Multifocal emphysematous osteomyelitis, a do not miss diagnosis for the emergency radiologist: a case report with literature review

Emphysematous osteomyelitis (EO) is an uncommon fatal condition with high morbidity and mortality. Simultaneous involvement of the axial and appendicular skeleton with multifocal disease is even rarer, with only a few cases being reported in the literature. We present a case of multifocal emphysematous osteomyelitis in a 56-year-old woman with concurrent emphysematous pyelonephritis complicated by psoas and epidural abscesses. The causative organism in our patient was Escherichia coli. Emergency radiologists should be aware of this condition and differentiate it from other benign entities that can present with intraosseous gas. Prompt diagnosis is important given the high morbidity and mortality with this condition. This case report emphasizes the specific pattern of intraosseous gas seen with EO, which can help diagnose EO with confidence.

Emphysematous pyelonephritis with progression to necrotising fasciitis of the posterior cervical region and the retropharyngeal space

A man in his 50s with diabetes presented with backache, left flank pain and fever. On evaluation, he was found to have emphysematous pyelonephritis of the left kidney with a paranephric abscess extending into the posterior abdominal wall and superiorly up to the posterior chest wall and inferiorly extending up to the posterior superior iliac spine. The management involved the initiation of broad-spectrum antibiotics and percutaneous drainage of the abscess. However, as he continued to worsen symptoms-wise, he underwent computed-enhanced CT of the abdomen and thorax. The imaging revealed the presence of a purulent collection in the left lumbar region with an extension along the posterior cervical region and the retropharyngeal space. He underwent a fasciotomy of the lumbar region. The occurrence of emphysematous pyelonephritis along with necrotising fasciitis is uncommon and requires early aggressive management with broad-spectrum antibiotics and adequate drainage. This emphasises the need for early reimaging if the patient does not settle with antibiotics or percutaneous drainage.

Added value of non-contrast CT for the diagnosis of acute pyelonephritis in older patients with suspected infection with an unknown focus: a retrospective diagnostic study

OBJECTIVES

In older patients, the diagnosis of acute pyelonephritis (APN) is challenging. The aim was to evaluate the added value of CT to history, physical examination and urinalysis for the diagnosis of APN in older patients with suspected infection with an unknown focus.

DESIGN

Retrospective diagnostic study.

SETTING

Department of General Medicine in an acute care hospital in Japan.

PARTICIPANTS

Patients aged ≥65 years who underwent blood cultures, a urine culture, and chest and abdominal CT to detect the focus of infection were included.

PRIMARY OUTCOME MEASURES

Two radiologists independently reviewed four non-contrast CT signs: perirenal fat stranding, pelvicalyceal wall thickening, enlargement of the kidney and thickening of Gerota's fascia. Findings on contrast-enhanced CT could not be evaluated due to an insufficient number of patients in whom contrast-enhanced CT was performed. An expert panel was used as the reference standard for APN. The added value of CT findings was quantified by comparing the diagnostic performance between a model based on 10 predictors available before CT and an extended model including the CT findings.

RESULTS

Of 473 patients, 61 (14.8%) were diagnosed with APN. When the laterality of the CT findings was taken into account, the model fit was not improved by adding them. In the laterality-insensitive analysis, the model performance was significantly improved by adding the CT signs (likelihood-ratio test p=0.03; c-index 0.89 vs 0.91, p=0.03). However, their clinical utility was only to improve the classification of 11.5% of patients with APN.

CONCLUSIONS

The added value of non-contrast CT findings to history, physical examination and urinalysis was limited for the diagnosis of APN in older patients with a suspected infection with an unknown focus.

An update on pyelonephritis: role of contrast enhancement ultrasound (CEUS)

Acute pyelonephritis (APN) is a bacterial infection causing inflammation of the kidneys. Diagnosis is usually based on clinical and laboratory findings. Imaging is required if a complication is suspected in acute pyelonephritis to assess the nature and extent of the lesions and to detect underlying causes. CT represents the current imaging modality of choice in clinical practice. CEUS is an alternative that has been proven to be equally accurate in the detection of acute pyelonephritis renal lesions. CEUS allows us to distinguish small simple nephritic involvement from abscess complications and to follow their evolution over time during antibiotic therapy. The absence of ionizing radiation and the lack of nephrotoxicity make CEUS an ideal tool in the study of pyelonephritis.

Altered Biodistribution on 99m Tc-Dimercaptosuccinic Acid Renal Scan

ABSTRACT

99m Tc-dimercaptosuccinic acid ( 99m Tc-DMSA) scans are used to evaluate renal cortical defects typically related to parenchymal scarring or pyelonephritis, and ectopic renal parenchyma. 99m Tc-DMSA binds to metalloproteins in proximal tubular cells and typically localizes to the renal cortex, with minimal excretion. Planar and SPECT images are obtained 2 to 4 hours after IV administration of 99m Tc-DMSA. Altered 99m Tc-DMSA biodistribution has been reported in various conditions, including renal injury, technical issues, infiltrative processes, and hematologic disorders. Here, we present a case of altered biodistribution, with hepatic and splenic radiotracer uptake in the setting of hepatosplenomegaly and hematologic abnormalities concerning for a systemic hematologic disorder/lymphohistiocytosis.

Isolated renal mucormycosis masquerading as emphysematous pyelonephritis

Mucormycosis is an acute, life-threatening infection and isolated renal involvement is rare. Due to the angioinvasive nature of the disease, it is rapidly progressive and can be lethal if not managed expeditiously. In patients with underlying conditions of immunosuppression, diabetes mellitus, transplantation, COVID-19, intravenous drug and substance use and pyelonephritis, which is unable to be controlled via regular antibiotics, mucormycosis must be considered on the differential and antifungals must be empirically started. Most cases are often diagnosed on histopathology, which causes delayed treatment and resolution. We present a case of emphysematous pyelonephritis diagnosed on imaging and was later found to have mucormycosis on histopathological examination.

