Role of PCA3 test in clinical decision making for prostate cancer diagnosis

AIM: To assess the role of PCA3 urine test in the management of patients with suspected prostate cancer after repeat negative prostate biopsies.

METHODS: Patients with suspected prostate cancer either due to high or rising prostate specific antigen (PSA) levels and with a history of prostate biopsy who were candidates for repeat procedure were prospectively recruited to undergo PCA3 urine test. The recommendations on further management including the decision whether to proceed or not to the biopsy were made based on the PCA3 score. Patients’ adherence with the recommendations and influence of the PCA3 test on clinical decision making were assessed. The contribution of the multivariate model was measured with a decision curve analysis.

RESULTS: Three hundred and fifty-six patients were recruited to the study and underwent the PCA3 test. Twenty-six percent of 263 patients underwent prostate biopsy despite the low risk designation by PCA3 and 30% of 93 men did not proceed to biopsy despite a high risk result, rendering overall adherence of 73%. The variables that significantly correlated with adherence were positive family history of prostate cancer and PSA more than 10 ng/mL. Pre-test clinical stage, the number and the results of previous biopsies were not associated with the adherence. The decision curve analysis gave identical results for cut-off points of 25 and 35. On multivariate analysis the model that included PCA3 score, serum PSA, family history and result of the previous biopsy best performed with Area Under the Curve of 0.77.

CONCLUSION: PCA3 urine test markedly outperforms PSA in a repeat biopsy setting. Urologists and patients demonstrate substantial confidence in this analysis and tend to follow its recommendations.

Non-pharmacologic options for the management of voiding dysfunction in multiple sclerosis

Multiple sclerosis is a neuroinflammatory condition that can cause significant bladder dysfunction manifesting either as overactive bladder or impaired bladder emptying. Patients will often complain of urgency, frequency, nocturia, urgency incontinence, hesitancy, straining to void, and incomplete bladder emptying. While these symptoms can be treated with pharmacologic agents, often patients will require more significant treatments. Patients should first be evaluated with urodynamics in order to adequately diagnose the pathologic condition causing their symptoms. These interventions include catheter use, injection of botulinum toxin, neuromodulation, urethral stenting, sphincterotomy, suprapubic catheter with bladder neck closure, bladder augmentation and urinary diversion. The purpose of this review is to examine the evidence supporting each of these treatment options so urologic providers can better provide for this unique and complex patient population.

Innovative microsurgical treatment of male external genitals lymphedema

Secondary lymphedema of male external genital organs, characterized by increase in genital organs volume, tissue fibrosis, erysipelas, and objective difficulties in the normal use of lower limbs and the penis, is a very common and impairing consequence of invasive surgery, radical lymphadenectomy and radiotherapy of the pelvic-inguinal area. Standard surgical approach to lymphedema are either very invasive and/or at high risk of lymphedema recurrence and do not guarantee an efficient long-term treatment. Alternatively, we developed a microsurgical technique to perform direct anastomoses between the lymphatic collectors of the spermatic funiculum afferent to the external iliac chains and the vessels tributary to the spermatic vein. This innovative approach, although surgically demanding, provided a long term successful treatment of external genitals with no clinical complications, low invasivity, rapid post-surgical recovery, minor tissue demolition and satisfactory post-surgical functional and esthetic results. In addition, lympho-venous microsurgery seems to trigger the local development of new lymphatic vessels that not only canalize along new collecting channels, but also form complex meshes in proximity to the anastomosis area, thus improving lymphedema also in adjacent tissues like lower limbs, supplied by lymphatics emptying into common developed lymphatic shunt.

