This diagnostic fluoroscopic image captures a percutaneous nephrolithotomy (PCNL) procedure. The image displays the renal collecting system opacified by contrast medium, highlighting the anatomy of the renal pelvis and several minor and major calyces. A radiopaque kidney stone (urolithiasis) is clearly visible within one of the lower pole calyces. A thin, linear hydrophilic guidewire is seen entering the kidney through a percutaneous access tract, directed toward the target calyx containing the stone. The image demonstrates the critical intraoperative step of achieving and maintaining percutaneous access to the intrarenal collecting system under fluoroscopic guidance. This material is pedagogically relevant for urology trainees and medical students to understand the radiological appearance of the pyelocaliceal system during minimally invasive surgical interventions for renal calculi.

Endoscopic view of a percutaneous nephrolithotomy (PCNL) procedure, segmented into three clinical frames (a, b, and c). Frames a and b demonstrate the intra-renal management of a large renal calculus. The stone is light brown with a rough, crystalline texture, characteristic of calcium oxalate calculi. In frame a, a pneumatic lithotripter probe is applied directly to the stone surface for fragmentation. Frame b shows the use of metallic stone-grasping forceps to manipulate or extract fragmented stone pieces within the renal collecting system. Frame c depicts the placement of a flexible, light-blue ureteral stent or drainage tube, featuring dark graduation markings and a distinct distal lumen. The background shows the hyperemic mucosal lining of the renal pelvis. These images illustrate the key stages of PCNL: endoscopic stone identification, fragmentation, and post-procedural drainage in a patient with a complex renal anatomy, such as a horseshoe kidney.

This intraoperative endoscopic image demonstrates a renal pelvic stone undergoing percutaneous nephrolithotomy (PCNL). The stone presents as a large, irregularly shaped, tan-to-brown mass with a rough, crystalline surface texture and focal white deposits. A key pathological feature is a migrated stainless steel embolization coil, visible as a bright, metallic, reflective spiral structure (indicated by an arrow) embedded within the stone matrix. The coil appears to have acted as a nidus for lithogenesis, with calculus material encrusting and engulfing the metallic loops within the pelvicalyceal system. The image illustrates a rare complication where a migrated vascular device facilitates secondary stone formation in the kidney. The surrounding field shows fragmented stone material and the moist internal mucosal environment typical of a urological endoscopic procedure.

This diagnostic image pair displays retrograde pyelography of a human kidney, specifically within the context of a percutaneous nephrolithotomy (PCNL) procedure. The imaging modality uses a radiopaque contrast agent to opacify the renal collecting system, including the renal pelvis, major and minor calyces, and the ureter. In panel (a), a radiopaque 'target stone' is clearly visible in a lower calyx, and a flexible ureteroscope/catheter is seen traversing the ureter into the renal pelvis. In panel (b), the image demonstrates the deployment of a Lawson retrograde nephrostomy puncture wire, which appears as a thin radiopaque line extending from the upper calyx toward the skin surface. This illustrates a retrograde puncture technique for establishing percutaneous access in a kidney with complex anatomy (horseshoe kidney). The visualization highlights the relationship between medical instrumentation and the internal urinary tract architecture to guide surgical intervention for nephrolithiasis.