The Problem of Occult Pyelonephritis: Acute Pyelonephritis in Patients Presenting Only with Lower Urinary Tract Symptoms

Pyelonephritis is a prevalent diagnosis of emergency department visits. It commonly presents as flank pain and costovertebral tenderness with urinary symptoms. However, some cases occur without typical symptoms. Our study highlights the dubious presentation of pyelonephritis with lower urinary tract symptoms (LUTS) only. This study was conducted at a tertiary care hospital, where charts and files were reviewed from January 11, 2018 to February 28, 2019 for all the patients with a diagnosis of acute pyelonephritis from medical records. In our study, 521 patients were included and 492 (94%) of the participants were suffering from pyelonephritis. Approximately 22.8% of the patients showed the absence of both flank pain and costovertebral tenderness but were diagnosed with pyelonephritis based on computed tomography (CT) and magnetic resonance imaging (MRI). Moreover, 27% of the patients reported upper urinary tract symptoms only and were diagnosed by CT or MRI findings. Out of that only 24% and 16% of the patients reported flank pain and costovertebral tenderness, respectively. Insignificant associations with pyelonephritis were found for age, gender and other comorbidities. Our study showed a significant number of patients with pyelonephritis without any upper urinary tract symptoms. Patients with LUTS should be evaluated further by imaging if they belong to the high-risk population.

ACR Appropriateness Criteria® Acute Pyelonephritis: 2022 Update

Acute pyelonephritis (APN) is a severe urinary tract infection (UTI) that has the potential to cause sepsis, shock, and death. In the majority of patients, uncomplicated APN is diagnosed clinically and is responsive to treatment with appropriate antibiotics. In patients who are high risk or when treatment is delayed, microabscesses may coalesce to form an acute renal abscess. High-risk patients include those with a prior history of pyelonephritis, lack of response to therapy for lower UTI or for APN, diabetes, anatomic or congenital abnormalities of the urinary system, infections by treatment-resistant organisms, nosocomial infection, urolithiasis, renal obstruction, prior renal surgery, advanced age, pregnancy, renal transplant recipients, and immunosuppressed or immunocompromised patients. Pregnant patients and patients with renal transplants on immunosuppression are at an elevated risk of severe complications. Imaging studies are often requested to aid with the diagnosis, identify precipitating factors, and differentiate lower UTI from renal parenchymal involvement, particularly in high-risk individuals. Imaging is usually not appropriate for the first-time presentation of suspected APN in an uncomplicated patient. The primary imaging modalities used in high-risk patients with suspected APN are CT, MRI, and ultrasound, although CT was usually not appropriate for initial imaging in a pregnant patient with no other complications. The ACR 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 in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Acute focal bacterial nephritis and prolonged fever

Acute focal bacterial nephritis (AFBN) is characterised by a complicated upper urinary tract infection ranging from acute pyelonephritis to renal abscess. Timely diagnosis of AFBN is important because antibiotic therapy of longer duration is required. A 10-year-old boy presented with fever for 5 days and bilateral flank pain. He was oriented and cooperative but appeared ill. Physical examination did not reveal any oedema or costovertebral angle tenderness. Acute phase reactants such as erythrocyte sedimentation rate and C-reactive protein were raised, serum creatinine was 1.25 mg/dL (0.31-0.88) and leucocyte esterase was positive in the urine. Ultrasonographic examination demonstrated bilaterally enlarged kidneys with increased echogenicity. Because of the high creatinine level, abdominal magnetic resonance imaging (MRI) was performed instead of computed tomography (CT) for further evaluation. The MRI showed an increase in the size of both kidneys, renal cortical heterogeneity and multiple cortical nodular lesions with diffusion restriction (constrained Brownian movement of water molecules) on diffusion-weighted MRI. A negative urine culture result in children presenting with fever and abdominal pain may mislead the clinicians, causing them to miss a nephro-urological diagnosis. It is therefore recommended that patients in whom the cause of fever cannot be determined be scanned by ultrasound and examined by CT or MRI so that undiagnosed and/or suspected cases of AFBN might be detected.

Usefulness of computed tomography in the diagnosis of acute pyelonephritis in older patients suspected of infection with unknown focus

BACKGROUND

In older adults, the diagnosis of acute pyelonephritis is challenging because of non-specific symptoms and false-positive urine test results. Few studies have investigated the diagnostic performance of computed tomography (CT) signs.

PURPOSE

To evaluate the diagnostic performance of CT signs for acute pyelonephritis in older patients suspected of infection with unknown focus.

MATERIAL AND METHODS

This cross-sectional study was conducted between 2015 and 2018. Patients aged ≥65 years who underwent blood cultures, urine culture, and non-contrast or contrast-enhanced CT on admission were included. Cases with clinically presumable infection focus before CT were excluded. Two radiologists blinded to clinical information independently reviewed five CT signs: perirenal fat stranding; pelvicalyceal wall thickening and enhancement; renal enlargement; thickening of Gerota's fascia; and area(s) of decreased attenuation. The final diagnoses were made by a clinical expert panel.

RESULTS

Among 473 eligible patients, 61 were diagnosed with acute pyelonephritis. When the laterality of findings between the left and right kidneys were considered, the positive and negative likelihood ratios of perirenal fat stranding were 4.0 (95% confidence interval [CI] = 2.3-7.0) and 0.8 (95% CI = 0.7-0.9) in non-contrast CT, respectively. The other signs in non-contrast CT showed similar diagnostic performance with positive and negative likelihood ratios of 3.5-11.3 and 0.8-0.9, respectively.

