Body CT during pregnancy: utilization trends, examination indications, and fetal radiation doses. AJR Am J Roentgenol. 2011;196:146-151. [PMID: 21178060 DOI: 10.2214/ajr.10.4271]

Management and outcomes of aortic dissection type B in late pregnancy: A retrospective case series

OBJECTIVE

Pregnancy complicated with type B aortic dissection is a rare but devastating condition. Guidelines for managing this condition are lacking. We present our observation and experiences in managing five pregnant women with complicated type B aortic dissection in the second or third trimesters, aiming to gain insights that can aid in proposing an appropriate management strategy.

DESIGN

A retrospective study.

SETTING

Zhongnan Hospital of Wuhan University.

POPULATION

Pregnant women with complicated type B aortic dissection.

METHODS

Clinical data of five pregnant women with complicated type B aortic dissection admitted to Zhongnan Hospital of Wuhan University from January 2022 to June 2023 were collected. The clinical characteristics, treatment strategies, and corresponding maternal and infant outcomes were retrospectively analysed.

MAIN OUTCOME MEASURES

Survival of mothers and foetuses.

RESULTS

All five study participants were diagnosed with complicated type B aortic dissection by computed tomography angiography (CTA). The range of gestational weeks at admission was 27 weeks + 3 days to 36 weeks + 6 days. The first patient, planning a caesarean section (C-section) followed by thoracic endovascular aortic repair (TEVAR), died of aortic dissection rupture during C-section. Her neonate was successfully rescued. In contrast, the remaining four patients who underwent TEVAR first survived. Among them, three patients underwent single-stage aortic repair and delivery, while one patient received C-section 31 days after TEVAR. Three preterm live births were recorded among these surviving mothers. Neonatal death occurred in one case with a gestational age of 29 weeks + 5 days, who had foetal distress before surgery. During the follow-up period of up to 3 months, no maternal or infant death occurred. No device-related or systemic complications were observed in the surviving mothers after discharge. Routine physical examinations of the four live births showed no abnormalities.

CONCLUSIONS

For pregnant women with thoracic back pain and high suspicion of aortic dissection, CTA should be conducted promptly to prevent missed or delayed diagnosis. Maternal survival should be prioritised over foetal outcome once diagnosed. TEVAR was demonstrated to be safe and feasible for such patients. For women with complicated type B aortic dissection in late pregnancy, TEVAR followed by C-section may be a promising treatment strategy.

Management of pregnant or potentially pregnant patients undergoing diagnostic and interventional radiology procedures: Investigation of clinical routine practice

It is well known that foetuses are highly sensitive to ionising radiation and special attention to justification and optimisation of radiological procedures involving a pregnant patient is required. A task to review, validate and compare different approaches to managing the pregnant patient and to estimating the associated foetal doses arising from a diagnostic or interventional radiology (DIR) procedure was designed in the framework of EURADOS working group 12. As a first step, a survey of radiation protection practice including dosimetry considerations among EURADOS members was performed using online questionnaire. Then, to evaluate the possible differences in the estimated foetal doses, a comparison of assessed dose values was made for three cases of pregnant patients that underwent different CT procedures. More than 120 professionals from 108 institutions and 17 countries that are involved in managing pregnant patients undergoing DIR procedures answered the questionnaire. Most of the respondents use national or hospital guidelines on the management of pregnant patients undergoing DIR procedures. However, the guidelines differ considerably among respondents. Comparison of foetal dose assessments performed by dosimetry experts showed the variety of methods used as well as large variability of estimated foetal doses in all three cases. Although European and International commission on radiation protection guidelines already exist, they are more than 20 years old and, in some aspects, they are obsolete. This paper shows that there is a need to revise and update these guidelines.

Pregnancy and Gastric Cancer: A Narrative Review

Cases of digestive cancers diagnosed during pregnancy are rare. The increasing prevalence of pregnancy in women aged 30-39 years (and not exceptionally 40-49 years) could explain the frequent co-occurrence of cancers and pregnancy. The diagnosis of digestive cancers in pregnancy is difficult due to the overlap between neoplasm symptomatology and the clinical picture of pregnancy. A paraclinical evaluation may also be difficult depending on the trimester of the pregnancy. Diagnosis is also delayed by practitioners' hesitation to use invasive investigations (imaging, endoscopy, etc.) due to fetal safety concerns. Therefore, digestive cancers are often diagnosed during pregnancy in advanced stages, where complications such as occlusions, perforations, and cachexia have already arisen. In this review, we highlight the epidemiology, clinical aspects, paraclinical evaluation, and particularities of the diagnosis and treatment of gastric cancer during pregnancy.

The why, who, how, and what of communicating CT radiation risks to patients and healthcare providers

Computed tomography (CT) has witnessed tremendous growth in utilization. Despite its immense benefits, there is a growing concern from the general public and the medical community about the detrimental consequences of ionizing radiation from CT. Anxiety from the perceived risks associated with CT can deter referring physicians from ordering clinically indicated CT scans and patients from undergoing medically necessary exams. This article discusses various strategies for educating patients and healthcare providers on the benefits and risks of CT scanning and salient techniques for effective communication.