Periodontitis: Tip of the iceberg in chronic kidney disease

The prevalence of chronic kidney disease (CKD) is constantly escalating not only in industrialized countries but throughout the world. It is of major significance because of to its high morbidity and mortality. Strategies to tackle this worldwide health problem include identification of its associated risk factors, comorbidities, and complications as well as proper management to handle all the pertinent issues. Periodontal disease, a treatable infectious state of the dental supporting tissues, is common in CKD patients. Its association with CKD is believed to be in a reciprocal or bidirectional fashion and has been massively studied. This paper, therefore, aims to review the recent evidence pertaining to the association between periodontal disease and a variety of renal illnesses. Most of the current evidence was collected from cross-sectional studies and clinical trials. There is substantial evidence indicating that periodontal disease contributes markedly to the chronic systemic inflammatory burden, leading to cardiovascular and cerebrovascular complications, the principal causes of death among chronic renal disease patients. Furthermore, several studies demonstrated that proper periodontal intervention could help improve systemic inflammation and even nutritional status among CKD patients, resulting in a better quality of life. Suggestions have been made that periodontal disease should be diagnosed early, and managed and controlled to, at least, eradicate a source of inflammation in this population. Awareness of such an important issue should be increased in the relevant medical personnel.

Metabolic syndrome in the development and progression of prostate cancer

Prostate cancer (PCa) is the most common noncutaneous malignancy and second leading cause of cancer-specific mortality for men in the United States. There is a wide spectrum of aggressiveness ranging from biologically significant to indolent disease, which has led to an interest in the identification of risk factors for its development and progression. Emerging evidence has suggested an association between metabolic syndrome (MetS) and PCa. MetS represents a cluster of metabolic derangements that confer an increased risk of cardiovascular disease and type 2 diabetes mellitus. Its individual components include obesity, dyslipidemias, high blood pressure, and high fasting glucose levels. MetS has become pervasive and is currently associated with a high socioeconomic cost in both industrialized and developing countries throughout the world. The relationship between MetS and PCa is complex and yet to be fully defined. A better understanding of this relationship will facilitate the development of novel therapeutic targets for the prevention of PCa and improvement of outcomes among diagnosed men in the future. In this review, we evaluate the current evidence on the role of MetS in the development and progression of PCa. We also discuss the clinical implications on the management of PCa and consider the future direction of this subject.

Top 50 most cited articles on prostatic artery embolization for benign prostatic hyperplasia: A bibliometric review

BACKGROUND

Bibliometric analysis can be used to assess the current state of the literature and publication trends on a given topic. There has not been a review of this kind on prostatic artery embolization (PAE) for benign prostatic hyperplasia (BPH). PAE is a relatively new and somewhat controversial treatment option for BPH. Given the novelty and controversy, there has been much research published on the topic recently.

AIM

To survey the current state of research on PAE for BPH by using bibliometric analysis to analyze the top 50 most highly cited articles.

METHODS

A cross-sectional study was performed using the Web of Science database to identify the most cited articles published on PAE for BPH as of June 2022. Articles that did not primarily focus on PAE or BPH as an indication were eliminated. The 50 most cited articles were carried forward for analysis.

RESULTS

All but 6 articles were published in the last decade with contributions from 15 countries. Fifty-two percent of the studies had a C level of evidence. The majority were published in the Journal of Vascular and Interventional Radiology and Cardiovascular and Interventional Radiology. Twenty percent (n = 10) of the articles were published in urologic journals. On average, articles published in urologic journals tended to be more recent. The mean year of publication for an article in a urological journal was 2016.6 compared to 2013.9 in a non-urologic journal (P = 0.02). Seventy percent of the articles focused on clinical outcomes, while only 2% focused on practice guidelines. Self-citations accounted for 11.4 citations per article on average, corresponding to 14.7% of all citations analyzed.

CONCLUSION

The most influential papers on this topic represent a fairly recent body of work with contributions from a wide variety of countries and journals. The fact that articles in urologic journals were published significantly more recently than articles on the list in non-urologic journals may suggest that the field of urology is starting to accept PAE for a wider range of indications. Finally, while there has been much high-quality research published, more influential studies on practice guidelines and technique may be beneficial.