CONCLUSION

CT signs can help physicians diagnose acute pyelonephritis in older patients suspected of infection with unknown focus.

Microvascular Doppler ultrasound in children with acute pyelonephritis

AIMS

To compare the diagnostic performance of microvascular Doppler ultrasonography (MVUS) to B-mode and con-ventional colour Doppler US (CDUS) for detecting acute pyelonephritis (APN) lesions in children.

MATERIAL AND METHODS

An IRB-approved retrospective study was performed. From July 2018 to January 2019, 41 APN lesions in 28 children (15 boys, 13 girls; age range, 1-196 months; mean age, 53 months) who underwent 99mTc‒dimercaptosuccinic acid renal scintig-raphy (DMSA) or contrast-enhanced computed tomography (CECT) and US including B-mode, CDUS, and MVUS were enrolled in this study. Three paediatric radiologists independently reviewed the B-mode, CDUS and MVUS images for the DMSA or CECT-proven APN lesions and evaluated the lesion visibility, lesion distinguishability and diagnostic confidence between the MVUS and CDUS images.

RESULTS

A total 41 of APN lesions were verified by DMSA (41 lesions) or CECT (3 lesions) during the same hospitalization period with renal US. Among 41 APN lesions, 52.8% was visible on B-mode, 85.4% on CDUS, and 94.3% on MVUS (p<0.001). Comparing the extent and margins of the lesions, MVUS had better results than CDUS in 41.5% of the lesions, CDUS had better results in 6.5% and they were equal in 52% (p<0.001). The diagnostic con-fidence of the APN lesions was higher for MVUS than CDUS in 36.6%, higher for CDUS than MVUS in 4.9%, and equal in the remaining 58.5% (p<0.05). The interobserver agreement was fair to moderate.

CONCLUSIONS

MVUS showed improved detectability of hypoperfused areas in paediatric APN and provided higher diagnostic confidence.

Clinical and computed tomography factors associated with sepsis in women with clinically uncomplicated pyelonephritis

OBJECTIVE

Sepsis is major determinants of prognosis in acute pyelonephritis (APN). This study aimed to assess factors associated with the development of sepsis among patients with clinically uncomplicated APN.

SUBJECTS AND METHODS

We examined 463 patients presenting to our hospital without complications. We assessed clinical factors including demographic and laboratory features. Renal and extrarenal features on computed tomography (CT) were also analyzed. Risk factors of sepsis are assessed.

RESULTS

The study included 361 patients without (78.0%) and 102 patients with sepsis (22.0%). Crude and attributable mortality rates were 3.9% and 2.0% versus 1.4% and 0.6%, respectively, among patients with and without sepsis. Clinical risk factors for sepsis were age >65 years (odds ratio [OR] 1.79, P = 0.02), absence of flank pain (OR 1.59, P = 0.04), absence of costovertebral tenderness (OR 1.89, P = 0.03), diabetes mellitus (OR 2.25, P = 0.02), bacteremia (OR 2.8, P = 0.01), C-reactive protein level >100 mg/L (OR 1.42, P = 0.02), and lack of previous APN history (OR 1.76, P = 0.04). APN grade IV (OR 3.16, P = 0.01), high grade hydronephrosis (OR 1.50, P = 0.03), diffuse peritoneal thickening (OR 4.12, P = 0.01), and acute interstitial pulmonary edema (OR 3.73, P = 0.01) were the CT features predictive of septic shock.

CONCLUSIONS

Although uncomplicated APN was largely non-fatal, several clinical and CT features could lead to sepsis. Our findings may be useful for predicting sepsis risk and deciding whether intravenous antibiotic treatment and intensive management should be initiated for uncomplicated APN.

Imaging Characterization of Renal Masses

The detection of a renal mass is a relatively frequent occurrence in the daily practice of any Radiology Department. The diagnostic approaches depend on whether the lesion is cystic or solid. Cystic lesions can be managed using the Bosniak classification, while management of solid lesions depends on whether the lesion is well-defined or infiltrative. The approach to well-defined lesions focuses mainly on the differentiation between renal cancer and benign tumors such as angiomyolipoma (AML) and oncocytoma. Differential diagnosis of infiltrative lesions is wider, including primary and secondary malignancies and inflammatory disease, and knowledge of the patient history is essential. Radiologists may establish a possible differential diagnosis based on the imaging features of the renal masses and the clinical history. The aim of this review is to present the contribution of the different imaging techniques and image guided biopsies in the diagnostic management of cystic and solid renal lesions.

[Emphysematous pyelonephritis: case of successful conservative treatment]

Emphysematous pyelonephritis is rare form of pyelonephritis, which has mortality of nearly 80%. Conservative treatment can be successful in less than 30% of cases. Currently, in the guidelines there is no standard approach to conservative and surgical treatment of this entity. The clinical observation of successful conservative treatment of a patient with emphysematous pyelonephritis, associated with decompensated diabetes mellitus, from the diagnosis to recovery without performing nephrectomy in order to preserve kidney function, is described in the article.

