MRI in pregnant patients with suspected abdominal and pelvic cancer: a practical guide for radiologists

Whole-body MRI in oncology: A comprehensive review

Whole-Body Magnetic Resonance Imaging (WB-MRI) has cemented its position as a pivotal tool in oncological diagnostics. It offers unparalleled soft tissue contrast resolution and the advantage of sidestepping ionizing radiation. This review explores the diverse applications of WB-MRI in oncology. We discuss its transformative role in detecting and diagnosing a spectrum of cancers, emphasizing conditions like multiple myeloma and cancers with a proclivity for bone metastases. WB-MRI's capability to encompass the entire body in a singular scan has ushered in novel paradigms in cancer screening, especially for individuals harboring hereditary cancer syndromes or at heightened risk for metastatic disease. Additionally, its contribution to the clinical landscape, aiding in the holistic management of multifocal and systemic malignancies, is explored. The article accentuates the technical strides achieved in WB-MRI, its myriad clinical utilities, and the challenges in integration into standard oncological care. In essence, this review underscores the transformative potential of WB-MRI, emphasizing its promise as a cornerstone modality in shaping the future trajectory of cancer diagnostics and treatment.

Prediction of the Risk of Malignancy of Adnexal Masses during Pregnancy Comparing Subjective Assessment and Non-Contrast MRI Score (NCMS) in Radiologists with Different Expertise

Ovarian cancer represents 7% of all cancers in pregnant women. Characterising an ovarian mass during pregnancy is essential to avoid unnecessary treatment and, if treatment is required, to plan it accordingly. Although ultrasonography (US) is the first-line modality to characterise adnexal masses, MRI is indicated when adnexal masses are indeterminate at the US examination. An MRI risk stratification system has been proposed to assign a malignancy probability based on the adnexal lesion's MRI, but features of the scoring system require the administration of intravenous gadolinium-based contrast agents, a method that might have a limited use in pregnant women. The non-contrast MRI score (NCMS) has been used and evaluated in non-pregnant women to characterise adnexal masses indeterminate at the US examination. Therefore, we evaluated the diagnostic accuracy of the NCMS in pregnant women, analysing 20 cases referred to our specialised institution. We also evaluated the diagnostic agreement between two radiologists with different expertise. The two readers classified ovarian masses as benign or malignant using both subjective assessment (SA), based on the interpretive evaluation of imaging findings derived from personal experience, and the NCMS, which includes five categories where 4 and 5 indicate a high probability of a malignant mass. The expert radiologist correctly classified 90% of the diagnoses, using both SA and the NCMS, relying on a sensitivity of 85.7% and a specificity of 92.3%, with a false positive rate of 7.7% and a false negative rate of 14.3%. The non-expert radiologist correctly identified patients at a lower rate, especially using the SA. The analysis of the inter-observer agreement showed a K = 0.47 (95% CI: 0.48-0.94) for the SA (agreement in 71.4% of cases) and a K = 0.8 (95% CI: 0.77-1.00) for the NCMS (agreement in 90% of cases). Although in pregnant patients, non-contrast MRI is used, our results support the use of a quantitative score, i.e., the NCMS, as an accurate tool. This procedure may help less experienced radiologists to reduce the rate of false negatives or positives, especially in centres not specialised in gynaecological imaging, making the MRI interpretation easier and more accurate for radiologists who are not experts in the field, either.

Assessment of Female Pelvic Pathologies: A Cross-Sectional Study Among Patients Undergoing Magnetic Resonance Imaging for Pelvic Assessment at the Maternity and Children Hospital, Qassim Region, Saudi Arabia

Background and objectives Pelvic pathologies affect females in all age groups. They vary in size and location and can be wide in classification, such as masses, ectopic pregnancy, ovarian torsion, and ruptured ovarian follicles. Patients commonly present with gynecological complaints such as menstrual irregularities, abnormal pelvic bleeding, and infertility. Extra-gynecological symptoms such as dysuria and painful defecation can also manifest. To diagnose these pathologies, magnetic resonance imaging (MRI) and other imaging modalities can be useful alongside history and physical examination for early clinical diagnosis. Due to the importance of prevalence rate in predicting pathologies in a certain age and due to the lack of research studies on pelvic MRI studies in Qassim region, Saudi Arabia, this study aimed to demonstrate the wide spectrum of female pelvic pathologies that can be diagnosed using MRI in Qassim region, Saudi Arabia.  Methods and results A cross-sectional study was conducted among patients referred to the MRI Department for evaluation of female pelvic pathologies at the Department of Radiology at Maternity and Children Hospital in Buraydah, Qassim region, Saudi Arabia. A total of 325 patients were included in the study, with the majority being in the age group of 31-40 years. Fibroids were the most common pathology, being present in more than one-fifth of the study sample, followed by neoplastic growths and placental pathologies. Inflammatory pathologies were the least common pathologies, being present in approximately 5% of the participants. Statistically significant associations were found between the age groups, and the presence of anomalies (p = 0.009), existence of neoplastic changes (p < 0.001), presence of placental pathologies (p < 0.001), inflammatory changes (p = 0.025), and adenomyosis (p = 0.028). Conclusion MRI data offer important new information about the prevalence of various disorders among different age groups in the Qassim region of Saudi Arabia. Younger age groups had much higher rates of anomalies, whereas older age groups had much lower rates. Adenomyosis and neoplastic alterations were more prevalent in the later age groups, but endometrioma was more prevalent in younger age groups. Placental pathologies were more prevalent in women in their middle years, while scar pregnancy was more prevalent in women between 31 and 40 years of age. Younger people, especially those between 16 and 20 years of age, were more likely to experience inflammatory alterations. In the younger age group, there was no discernible association between age and the prevalence of normal outcomes. These findings help us understand how different illnesses manifest differently as we get older and emphasize the value of taking aging into account when diagnosing and treating disorders.

