Radiologic evaluation of patients with renal infections

Although renal imaging is not indicated routinely in cases of uncomplicated renal infection, CT is a highly sensitive modality to diagnose and guide the management of patients with acute renal infection. CT is particularly useful in identifying complications of renal infection. Intravenous urography and US are limited to screening for urinary obstruction, renal calculi, and underlying anomalies. CT is also of value in establishing the diagnosis in equivocal cases, in evaluating high-risk patients, and in determining the nature and extent of disease. CT urography is increasingly performed as a comprehensive urinary tract imaging study. MRI may be performed when patients have contraindications to iodinated contrast material. Cortical scintigraphy is the preferred imaging study for the evaluation of children with acute pyelonephritis, although power Doppler US can be considered as a possible alternative. Recent limited studies using gadolinium-enhanced MRI have been shown to be valuable in the depiction of changes of acute pyelonephritis.     

妊娠期尿石症诊疗体会

目的 探讨妊娠期尿石症的诊断和治疗方法.方法 对28例妊娠期尿石症的临床资料及诊治过程进行回顾性分析,结合文献讨论其临床特点和诊疗方法.结果 25例B超检查发现有结石;全部患者均先行保守治疗,但有反复尿路感染并不完全梗阻,肾绞痛反复发作者行膀胱镜逆行置入双J管;输尿管结石合并肾积水患者行经皮肾造瘘;全部患者均足月分娩.结论 妊娠期尿石症的诊断首选B超检查,治疗上以保守治疗为主,不提倡创伤较大的治疗方法,以避免出现流产或早产;出现肾功能损害、尿路感染或保守治疗无效时,应及时进行外科治疗,主要是经膀胱镜逆行置入双J管、经皮肾造瘘和输尿管镜碎石.     

CT urography for hematuria

Hematuria can signify serious disease such as bladder cancer, upper urinary tract urothelial cell carcinoma (UUT-UCC), renal cell cancer or urinary tract stones. CT urography is a rapidly evolving technique made possible by recent advances in CT technology. CT urography is defined as CT examination of the kidneys, ureters and bladder with at least one series of images acquired during the excretory phase after intravenous contrast administration. The reasoning for using CT urography to investigate hematuria is based on its high diagnostic accuracy for urothelial cell carcinoma (UCC) and favorable comparison with other imaging techniques. The optimum diagnostic imaging strategy for patients with hematuria at high-risk for UCC involves the use of CT urography as a replacement for other imaging tests (ultrasonography, intravenous urography, or retrograde ureteropyelography) and as a triage test for cystoscopy, resulting in earlier diagnosis and improved prognosis of bladder cancer, UUT-UCC, renal cell cancer and stones. Current problems with CT urography for investigating hematuria might be solved with a formative educational program simulating clinical reporting to reduce reader error, and a new technique for image-guided biopsy of UUT-UCC detected by CT urography for histopathological confirmation of diagnosis and elimination of false-positive results. CT urography is recommended as the initial imaging test for hematuria in patients at high-risk for UCC.     

Management of symptomatic urolithiasis during pregnancy

Urinary calculi during pregnancy present not only a diagnostic challenge but also a management dilemma. In this retrospective study, we describe our experience with diagnosis and management of symptomatic urolithiasis in pregnant women. A total of 18 pregnant women were treated for urolithiasis at the Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, between 1999 and 2004. The incidence of symptomatic urolithiasis during pregnancy was 0.35%. Of the 20 stones found, nine were on the right side and 11 were on the left, and two patients had bilateral urinary stones. Most urolithiasis cases during pregnancy (55.5%) occurred in the third trimester. Flank pain (94.4%) was the most common clinical presentation. Conservative management was successful in 10 patients until the end of pregnancy and then definite treatment was performed. In four patients, a double-J stent was inserted successfully for persistent pain. In three cases with persistent pain, failure of double-J stent placement was treated with ureteroscopic lithotripsy under epidural anesthesia. One patient received percutaneous nephrostomy for persistent renal colic and pyonephrosis. Ultrasonographic evaluation of pregnant women with suspected renal colic is a reasonable diagnostic procedure. Ureteroscopy is another choice when conservative treatment fails.     