Fetal Dose from PET and CT in Pregnant Patients

When pregnancy is discovered during or after a diagnostic examination, the physician or the patient may request an estimate of the radiation dose received by the fetus as per guidelines and standard operating procedures. This study provided the imaging community with dose estimates to the fetus from PET/CT with protocols that are adapted to University of Michigan low-dose protocols for patients known to be pregnant. Methods: There were 9 patients analyzed with data for the first, second, and third trimesters, the availability of which is quite rare. These images were used to calculate the size-specific dose estimate (SSDE) from the CT scan portion and the SUV and ¹⁸F-FDG uptake dose from the PET scan portion using the MIRD formulation. The fetal dose estimates were tested for correlation with each of the following independent measures: gestational age, fetal volume, average water-equivalent diameter of the patient along the length of the fetus, SSDE, SUV, and percentage of dose from ¹⁸F-FDG. Stepwise multiple linear regression analysis was performed to assess the partial correlation of each variable. To our knowledge, this was the first study to determine fetal doses from CT and PET images. Results: Fetal self-doses from ¹⁸F for the first, second, and third trimesters were 2.18 mGy (single data point), 0.74-1.82 mGy, and 0.017-0.0017 mGy, respectively. The combined SSDE and fetal self-dose ranged from 1.2 to 8.2 mGy. These types of images from pregnant patients are rare. Conclusion: Our data indicate that the fetal radiation exposure from ¹⁸F-FDG PET and CT performed, when medically necessary, on pregnant women with cancer is low. All efforts should be made to minimize fetal radiation exposure by modifying the protocol.

Guidelines for the management of urgent obstetric situations in emergency medicine, 2022

OBJECTIVE

To provide recommendations on the management of urgent obstetrical emergencies outside the maternity ward.

DESIGN

A group of 24 experts from the French Society of Emergency Medicine (SFMU), the French Society of Anaesthesia and Intensive Care Medicine (SFAR) and the French College of Gynaecologists and Obstetricians (CNGOF) was convened. Potential conflicts of interest were formally declared at the outset of the guideline development process, which was conducted independently of industry funding. The authors followed the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method to assess the level of evidence in the literature. The potential drawbacks of strong recommendations in the presence of low-level evidence were highlighted. Some recommendations with an insufficient level of evidence were not graded.

METHODS

Eight areas were defined: imminent delivery, postpartum haemorrhage (prevention and management), threat of premature delivery, hypertensive disorders in pregnancy, trauma, imaging, cardiopulmonary arrest, and emergency obstetric training. For each field, the expert panel formulated questions according to the PICO model (population, intervention, comparison, outcomes) and an extensive literature search was conducted. Analysis of the literature and formulation of recommendations were conducted according to the GRADE method.

RESULTS

Fifteen recommendations on the management of obstetrical emergencies were issued by the SFMU/SFAR/CNGOF panel of experts, and 4 recommendations from formalised expert recommendations (RFE) established by the same societies were taken up to answer 4 PICO questions dealing with the pre-hospital context. After two rounds of voting and several amendments, strong agreement was reached for all the recommendations. For two questions (cardiopulmonary arrest and inter-hospital transfer), no recommendation could be made.

CONCLUSIONS

There was significant agreement among the experts on strong recommendations to improve practice in the management of urgent obstetric complications in emergency medicine.

SIZE-SPECIFIC DOSE ESTIMATES IN FETAL COMPUTED TOMOGRAPHY

During fetal computed tomography (CT) imaging, because of differences in the pregnancy period and scanning conditions, different doses of radiation are absorbed by the fetus. We propose a correction coefficient for determining the fetal size-specific dose estimate (SSDE) from the CT dose index (CTDI) displayed on the console at tube voltages of 80-135 kVp. The CTDIs corresponding to pregnant women and fetuses were evaluated using a Monte Carlo (MC) simulation, and the ratio of these CTDIs was defined as the Fetus-factor. When the effective diameter of a fetus was approximately 10 cm, the Fetus-factor was 1.0. The estimated pregnant SSDE was multiplied by the Fetus-factor to estimate the fetal SSDE, which was compared with the fetal dose obtained by the MC simulation of the image of the fetal CT examination. The fetal dose could be estimated with an error of 31.5% in fetal examinations conducted using helical CT.

Role of Ultrasound in the Assessment and Differential Diagnosis of Pelvic Pain in Pregnancy

Pelvic pain (PP) is common in pregnant women and can be caused by several diseases, including obstetrics, gynaecological, gastrointestinal, genitourinary, and vascular disorders. Timely and accurate diagnosis as well as prompt treatment are crucial for the well-being of the mother and foetus. However, these are very challenging. It should be considered that the physiological changes occurring during pregnancy may confuse the diagnosis. In this setting, ultrasound (US) represents the first-line imaging technique since it is readily and widely available and does not use ionizing radiations. In some cases, US may be conclusive for the diagnosis (e.g., if it detects no foetal cardiac activity in suspected spontaneous abortion; if it shows an extrauterine gestational sac in suspected ectopic pregnancy; or if it reveals a dilated, aperistaltic, and blind-ending tubular structure arising from the cecum in suspicious of acute appendicitis). Magnetic resonance imaging (MRI), overcoming some limits of US, represents the second-line imaging technique when an US is negative or inconclusive, to detect the cause of bowel obstruction, or to characterize adnexal masses.

Pancreatic neuroendocrine carcinoma in a pregnant woman: A case report and review of the literature

BACKGROUND

Portal venous thromboembolism caused by malignant pancreatic neuroendocrine tumor metastasis, as the initial presentation of portal hypertension and upper gastrointestinal bleeding, is a rare entity. To our knowledge, there are no reports of this entity in pregnant women. We describe a case of pancreatic neuroendocrine carcinoma during pregnancy with hematemesis and hematochezia as the initial presentation and review the literature to analyze the demographic, clinical, and pathological features to provide a reference for clinical diagnosis and treatment.

CASE SUMMARY

A 40-year-old woman presented with hematemesis and hematochezia at 26-wk gestation; she had no other remarkable medical history. The physical examination revealed normal vital signs, an anemic appearance, and lower abdominal distension. Abdominal color Doppler ultrasonography showed portal vein thrombosis, splenomegaly, intrauterine pregnancy, and intrauterine fetal death. Esophagogastroduodenoscopy revealed esophageal and gastric varicose veins and portal hypertensive gastropathy. Contrast-enhanced computed tomography demonstrated multiple emboli formation in the portal and splenic veins, multiple round shadows in the liver with a slightly lower density, portal vein broadening, varicose veins in the lower esophagus and gastric fundus, splenomegaly, bilateral pleural effusion, ascites and pelvic effusion, broadening of the common bile duct, and increased uterine volume. According to the results of Positron emission tomography-computed tomography and immunohistochemical staining, the final diagnoses were that the primary lesion was a pancreatic neuroendocrine tumor and that there were secondary intrahepatic metastases and venous cancer thrombogenesis.

