Normal physiological variants and benign conditions in pelvic oncologic fluorodeoxyglucose positron emission tomography/magnetic resonance imaging - Pictorial Essay

Sep 29, 2026

Uploaded by Bintang

Fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) functions as a hybrid approach with major value in oncologic imaging. FDG PET reflects tumor glucose metabolism, while MRI provides superior soft-tissue contrast for precise localization of PET findings. This pictorial essay documents physiological FDG uptake variants in female pelvic organs and bowel structures, then details benign conditions that can show FDG activity and imitate malignancy. It also demonstrates FDG-avid post-treatment changes and infectious or inflammatory lesions that complicate interpretation.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Main Points

Introduction

Normal Physiological Variants

Physiological endometrial uptake

Physiological uptake in fallopian tubes

Physiological ovarian uptake

Copyright @ 2026 Author(s) -[Available online at dirjournal.org](Available online at dirjournal.org). Content of this journal is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. PICTORIAL ESSAY Normal physiological variants and benign conditions in pelvic oncologic fluorodeoxyglucose positron emission tomography/magnetic resonance imaging Ayşe Erden1 Diğdem Kuru Öz1 Nuriye Özlem Küçük2 1Ankara University Faculty of Medicine, Department of Radiology, Ankara, Türkiye 2Ankara University Faculty of Medicine, Department of Nuclear Medicine, Ankara, Türkiye Corresponding author: Ayşe Erden [E-mail:](E-mail: ayse.erden@medicine.ankara.edu.tr)[ ayse.erden@medicine.ankara.edu.tr](E-mail: ayse.erden@medicine.ankara.edu.tr) Received 10 April 2025; revision requested 15 May 2025; last revision received 16 July 2025; accepted 27 July 2025. Epub: 06.10.2025 Publication date: 02.01.2026 DOI: 10.4274/dir.2025.253390 ABSTRACT Fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) is an advanced hybrid imaging modality that holds substantial promise in oncologic imaging. FDG PET, a well-established molecular imaging technique, enables assessment of tumor glucose metabolism and is widely utilized for diagnosing and monitoring a range of malignancies; MRI offers superior soft tissue contrast, facilitating precise anatomical localization of PET findings. This pictorial essay presents a series of physiological FDG uptake variants observed in the uterus, fallopian tubes, ovaries, colon, internal anal sphincter, pelvic musculature, and bone marrow. Additionally, it highlights benign conditions such as uterine tumors, vaginal condyloma acuminatum, and infected Bartholin cysts that may exhibit FDG uptake and potentially mimic malignancy. The essay also illustrates FDG-avid post-treatment changes and various infectious and inflammatory lesions such asosteitis pubis, perianal fistulas, and pelvic abscesses that may complicate oncologic interpretation. KEYWORDS Benign, bone marrow, bowel, fallopian tube, false positive results, inflammation, magnetic resonance imaging, ovary, positron emission tomography, radiation therapy, uterus P ositron emission tomography (PET) combined with magnetic resonance imaging (MRI) using fluorodeoxyglucose (FDG) is a promising hybrid imaging tool for evaluating gynecologic and genitourinary malignancies. It has a potential pivotal role in staging, treat- ment planning, recurrence detection, and prognosis assessment. However, interpreting pelvic PET/MRI is often challenging due to physiological uptake patterns and benign mimickers that may resemble pathology. In this pictorial essay, we aim to illustrate incidental FDG uptake in various pelvic structures encountered during routine oncologic PET/MRI examinations. Normal Physiological Variants Physiological uptake of FDG in the uterus, fallopian tubes, and ovaries is a common finding on FDG PET/computed tomography (CT), particularly in premenopausal women, and may mimic pathological processes if not carefully interpreted. Physiological endometrial uptake FDG uptake in the uterus varies with hormonal changes during the menstrual cycle, especially in premenopausal women. Increased endometrial FDG activity is commonly observed during the menstrual (Figure 1) and ovulatory phases and is considered physiological.1 This uptake likely reflects the peristaltic activity of the subendometrial myometrium, which facilitates menstrual blood expulsion.2 You may cite this article as: Erden A, Kuru Öz D, Küçük NÖ. Normal physiological variants and benign conditions in pelvic oncologic fluorodeoxyglucose positron emission tomography/magnetic resonance imaging. Diagn Interv Radiol. 2026;32(1):81-90 . 81 In postmenopausal women, endometrial FDG uptake is typically low. Any focal or intense uptake in this age group should prompt further investigation.1 Physiologica

FAQs

Why can pelvic FDG PET/MRI be difficult to interpret?

Physiological uptake patterns and benign conditions can mimic malignant pathology, creating false-positive interpretations during oncologic evaluation.

Which physiological pelvic structures commonly show FDG uptake?

FDG uptake is frequently observed in the uterine cavity, fallopian tubes, corpus luteum, colon, and the distal internal anal sphincter, particularly in premenopausal women.

What benign conditions may show FDG uptake and resemble malignancy?

The essay highlights benign mimickers such as uterine tumors, vaginal condyloma acuminatum, infected Bartholin cysts, osteitis pubis, perianal fistulas, and pelvic abscesses.

Sep 29, 2026

Uploaded by Bintang