How do MRI and diceCT imaging studies differ in what they reveal about internal clitoral anatomy?
Executive summary
Magnetic resonance imaging (MRI) and diffusible iodine contrast-enhanced micro-CT (diceCT) are complementary tools for studying internal clitoral anatomy: MRI excels at noninvasive, multiplanar visualization of soft-tissue architecture in living subjects and clinically relevant contexts, while diceCT provides much higher spatial resolution and tissue contrast for small or preserved specimens, revealing fine morphological detail that MRI can miss [1] [2]. Both approaches have trade-offs—MRI’s limited ability to resolve the smallest neurovascular structures without contrast and diceCT’s reliance on ex vivo staining and micro-CT hardware—so a combined strategy yields the best anatomical picture [3] [2].
1. MRI as the clinical, live-state map of the clitoral complex
Multiple MRI studies demonstrate that noncontrast and contrast-enhanced MRI can depict the clitoral body, paired crura, bulbs, glans and their relationships to surrounding pelvic structures in living, premenopausal women, with axial, sagittal and coronal planes delivering complementary views that preserve in vivo geometry [4] [1] [5]. MRI has been described as the most sensitive way to distinguish soft-tissue planes of the clitoral complex and to provide multiplanar representations in the live state—advantages for correlating anatomy with function or pathology without dissection [6] [1]. Contrast agents such as the blood‑pool MS‑325 markedly enhance visualization of the clitoris, vestibular bulbs and adjacent organs on T1-weighted images, with optimal enhancement several minutes post‑injection [7] [8].
2. MRI’s resolution ceiling: where tiny neurovascular bundles blur
Despite MRI’s strengths, some anatomically important elements—particularly the relatively small clitoral neurovascular bundles identified on dissection—are not consistently visible on routine MRI sequences; authors note that structures easily seen in cadaver dissection were often below MRI’s detection threshold unless specific fat‑saturation or contrast techniques were used [3]. Even advanced 2D and 3D clinical MRI can show variability in image quality and may exclude many scans where the clitoral structures of interest are not visible, which motivates computational 3D approaches to improve measurement consistency [9] [10].
3. diceCT: microanatomy in high definition, usually ex vivo
diceCT combines diffusible iodine staining with high‑resolution micro‑CT scanning to render soft tissues with CT‑level contrast, enabling visualization of muscle, erectile tissues and minute morphological differences across specimens and species that MRI cannot resolve at the same scale [2] [11]. Researchers using diceCT emphasize its power for museum and small‑animal specimens: iodine staining increases soft‑tissue contrast and microCT provides the spatial resolution that reveals interspecific variation in clitoral morphology, including fine muscular and erectile elements [2] [11].
4. Trade-offs: in vivo safety versus spatial detail
The methodological tradeoffs are clear in the reporting: MRI can be applied in vivo to volunteers and patients, preserving live tissue relationships and allowing functional correlation, whereas diceCT is typically an ex vivo technique that requires staining and microCT equipment but yields higher spatial resolution useful for comparative and evolutionary anatomy [1] [2]. That dichotomy explains why contemporary teams pair techniques—using MRI for clinical and functional contexts and diceCT/microCT for detailed morphological and comparative work—rather than treating one modality as a wholesale replacement for the other [2] [11].
5. Where the evidence diverges and what remains unknown
Authors caution that MRI literature can be limited by sample selection (often premenopausal volunteers) and by scans excluded for poor quality, which constrains generalizability of measurement norms and functional correlations [9] [10]. Meanwhile, diceCT studies have yielded striking interspecies variation but do not by themselves establish how structural differences map to sexual function or behavior in living primates; investigators acknowledge that the relationship between clitoral morphology and mating systems or social behavior remains an open research question [2]. Combining modalities and expanding sample diversity are the explicit next steps noted by researchers [2] [10].