CONCLUSION

Upper gastrointestinal bleeding in a pregnant woman may be caused by portal hypertension due to a malignant pancreatic neuroendocrine tumor.

Imaging during pregnancy: What the radiologist needs to know

During the last decades, there has been a growing demand for medical imaging in gravid women. Imaging of the pregnant woman is challenging as it involves both the mother and the fetus and, consequently, several medical, ethical, or legal considerations are likely to be raised. Theoretically, all currently available imaging modalities may be used for the evaluation of the pregnant woman; however, in practice, confusion regarding the safety of the fetus often results in unnecessary avoidance of useful diagnostic tests, especially those involving ionizing radiation. This review article is focused on the current safety guidelines and considerations regarding the use of different imaging modalities in the pregnant population; also presented is an imaging work-up for the most common medical conditions of pregnant women, with emphasis on fetal and maternal safety.

Radiation Dose to the Fetus From Computed Tomography of Pregnant Patients-Development and Validation of a Web-Based Tool

OBJECTIVE

Estimations of radiation dose absorbed by the fetus from computed tomography (CT) in pregnant patients is mandatory, but currently available methods are not feasible in clinical routine. The aims of this study were to develop and validate a tool for assessment of fetal dose from CT of pregnant patients and to develop a user-friendly web interface for fast fetal dose calculations.

METHODS

In the first study part, 750 Monte Carlo (MC) simulations were performed on phantoms representing pregnant patients at various gestational stages. The MC code simulating vendor-independent dose distributions was validated against CT dose index (CTDI) measurements performed on CT scanners of 2 vendors. The volume CTDI-normalized fetal dose values from MC simulations were used for developing the computational algorithm enabling fetal dose assessments from CT of various body regions at different exposure settings. In the institutional review board-approved second part, the algorithm was validated against patient-specific MC simulations performed on CT data of 29 pregnant patients (gestational ages 8-35 weeks) who underwent CT. Furthermore, the tool was compared with a commercially available software. A user-friendly web-based interface for fetal dose calculations was created.

RESULTS

Weighted CTDI values obtained from MC simulations were in excellent agreement with measurements performed on the 2 CT systems (average error, 4%). The median fetal dose from abdominal CT in pregnant patients was 2.7 mGy, showing moderate correlation with maternal perimeter (r = 0.69). The algorithm provided accurate estimates of fetal doses (average error, 11%), being more accurate than the commercially available tool. The web-based interface (www.fetaldose.org) enabling vendor-independent calculations of fetal doses from CT requires the input of gestational age, volume CTDI, tube voltage, and scan region.

CONCLUSIONS

A tool for fetal dose assessments from CT of pregnant patients was developed and validated being freely available on a user-friendly web interface.

Chest CT versus RT-PCR for the detection of COVID-19: systematic review and meta-analysis of comparative studies

OBJECTIVES

To compare the performance of chest computed tomography (CT) scan versus reverse transcription polymerase chain reaction (RT-PCR) as the reference standard in the initial diagnostic assessment of coronavirus disease 2019 (COVID-19) patients.

DESIGN

A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A search of electronic information was conducted using the following databases: MEDLINE, EMBASE, EMCARE, CINAHL and the Cochrane Central Register of Controlled Trials.

SETTING

Studies that compared the diagnostic performance within the same patient cohort of chest CT scan versus RT-PCR in COVID-19 suspected patients.

PARTICIPANTS

Thirteen non-randomised studies enrolling 4092 patients were identified.

MAIN OUTCOME MEASURES

Sensitivity, specificity and accuracy were primary outcome measures. Secondary outcomes included other test performance characteristics and discrepant findings between both investigations.

RESULTS

Chest CT had a median sensitivity, specificity and accuracy of 0.91 (range 0.82-0.98), 0.775 (0.25-1.00) and 0.87 (0.68-0.99), respectively, with RT-PCR as the reference. Importantly, early small, China-based studies tended to favour chest CT versus later larger, non-China studies.

CONCLUSIONS

A relatively high false positive rate can be expected with chest CT. It is possible it may still be useful to provide circumstantial evidence, however, in some patients with a suspicious clinical presentation of COVID-19 and negative initial Severe Acute Respiratory Syndrome Coronavirus 2 RT-PCR tests, but more evidence is required in this context. In acute cardiorespiratory presentations, negative CT scan and RT-PCR tests is likely to be reassuring.

A retrospective audit of cumulative ionising radiation levels in hospitalised pregnant patients

BACKGROUND

Among hospitalised patients, diagnostic radiation is possibly used least on pregnant patients due to the fear of ionising radiation on the fetus; however, what levels are currently being prescribed?

AIMS

To assess the cumulative levels of ionising radiation received by pregnant patients during a single admission to a tertiary hospital.

MATERIALS AND METHODS

A retrospective audit of pregnant patients admitted to Flinders Medical Centre, South Australia, Australia, between 2013 and 2017 inclusive was performed. All procedures utilising ionising radiation were collected including conventional radiology, computed tomography, fluoroscopy and nuclear medicine. Individual and cumulative effective doses for mother and fetus were calculated using patient dose reports and published conversion factors.

RESULTS

From 547 patients, the median cumulative effective dose was 0.02 mSv and only five patients received more than 10 mSv, with 19.07 mSv the highest dose received. The median fetal cumulative effective dose was 0.01 mSv but only three fetuses received more than 10 mSv, likely due to fetal exclusion in some procedural fields of view. Stays longer than ten days were associated with significantly higher cumulative effective dose, as did those with maternal cardiovascular related admission, for both maternal and fetal exposures.