The intravenous pyelogram in acute pyelonephritis

In a cohort of 67 otherwise healthy patients with acute pyelonephritis that was severe enough to warrant hospitalization and uroradiography, 8% had a genitourinary abnormality that influenced management. Consequently, over 90% of patients had studies that did not alter their care. In an attempt to identify clinical clues that might increase specificity without compromising sensitivity of the intravenous pyelogram in acute pyelonephritis, only the fever curve was statistically useful. Confined to patients who were febrile through 72 hours of appropriate antibiotic treatment, the yield of urography in demonstrating anomalies of immediate clinical significance rose from 8% to 36%. The likelihood of an acutely important abnormality was also increased fivefold in both diabetic patients and patients with a urinary pathogen other than ampicillin-sensitive Escherichia coli, but small numbers precluded statistical significance. Bacteremia was common (27%), but not helpful other than in confirming the microbiological diagnosis. Nonacute structural abnormalities were present in 43% of the patients, three to nine times more frequently than in reported cases without upper tract infection.     

Ultrasonography and computed tomography in severe urinary tract infection

A prospective study evaluated the utility of renal computed tomography (CT) and ultrasonography in 35 patients hospitalized for treatment of urinary tract infection. Renal computed tomograms were abnormal in 18 of 28 patients with acute pyelonephritis and three of four patients with urosepsis, showing findings consistent with pyelonephritis in 17 patients and intrarenal abscess or focal bacterial nephritis in four patients. Renal sonograms were abnormal in only eight patients, showing findings compatible with pyelonephritis in four and intrarenal abscess or focal bacterial nephritis in the other four. Flank tenderness was absent in only four patients with CT findings of pyelonephritis, of whom three were diabetic. We therefore found that (1) renal CT is a sensitive test for acute upper urinary tract infection, (2) ultrasonography detects focal bacterial nephritis and abscesses but is insensitive to uncomplicated upper urinary tract infection, and (3) painless pyelonephritis may be more common in patients with diabetes mellitus.     

Renal stones in Wilson's disease.

Fifty-four patients with Wilson's disease were studied with regard to renal stones. Seven of the 45 patients (16 per cent) who underwent roentgenographic procedures of the urinary tract had unequivocal evidence of renal stones. In four of the seven patients with Wilson's disease who had renal stones, the stones were discovered at the time or before the diagnosis of Wilson's disease was made. Of the several possible factors that may predispose patients with Wilson's disease to renal stone formation, the renal tubular acidosis pattern of abnormality in acid-base excretion is probably the most significant. In general, patients with renal stones and unexplained neurologic, bony or hepatic abnormalities should be screened for Wilson's disease by slit-lamp examination, determination of serum copper and ceruloplasmin concentrations, and urinary excretion of copper, particularly if they have relatively alkaline urine.     

Urological Aspects of Management

Renal colic describes the acute, severe, and paroxysmal pain caused by the obstruction, distension, and resultant increase in intraluminal pressure of the urinary tract. The treatment of renal colic is aimed at relief of symptoms, facilitating urinary drainage to preserve renal function and treat infection and ultimately removal or passage of the obstructing stone. The medical management of renal colic is directed at mitigating, through pharmacologic intervention, one or more of the complex processes contributing to the clinical sequelae of obstruction including pain, nausea, vomiting, and irritative voiding symptoms. Numerous medications and combinations of medications have been employed with varying degrees of clinical success. Urgent interventions are typically directed at bypassing ureteral obstruction in order to palliate the patient until such time as definitive treatment may be accomplished or facilitate drainage to further the treatment of urinary tract infection. Timing and mode of urgent intervention are dependent on clinical factors, clinician expertise, and preference and the availability of specialized equipment. Definitive management of ureteral stones is typically performed in an elective fashion and seeks to balance the risks of intervention with the clinical benefits of the various treatment modalities. Treatment approaches vary according to clinical indications, patient preference, clinician expertise, and the availability of facilities and equipment. This section covers current supporting evidence and rationale, indications and techniques for the medical management, urgent intervention, and definitive management of acute renal colic caused by ureteral stones.     