Clinical impact of perinephric fat stranding detected on computed tomography in patients with acute pyelonephritis: a retrospective observational study

Perinephric fat stranding (PFS) is often detected on computed tomography (CT) in patients with acute pyelonephritis (APN). However, its clinical impact remains unclear. This study aimed to evaluate the clinical impact of PFS detected on CT in patients with APN. This retrospective observational study included patients with APN who underwent CT (median age, 79.5 years). Patients were classified into PFS (patients with PFS observed on CT) and non-PFS (patients without PFS observed on CT) groups, which were further classified into bacteraemia and non-bacteraemia groups. Clinical findings between the groups were compared. Among 194 patients who underwent CT, 111 (57.2%) patients demonstrated PFS. The rate of bacteraemia was significantly higher in the PFS group than in the non-PFS group (55.2 vs. 23.1%, p < 0.001). CT findings other than PFS were not associated with bacteraemia. The median peak body temperature was significantly higher in the PFS group than in the non-PFS group (38.8 vs. 38.5 °C, p < 0.001); however, the duration of fever and in-hospital mortality rates were not significantly different between the groups. Concordance between blood and urine culture results was observed in 75.0% of the patients; the presence of PFS was not different between patients with concordant and discordant results, regardless of the pre-treatment antibiotic used. Our findings suggest that the presence of PFS in patients with APN predicts bacteraemia; thus, clinicians should consider obtaining blood cultures if PFS is found on CT in patients with APN, even if the patients had received antibiotics prior to admission.

Clinical Usefulness of Unenhanced Computed Tomography in Patients with Acute Pyelonephritis

BACKGROUND

Unenhanced computed tomography (UCT) may be useful for evaluating acute pyelonephritis; however, no study has compared UCT with enhanced computed tomography (ECT) as a diagnostic tool. We evaluated a clinical usefulness of UCT versus ECT in acute pyelonephritis (APN).

METHODS

We reviewed the clinical and radiological data from 183 APN-suspected patients who underwent UCT and ECT simultaneously at emergency room (ER) over a two-year period. Demographic, clinical parameters and computed tomography (CT) parameters of 149 patients were compared.

RESULTS

The average patient age was 61.2 (± 10) years: 31 patients were men. Ninety-nine (66.4%) patients showed stones (18.7%), perinephric infiltration (56%), swelling (21%), and hydronephrosis (6.7%) on UCT. Seventeen patients (11.4%) had an atypical clinical course, requiring additional tests for accurate diagnosis. In 7 patients UCT and ECT results did not differ; in 10 patients, the diagnosis changed on ECT. On ECT, 112/149 (75.2%) patients had stones (16.7%), perinephric infiltrations (57%), swelling (21%), and hydronephrosis (6.7%); 62.5% showed parenchymal involvement: 34 (22.8%) patients had no abnormal ECT findings. APN CT findings are similar on stone, perinephric infiltration, swelling and hydronephrosis on both CTs. Twelve patients (8.0%) had an abnormal ECT finding, i.e., low-grade (1 and 2) parenchymal involvement. Six (4%) patients developed contrast-induced acute kidney injury within 2 days after ECT.

CONCLUSION

We demonstrate that UCT is not inferior to ECT as an initial tool for evaluating APN for screening nephrolithiasis and hydronephrosis without the risk of contrast-induced acute kidney injury (CIAKI). However, patients with an atypical clinical course may still need ECT.

[Xanthogranulonatous pyelonephritis: report of 5 cases]

Xanthogranulomatous pyelonephritis (XGP) is an unusual form of chronic pyelonephritis in which the renal parenchyma is destroyed and replaced by lipid-laden foamy macrophages. It usually affects middle-aged women with a history of recurrent urinary tract infection, diabetes, or kidney stones. The inflammatory process is usually diffuse and can extend beyond the kidney. The rare focal forms may simulate primary renal tumours. The preoperative imaging diagnosis may be difficult. We reported five cases of XGP, The findings of ours were recorded including kidney size, shape, contour, the echogenecity of the renal parenchyma, the internal echoes of the dilate collecting system, the presence of perinephric fluid accumulation and obstruction. One of the 5 cases was a male patient, and the other four were female, with a mean age of 53 years. He affected kidneys of the 5 cases swelled in different degrees, and one of them was found with line-like anechoic fluid. Among the 5 cases, one kidney appeared as diffusely reducing of the parenchyma echogenicity, multiple hypoechoic areas, disappearance of corticomedullary differentiation and multiple hyperecho with shadow. A round cystic anechoic lesion was found in one kidney, with internal punctate echo and peripheral fluid. Ultrasonographic finding of 1 case was extremely hypoechoic lesion on the left kidney, protruding from the outline of the kidney, with the partial renal capsule discontinuous, the less clear boundary, and a little blood flow in it. Ultrasonographic demonstration of 2 cases was mild dilatation of the collecting system with irregular wall thickening and internal hypoechogenicity, and 1 case was solid lesion with less clear boundary to the pelvic wall and a small amount of blood flow signal, the another 1 case was showed floccule without internal blood flow. Three cases were caused by chronic obstruction verified by operation, of which one was staghorn calculi, one was poorly differentiated squamous cell carcinoma in the middle part of the ureter, and one was inflammatory stricture of upper ureteral. Through analysis of the above five cases and review of related literature, we explored diagnoses and management of the patients with XGP. Xanthogranulomatous pyelonephritis (XGP) is a rare chronic variant of pyelonephritis characterized by destruction of the renal parenchyma. Combining ultrasonographic features of XGP with clinical recurrent urinary infection and chronic obstruction, XGP can be included in the differentiation. The diagnosis of XGP suspected by ultrasound can be clarified by CT, MRI, contrast-enhanced ultrasound.

Follow-up of acute pyelonephritis: what causes the diffusion-weighted magnetic resonance imaging recovery to lag clinical recovery?

PURPOSE

To analyze with diffusion-weighted magnetic resonance imaging (DW-MRI) the evolution and progress to resolution of acute pyelonephritis (APN) foci over a period of 3 months after onset.