CONCLUSION

These results suggest that pregnant patients are exposed to low doses of ionising radiation, in both individual procedures and cumulative doses. The detrimental risks associated with these levels of ionising radiation are not overt and so clinicians should question which risk is higher, the ionising radiation from the radiological procedures received or the lack of diagnostic information if avoided?

How I treat lymphoma in pregnancy

Lymphomas afflict all age groups of people, with certain types demonstrating a female predilection in adolescents and young adults. A proportion of lymphomas that are diagnosed in this population demographic occur in the setting of pregnancy. Most of these behave aggressively at presentation and require immediate or urgent therapy. Treatment must consider both maternal and fetal health, and management approaches are therefore influenced by gestational age at diagnosis and treatment and timing of delivery. Although there is a paucity of literature on how to treat these patients, limited retrospective reports demonstrate generally good outcomes and highlight the necessity of an experienced multidisciplinary team approach to management.

The application of in utero magnetic resonance imaging in the study of the metabolic and cardiovascular consequences of the developmental origins of health and disease

Observing fetal development in utero is vital to further the understanding of later-life diseases. Magnetic resonance imaging (MRI) offers a tool for obtaining a wealth of information about fetal growth, development, and programming not previously available using other methods. This review provides an overview of MRI techniques used to investigate the metabolic and cardiovascular consequences of the developmental origins of health and disease (DOHaD) hypothesis. These methods add to the understanding of the developing fetus by examining fetal growth and organ development, adipose tissue and body composition, fetal oximetry, placental microstructure, diffusion, perfusion, flow, and metabolism. MRI assessment of fetal growth, organ development, metabolism, and the amount of fetal adipose tissue could give early indicators of abnormal fetal development. Noninvasive fetal oximetry can accurately measure placental and fetal oxygenation, which improves current knowledge on placental function. Additionally, measuring deficiencies in the placenta’s transport of nutrients and oxygen is critical for optimizing treatment. Overall, the detailed structural and functional information provided by MRI is valuable in guiding future investigations of DOHaD.

Fetal Dosimetry at CT: A Primer

CT scanning of a pregnant patient is often a source of distress for both patient and staff. Despite having expertise in image interpretation, a radiologist may not feel equipped to discuss the radiation-related safety issues during CT scanning of the fetus. In addition, patients are frequently concerned about the risk of adverse effects on the fetus from exposure to ionizing radiation. Recognizing the possibility of adverse effects from fetal exposure and the impossibility of direct in vivo measurement, medical physicists have developed several methods to estimate the amount of radiation reaching the fetus. A physician should know the potential biologic effects of fetal irradiation and at what radiation dose thresholds they occur. Physicians should also have an understanding of these methods and how the numbers they produce relate to potential fetal bioeffects. Furthermore, radiologists should have some understanding of how a qualified medical physicist calculates the fetal dose, how much they should trust those numbers, and the relevant variables that can affect the outcomes. Finally, the radiologist should know the magnitude of doses for CT scans commonly used in pregnant patients. Armed with this knowledge, a radiologist should be confident when discussing fetal dose and determining the best course of action for the pregnant patient. Online supplemental material is available for this article. ^©RSNA, 2020.

Clinical Practice Guidelines for Childbearing Female Candidates for Bariatric Surgery, Pregnancy, and Post-partum Management After Bariatric Surgery

Emerging evidence suggests that bariatric surgery improves pregnancy outcomes of women with obesity by reducing the rates of gestational diabetes, pregnancy-induced hypertension, and macrosomia. However, it is associated with an increased risk of a small-for-gestational-age fetus and prematurity. Based on the work of a multidisciplinary task force, we propose clinical practice recommendations for pregnancy management following bariatric surgery. They are derived from a comprehensive review of the literature, existing guidelines, and expert opinion covering the preferred type of surgery for women of childbearing age, timing between surgery and pregnancy, contraception, systematic nutritional support and management of nutritional deficiencies, screening and management of gestational diabetes, weight gain during pregnancy, gastric banding management, surgical emergencies, obstetrical management, and specific care in the postpartum period and for newborns.

Management of surgical complications of previous bariatric surgery in pregnant women. A systematic review from the BARIA-MAT Study Group

Considering the large and increasing population of women of childbearing age with history of bariatric surgery, surgical complications of bariatric surgery during pregnancy may become more frequent in the future. The aim of this study was to analyze the clinical presentation, diagnostic procedures, and treatment of surgical complications of bariatric surgery during pregnancies. A systematic literature search was performed in accordance with the PRISMA (preferred reporting items for systematic review and meta-analysis) guidelines to identify all studies published up to and including December 2018 that included women with previous bariatric surgery undergoing emergency surgery during pregnancy. Sixty-eight studies were selected, including 120 women with previous bariatric surgery undergoing emergency surgery during pregnancy. Fifty cases were reported as case reports and 70 in case series. Included patients had previous history of Roux-en-Y gastric bypass (n = 99), laparoscopic adjustable gastric banding (n = 17), Scopinaro procedure (n = 2), vertical banded gastroplasty (n = 1), or one-anastomosis gastric bypass (n = 1). Final diagnosis in 50 case reports was internal hernia in 26 cases, bowel intussusception in 10, intestinal obstruction in 2, laparoscopic adjustable gastric banding slippage in 3, bowel volvulus in 3, gastric or jejunal perforation in 2, and other complications in 4 cases. Maternal and fetal death occurred in 3 (2.5%) and 9 cases (7.5%), respectively. In the case series, the majority of women were operated for internal hernia and laparoscopic adjustable gastric banding slippage. Surgical complications of previous bariatric surgery during pregnancy have potentially severe outcomes. Availability of multidisciplinary expertise, including bariatric/digestive surgeons, and education of healthcare providers and women on clinical signs that require urgent surgical examination are recommended in this setting. Prompt diagnosis is fundamental and based on clinical and laboratory findings and on radiologic examinations if needed, including computed tomography scan or magnetic resonance if available. Rapid surgical exploration is mandatory in case of high clinical and/or radiologic suspicion.