Vasectomy reversal: A review of the evaluation, techniques, and outcomes

This review highlights the evaluation and treatment of men who have undergone vasectomy and desire vasectomy reversal to father children. For surgeons offering this treatment, the appropriate evaluation and treatment are crucial for acceptable outcomes. Although variations on surgical approaches have evolved over the years, one constant is the need for a high level of training and skill in microsurgical techniques.

Neutrophil-lymphocyte ratio in the management and prediction of outcomes in renal cell carcinoma

Renal cell carcinoma (RCC) is one of the ten most common malignancies. The prognosis of RCC is poor when the disease is in advanced stages, with five-year survival of less than 10%. However current assessment approaches are limited in their ability to prognosticate and guide therapeutic decision-making. Cellular-mediated inflammatory response is increasingly being recognised to have an important role in carcinogenesis of RCC. Various inflammatory markers have been found to identify patients with RCC at high risk of recurrence and predict survival. Neutrophil-lymphocyte ratio (NLR) is a simple and inexpensive inflammatory marker that has been shown to be of value in the assessment of patients with RCC. An elevated pretreatment NLR has been found to be associated with reduced overall survival, recurrence-free survival and progress-free survival and risk of recurrence in localized RCC. In addition, lower pretreatment NLR has been demonstrated to be associated with better clinical response to systemic therapy including vascular endothelial growth factor inhibitors, among patients with metastatic RCC. However, NLR has not been found to differentiate whether small renal masses of less than 40 mm are benign or malignant. Further research is needed to determine the cut-offs for NLR to predict different clinical outcomes and how post-treatment NLR can be used. In addition, more work is also needed to evaluate combining NLR with other biomarkers in a model to predict patients’ clinical outcome or response to treatment for RCC.

Why is there a need for an interdisciplinary approach to assess erectile dysfunction?

Erectile dysfunction is a prevalent complaint among men. The majority of patients suffering erectile dysfunction exhibit various risk factors of vascular diseases. Erectile dysfunction used to be recognised as one of the consequences of vascular diseases in patients suffering heart attack or myocardial infarction. During the last decade, however, the role of endothelial dysfunction in the occurrence of erectile dysfunction has been signified, and it has been suggested that erectile dysfunction may not be simply a consequence of vascular diseases but an indicator of future vascular problems. Erectile dysfunction has been known as “the tip of iceberg” of a generalised vascular dysfunction, which typically happens before serious vascular problems. Considerable evidence shows a link between erectile dysfunction and vascular disorders. Several theories have been considered for the association between erectile dysfunction and vascular diseases. One of them is the “artery size” theory focusing on the differences between the diameter of the penile artery and other arteries. Another theory is based on “endothelial dysfunction”, which highlights inappropriate vasoconstriction as a cause of erectile dysfunction and vascular diseases. “Age” has also been reported to have pivotal role in the development of vascular dysfunction resulting in erectile dysfunction and ultimately vascular diseases. Another theory explaining the pathophysiology of erectile dysfunction and its relationship with vascular diseases focuses on the formation of atherosclerosis plaques. This article endeavours to review the current literature and discuss why a multidisciplinary approach is needed while assessing erectile dysfunction.

Potential of metastin and metastin receptor as biomarkers for urological cancers

AIM: To investigate the current state of the research of metastin and metastin receptor in the urological cancer field.

METHODS: For analyzing the value of metastin and metastin receptor as molecular biomarkers for the patients with urological cancer, MEDLINE database searches were performed using these terms: metastin, KISS1, kisspeptin, renal (cell) carcinoma (RCC), kidney cancer or urothelial cancer or bladder cancer or prostate cancer or testicular cancer (tumor). Since the articles were evaluated by the validity of the articles based on plausibility, credibility, and evidence levels, the articles were graded according to their level of evidence, using the grading system defined by the Oxford Centre for Evidence-based Medicine.

