Renal Colic Imaging: Myths, Recent Trends, and Controversies

Visceral Adiposity and Its Impact on Nephrolithiasis: A Narrative Review

Kidney stones represent a serious medical problem, resulting from several factors such as diet, genetics, and certain medical conditions. Visceral adipose tissue has been shown in recent research to play a significant role in kidney stone formation, making it a more precise indicator than traditional obesity indicators such as body mass index. The main aim of this review is to summarize studies on visceral obesity as a predictive marker for nephrolithiasis and to highlight new mechanistic pathways such as adipokine-mediated inflammation and its impact on kidney stone formation. This review emphasizes the importance of considering visceral fat in the prevention and management of kidney stones, suggesting that targeted strategies to reduce visceral fat could decrease the incidence of kidney stones and their management costs. Further prospective studies are needed to validate these findings and propose preventive strategies based on visceral adiposity assessments.

ACR Appropriateness Criteria® Hydronephrosis on Prior Imaging-Unknown Cause

Initial imaging evaluation of hydronephrosis of unknown etiology is a complex subject and is dependent on clinical context. In asymptomatic patients, it is often best conducted via CT urography (CTU) without and with contrast, MR urography (MRU) without and with contrast, or scintigraphic evaluation with mercaptoacetyltriglycine (MAG3) imaging. For symptomatic patients, CTU without and with contrast, MRU without and with contrast, MAG3 scintigraphy, or ultrasound of the kidneys and bladder with Doppler imaging are all viable initial imaging studies. In asymptomatic pregnant patients, nonionizing imaging with US of the kidneys and bladder with Doppler imaging is preferred. Similarly, in symptomatic pregnant patients, US of the kidneys and bladder with Doppler imaging or MRU without contrast is the imaging study of choice, as both ionizing radiation and gadolinium contrast are avoided in pregnancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The “Black Pattern”, a Simplified Ultrasound Approach to Non-Traumatic Abdominal Emergencies

Background: A key issue in abdominal US is the assessment of fluid, which is usually anechoic, thus appearing “black”. Our approach focuses on searching for fluid in non-traumatic patients, providing a new, simplified method for point-of-care US (POCUS). Objective: Fluid assessment is based on a three-step analysis that we can thus summarize. 1. Look for black where it should not be. This means searching for effusions or collections. 2. Check if black is too much. This means evaluating anatomical landmarks where fluid should normally be present but may be abnormally abundant. 3. Look for black that is not clearly black. This means evaluating fluid aspects, whether wholly anechoic or not (suggesting heterogeneous or corpusculated fluid). Discussion: Using this simple method focused on US fluid presence and appearance should help clinicians to make a timely diagnosis. Although our simplified, systematic algorithm of POCUS may identify abnormalities; this usually entails a second-level imaging. An accurate knowledge of the physio–pathological and anatomical ultrasound bases remains essential in applying this algorithm. Conclusion: The black pattern approach in non -traumatic emergencies may be applied to a broad spectrum of abnormalities. It may represent a valuable aid for emergency physicians, especially if inexperienced, involved in a variety of non-traumatic scenarios. It may also be a simple and effective teaching aid for US beginners.

Prevalence of Urolithiasis by Ultrasonography Among Patients with Gout: A Cross-Sectional Study from the UP-Philippine General Hospital

CONTEXT

While urolithiasis is epidemiologically and mechanistically linked to gout, urologic stone disease is not actively investigated in gout patients. Prevalence estimates on the coexistence of urolithiasis in gout have mostly relied on clinical history alone.

PURPOSE

To estimate the prevalence of urolithiasis among adult Filipinos with primary gout through clinical history and ultrasonography.

PATIENTS AND METHODS

Patients diagnosed with primary gout were consecutively enrolled from outpatient clinics of the University of the Philippines Manila-Philippine General Hospital. Clinical data including sex; current age; age at diagnosis, duration of and attack frequency of gout; comorbidities such as hypertension, chronic kidney disease, type 2 diabetes mellitus, and dyslipidemia; personal history of urolithiasis; family history of gout; presence of tophus and laboratory samples to assess general kidney function, serum uric acid level, and urine pH were obtained from each patient who was subsequently subjected to ultrasonographic examination for urolithiasis. Lithiasic and non-lithiasic patients were identified and compared aggregately in terms of the aforementioned features.

RESULTS

We recruited 121 patients, 86.8% of whom are male, and 37 (30.6%; 95% CI=23.1-39.3%) were identified to have urolithiasis of which only 12 (9.9%) had history consistent with urolithiasis and 30 (24.8%) were diagnosed solely through ultrasonography. None of the variables of interest were found to be statistically associated (P>0.05) with urologic stone formation.

CONCLUSION

Urolithiasis among adult Filipino patients with primary gout was found to be more prevalent in this study than previous estimates, which were based only on clinical history. We discovered that 25/37 (67.6%) of patients with urolithiasis denied history of urologic stone.

Viscero-visceral hyperalgesia in dysmenorrhoea plus previous urinary calculosis: Role of myofascial trigger points and their injection treatment in the referred area

BACKGROUND

Women with dysmenorrhoea plus symptomatic urinary calculosis experience enhanced pain and referred muscle hyperalgesia from both conditions than women with one condition only (viscero-visceral hyperalgesia). The study aimed at verifying if enhanced dysmenorrhoea persists after urinary stone elimination in comorbid women and if local anaesthetic inactivation of myofascial trigger points (TrPs) in the lumbar area (of urinary pain referral) also relieves dysmenorrhoea.

METHODS

Thirty-one women with dysmenorrhoea plus previous urinary calculosis (Dys+PrCal) and lumbar TrPs, and 33 women with dysmenorrhoea without calculosis (Dys) underwent a 1-year assessment of menstrual pain and muscle hyperalgesia in the uterus-referred area (electrical pain threshold measurement in rectus abdominis, compared with thresholds of 33 healthy controls). At the end of the year, 16 comorbid patients underwent inactivation of TrPs through anaesthetic injections, whereas the remaining 12 received no TrP treatment. Both groups were monitored for another year at the end of which thresholds were re-measured.

RESULTS

In year1, Dys+PrCal presented significantly more painful menstrual cycles and lower abdominal thresholds than Dys, thresholds of both groups being significantly lower than normal (p < .001). Anaesthetic treatment versus no treatment of the lumbar TrP significantly reduced the number of painful cycles during year2 and significantly increased the abdominal thresholds (p < .0001).

CONCLUSION

Viscero-visceral hyperalgesia between uterus and urinary tract may persist after stone elimination due to nociceptive inputs from TrPs in the referred urinary area, since TrPs treatment effectively reverses the enhanced menstrual symptoms. The procedure could represent an integral part of the management protocol in these conditions.

SIGNIFICANCE

A past pain process from an internal organ can continue enhancing pain expression from a painful disease in another neuromerically connected organ (viscero-visceral hyperalgesia) if secondary myofascial trigger points (TrPs) developed in the referred area at the time of the previous visceral disease. Inactivation of these TrPs reverts the enhancement. Assessment and treatment of TrPs in referred areas from past visceral pain conditions should be systematically carried out to better control pain from current diseases in other viscera.