[Acute appendicitis during pregnancy]

Acute appendicitis is the most frequent surgical disease complicating pregnancy. Accurate diagnosis is difficult due to atypical and misleading clinical manifestations. Surgeons frequently do not know about advantages and disadvantages of different diagnostic methods applied during pregnancy. Treatment of acute appendicitis in pregnant women remains the real challenge for surgeons. There are enough researches indicating on benefits and risks of both open and laparoscopic operations. The main risk is due to fetal loss after laparoscopic procedure. Safety of diagnostic techniques and laparoscopic procedures, surgical tactics and independent risk factors of pregnancy loss are touched in the article.

Management of pregnancy-associated pancreatic cystic tumors: Review of the literature and results of a Pancreas Club Inc. Survey

BACKGROUND/OBJECTIVES

Management of patients with pregnancy-associated cyst pancreatic cystic tumors (PA-PCT) is complicated by lack of large series.

METHODS

A systematic literature review was conducted to extrapolate data on management of PA-PCT, and make a questionnaire on pending issues to be administered to the members of the Pancreas Club Inc.

RESULTS

The literature review demonstrated a total of 35 PA-PCT in 34 women, described exclusively in the form of case reports, and permitted the identification of eleven key questions to be addressed in the survey. The combined analysis of literature review and survery responses provided several information. First, PA-PCT are predominantly located in the body-tail of the pancreas, cause non-specific symptoms, are of large size (mean size: 11.2 ± 4.5 cm), and are nearly always malignant or premalignant, making timing of surgery, and not indication for surgery, the main issue in the management of these tumors. Second, there is a risk of PA-PCT rupture during pregnancy. Ruptured PA-PCT had a mean size 13.5 ± 4.9 cm, but no prognostic factor could be identified. Survey opinions suggested that this occurrence is quite rare, even for large tumors. Third, most pregnancies were conducted to term (mean gestational age: 40.5 ± 0.7 weeks), with a vaginal delivery. Fourth, all procedures were carried out through an open approach and the spleen was rarely preserved. Survey indicated instead that laparoscopy could play a role, and that the spleen should be preserved when feasible.

CONCLUSIONS

PA-PCT require individualized treatment. The definition of a management algorithm requires the implementation of an International Registry.

Imaging of Cardiovascular Disease in Pregnancy and the Peripartum Period

OPINION STATEMENT

Cardiovascular disease is an important cause of morbidity and mortality during pregnancy and the postpartum period. During pregnancy, the cardiovascular system undergoes extensive hemodynamic, hormonal, and microstructural changes which may exacerbate a preexisting underlying cardiovascular condition or predispose to cardiovascular complications not typically seen in young healthy women. Such conditions include spontaneous coronary artery dissection, atherosclerotic coronary artery disease, and peripartum cardiomyopathy. When evaluating this patient population, the diagnostic strategy should be tailored to specifically assess this distinct disease spectrum. The choice of imaging techniques must also consider potential risks to both the mother and child; a unique challenge of diagnostic imaging during pregnancy. The risk of radiation from radiography, computed tomography, and nuclear medicine imaging; iodinated and gadolinium-based contrast media for computed tomography and magnetic resonance imaging respectively; and heat deposition from sonography are of special importance during pregnancy. A thorough understanding of pregnancy-specific cardiovascular complications and the capabilities and risks of available diagnostic imaging modalities is crucial to appropriately manage the pregnant patient.

Fetal radiation dose in three common CT examinations during pregnancy - Monte Carlo study

PURPOSE

To determine fetal doses in different stages of pregnancy in three common computed tomography (CT) examinations: pulmonary CT angiography, abdomino-pelvic and trauma scan with Monte Carlo (MC) simulations.

METHODS

An adult female anthropomorphic phantom was scanned with a 64-slice CT using pulmonary angiography, abdomino-pelvic and trauma CT scan protocols. Three different sized gelatin boluses placed on the phantom's abdomen simulated different stages of pregnancy. Intrauterine dose was used as a surrogate to a dose absorbed to the fetus. MC simulations were performed to estimate uterine doses. The simulation dose levels were calibrated with volumetric CT dose index (CTDI_vol) measurements and MC simulations in a cylindrical CTDI body phantom and compared with ten point doses measured with metal-oxide-semiconductor field-effect-transistor dosimeters. Intrauterine volumes and uterine walls were segmented and the respective dose volume histograms were calculated.

RESULTS

The mean intrauterine doses in different stages of pregnancy varied from 0.04 to 1.04mGy, from 4.8 to 5.8mGy, and from 9.8 to 12.6mGy in the CT scans for pulmonary angiography, abdomino-pelvic and trauma CT scans, respectively. MC simulations showed good correlation with the MOSFET measurement at the measured locations.

CONCLUSIONS

The three studied examinations provided highly varying fetal doses increasing from sub-mGy level in pulmonary CT angiography to notably higher levels in abdomino-pelvic and trauma scans where the fetus is in the primary exposure range. Volumetric dose distribution offered by MC simulations in an appropriate anthropomorphic phantom provides a comprehensive dose assessment when applied in adjunct to point-dose measurements.

Pneumocystis Pneumonia in Non-HIV Pregnant Women Receiving Chemotherapy for Malignant Lymphoma: Two Case Reports

Pneumocystis pneumonia (PCP) is a life-threatening opportunistic infection that sometimes occurs in immunocompromised patients with human immunodeficiency virus (HIV). Here, we report two extremely rare cases of PCP in non-HIV pregnant women who underwent chemotherapy for malignant lymphoma. Case  1 is a 34-year-old primigravida who was diagnosed with Hodgkin's lymphoma. She received ABVD chemotherapy and developed PCP at 37 weeks of gestation. After the onset of PCP, emergent cesarean section was performed due to a nonreassuring fetal status. Case  2 is a 31-year-old multigravida with diffuse large B-cell lymphoma who was administered R-CHOP chemotherapy. At 34 weeks of gestation, she complained of dyspnea and developed PCP. She delivered her baby vaginally immediately after the onset of symptoms. Both patients were treated with sulfamethoxazole-trimethoprim (ST) and recovered shortly thereafter. The babies' courses were also uneventful. PCP remains a serious cause of death, especially in non-HIV patients, and, therefore, appropriate prophylaxis and a prompt diagnosis are imperative.

