Background
Despite the widespread use of cross-sectional imaging to evaluate the urinary tract, fluoroscopy is still a necessary and preeminent diagnostic modality, particularly for the lower urinary tract. Its utility in clinical diagnosis and in guiding medical and/or surgical management stems from the unique features of fluoroscopy and radiography: dynamic real time imaging, high temporal resolution, lower radiation exposure compared to CT, and the option to reposition the patient and repeat portions of the examination. Nonetheless, a high-quality fluoroscopic examination is heavily dependent on the technique of the radiologist and a complete understanding of the anatomy, types of abnormalities and the scope of any prior surgical procedures. Poor fluoroscopic technique may beget studies that provide limited or no clinical information. Clear communication between the radiologist and the urologist is essential.
Educational Goals / Teaching Points
The objective for this educational exhibit is to review the protocol behind and the utility of fluoroscopic evaluation of the lower urinary tract. The three lower urinary tract fluoroscopic studies (retrograde urethrogram, cystogram, and voiding cystourethrogram) will be discussed in detail, with emphasis on correct technique and the pearls and pitfalls that may ultimately render the study either a success or a limited evaluation. Structural and functional anatomy will be reviewed, and the study indications will be discussed. The normal and abnormal findings of each study will be elaborated and, where applicable, we will introduce clinical correlates to reinforce concepts on the topic of traumatic injury, lower urinary tract symptoms, structural irregularities secondary to benign/malignant masses, and post-operative conditions. Furthermore, the limitations of the three fluoroscopic studies will be reviewed, including contraindications and other clinical considerations.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
(Please see above in "Education Goals/Teaching Points")
Conclusion
In summary, the ability to correctly perform and accurately interpret fluoroscopic studies of the lower urinary tract is essential for the radiologist in-training or an experienced radiologist who is returning to these procedures after a hiatus. We hope this educational exhibit provides satisfactory guidance for the radiologist and results in diagnostic examinations for the patient and referring physician.