METHODS

30 women (age 22-51 years) with clinical, laboratory (white blood cell and C-reactive protein), and DW-MRI (4b-values 0, 50, 600, 1000 s/mm²) diagnosis of APN were prospectively enrolled. Two double-blinded radiologists evaluated the number of APN foci, and for each of them dimension (D), absolute diffusion coefficient (ADC), and its ratio R to the ADC of unaffected parenchyma. Signature of radiological recovery was focus no longer visible (DW-) and ADC of its site not inferior to the ADC of the unaffected parenchyma, i.e., R ≥ 0.9. Clinical and DW-MRI follow-ups (FU) were performed at 1 and 3 months.

RESULTS

At the acute stage (t ₀), 187 APN foci were found, with ADC₀ = 1.3 ± 0.2 × 10^-3 mm²/s, R ₀ = 0.65 ± 0.12, and D ₀ = 14 ± 7.5 mm. By the 1-month FU (t ₁), all patients had no symptoms and physiological laboratory values; despite this, only 80 (43%) foci were solved, increasing to 138 (74%) by at the 3-month FU. The ROC curve (AUC ≥ 0.80) identified R ₀ ≤ 0.6 and D ₀ > 15 mm as forecast of slow radiologic resolution. About 80% of foci unsolved at 1 month but with R ₁ ≥ 0.8 and D ₁ ≤ 10 mm reached solution at 3 months.

CONCLUSIONS

DW-MRI recovery of APN foci does not always coincide with clinical recovery. The evolution of an APN focus is shaped by its initial values R ₀ and D ₀. About half of the foci still visible at 1 month reached radiological resolution in the two following months.

Interobserver variability for interpretation of DMSA scans in the RIVUR trial

INTRODUCTION

Technetium-99m dimercaptosuccinic acid (DMSA) renal scans are used in the diagnosis of renal scarring. In the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial that randomized 607 children, DMSA renal scans were used for evaluating the presence and the severity of renal scarring.

OBJECTIVE

The aim was to determine interobserver variability in reporting of DMSA renal scans in the RIVUR trial.

STUDY DESIGN

We compared DMSA renal scan reports for renal scarring and acute pyelonephritis from all non-reference local radiologists (ALRs) at study sites with adjudicated as well as non-adjudicated reports from two reference radiologists (RRs) of the RIVUR trial. Two-way comparisons of concordant and discrepant responses were analyzed using an unweighted kappa statistic between the ALR and the adjudicated RR interpretations. All analyses were performed using SAS v 9.4 (SAS institute 2015) and significance was determined at the 0.05 level.

RESULTS

Of the 2872 kidneys evaluated, adjudicated RR reports had 119 (4%) kidneys with renal scarring compared with 212 (7%) by the ALRs. For 79% kidneys the grading for scarring reported by ALRs was either upgraded (24%) or downgraded (55%) by RRs. For acute pyelonephritis (n = 2924), adjudicated RR reports had 85 (3%) kidneys with pyelonephritis compared with 151 (5%) by the ALRs. For 85% kidneys, the grading for pyelonephritis reported by the ALRs was either upgraded (28%) or downgraded (57%) by the RRs. A three-way comparison revealed that all three (RR1, RR2, and ALR) agreed over presence of renal scarring in 19% cases and two of the three agreed in 80% cases. The respective numbers for pyelonephritis were 13% and 84%. The agreement rate for all DMSA scan reports between the RRs and the ALRs was 93%.

DISCUSSION

The study revealed significant interobserver variability in the reporting of abnormal DMSA renal scans compared with the previously published studies. A noteworthy limitation was a lack of uniformity in local reporting of the scans.

CONCLUSIONS

Our study highlights the need for optimizing the clinical yield of DMSA renal scans by more specific guidelines, particularly for standardized and uniform interpretation.

Urgent laparoscopic ureterolithotomy for proximal ureter stones accompanied with obstructive pyelonephritis: Is it safe and effective without preoperative drainage?

To evaluate the safety and efficacy of retroperitoneal laparoscopic ureterolithotomy (RLU) in the treatment of proximal ureteral stones accompanied with obstructive pyelonephritis without preoperative drainage.We retrospectively reviewed 21 cases of proximal ureteral stones with infected kidney undergoing RLU between July 2013 and September 2016. Stone-induced obstructive infected hydronephrosis was diagnosed using blood and urine tests and imaging modalities. Empirical effective broad spectrum antibiotic therapy was initiated immediately, and then urgent RLU was performed without preoperative drainage. During the surgical procedure, infected urine was also aspirated before stone was removed. Preoperative, intraoperative, and postoperative clinical data were collected.Operations were performed successfully without open conversion or blood transfusion. The mean operation time was 69.3 ± 12.33 minutes. For all the patients, the level of plasma procalcitonin decreased after RLU. The mean hospital stay duration was 6.4 ± 1.54 days. No septic shock or other severe complications occurred. By discharge, the body temperature and hemogram of each patient returned to normal. A 100% stone-free rate was achieved.Our study suggests that RLU is a potentially safe and effective method to treat proximal ureteral stones accompanied with obstructive pyelonephritis without any need of preoperative drainage.