Contemporary Modalities to Image the Fetal Brain

Fetal brain ultrasound remains as the mainstay for screening fetal intracranial anatomy. One of its main advantages is the availability of 3 dimensional and other ultrasound modalities for a better understanding of fetal neurodevelopment. Neurosonography is performed when findings, suggestive of an abnormality, are present on a screening ultrasound or if a high-risk situation of brain injury is present. This technique offers the use of complementary imaging planes, axial, coronal and sagittal, and the ability to image intracranial anatomy from the transabdominal and transvaginal approaches. Fetal brain magnetic resonance imaging is more sensitive than ultrasound. As an adjunctive imaging modality, magnetic resonance imaging offers additional sequences to complete the information on neurodevelopment from different perspectives, such as brain metabolism, microstructure, and connectivity.

Imaging Pregnant and Lactating Patients

As use of imaging in the evaluation of pregnant and lactating patients continues to increase, misperceptions of radiation and safety risks have proliferated, which has led to often unwarranted concerns among patients and clinicians. When radiologic examinations are appropriately used, the benefits derived from the information gained usually outweigh the risks. This review describes appropriateness and safety issues, estimated doses for imaging examinations that use iodizing radiation (ie, radiography, computed tomography, nuclear scintigraphy, and fluoroscopically guided interventional radiology), radiation risks to the mother and conceptus during various stages of pregnancy, and use of iodinated or gadolinium-based contrast agents and radiotracers in pregnant and lactating women. Maternal radiation risk must be weighed with the potential consequences of missing a life-threatening diagnosis such as pulmonary embolus. Fetal risks (ie, spontaneous abortion, teratogenesis, or carcinogenesis) vary with gestational age and imaging modality and should be considered in the context of the potential benefit of medically necessary diagnostic imaging. When feasible and medically indicated, modalities that do not use ionizing radiation (eg, magnetic resonance imaging) are preferred in pregnant and lactating patients. Radiologists should strive to minimize risks of radiation to the mother and fetus, counsel patients effectively, and promote a realistic understanding of risks related to imaging during pregnancy and lactation.

JOURNAL CLUB: Quantification of Fetal Dose Reduction if Abdominal CT Is Limited to the Top of the Iliac Crests in Pregnant Patients With Trauma

OBJECTIVE

The purposes of this study were to correlate fetal z-axis location within the maternal abdomen on CT with gestational age and estimate fetal dose reduction of a study limited to the abdomen only, with its lower aspect at the top of the iliac crests, compared with full abdominopelvic CT in pregnant trauma patients.

MATERIALS AND METHODS

We performed a study of pregnant patients who underwent CT of the abdomen and pelvis for trauma at a single institution over a 10-year period. The inferior aspect of maternal liver, spleen, gallbladder, pancreas, adrenals, and kidneys was recorded as above or below the iliac crests. The distance from the iliac crest to the top of the fetus or gestational sac was determined. The CT images of the limited and full scanning studies were independently reviewed by two blinded radiologists to identify traumatic injuries. Fetal dose profiles, including both scatter and primary radiation, were computed analytically along the central axis of the patient to estimate fetal dose reduction. Linear regression analysis was performed between gestational age and distance of the fetus to the iliac crests.

RESULTS

Thirty-five patients were included (mean age, 26.2 years). Gestational age ranged from 5 to 38 weeks, with 5, 19, and 11 gestations in the first, second, and third trimesters, respectively. All solid organs were above the iliac crests in all patients. In three of six patients, traumatic findings in the pelvis would have been missed with the limited study. There was high correlation between gestational age and distance of the fetus to the iliac crests (R(2) = 0.84). The mean gestational age at which the top of the fetus was at the iliac crest was 17.3 weeks. Using the limited scanning study, fetuses at 5, 20, and 40 weeks of gestation would receive an estimated 4.3%, 26.2%, and 59.9% of the dose, respectively, compared with the dose for the full scanning study.

CONCLUSION

In pregnant patients in our series with a history of trauma, CT of the abdomen only was an effective technique to reduce fetal radiation exposure compared with full abdomen and pelvis CT.

Ionizing Radiation Impacts on Cardiac Differentiation of Mouse Embryonic Stem Cells

Little is known about the effects of ionizing radiation on the earliest stages of embryonic development although it is well recognized that ionizing radiation is a natural part of our environment and further exposure may occur due to medical applications. The current study addresses this issue using D3 mouse embryonic stem cells as a model system. Cells were irradiated with either X-rays or carbon ions representing sparsely and densely ionizing radiation and their effect on the differentiation of D3 cells into spontaneously contracting cardiomyocytes through embryoid body (EB) formation was measured. This study is the first to demonstrate that ionizing radiation impairs the formation of beating cardiomyocytes with carbon ions being more detrimental than X-rays. However, after prolonged culture time, the number of beating EBs derived from carbon ion irradiated cells almost reached control levels indicating that the surviving cells are still capable of developing along the cardiac lineage although with considerable delay. Reduced EB size, failure to downregulate pluripotency markers, and impaired expression of cardiac markers were identified as the cause of compromised cardiomyocyte formation. Dysregulation of cardiac differentiation was accompanied by alterations in the expression of endodermal and ectodermal markers that were more severe after carbon ion irradiation than after exposure to X-rays. In conclusion, our data show that carbon ion irradiation profoundly affects differentiation and thus may pose a higher risk to the early embryo than X-rays.

