutaneous biopsies were performed in patients with suspected ovarian cancer. The following variables were recorded: tissue biopsied, imaging technique, experience of operator, biopsy needle gauge, number of passes, complications, and final histology. Forty-seven patients had omental biopsies, 12 pelvic mass biopsies, and 1 para-aortic lymph node biopsy. Thirty-five biopsies were performed under ultrasound, 25 under computed tomography guidance. Biopsy needle gauges ranged from 14-20 swg with two to five passes for each patient. There were no complications. Histology was obtained in 52 (87%) patients. Percutaneous image-guided biopsy of peritoneal disease or pelvic mass is safe with high diagnostic accuracy. The large-gauge biopsy needle is as safe as the small gauge needle, but has the added value of obtaining tissue samples for immunohistochemistry and genomic studies.

Sodium MRI with 3D-cones as a measure of tumour cellularity in high grade serous ovarian cancer.

The aim of this study was to assess the feasibility of rapid sodium MRI (23Na-MRI) for the imaging of peritoneal cancer deposits in high grade serous ovarian cancer (HGSOC) and to evaluate the relationship of 23Na-MRI with tumour cellularity. 23Na-MRI was performed at 3 T on twelve HGSOC patients using a 3D-cones acquisition technique. Tumour biopsies specimens were collected after imaging and cellularity was measured from histology. Total 23Na-MRI scan time for each patient was approximately 11 min. At an isotropic resolution of 5.6 mm, signal-to-noise ratios (SNRs) of 82.2 ± 15.3 and 15.1 ± 7.1 (mean ± standard deviation) were achieved for imaging of tumour tissue sodium concentration (TSC) and intracellular weighted sodium concentration (IWS) respectively. Tumour TSC and IWS concentrations were: 56.8 ± 19.1 mM and 30.8 ± 9.2 mM respectively and skeletal muscle TSC and IWS concentrations were 33.2 ± 16.3 mM and 20.5 ± 9.9 mM respectively. There were significant sodium concentration differences between cancer and skeletal muscle, Wilcoxon signed-rank test, P < 0.001 for TSC and P = 0.01 for IWS imaging. Tumour cellularity displayed a strong negative correlation with TSC, Spearman's rho = -0.92, P < 0.001, but did not correlate with IWS. This study demonstrates that 23Na-MRI using 3D-cones can rapidly assess sodium concentration in peritoneal deposits of HGSOC and that TSC may serve as a biomarker of tumour cellularity.

Quality of CT pulmonary angiography for suspected pulmonary embolus in pregnancy.

The main objective of this study was to assess the quality of CT pulmonary angiography (CTPA) for suspected pulmonary embolus (PE) in the pregnant population. We retrospectively identified 40 consecutive pregnant patients who underwent CTPA from January 2005 to December 2006. Forty consecutive age-matched non-pregnant women were used as a control group. Studies were subjectively graded according to overall image quality by two readers in consensus, in randomised and blinded manner. Moreover, contrast enhancement of pulmonary arteries was subjectively and objectively evaluated. The proportion of sub-optimal studies was more than three times higher in the pregnant group (27.5%, n = 11) compared with the non-pregnant group (7.5%, n = 3; p = 0.015). Mean contrast enhancement was consistently higher in the non-pregnant group compared with pregnant group, both subjectively and objectively. The percentage of inadequately opacified vascular segments was more than two times higher in the pregnant group (28.7%, n = 264) than in the non-pregnant group (13.3%, n = 122; p = 0.0001). The incidence of sub-optimal CTPA studies is higher in pregnancy when compared with an age-matched non-pregnant control group. In addition to radiation issues, this should also be considered when implementing diagnostic strategies for suspected PE in pregnancy.

Pancreatic transplantation: surgical technique, normal radiological appearances and complications.

Pancreas transplantation is a surgical treatment for diabetes mellitus. More than 23,000 pancreas transplants have now been reported to the International Transplant Registry (IPTR). Early diagnosis and therapy for graft-related complications are essential for graft survival. Radiologists must therefore understand the surgical procedure and the potential complications. During the course of this review, we will illustrate the normal post-operative anatomy and the imaging appearances of common potential complications.