Dimercaptosuccinic acid scan challenges in childhood urinary tract infection, vesicoureteral reflux and renal scarring investigation and management

Vesicoureteral reflux (VUR) is a precipitating factor in acute pyelonephritis (APN), and a risk factor for renal scar formation, even if VUR and APN occur independently. There is no scientific evidence on a specific diagnostic evaluation of children after a febrile urinary tract infection (UTI). Based on recent literature and our clinical experience, we reviewed the role of 99mTc dimercaptosuccinic acid (DMSA) renal scan in UTI/VUR imaging. We also reviewed the DMSA challenges and controversies in UTI/VUR management. A DMSA renal scan is the most reliable tool for the establishment of the diagnosis of APN during febrile UTIs acute phase. The "top-down" approach focuses on kidney involvement during UTI rather than on VUR existence, with a goal of diagnosing APN and/or renal dysplasia. Therefore, DMSA is performed before void cysteourethrography (VCUG). Late DMSA scanning should be performed to evaluate the presence of permanent renal scars. DMSA may be considered valuable in the follow-up of children with VUR, in order to detect new renal scarring after breakthrough or recurrent UTIs. An abnormal DMSA scan comprises a risk factor for VUR identification after UTI, for recurrent UTIs, renal damage/scarring, renal function deterioration, and a negative predictive risk factor for VUR improvement and/or spontaneous resolution. An individualized DMSA risk-based dynamic approach may assist physicians on VUR management decisions. DMSA could play an important role in selecting children with UTI/VUR who would benefit from close monitoring and/or early intervention. However, more data are needed for evidence-based guidelines.

Derivation of decision rules to predict clinically important outcomes in acute flank pain patients

OBJECTIVE

Routine CT for patients with acute flank pain has not been shown to improve patient outcomes, and it may unnecessarily expose patients to radiation and increased costs. As preliminary steps toward the development of a guideline for selective CT, we sought to determine the prevalence of clinically important outcomes in patients with acute flank pain and derive preliminary decision rules.

METHODS

We analyzed data from a randomized trial of CT vs. ultrasonography for patients with acute flank pain from 15 EDs between October 2011 and February 2013. Clinically important outcomes were defined as inpatient admission for ureteral stones and alternative diagnoses. Clinically important stones were defined as stones requiring urologic intervention. We sought to derive highly sensitive decision rules for both outcomes.

RESULTS

Of 2759 participants, 236 (8.6%) had a clinically important outcome and 143 (5.2%) had a clinically important stone. A CDR including anemia (hemoglobin <13.2g/dl), WBC count >11000/μl, age>42years, and the absence of CVAT had a sensitivity of 97.9% (95% CI 94.8-99.2%) and specificity of 18.7% (95% 17.2-20.2%) for clinically important outcome. A CDR including hydronephrosis, prior history of stone, and WBC count <8300/μl had a sensitivity of 98.6% (95% CI 94.5-99.7%) and specificity of 26.0% (95% 24.2-27.7%) for clinically important stone.

CONCLUSIONS

We determined the prevalence of clinically important outcomes in patients with acute flank pain, and derived preliminary high sensitivity CDRs that predict them. Validation of CDRs with similar test characteristics would require prospective enrollment of 2100 patients.

Recurrent obstructive acute pyelonephritis: A rare form of Actinotignum (Actinobaculum) schaalii infection in a HIV-1 infected patient

Actinobaculum schaalii is a rarely reported, anaerobic, Gram-positive bacterium which role as uropathogen is emerging. We report here the case of a 47 year old HIV-1 infected woman presented with five recurrent episodes of obstructive pyelonephritis in the context of multiple renal stones. No bacteria was found until the fifth episode, during which prolonged urinary cultures as well as 16S rDNA sequencing allowed the diagnosis of A. schaalii infection. She had developed a life-threatening condition with severe renal failure. A right nephrectomy was performed and found that the intrarenal stones were attributed to the antiretroviral therapy. The renal parenchyma corresponded to an end-stage renal disease with chronic pyelonephritis without abcesses or granules. The situation improved after six months of amoxicillin therapy.

Long-term follow-up of reflux nephropathy in adults with vesicoureteral reflux – radiological and pathoanatomical analysis

Purpose: To study the long-term development of urographic renal morphology in adults with vesicoureteral reflux, to investigate the relationship between renal damage and reflux grade, and to analyse the association between the long-term urographic outcome and the occurrence of acute pyelonephritis and reflux during follow-up. The purpose was also to try to distinguish between acquired and developmental renal damage, based on analyses of renal histological specimens and urographic features, and to analyse associated congenital urogenital abnormalities and family history of reflux, reflux nephropathy, urological malformation or death from end-stage renal disease.

Material and Methods: Renal damage was identified in 100 (83 women) of 115 adults, selected because of documented reflux. Eighty-seven patients had two urographies done (median interval 14.3 years). The extent and progression of renal damage were assessed and features of developmental renal damage were determined. Histological renal specimens were available in 23 patients with renal damage.

Results and Conclusions: The extent of renal damage correlated positively with the severity of reflux. No renal damage developed during the follow-up in 45 previously undamaged kidneys and progression of renal damage was rare (4 of 120 previously damaged kidneys), despite persisting reflux in half of the cases and episodes of acute pyelonephritis during follow-up. Thus, repeated renal imaging is rarely justified in adults with reflux nephropathy. Histological examination showed "chronic pyelonephritis" in all 23 cases and co-existing renal dysplasia in 1 case. The detailed urographic analysis did not reveal support for developmental renal damage. High frequencies of associated congenital urogenital abnormalities and of a positive family history were found. Thus, congenital and/or hereditary factors cannot be discarded as background factors for the development of renal damage.

Usefulness of analytical parameters in the management of paediatric patients with suspicion of acute pyelonephritis. Is procalcitonin reliable?

OBJECTIVE

To investigate the usefulness of procalcitonin (PCT) and other analytical parameters (white blood cell count [WBC], C-reactive protein [CRP]) as markers of acute renal damage in children after a first febrile or afebrile urinary tract infection (UTI).