Risks to the fetus from diagnostic imaging during pregnancy: review and proposal of a clinical protocol

Every day, medical practitioners face the dilemma of exposing pregnant or possibly pregnant patients to radiation from diagnostic examinations. Both doctors and patients often have questions about the risks of radiation. The most vulnerable period is between the 8th and 15th weeks of gestation. Deterministic effects like pregnancy loss, congenital malformations, growth retardation and neurobehavioral abnormalities have threshold doses above 100-200 mGy. The risk is considered negligible at 50 mGy and in reality no diagnostic examination exceeds this limit. The risk of carcinogenesis is slightly higher than in the general population. Intravenous iodinated contrast is discouraged, except in highly selected patients. Considering all the possible noxious effects of radiation exposure, measures to diminish radiation are essential and affect the fetal outcome. Nonionizing procedures should be considered whenever possible and every radiology center should have its own data analysis on fetal radiation exposure. In this review, we analyze existing literature on fetal risks due to radiation exposure, producing a clinical protocol to guide safe radiation use in a clinical setting.

Fetal radiation dose in computed tomography

The connection between recorded volumetric CT dose index (CTDI vol) and determined mean fetal dose (Df) was examined from metal-oxide-semiconductor field-effect transistor dose measurements on an anthropomorphic female phantom in four stages of pregnancy in a 64-slice CT scanner. Automated tube current modulation kept the mean Df fairly constant through all pregnancy stages in trauma (4.4-4.9 mGy) and abdomino-pelvic (2.1-2.4 mGy) protocols. In pulmonary angiography protocol, the mean Df increased exponentially as the distance from the end of the scan range decreased (0.01-0.09 mGy). For trauma protocol, the relative mean Df as a function of gestational age were in the range 0.80-0.97 compared with the mean CTDI vol. For abdomino-pelvic protocol, the relative mean Df was 0.57-0.79 and for pulmonary angiography protocol, 0.01-0.05 compared with the mean CTDI vol, respectively. In conclusion, if the fetus is in the primary beam, the CTDI vol can be used as an upper estimate of the fetal dose. If the fetus is not in the primary beam, the fetal dose can be estimated by considering also the distance of the fetus from the scan range.

Reduction of fetal dose in computed tomography using anterior shields

OBJECTIVE

The objective of this study was to assess the potential of anterior in beam bismuth shields placed on the abdomen and the pelvis of a RANDO phantom to decrease radiation dose to a simulated fetus.

METHODS

Thermal luminescent dosimeters irradiated in a RANDO phantom were used to measure radiation dose at 0 weeks and 18 weeks after conception. An 18-week gestation was simulated by adding the corresponding equivalent of super-stuff to account for additional subcutaneous tissue. To assess image quality, a 461A body phantom with low contrast resolution phantom insert was used. The minimum size of low contrast resolution target visualize was recorded with no shielding and 25-cm-wide shielding.

RESULTS

With shields, there was a radiation dose reduction of 19% to 23% at 0-week gestation and 16% to 24% at 18-week gestation. No qualitative difference was found in low contrast detectability with the shields.

CONCLUSIONS

These shields reduce fetal radiation exposure early in pregnancy with acceptable image quality.

Impact of appendicitis during pregnancy: no delay in accurate diagnosis and treatment

BACKGROUND

Acute appendicitis during pregnancy may be associated with serious maternal and/or fetal complications. To date, the optimal clinical approach to the management of pregnant women suspected of having acute appendicitis is subject to debate. The purpose of this retrospective study was to provide recommendations for prospective clinical management of pregnant patients with suspected appendicitis.

METHOD

Case records of all pregnant patients suspected of having appendicitis whom underwent appendectomy at our hospital between 1990 and 2010 were reviewed.

RESULTS

Appendicitis was histologically verified in fifteen of twenty-one pregnant women, of whom six were diagnosed with perforated appendicitis. Maternal morbidity was seen in two cases. Premature delivery occurred in two out of six cases with perforated appendicitis cases and two out of six cases following a negative appendectomy. Perinatal mortality did not occur.

CONCLUSION

Both (perforated) appendicitis and negative appendectomy during pregnancy are associated with a high risk of premature delivery. Clinical presentation and imaging remains vital in deciding whether surgical intervention is indicated. We recommend to cautiously weigh the risks of delay until correct diagnosis with associated increased risk of appendiceal perforation and the risk of unnecessary surgical intervention. Based upon current literature, we recommend clinicians to consider an MRI following an inconclusive or negative abdominal ultrasound aiming to improve diagnostic accuracy to reduce the rate of negative appendectomies. Accurate and prompt diagnosis of acute appendicitis should be strived for to avoid unnecessary exploration and to aim for timely surgical intervention in pregnant women suspected of having appendicitis.

Stone disease in pregnancy: imaging-guided therapy

Renal colic is the most frequent nonobstetric cause for abdominal pain and subsequent hospitalization during pregnancy. The physio-anatomical changes in the urinary tract and the presence of the fetus may complicate the clinical presentation and management of nephrolithiasis. Ultrasound (US) is the primary radiological investigation of choice. Magnetic resonance urography (MRU) and low-dose computed tomography (CT) have to be considered as a second- and third-line test, respectively. If a study that uses ionizing radiation has to be performed, the radiation dose to the fetus should be as low as possible. The initial management of symptomatic ureteric stones is conservative during pregnancy. Intervention will be necessary in patients who do not respond to conservative measures. Therefore, it is crucial to obtain a prompt and accurate diagnosis to optimize the management of these patients. Teaching Points • In pregnancy, renal colic is the most frequent nonobstetric cause for abdominal pain and hospitalization. • Magnetic resonance urography should be considered when ultrasound is nondiagnostic. • Low-dose CT should be considered as a last-line test during pregnancy.