RESULTS: A total of six clinical studies published by individual institutions between 2003 and 2013 were included in this review. The article numbers for each of the evidence levels 2a and 2b were three (50%) and three (50%), respectively. Immunohistochemistry and reverse transcriptase-polymerase chain reaction using tumor tissues were performed to analyze in five articles (83%) and in one article (17%). The value of metastin and/or metastin receptor as molecular biomarkers in clear cell RCC, upper tract urothelial carcinoma, and bladder cancer was evaluated by multivariate analysis. Low expression of metastin receptor in clear cell RCC and low expression of metastin in upper tract urothelial carcinoma were significant risk factors for metastasis, and low metastin expression was an independent prognostic factor in bladder cancer.

CONCLUSION: Metastin and metastin receptor have potential as suitable molecular biomarkers for urological cancers. However, future studies of metastin and metastin receptor should undergo external validation to ensure consistency across different patient series, since individual institutional studies lack generalization.

Mesenchymal stem cells for kidney transplantation

The long term consequence of immunosuppressive therapy in kidney transplantation has prompted investigation of alternative means to modify the immune response to the allograft. Cell based therapies are potentially attractive as they may provide a long lasting immunomodulatory effect, may repair tissues and reduce the necessity to take immunosuppressive drug therapy. Of the current cell therapies, mesenchymal stem cells have now been trialled in small numbers of human kidney transplantation with apparent safety and potential efficacy. Many issues however need to be resolved before these cells will become mainstays of transplant immunosuppression including ex vivo modification to enhance immunomodulatory properties, cell number, route and frequency of administration as well as cellular source of origin.

Safety of synthetic mesh in pelvic surgery

Mesh in the form of a midurethral sling is an acceptable and generally safe treatment option for stress urinary incontinence in patients who have failed conservative treatment options such as weight loss and pelvic floor muscle training. In patients with pelvic organ prolapse, when outcomes are measured in terms of improvement in postoperative physical exam (anatomic success), many studies have demonstrated that mesh augmented repairs are superior to prolapse repairs not using mesh (native tissue). However, from a symptomatic standpoint, the outcomes of mesh and native tissue repairs are equivalent. This means that even though the physician may see more prolapse on physical exam after native tissue repair, most patients do not perceive this as a problem because their sensation of a vaginal bulge is gone. The vaginal bulge is one of the most common complaints of a patient prior to pelvic organ prolapse repair. Based on interpretation of the available literature, it does not appear that mesh is superior to native tissue repair for anterior (cystocele) and posterior (rectocele) compartment pelvic organ prolapse repair. However, for apical repairs the native tissue repairs are more technically challenging and it appears that suspension of the apex of the vagina with mesh to the sacrum (sacrocolpopexy) may yield better outcomes. Unfortunately, like all mesh surgeries there is a significant risk of mesh complications with sacrocolpopexy. Surgeons should thoroughly counsel their patients about the permanent nature of synthetic mesh and the potential serious complications related to its use. Mesh augmented pelvic organ prolapse repairs carry unique complications that are not present with native tissue repairs and may not provide better outcomes.

Scrotal strangulation in the differential diagnosis of acute scrotum: A case report

BACKGROUND

Acute scrotal pain and swelling are common presentations in the emergency department. Urgent surgical intervention is justified in up to one-third of cases, whereas two-thirds of them should be treated conservatively.

CASE SUMMARY

We report a case of scrotal only strangulation in a child and review the available literature.

CONCLUSION

Due to its rarity, scrotal strangulation can be a diagnostic challenge. Skin ulceration and edema may well indicate the presence of a strangulation object. A high index of suspicion and appropriate physical examination, especially in patients with a mental disability or behavioral disorder, are key to early diagnosis and treatment.

Transurethral bipolar prostatectomy: Where do we stand now?