Fetal and neonatal kidney function. Implications for fetal urinary tract abnormalities

High-resolution sonography provides the opportunity for prenatal detection of fetal anomalies of the urinary tract. In view of various options of prenatal urinary diversion to alleviate obstruction, it has become a scientific goal to measure fetal renal function and to determine the prognosis of urinary tract malformations. The article outlines the accumulated knowledge of the development of fetal renal function and the diagnostic possibilities offered by sonography and by laboratory test with focus on the chemistry of the amniotic fluid. Taking into consideration the high risks of prenatal intervention, these findings are discussed as to their relevance for the clinical management of pregnancies complicated by fetal urinary tract abnormalities. Lastly, criteria are proposed for the decision making in clinical practice.     

Clinico-epidemiologic study of urolithiasis in a Caribbean urban area

Urolithiasis is a common clinical disorder. Its frequency has risen with the development of humanity and varies wirl the country, geographic area, etc. It poses health problems in most countries. The urolithiasis has some potential risk factors such as intrinsic and extrinsic epidemiological, metabolic, physic-chemistry of the urine, mechanics and urinary infection. Our objective in this epidemiological study in a general population was to know the frequency, the potential risk factors, the morbidity, and social and economical impact of the urolithiasis in our subtropical Caribbean country. The prevalence was 4.64% and the annual incidence was 0.1%. Both are with in the estimated range of urolithiasis frequency in the world. It mainly started between 20 and 29 years in both genders. The white (5.2%) and the male (6.36%) patients were the most affected. 40% of all patients had a family history of urolithiasis. It was highly associated with diabetes mellitus, ischaemic cardiopathy, urinary tract infection and arterial hypertension. Stone formation was related to the warmer season. High calcium, protein-purine, carbohydrates and oxalic acid intake together with low fluid intake were closely associated with this disorder. 85% of patients had suffered renal colic and 75% of them more than once. Stone recurrence affected 33.8% of patients and 54.5% of them had more than one recurrence. Procedures for stone removal were needed in 33.8% of subjects. 40% of all patients were admitted to hospital due to urolithiasis morbidity. Non-specific medical treatment had been taken by 49.2% of the patients and specific treatment by none. Urolithiasis in this population was the some as has been reported in others studies. It has shown high frequency, increasing incidence, the same risks factors, high morbidity, and high social and economical impact. The low cost treatment is only taken by half of the patients.     

Recurrent renal stone disease-advances in pathogenesis and clinical management

Kidney stones are common in industrialised nations: up to 15% of white men and 6% of all women will develop one stone, with recurrence in about half these people. Risk factors for formation of stones include urinary promoters (calcium, urate, cystine, and sodium) and urinary inhibitors (magnesium, citrate, and nephrocalcin). Acute renal colic can be precipitated by dehydration and reduced urine output, increased protein intake, heavy physical exercise, and various medicines. Such colic manifests as severe loin pain and can be accompanied by frequent urination, dysuria, oliguria, and haematuria. Documentation of stone characteristics is extremely important: type, size, location, and underlying metabolic abnormalities. Such details can be obtained with a combination of biochemical investigations, microscopic examination of urine under polarised light, and an intravenous pyelogram. Ultrasonography and plain abdominal radiographs are also useful, especially for patients unable to tolerate an intravenous pyelogram. Acute therapy includes complete pain relief, rehydration, and encouragement of diuresis. Long-term management encompasses education of patients with regard to diet and fluid intake, control of calciuria, citrate replacement, and treatment of any underlying urinary-tract infection or metabolic abnormality. Stones smaller than 5 mm normally pass spontaneously, whereas larger stones, as big as 2 cm, are best treated with extracorporeal shock-wave lithotripsy. All physicians should have a clear understanding of the pathogenesis and clinical management (acute treatment and prevention of recurrence) of renal stone disease.     

Is There a Relation Between Irritable Bowel Syndrome and Urinary Stone Disease?