Cervical cancer in the pregnant population

Cervical cancer is the second most encountered cancer in pregnant patients. The 2018 International Federation of Gynecology and Obstetrics (FIGO) staging system for cervical cancer updated the staging of primary cervical carcinoma and disease process, with formal incorporation of imaging as a vital source of information in the management process to improve accuracy. Diagnosis and treatment of the pregnant population is a complex interplay of achieving adequate diagnostic information and optimal treatment while minimizing toxicity and risks to the mother and fetus. While novel imaging techniques and anticancer therapies are rapidly developed, much information on the safety and feasibility of different therapies is not yet available in the pregnant population. Therefore, managing pregnant patients with cervical cancer is complex and requires a multidisciplinary approach.

Imaging modalities and optimized imaging protocols in pregnant patients with cancer

Medical imaging during pregnancy may be necessary to diagnose conditions that affect the outcome of the mother and fetus. Diagnosis and staging of cancer in pregnant women can be particularly challenging due to fear of inherent risk to the fetus, lack of standardized imaging protocols, and ethical challenges posed while choosing the best imaging option. Ultrasound and MRI, due to lack of ionizing radiation, are preferred over CT and nuclear imaging. The latter may be considered only if the benefits of imaging outweigh maternal and fetal risk without exceeding the cumulative established fetal radiation dose threshold. This article provides an overview of all currently available imaging options that can be used for imaging cancer during pregnancy to support the best possible maternal and fetal outcomes.

Gastrointestinal malignancies in pregnancy

Gastrointestinal malignancies, though uncommon in pregnancy, present several unique challenges with regards to diagnosis, staging, and treatment. Imaging the pregnant patient with a suspected or confirmed GI malignancy requires modifications to the radiologic modality of choice and protocol in order to minimize harm to the fetus, ensure accuracy in diagnosis and staging and guide treatment decisions. In this review article, we discuss the imaging approach to the pregnant patient with GI cancer, including safe radiologic modalities and modifications to imaging protocols. We also review the most common GI cancers encountered in pregnancy, including colorectal, pancreatic, gastric, and small bowel tumors, with emphasis to imaging findings, staging, and treatment considerations.

Gadolinium-Based Contrast Agents: Updates and Answers to Typical Questions Regarding Gadolinium Use

Gadolinium-based contrast agents have expanded the diagnostic usefulness and capability of magnetic resonance imaging. Despite their highly favorable safety profile, these agents have been associated with nephrogenic systemic fibrosis in a small number of patients who have advanced kidney disease. Recently, trace amounts of gadolinium deposition in the brain and other organs have been reported after contrast exposure, even in patients with normal renal function. In this review, we provide a brief overview of recent updates and discuss typical clinical situations related to the use of gadolinium-based contrast agents.

How Could Nanomedicine Improve the Safety of Contrast Agents for MRI during Pregnancy?

Pregnancy is a delicate state, during which timely investigation of possible physiological anomalies is essential to reduce the risk of maternal and fetal complications. Medical imaging encompasses different technologies to image the human body for the diagnosis, course of treatment management, and follow-up of diseases. Ultrasound (US) is currently the imaging system of choice for pregnant patients. However, sonographic evaluations can be non-effective or give ambiguous results. Therefore, magnetic resonance imaging (MRI), due to its excellent tissue penetration, the possibility of acquisition of three-dimensional anatomical information, and its high spatial resolution, is considered a valid diagnostical alternative. Nevertheless, currently employed contrast agents to improve the MRI image quality are harmful to the fetus. Because of their ability to cross the placenta, their use on pregnant patients is avoided. This review will firstly recapitulate the most common non-obstetrical, obstetrical, and fetal indications for magnetic resonance imaging on pregnant women. Fetal safety risks, due to the use of strong magnetic fields and exogenous contrast agents, will be presented. Then, possible advantages of nanostructured contrast agents compared to current molecular ones are explored. Nanosystems’ characteristics affecting contrast efficiency, and their potential for improving contrast-enhanced MRI’s safety in pregnant women, are discussed. Lastly, promising examples of nanoparticles as safer alternatives to current MRI contrast agents in pregnancy are discussed.