Standardization and optimization of CT protocols to achieve low dose

The increase in radiation exposure due to CT scans has been of growing concern in recent years. CT scanners differ in their capabilities, and various indications require unique protocols, but there remains room for standardization and optimization. In this paper, the authors summarize approaches to reduce dose, as discussed in lectures constituting the first session of the 2013 UCSF Virtual Symposium on Radiation Safety and Computed Tomography. The experience of scanning at low dose in different body regions, for both diagnostic and interventional CT procedures, is addressed. An essential primary step is justifying the medical need for each scan. General guiding principles for reducing dose include tailoring a scan to a patient, minimizing scan length, use of tube current modulation and minimizing tube current, minimizing tube potential, iterative reconstruction, and periodic review of CT studies. Organized efforts for standardization have been spearheaded by professional societies such as the American Association of Physicists in Medicine. Finally, all team members should demonstrate an awareness of the importance of minimizing dose.

Trends in CT scan rates in children and pregnant women: teaching, private, public and nonprofit facilities

BACKGROUND

Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution.

OBJECTIVE

We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions.

MATERIALS AND METHODS

We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005-2012. We modeled trends overall and by facility type.

RESULTS

CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities.

CONCLUSION

CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care.

Fetal doses to pregnant patients from CT with tube current modulation calculated using Monte Carlo simulations and realistic phantoms

To investigate the radiation dose to the fetus using retrospective tube current modulation (TCM) data selected from archived clinical records. This paper describes the calculation of fetal doses using retrospective TCM data and Monte Carlo (MC) simulations. Three TCM schemes were adopted for use with three pregnant patient phantoms. MC simulations were used to model CT scanners, TCM schemes and pregnant patients. Comparisons between organ doses from TCM schemes and those from non-TCM schemes show that these three TCM schemes reduced fetal doses by 14, 18 and 25 %, respectively. These organ doses were also compared with those from ImPACT calculation. It is found that the difference between the calculated fetal dose and the ImPACT reported dose is as high as 46 %. This work demonstrates methods to study organ doses from various TCM protocols and potential ways to improve the accuracy of CT dose calculation for pregnant patients.

Imaging of pregnant and lactating patients: part 1, evidence-based review and recommendations

OBJECTIVE

The objectives of this article are to discuss the current evidence-based recommendations regarding radiation dose concerns, the use of iodinated and gadolinium-based contrast agents, and the comparative advantages of multimodality imaging (ultrasound, CT, and MRI) during pregnancy and lactation. We also discuss the use of imaging to evaluate pregnant trauma patients.

CONCLUSION

Maternal and fetal radiation exposure and dose are affected by gestational age, anatomic site, modality, and technique. The use of iodinated and gadolinium-based contrast agents during pregnancy and lactation has not been well studied in human subjects. Imaging should be used to evaluate pregnant trauma patients only when the benefits outweigh the risks.

Radiation dose management: part 2, estimating fetal radiation risk from CT during pregnancy

OBJECTIVE

The purpose of this article is to review fetal radiation doses and associated risks resulting from CT performed during pregnancy. The scanning parameters that influence dose and the techniques for estimating and reducing dose are explained.

CONCLUSION

Fetal radiation doses for CT examinations in which the fetus is not directly imaged-for example, head or chest CT-are minimal and need not figure in the risk-benefit analysis to perform the examination. In contrast, radiation dose should be considered with abdominopelvic CT because the fetus is likely to be exposed directly to the scanning beam. Safe implementation of CT in this setting requires an understanding of the factors influencing radiation dose. With this knowledge, when a risk-benefit analysis in a given clinical situation favors imaging using CT, the radiologist need not withhold or delay the examination and can achieve diagnostic-quality images while reducing radiation exposure.

Misdiagnosed uterine rupture of an advanced cornual pregnancy

Cornual pregnancy is a diagnostic and therapeutic challenge with potential severe consequences if uterine rupture occurs with following massive intraabdominal bleeding. We report a case of a misdiagnosed ruptured cornual pregnancy occurring at 21 weeks of gestation. Ultrasound examination and computer tomography revealed no sign of abnormal pregnancy. The correct diagnosis was first made at emergency laparotomy. Uterine rupture should be considered in pregnant women presenting with abdominal pain and haemodynamic instability.

Pulmonary CT angiography protocol adapted to the hemodynamic effects of pregnancy

OBJECTIVE

The purpose of this study was to compare the image quality of a standard pulmonary CT angiography (CTA) protocol with a pulmonary CTA protocol optimized for use in pregnant patients with suspected pulmonary embolism (PE).

MATERIALS AND METHODS

Forty-five consecutive pregnant patients with suspected PE were retrospectively included in the study: 25 patients (group A) underwent standard-protocol pulmonary CTA and 20 patients (group B) were imaged using a protocol modified for pregnancy. The modified protocol used a shallow inspiration breath-hold and a high concentration, high rate of injection, and high volume of contrast material. Objective image quality and subjective image quality were evaluated by measuring pulmonary arterial enhancement, determining whether there was transient interruption of the contrast bolus by unopacified blood from the inferior vena cava (IVC), and assessing diagnostic adequacy.

RESULTS

Objective and subjective image quality were significantly better for group B-that is, for the group who underwent the CTA protocol optimized for pregnancy. Mean pulmonary arterial enhancement and the percentage of studies characterized as adequate for diagnosis were higher in group B than in group A: 321 ± 148 HU (SD) versus 178 ± 67 HU (p = 0.0001) and 90% versus 64% (p = 0.05), respectively. Transient interruption of contrast material by unopacified blood from the IVC was observed more frequently in group A (39%) than in group B (10%) (p = 0.05).

CONCLUSION

A pulmonary CTA protocol optimized for pregnancy significantly improved image quality by increasing pulmonary arterial opacification, improving diagnostic adequacy, and decreasing transient interruption of the contrast bolus by unopacified blood from the IVC.