Our aim was to investigate the role of renal colic, a clinical condition characterized by excruciating pain, in the etiopathogenesis of irritable bowel syndrome (IBS). Two groups of patients were enrolled in the study. Group I consisted of 59 patients (33 male and 26 female) with a median age of 41.9 (18 to 58) years. The patients in group I were admitted to our clinic with urinary stone disease and with a medical history of acute renal colic. Group II consisted of 55 patients (25 male and 30 female) with a median age of 40.1 (18 to 56) years, complaining of urologic abnormalities other than stone disease. IBS was diagnosed using Rome criteria. Metabolic analysis for stone disease was performed on patients in group I. The incidence of five metabolic abnormalities—low urine volume, hypercalciuria, hyperoxaluria, hyperuricosuria and hypocitraturia—in patients with and without irritable bowel disease was investigated. IBS was found in 16 of the 59 patients (27.1%) in group I and in 6 of the 55 patients (10.9%) in group II. The difference was statistically significant (P < 0.05). Relative risk of developing IBS was 2.48 times higher in patients with urinary stone disease than in those without stone disease. There was no statistically significant difference in the metabolic analysis of patients with and without IBS in group I.IBS causes great suffering. Urinary stone disease should be considered as an etiological factor during management of IBS patients. In the presence of gastrointestinal symptoms, a patient with a medical history of acute renal colic might be referred to a gastroenterologist.     

The relationship of antibody-coated bacteria to clinical syndromes as found in unselected populations with bacteriuria.

In selected patients, detection of antibody-coated bacteria (ACB) in voided urine has correlated with upper urinary tract infection. From unselected patients, we studied 350 consecutive urine specimens submitted to the diagnostic laboratory with colony counts greater than or equal to 10(5)/ml. In 19% (55) among 288 specimens selected for final analysis ACB occurred. There were no substantial differences in the occurrence of ACB by age or sex of patients or by species of bacteria. The relationship of ACB to clinical syndromes was: asymptomatic bacteriuria, 15% (27/178); cystitis, 8% (6/75); acute hemorrhagic cystitis, 67% (4/6); prostatitis, 67% (2/3); and acute pyelonephritis, 62% (16/26). Among seven clinical findings, only structural abnormalities of the upper urinary tract correlated with the presence of ACB. Failure of fever and leukocytosis to correlate with ACB probably reflected the presence of other associated primary medical or surgical conditions.     

Ascending retrocecal appendicitis presenting with right upper abdominal pain： Utility of computed tomography

Acute appendicitis is a common surgical condition that is usually managed with early surgery, and is associated with low morbidity and mortality. However, some patients may have atypical symptoms and physical findings that may lead to a delay in diagnosis and increased complications. Atypical presentation may be related to the position of the appendix. Ascending retrocecal appendicitis presenting with right upper abdominal pain may be clinically indistinguishable from acute pathology in the gallbladder, liver, biliaw tree, right kidney and right urinary tract. We report a series of four patients with retrocecal appendicitis who presented with acute right upper abdominal pain. The clinical diagnoses at presentation were acute cholecystitis in two patients, pyelonephritis in one, and ureteric colic in one. Ultrasound examination of the abdomen at presentation showed subhepatic collections in two patients and normal findings in the other two. Computed tomography （CT） identified correctly retrocecal appendicitis and inflammation in the retroperitoneum in all cases. In addition, abscesses in the retrocecal space （n = 2） and subhepatic collections （n = 2） were also demonstrated. Emergency appendectomy was performed in two patients, interval appendectomy in one, and hemicolectomy in another. Surgical findings confirmed the presence of appendicitis and its retroperitoneal extensions. Our case series illustrates the usefulness of CT in diagnosing ascending retrocecal appendicitis and its extension, and excluding other in- fiammatory conditions that mimic appendicitis.     

Contemporary imaging of renal inflammatory disease

In addition to plain films and conventional excretory urography, ultrasound, computed tomography, and radionuclide scanning may contribute to the assessment of a wide spectrum of renal inflammatory diseases. This article discusses the role of contemporary imaging modalities in the diagnosis and management of patients with renal inflammatory lesions, including acute focal and diffuse bacterial infections, intra- and extrarenal abscess collections, pyonephrosis, xanthogranulomatous pyelonephritis, fungal infection, tuberculosis, and malakoplakia of the upper urinary tract.     