Transurethral resection of the prostate (TURP) is considered the gold standard surgical treatment of symptomatic benign prostatic hyperplasia. TURP has gained ground in urologic centers of excellence for its effective long term results with low incidence of complications. Far away from excellence, it associated with blood loss, and TUR syndrome particularly in patients with larger prostates. For this reasons, many minimally invasive new techniques have been implemented in recent years. Bipolar technique has recently been introduced, to minimize the complications of the standard TURP technique.

SCAD syndrome: A vicious cycle of kidney stones, CKD, and AciDosis

Cumulative evidence has shown that kidney stone formers are at high risk for developing end-stage renal disease (ESRD) and cardiovascular disease. The aim of this mini-review is to summarize the present knowledge about the close relationships among kidney stone formation, chronic kidney disease (CKD), and plasma and urine acidosis (SCAD). Part of the cause of the positive relationships between higher risk of developing ESRD and cardiovascular diseases in stone formers may be explained by inflammation and cell death due to the components of kidney stones. In CKD patients, acidic urine and loss of anti-crystallization factors may cause stone formation. Acidosis can promote tissue inflammation and may affect vascular tone. Correction of plasma and urine acidosis may improve renal and cardiovascular outcome of stone formers and CKD patients. More intensive and long-term interventions, which include correction of plasma and urine pH in patients with reduced renal function and correction of urine pH in patients with normal renal function, may be considered in treating patients with SCAD syndrome.

Pre-fabricated radial forearm phalloplasty with cadaveric bone graft

Phalloplasty is a complex set of procedures used in efforts to improve the anatomical, physiological, and aesthetic deficiencies caused by loss or absence of the penis. Methods have evolved significantly, and the use of free tissue transfer has become common amongst reconstructive surgeons. The inclusion of bone autograft, usually radius or fibula, within the neophallus has caused significant morbidity, and efforts continue to find the optimal solution. We present a novel approach using a pre-fabricated, radial forearm fasciocutaneous free flap containing cadaveric bone graft for phalloplasty following traumatic penis amputation.

Recirculating chemohyperthermia as a treatment for non-muscle invasive bladder cancer: Current and future perspectives

About 75% of all bladder cancer diagnosed are non-muscle invasive bladder cancer (NMIBC), recurring over 50% of them after transurethral resection of the bladder tumor. In order to prevent recurrences, adjuvant intravesical chemotherapy with mitomycin C and immunotherapy with bacillus Calmette-Guérin (BCG) is traditionally used. Unfortunately, many patients relapse after receiving these treatments and a significant proportion of them require surgery. After a one-to-three years BCG maintenance, the risk for progression at 5 years was 19.3% for T1G3 tumors. Many new treatment approaches are being investigated to increase the effectiveness of adjuvant intravesical therapy. One of the developing treatments for intermediate and high-risk NMIBC is the combination of intravesical chemotherapy and hyperthermia, called chemohyperthermia. This article provides a review of the mechanism of action, current status and indications, results and future perspectives.

Use of synthetic grafts in pelvic reconstruction: A path of continued discovery

Since the 1990s, mesh has been used in pelvic reconstruction to augment repairs for stress urinary incontinence and pelvic organ prolapse (POP). In 2008 and 2011, the United States Food and Drug Administration (FDA) issued Public Health Notifications ultimately informing providers and the public that complications associated with the use of synthetic mesh in the transvaginal repair of POP are not rare. In this review, we (1) examine literature characterizing surgical practice-patterns subsequent to the FDA announcements; (2) describe presentation of mesh-associated complications and outcomes of management; (3) discuss the most recent materials science research; and (4) seek to characterize whether or not mesh has lived up to the long-term efficacy promise of a permanent implant. Durability of mesh-augmented anatomical outcomes do not consistently translate into improved patient satisfaction and subjective outcomes. This, when coupled with the possibility of mesh-associated complications, emphasizes the need for continued innovation beyond the status quo of current synthetic grafts.