METHODS

A retrospective study was conducted on children with a first episode of UTI admitted between January 2009 to December 2011, and in whom serum PCT, CRP and white blood cell count were measured, as well as assessing the acute renal damage with renal scintigraphy with ^99mTc-DMSA (DMSA) within the first 72h after referral. A descriptive study was performed and ROC curves were plotted, with optimal cut-off points calculated for each parameter.

RESULTS

The 101 enrolled patients were divided into two groups according to DMSA scintigraphy results, with 64 patients being classified with acute pyelonephritis (APN), and 37 with UTI. The mean WBC, CRP and PCT values were significantly higher in patients with APN with respect to normal acute DMSA. The area under the ROC curve was 0.862 for PCR, 0.774 for WBC, and 0.731 for PCT. The optimum statistical cut-off value for PCT was 0.285ng/ml (sensitivity 71.4% and specificity 75%).

CONCLUSION

Although the mean levels of fever, WBC, CRP, and PCT were significantly increased in patients with APN than in those who had UTI, the sensitivity and specificity of these analytical parameters are unable to predict the existence of acute renal damage, making the contribution by renal DMSA scintigraphy essential.

[A giant fecalith complicated by acute urinary retention, hydronephrosis and acute obstructive pyelonephritis]

The article reports a rare case of a 30-year-old man with Hirschsprung's disease, who developed a giant fecalith in the rectum and sigmoid (weight 3.5 kg, the largest diameter 20 cm). The fecalith impaired urine flow by compressing urinary tract, thereby causing acute urinary retention and right-sided hydronephrosis with acute obstructive pyelonephritis. Removing fecalith resulted in the patient recovery and normal functioning of genitourinary system.

Acute pyelonephritis in transplanted kidneys: can diffusion-weighted magnetic resonance imaging be useful for diagnosis and follow-up?

PURPOSE

To assess reliability of diffusion-weighted magnetic resonance imaging (DW-MRI) in the management of acute pyelonephritis (APN) foci in transplanted kidneys.

MATERIALS AND METHODS

In the 2012-2014 period, 24 kidney-transplanted patients underwent MR screening for clinical suspicion of APN. Two readers independently analyzed all images, establishing presence and location of APN foci. The 22 patients who were positive at the MR exam constituted the study population. For each patient the apparent diffusion coefficient (ADC) was measured in the APN foci and in three sites of the healthy parenchyma (case-control comparison). The data were matched to the laboratory measurements for white blood cell, C-reactive protein, and serum creatinine.

RESULTS

Forty-six APN foci were found in 22/24 patients. At the acute stage, the difference in ADC between healthy parenchyma and APN foci was significant (2.06 ± 0.16 vs. 1.43 ± 0.32 × 10(-3) mm(2)/s; p < 0.0001). The performance of ADC as APN indicator was tested by the receiving operating characteristics (ROC) curve: the area under curve AUC = 0.99 witnessed an excellent discriminatory ability, with threshold APN/normal parenchyma 1.9 × 10(-3) mm(2)/s. At the 1-month follow-up 43/46 APN foci were no longer visible, with ADC values significantly higher than at the acute stage; all laboratory data were physiological, with WBC significantly reduced from the acute phase (5.2 ± 1.6 × 10(9)/L vs. 10.6 ± 4.8 × 10(9)/L; p < 0.0001). The other 3 patients underwent further therapy and exams, including a third MR.

CONCLUSIONS

DW-MRI with ADC measurement seems to be a reliable tool in diagnosing and monitoring APN foci in transplanted kidneys, with clinical impact on patient management.

[Bilateral nephrectomy in patients with end-stage renal failure and chronic active pyelonephritis]

This study analyzed the results of bilateral nephrectomy in 14 patients with end-stage renal disease (ESRD) and chronic active pyelonephritis. Seven patients had urosepsis, and 10 patients had a purulent form of pyelonephritis, which was one-sided in 7 of them. In the early postoperative period, on average, after 9.3 days, 9 patients died. Statistically significant risk factors for death were: chronic hemodialysis, long-term antibiotic therapy, and existing sepsis. Intraoperative complications and postoperative morbidity were not significantly associated with death. The study results imply the need of differentiated approach to bilateral nephrectomy in patients with ESRD and risk factors for fatal outcome. It must be performed on the strong indications since the intervention does not lead to eradication of sepsis. It is advisable to perform "preventive, sanation" bilateral nephrectomy in the "cold period" in patients at risk for developing urosepsis.

Prediction of Cortical Defect Using C-Reactive Protein and Urine Sodium to Potassium Ratio in Infants with Febrile Urinary Tract Infection

PURPOSE

We investigated whether C-reactive protein (CRP) levels, urine protein-creatinine ratio (uProt/Cr), and urine electrolytes can be useful for discriminating acute pyelonephritis (APN) from other febrile illnesses or the presence of a cortical defect on 99mTc dimercaptosuccinic acid (DMSA) scanning (true APN) from its absence in infants with febrile urinary tract infection (UTI).

MATERIALS AND METHODS

We examined 150 infants experiencing their first febrile UTI and 100 controls with other febrile illnesses consecutively admitted to our hospital from January 2010 to December 2012. Blood (CRP, electrolytes, Cr) and urine tests [uProt/Cr, electrolytes, and sodium-potassium ratio (uNa/K)] were performed upon admission. All infants with UTI underwent DMSA scans during admission. All data were compared between infants with UTI and controls and between infants with or without a cortical defect on DMSA scans. Using multiple logistic regression analysis, the ability of the parameters to predict true APN was analyzed.