Analysis of myocardial perfusion or myocardial function for detection of regional myocardial abnormalities. An echocardiographic multicenter comparison study using myocardial contrast echocardiography and 2D echocardiography.

BACKGROUND: Echocardiography based myocardial perfusion imaging and regional wall motion analysis are used for evaluation of coronary artery disease and regional myocardial abnormalities. AIM: This study sought to compare myocardial contrast echocardiography (MCE) and 2D echocardiography with regard to interobserver variability and detection of regional myocardial abnormalities. METHODS: In 70 patients evenly distributed between three ejection fraction groups based on biplane cineventriculography ( > 55%, 35-55%, < 35%), unenhanced and contrast enhanced 2D echocardiography and myocardial contrast echocardiography (MCE; SonoVue; Bracco) were performed. Regional wall motion and myocardial perfusion were assessed referring to a 16 segment model. Interobserver agreement (IOA) among 2 readers was determined within each imaging modality. To define a standard of truth for the presence of segmental myocardial disease an independent expert-panel decision was obtained based on clinical data, ECG, coronary angiography and blinded information from the imaging modalities. RESULTS: Regional wall motion assessment was possible in 98.1% of segments using contrast enhanced 2D echocardiography and in 87.2% using unenhanced 2D echocardiography (p < 0.001), while perfusion assessment was possible in 90.1% of segments (p < 0.001). IOA on presence of any regional wall motion abnormality expressed as Kappa coefficient was 0.71 (95% CI 0.53-0.89) for contrast enhanced echocardiography and 0.37 (95% CI 0.14-0.59) for unenhanced echocardiography. IOA on presence of any perfusion abnormality was 0.53 (95% CI 0.34-0.73). For MCE there was high IOA for the apical segments (kappa = 0.57) and lower IOA for the basal segments (kappa=0.14), while no such gradient was found for the IOA on wall motion abnormalities. Mean accuracy to detect expert-panel defined myocardial abnormalities was 80.6% for unenhanced echocardiography, 85.0% for contrast enhanced 2D echocardiography and 80.6% for MCE. CONCLUSIONS: MCE is inferior to contrast enhanced 2D echocardiography with regard to visibility of all LV segments and appears slightly inferior with regards to IOA, while both are superior to unenhanced 2D echocardiography. The methods demonstrated high accuracy in detection of panel defined regional myocardial abnormalities.     

Contemporary Imaging for the Management of Urinary Stones

Objective:

The factors associated with a successful outcome for the treatment of urinary lithiasis are well described. We reviewed current methods of imaging utilised in stone treatment planning, with specific reference to their ability to identify predictors of outcome.

Methods:

A literature search for articles concerning the investigation and management of patients with urolithiasis was conducted through PubMed (www.ncbi.nlm.nih.gov/PubMed/). In addition a hand search of the abstract books from the most recent major urological conferences was performed to identify data of interest that have so far been presented in abstract form only.

Results:

Non-contrast computed tomography is superior in terms of diagnostic efficacy, with sensitivity and specificity approaching 100%. The intravenous urogram and contrast CT with 3-dimensional reconstruction provide the best anatomical detail.

Conclusion:

Although non-contrast helical computed tomography is the most sensitive investigation for suspected ureteric colic, the anatomical and functional information afforded by intravenous urography remains important for treatment planning in some patients.     

Clinical study of ammonium acid urate urolithiasis

Ammonium acid urate (AAU) urolithiasis is a rare condition; however, it is endemic in some countries, with an especially high incidence in Asia. This study was conducted to investigate the special presentation of patients with AAU urolithiasis in Taiwan. Reports of 3457 stones were retrospectively reviewed from January 2005 to January 2010 and 25 patients with urinary stones (0.7%) containing AAU crystals were identified. The clinical and biochemical presentation of all stones were compared to evaluate the specific comorbidities of AAU stones. AAU stones were observed in 11 males (44%) and 14 females (56%) with a mean age of 60.60 ± 16.81 years and mean body mass index of 25.55 ± 3.73 kg/m(2). AAU stones were frequently observed in the bladder (44%) and they were significantly larger (mean size 1.90 cm) than the non-AAU stones (mean size 1.22 cm). Other significant comorbidities of AAU stones included chronic kidney disease (CKD) (60%), urinary tract infections (UTIs) (52%), irritable bowel syndrome (IBS) (36%), and gout (28%). In addition, there were also three patients with coexisting urothelial carcinoma (12%) in the AAU-stone group. Patients with AAU urolithiasis were predominantly female, older in age, had increased bladder presentation, larger stones and a high percentage of coexisting CKD, UTIs, IBS, gout, and even urothelial carcinoma. Therefore, it is important for clinicians to evaluate and protect renal function in patients with AAU urolithiasis.     

