Implementation of a Technique Based on Hounsfield Units and Hounsfield Density to Determine Kidney Stone Composition.

Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to the composition of kidney stones. In the standard acquisition method, these measures are arbitrary and dependent on the operator. This study describes the implementation of a technique based on the HU and Hounsfield density to predict the stone compositions of patients with nephrolithiasis. By conventional percutaneous nephrolithotomy, thirty kidney stone samples corresponding to the cortex, middle, and nucleus were obtained. The HU were obtained by CT scanning with a systematic grid. Hounsfield density was calculated as the HU value divided by the stone's greatest diameter (HU/mm). With that method and after analyzing the samples by IR-spectroscopy, anhydrous uric acid and ammonium magnesium phosphate were identified as the compounds of kidney stones. Additionally, anhydrous uric acid, magnesium ammonium phosphate, and calcium oxalate monohydrate were identified via Hounsfield density calculation. The study identified HU ranges for stone compounds using a systematic technique that avoids bias in its analysis. In addition, this work could contribute to the timely diagnosis and development of personalized therapies for patients with this pathology.

Simultaneous Ureteral and Renal Foreign Bodies.

Clinical presentation of patients with foreign bodies is highly variable. We received a 55-year-old female patient with fever and right flank pain. She was treated previously for kidney stones by percutaneous nephrolithtomy with partial resolution, requiring renal embolization during this procedure because of bleeding. CT evidenced metallic density images localized in kidney and ureter, associated with kidney stones located in lower calix. Semirigid ureteroscopy and retrograde intrarenal surgery were performed, revealing the presence of foreign bodies in both localizations and lower calix stones. Complete removal of foreign bodies and stones was performed. Foreign bodies were found to be embolization coils applied in the previous procedure.

“I will not cut, even for the stone”: origins of urology in the hippocratic collection

The Hippocratic Collection, including the most of ancient Greek medicine, remains still interesting, despite the recent advances that transformed definitely the urological healing methods. Considering the patient as a unique psycho-somatic entity and avoiding high risk surgical manipulations were the leading principles dictating the everyday practice. Contemporary physicians can still learn from the clinical observations in times of complete absence of laboratory or imaging aid, from the prognostic thoughts, the ethics, and the philosophical concepts, represented by the Hippocratic writings, tracing into them the roots of Rational Medicine in general and Urology in particular.