Estimation of successful capping with complete aspiration of bladder via nephroureterostomy tube

BACKGROUND

Ureteral stent and nephroureterostomy tube (NUT) are treatments of ureteral obstruction. Ureteral stent provides better quality of life. Internalization of NUT is desired whenever possible.

AIM

To assess outcomes of capping trial among cancer patients with complete aspiration of retained contrast from bladder via NUT.

METHODS

Our Institutional Review Board approved retrospective review of all NUT placement, NUT exchange and conversion of nephrostomy catheter into NUT performed during June 2013 to June 2015 (n = 578). Cases were excluded due to lack of imaging of bladder (n = 37), incomplete aspiration of bladder (n = 324), no attempt at capping NUT (n = 166), and patients with confounding factors interfering with results of capping trial including non-compliant bladder, bladder outlet obstruction and catheter malposition (n = 14). Study group consisted of 37 procedures in 34 patients (male 19, female 15, age 2-83 years, average 58, median 61) most with cancer (prostate 8, endometrial 5, bladder 4, colorectal 4, breast 2, gastric 2, neuroblastoma 2, cervical 1, ovarian 1, renal 1, sarcoma 1, urothelial 1 and testicular 1) and one with Crohn’s disease. Medical records were reviewed to assess outcomes of capping trial. Exact 95% confidence intervals (95%CI) were calculated.

RESULTS

Among patients with complete aspiration of retained contrast, 30 (81%, 95%CI: 0.65-0.92) catheters were successfully capped (range 12-94 d, average 40, median 24.5) until planned conversion to internal stent (23), routine exchange (5), removal (1) or death unrelated to catheter (1). Seven capping trials (19%, 95%CI: 0.08-0.35) were unsuccessful (range 2-22 d, average 12, median 10) due to leakage (3), elevated creatinine (2), fever/hematuria (1) and nausea/vomiting (1).

CONCLUSION

Capping trial success among patients with complete aspiration of retained contrast/urine from bladder via NUT appears high.

What is the purpose of launching World Journal of Clinical Urology?

The first issue of the World Journal of Clinical Urology (WJCU), whose preparatory work was initiated on December 6, 2010, will be published on December 28, 2011. The WJCU Editorial Board has now been established and consists of 101 distinguished experts from 25 countries. Our purpose in launching the WJCU is to publish peer-reviewed, high-quality articles via an open-access online publishing model, thereby acting as a platform for communication between peers and the wider public, and maximizing the benefits to editorial board members, authors and readers.

Update summarising the conclusions of the international consultation on male lower urinary tract symptoms

The International Consultation on Urological Disease have recently published comprehensive conclusions, based on evidence reviewed by eight committees, on aspects of male lower urinary tract symptoms (LUTS). In this review, we summarise the conclusions from four of the committees, namely, the evidence regarding the epidemiology of male LUTS, patient assessment, nocturia and medical management. It is indisputable that with an expanding and ageing global population the prevalence of male LUTS is likely to increase. Therefore symptom prevention and preservation of quality of life (QoL) feature highly in the guidelines. There are now a number of different medical options, proven to lead to significant improvements in symptom scores, flow rate and QoL available to men with LUTS. Meta-analyses have shown the benefits for alpha blockers, antimuscarinics, 5-α reductase and phosphodiesterase-5 inhibitors. High level evidence also exists for combinations of all of the above with alpha blockers and so men with concomitant storage symptoms, prostate volume > 30 mL, PSA > 1.4 or erectile dysfunction may be considered for combination treatment of an alpha blocker with an antimuscarinic, 5-α reductase inhibitor or phosphodiesterase-5 inhibitor respectively. In an era of personalised medicine, appropriate patient selection is likely to provide the key to the most effective clinical management strategy.