Clinical correlates of eosinophiluria

We assessed the clinical correlates of eosinophils in the urine in 65 patients. In 16% of 470 patients whose urine was specifically examined, eosinophils were noted in the urine sediment. Review of the 65 patients with eosinophiluria demonstrated that when eosinophils were expressed as a percentage of total urine white blood cells, 85% (55/65 patients) had less than 5% urine eosinophils and 45% (29/65 patients) had less than 1%. Infection of the upper and lower urinary tract accounted for 45% of the clinical conditions associated with eosinophiluria. In nine (14%) of the 65 patients a diagnosis of acute interstitial nephritis could be made by clinical criteria or from renal biopsy specimens. We conclude that the finding of urine eosinophils is associated with a variety of clinical conditions and may be most useful when expressed as a percentage of total white blood cells in the urine. At a low-percentage positive (less than 5%), it may not be a good predictor of acute interstitial nephritis, but at a higher level (greater than 5%) it may be a more valuable predictor.     

Acute bacterial nephritis: a clinicoradiologic correlation based on computed tomography.

PURPOSE: Acute bacterial nephritis (ABN) represents localized, nonliquefied renal infection, and the subsequent alteration of tissue densities can be readily detected by computed tomography (CT). In recent literature, a variety of renal parenchymal alterations observed on CT were reported. However, previous reports on the clinical course of ABN were inconsistent and lacked correlation with radiologic findings. In this investigation, we attempt to correlate the severity of clinical manifestations with CT findings in ABN and draw some conclusions regarding the natural history, pathophysiology, and clinical management of this disease. PATIENTS AND METHODS: From July 1988 to June 1991, 30 cases of ABN were evaluated at our institute. On the basis of postcontrast-enhanced CT findings, 28 cases were grouped into (1) Group I (7 cases), wedge-shaped lesions (focal or diffuse); (2) Group II (12 cases), focal mass-like lesions; and (3) Group III (9 cases), diffuse (multifocal) mass-like lesions. The clinical features and outcomes of the three groups were compared. The positive detecting rates and clinical usefulness of ultrasonographic (US) and urographic examinations were also studied in each group. RESULTS: An excellent correlation can be demonstrated between the clinical parameters (including underlying diseases, maximum temperature and leukocyte count, duration of fever, flank pain, leukocytosis, and pyuria; the incidence of septic shock, diabetic ketoacidosis, and acute renal failure; and outcome) and the pattern of renal parenchymal abnormalities detected on CT. The clinical features in Group I patients displayed many similarities with those in uncomplicated acute pyelonephritis (APN) reported previously, and responded to antibiotic therapy promptly. Most patients in Group II were successfully treated with antibiotics but had a protracted clinical course with a slower clinical improvement than Group I. Only one case with a Group II lesion was noted to progress to renal abscess formation and extrarenal involvement. In comparison, 33% of the patients in Group III died despite antibiotic therapy. Our data also show that US examination is sensitive in detecting Group II ABN lesions (62% positive rate), and revealed marked renal enlargement in most Group III lesions (89%). It is therefore a useful initial imaging modality in providing information vital to clinical decision making. CONCLUSION: Our experiences suggest that renal bacterial infection may show the continuum of severity from uncomplicated APN to ABN, demonstrated on postcontrast CT scan as wedge-shaped lesions to mass-like lesions, and possibly, finally to frank abscess formation. We classify ABN into three subgroups according to CT findings, and good correlation with clinical severity is demonstrated. These findings deliver valuable concepts regarding the pathophysiology and clinical management of this disease.