Investigation of Effects of Gadolinium-Based Contrast Agents on Uterine Contractility Using Isolated Rat Myometrium

BACKGROUND

Despite concerns about safety, gadolinium-based contrast agents (GBCAs) are still used for abdominal and pelvic imaging during pregnancy. Researchers have mainly focused on teratogenicity, while very little is known about their possible direct effects on uterine contractility, yet free gadolinium potentially impacts contractility through interaction with calcium channels.

PURPOSE

To investigate possible effects of selected GBCAs (namely gadoteridol, gadoversetamide, gadobutrol, gadoterate meglumine, and gadoxetic acid) on the contractility of rat myometrium.

STUDY TYPE

In vitro organ bath study.

ANIMAL MODEL

Myometria were isolated from adult (10-12 weeks old) Sprague Dawley rats, both pregnant (N = 8) and nonpregnant (N = 36).

FIELD STRENGTH/SEQUENCE

NA.

ASSESSMENT

Myometrial strips were suspended in tissue bath containing physiological saline and isometric contractions were recorded. GBCAs were added to the tissue bath cumulatively, and their effects on contractility parameters (quantified by amplitude, frequency, and area under contractility curve [AUC]) were evaluated by 10-minute intervals.

STATISTICAL TESTS

Normality data, checked by Shapiro-Wilk test, were transformed by arcsine when needed. One- or two-way analysis of variance was performed, where appropriate, followed by Student-Newman-Keuls test. A P value of <0.05 was considered statistically significant.

RESULTS

All of the assayed GBCAs elicited some alterations in the myometrial contractility in a concentration-dependent manner. Gadoterate meglumine, gadoxetic acid, and gadoversetamide caused a concentration-dependent significant attenuation in AUC (oxytocin-induced, from 100% during control period to 45.1 ± 9.0% (nonpregnant) and 59.9 ± 8.5% (pregnant), for 90 μM gadoterate meglumine; respectively), and frequency of the spontaneous and oxytocin-induced contractions. Gadobutrol and gadoteridol at highest dose significantly attenuated mean AUC and frequency of oxytocin-induced contractions of nonpregnant myometrium.

DATA CONCLUSION

Results from this in vitro study indicate that GBCAs elicit modulation of myometrial contractions at clinically relevant concentrations. These effects may account, at least partially, for the known potential side effects (rare cases of miscarriages and elective abortion) of these agents.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 5.

CT and MRI Evaluations in Crohn's Complications: A Guide for the Radiologist

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory intestinal conditions with unknown etiology. Crohn's disease (CD) and ulcerative colitis (UC) are the two main types of IBD and they have some interchangeable and some different clinical and pathological characteristics. When diagnosis is performed for the first time, the majority of CD patients have a predominant inflammatory condition. As the disease progresses most patients experience the development of complications, such as abscesses, fistulas, perforation, strictures, and others. Both computed tomography (CT) and Magnetic Resonance Imaging (MRI) allow great view of the whole length of the intestinal tract together with the eventual extra-and intra-intestinal complications. MR enterography (MRE) and CT enterography (CTE), performed after oral administrations of contrast medium, have similar diagnostic accuracy for the diagnosis of CD and its complications. Even though CT is still the most familiar diagnostic technique used for studying CD worldwide, MRE have several important benefits that are leading to rapid increase in its employment in the last years. In particular, MRE allows a superior soft tissue contrast resolution compared to CT, offering a better visualization of bowel wall and its inflammatory and fibrotic characteristics. Moreover, Pelvic Magnetic Resonance is the principal technique in patients with perianal disease due to its ability of providing precise and fine detail images of the sphincter complex, which are crucial for evaluating pelvic disease. In this paper we describe common and uncommon complications in patients with CD, and explain how to identify their findings in CT and MR exams.

Imaging modalities in pregnant cancer patients

Cancer during pregnancy is increasingly diagnosed due to the trend of delaying pregnancy to a later age and probably also because of increased use of non-invasive prenatal testing for fetal aneuploidy screening with incidental finding of maternal cancer. Pregnant women pose higher challenges in imaging, diagnosis, and staging of cancer. Physiological tissue changes related to pregnancy makes image interpretation more difficult. Moreover, uncertainty about the safety of imaging modalities, fear of (unnecessary) fetal radiation, and lack of standardized imaging protocols may result in underutilization of the necessary imaging tests resulting in suboptimal staging. Due to the absence of radiation exposure, ultrasound and MRI are obvious first-line imaging modalities for detailed locoregional disease assessment. MRI has the added advantage of a more reproducible comprehensive organ or body region assessment, the ability of distant staging through whole-body evaluation, and the combination of anatomical and functional information by diffusion-weighted imaging which obviates the need for a gadolinium-based contrast-agent. Imaging modalities with inherent radiation exposure such as CT and nuclear imaging should only be performed when the maternal benefit outweighs fetal risk. The cumulative radiation exposure should not exceed the fetal radiation threshold of 100 mGy. Imaging should only be performed when necessary for diagnosis and likely to guide or change management. Radiologists play an important role in the multidisciplinary team in order to select the most optimal imaging strategies that balance maternal benefit with fetal risk and that are most likely to guide treatment decisions. Our aim is to provide an overview of possibilities and concerns in current clinical applications and developments in the imaging of patients with cancer during pregnancy.