Enuresis and sleep disordered breathing: An old and new link

The causes of nocturnal enuresis (NE) are likely multifactorial. It has been related to several (urological-nephrological-hormonal) reasons but clear and univocal pathogenesis remains mostly undetermined. Sleep disordered breathing (SDB) is a syndrome of upper airway dysfunction that occurs during sleep and is characterized by snoring and/or increased respiratory effort secondary to increased upper airway resistance and pharyngeal collapsibility. Adenotonsillar hypertrophy is the main cause of SDB in children. To date, several studies have associated childhood NE with coexistent SDB. Adenotonsillectomy was successful for both SDB and NE in about half of patients. Unfortunately, practical consensus guidelines for the management of primary NE do not mention, or marginally concern, SDB in these children, particularly in those who have treatment resistance and comorbidities. The concerns regard the concomitant presence of two relatively frequent sleep disorders, raising the question whether they are really coincidental problems of childhood.

Conservative management of an early abdominal complication during a Tullio percutaneous endoscopic excision of renal pelvis urothelial carcinoma: A case report

BACKGROUND

Upper tract urothelial carcinoma (UTUC) representing only a small fraction of all urothelial tumors. It predominantly affects the renal pelvis in men, often coexisting with bladder carcinoma. UTUC displays a more aggressive genetic profile compared to bladder neoplasms, with the majority of patients presenting with advanced disease. Histologically, about a quarter of UTUC cases exhibit high-grade subtypes, associated with a worse prognosis. Tobacco use and past exposure to aromatic amines are significant risk factors for UTUC. Imaging modalities such as Uro-computed tomography and magnetic resonance imaging play crucial roles in diagnosis. Ureterorenoscopy is vital for direct visualization and biopsy sampling, but its limited sampling capacity presents challenges in determining tumor depth and staging. Traditionally, nephroureterectomy with bladder cuff excision has been the gold-standard treatment for UTUC. Endoscopic conservative treatment has recently emerged as a viable option for selected patients, offering comparable oncological outcomes to radical surgery. Percutaneous access is also feasible for larger intrarenal tumors.

CASE SUMMARY

We present a case of an 84-year-old woman who underwent percutaneous endoscopic excision of a renal pelvis neoplasm using the Tullio laser. Despite successful tumor removal, the patient experienced a postoperative complication with abdominal fluid leakage. Conservative management effectively resolved the complication. Given the patient's age and refusal for radical surgery, the conservative approach proved to be a valid therapeutic choice.

CONCLUSION

Overall, UTUC remains a diagnostic and therapeutic challenge due to its rarity. However, advances in endoscopic and percutaneous techniques provide valuable alternatives for selected patients, warranting further exploration in this evolving field.

Morphological and functional evaluation of chronic kidney disease using magnetic resonance imaging

X-ray computed tomography (CT), ultrasonography (US) and radionuclide scanning are important clinical methods for evaluating morphology of the kidney. These modalities are also applicable for estimating kidney function with time lapse analysis using proper contrast-media as may be necessary. In the case of US, it can estimate kidney function based on the measurement of blood flow using the Doppler effect. Formerly, magnetic resonance imaging (MRI) was an inappropriate diagnostic imaging technique for abdominal organs because of their respiratory displacements. However, MRI is now actively used for kidney as well as liver or other parenchymal organs, in tandem with the technological advances. Unlike unenhanced X-ray CT, “conventional” MRI can distinguish the border between cortex and medulla in T1 or T2 weighted images. It was known that the border blurred with decreasing kidney function. Moreover, several other particular imaging methods were introduced in recent years, and these could be called “functional” MRI. In this review, the following are discussed: functional MRI for chronic kidney disease, which include blood oxygenation level-dependent MRI for evaluation of hypoxia, diffusion-weighted imaging for evaluation of fibrosis, diffusion tensor imaging for evaluation of microstructure, and arterial spin labeling to evaluate the amount of organ perfusion, accompanied with several related articles. The ultimate goal of functional MRI is to provide useful in vivo information repeatedly for daily medical treatment non-invasively.