RESULTS

CRP levels and uProt/Cr were significantly higher in infants with true APN than in controls. uNa levels and uNa/K were significantly lower in infants with true APN than in controls. CRP levels and uNa/K were relevant factors for predicting true APN. The method using CRP levels, u-Prot/Cr, u-Na levels, and uNa/K had a sensitivity of 94%, specificity of 65%, positive predictive value of 60%, and negative predictive value of 95% for predicting true APN.

CONCLUSION

We conclude that these parameters are useful for discriminating APN from other febrile illnesses or discriminating true APN in infants with febrile UTI.

[IMPACT OF THE UPPER URINARY WAYS DRAINAGE METHOD ON RESTORATION OF RENAL FUNCTION IN PATIENTS, SUFFERING ACUTE OBSTRUCTIVE PYELONEPHRITIS]

Renal function was studied, using radionuclide renography, in 142 patients, suffering acute obstructive pyelonephritis, in 73 of whom transcutaneous nephrostomy was applied and in 69--the ureter's stenting, for the urine passage restoration. The investigation was peformed in 1 month and 1 year after miniinvasive treatment. After comparison of the investigation results there was established, that after transcutaneous nephrostomy, using miniinvasive technologies, the affected kidney's functional inhibition was trustworthy less, than after stenting. Because of better preservation of renal function, the transcutaneous nephrostomy conduction in patients, suffering an acute obstructive pyelonephritis, constitutes a less invasive method, than the ureter's stenting.

[Emphysematous pyelonephritis in a non-diabetic patient with a kidney tumour]

Emphysematous pyelonephritis (EPN) is a potentially life-threatening infection, where gas produced by bacteria accumulates in the kidney and the surrounding tissue. Although EPN usually presents in diabetic women, it is also associated with urinary tract obstruction and kidney tumours in non-diabetic patients. We present a case of EPN in a non-diabetic patient with a known kidney tumour, successfully treated with double-J catheter, antibiotics and delayed nephrectomy.

[What if it is not an acute pyelonephritis? A monocentric experience of renal infarcts]

BACKGROUND

Often the reduced contrast enhancement on CT renal imaging is radiologically interpreted as acute pyelonephritis (PNA), but it is the task of the clinician to assess a possible differential diagnosis such as a renal infarct and look for a cause.

METHODS

In our experience (2010-2013), we hospitalized 51 patients with radiological imaging consistent with acute pyelonephritis in native kidneys. However, three of these cases result, after a second look, to be ischemic lesions, only sometimes complicated by over-infections (Tabella 1).

FIRST CASE

a woman hospitalized for fever and flank pain with blood culture positive for Klebsiella Pneumoniae. Antibiotic therapy allowed a clinical-laboratory improvement, but after 45 days persisted a focal wedge to the CT scan. The labs showed a anemia due to a sickle cell disease (SLC). The overview was finally interpreted as a renal infarct secondary to a sickle cell anemia, initially complicated by over-infection.

SECOND CASE

a men hospitalized for a acute flank pain. The CT scan showed a left renal infarct and a partial renal artery thrombosis, resulting in abuse of cannabinoids and LAC positivity.Third case: a woman hospitalized for flank pain and slight movement of inflammatory markers. CT showed a cuneiform area in the right kidney not vascularized, that did not resolved after prolonged antibiotic therapy. The labs evidence a heterozygous mutation of prothrombin and MTHFR causing the renal infarction.

CONCLUSIONS

6% of radiographic imaging consistent with acute pyelonephritis concealed an underlying infarct, due to a unknown state of thrombophilia. The presence of hypovascular imaging to the TC scan, therefore, requires a differential diagnosis between PNA and infarct, especially in the case of atypical development.

Vitamin E as adjuvant treatment for urinary tract infection in girls with acute pyelonephritis

INTRODUCTION

Vitamin E is a fat-soluble vitamin that functions as an antioxidant. The aim of this study was to investigate the effects of vitamins E supplementation in combination with antibiotics for the treatment of girls with acute pyelonephritis.

MATERIALS AND METHODS

This double-blinded randomized controlled trial was conducted on 152 girls aged 5 to 12 years with a first acute pyelonephritis episode based on technetium Tc 99m dimercaptosuccinic acid (99mTc-DMSA). They were randomized to receive a 14-day treatment with only antibiotics (control group; n = 76) and 14-day treatment with supplements of vitamin E (intervention group; n = 76) in addition to the antibiotics. Patients' clinical symptoms were monitored for 14 days and urine culture was performed 3 to 4 days and 7 to 10 days after the start of the treatment and its completion, respectively. All of the girls once underwent DMSA scan 4 to 6 months after the treatment.

RESULTS

During the follow-up days, the mean frequency of fever (P = .01), urinary frequency (P = .001), urgency (P = .003), dribbling (P = .001), and urinary incontinence (P = .006) were significantly lower in the intervention group compared to the control group. There was no significant difference in the results of urine culture 3 to 4 days after the start of treatment (P = .16) and 7 to 10 days after its termination (P = .37). There was also no significant difference between the results of DMSA scan 4 to 6 months after the start of treatment (P = .31).

CONCLUSIONS

Vitamin E supplementation has a significant effect in ameliorating sign and symptoms of UTI. However, further studies are recommended to confirm these findings.

[Ischaemic colitis secondary to emphysematous pyelonephritis]

Emphysematous pyelonephritis is an acute severe necrotizing infection of the renal parenchyma and its surrounding tissues and up to 95% of the patients have diabetes. We describe a concurrent manifestation of emphysematous pyelonephritis and ischaemic colitis in a 51-year-old diabetic woman and conclude that the colitis was due to pressure from a large retroperitoneal mass and sepsis complications combined with underlying peripheral vascular disease because of diabetes mellitus and hypertension.