Walking Dead Macrophage-Based Positive Enhancement MRI for Ultrahighly Efficient Diagnosis of Nephritis.

Nephritis is an inflammatory condition of the glomerulus, and the clinical gold standard for its diagnosis is a kidney biopsy. However, obtaining biopsy results can take several days, which does not meet the requirement of rapid diagnosis, especially for rapidly progressive types. To achieve an effective and noninvasive diagnosis, we propose a nephritis-specific, positive magnetic resonance imaging (MRI) contrast agent based on Gd3+ anchored walking dead macrophage Gd-RAW. Gd-RAW exhibits high selectivity for inflammatory renal parenchyma and provides comparable results to histopathology methods. The Gd-RAW-based MRI contrast agent reduces the diagnostic time of nephritis from 14 days of biopsy to 1 h. Furthermore, in a unilateral nephritis model constructed by increasing the glycerol concentration, the T1WI of renal parenchyma exhibits an increased signal-to-noise ratio, which is crucial for evaluating nephritic severity. This work promotes rapid diagnosis of nephritis and potentially provides sufficient evidence for clinicians to offer timely treatment to patients. The methodology of paramagnetic ion-anchored macrophage corpse also opens up new prospects for designing more specific and biosafe MRI contrast agents.

Imaging features of immune checkpoint inhibitor-related nephritis with clinical correlation: a retrospective series of biopsy-proven cases.

OBJECTIVES: Imaging appearances of immune checkpoint inhibitor-related nephritis have not yet been described. The primary objective of this study is to describe the appearances of immunotherapy-related nephritis on computerized tomography (CT) and positron emission tomography (PET). The secondary objectives are to investigate the association of radiologic features with clinical outcomes. METHODS: CT and PET-CT scans before the initiation of immunotherapy (baseline), at nephritis, and after resolution of pathology-proven nephritis cases were reviewed. Total kidney volume, renal parenchymal SUVmax, renal pelvis SUVmax, and blood pool SUVmean were obtained. RESULTS: Thirty-four patients were included. The total kidney volume was significantly higher at nephritis compared to baseline (464.7 ± 96.8 mL vs. 371.7 ± 187.7 mL; p < 0.001). Fifteen patients (44.1%) had > 30% increase in total kidney volume, which was associated with significantly higher renal toxicity grade (p = 0.007), higher peak creatinine level (p = 0.004), and more aggressive medical treatment (p = 0.011). New/increasing perinephric fat stranding was noted in 10 patients (29.4%) at nephritis. Among 8 patients with contrast-enhanced CT at nephritis, one (12.5%) developed bilateral wedge-shaped hypoenhancing cortical. On PET-CT, the renal parenchymal SUVmax-to-blood pool ratio was significantly higher at nephritis compared to baseline (2.13 vs. 1.68; p = 0.035). The renal pelvis SUVmax-to-blood pool SUVmean ratio was significantly lower at nephritis compared to baseline (3.47 vs. 8.22; p = 0.011). CONCLUSIONS: Bilateral increase in kidney size, new/increasing perinephric stranding, and bilateral wedge-shaped hypoenhancing cortical foci can occur in immunotherapy-related nephritis. On PET-CT, a diffuse increase in radiotracer uptake throughout the renal cortex and a decrease in radiotracer activity in the renal pelvis can be seen. KEY POINTS: • CT features of immune checkpoint inhibitor-related nephritis include an increase in kidney volume, new/increasing perinephric stranding, and bilateral ill-defined wedge-shaped hypoenhancing cortical foci. • FDG-PET features of immune checkpoint inhibitor-related nephritis include an increase in FDG uptake throughout the renal cortex and a decrease in FDG activity/excretion in the collecting system. • > 30% increase in total kidney volume is associated with worse toxicity grade and more aggressive medical management.

Detecting Proteomic Indicators to Distinguish Diabetic Nephropathy from Hypertensive Nephrosclerosis by Integrating Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging with High-Mass Accuracy Mass Spectrometry.

INTRODUCTION: Diabetic nephropathy (DN) and hypertensive nephrosclerosis (HN) represent the most common causes of chronic kidney disease (CKD) and many patients progress to -end-stage renal disease. Patients are treated primarily through the management of cardiovas-cular risk factors and hypertension; however patients with HN have a more favorable outcome. A noninvasive clinical approach to separate these two entities, especially in hypertensive patients who also have diabetes, would allow for targeted treatment and more appropriate resource allocation to those patients at the highest risk of CKD progression. Meth-ods: In this preliminary study, high-spatial-resolution matrix-assisted laser desorption/ion-ization (MALDI) mass spectrometry imaging (MSI) was integrated with high-mass accuracy MALDI-FTICR-MS and nLC-ESI-MS/MS analysis in order to detect tissue proteins within kidney biopsies to discriminate cases of DN (n = 9) from cases of HN (n = 9). RESULTS: Differences in the tryptic peptide profiles of the 2 groups could clearly be detected, with these becoming even more evident in the more severe histological classes, even if this was not evident with routine histology. In particular, 4 putative proteins were detected and had a higher signal intensity within regions of DN tissue with extensive sclerosis or fibrosis. Among these, 2 proteins (PGRMC1 and CO3) had a signal intensity that increased at the latter stages of the disease and may be associated with progression. DISCUSSION/CONCLUSION: This preliminary study represents a valuable starting point for a future study employing a larger cohort of patients to develop sensitive and specific protein biomarkers that could reliably differentiate between diabetic and hypertensive causes of CKD to allow for improved diagnosis, fewer biopsy procedures, and refined treatment approaches for clinicians.

Comparison of imaging findings between acute focal bacterial nephritis (acute lobar nephronia) and acute pyelonephritis: a preliminary evaluation of the sufficiency of ultrasound for the diagnosis of acute focal bacterial nephritis.

OBJECTIVE: The recommended durations of treatment for acute focal bacterial nephritis (AFBN) and acute pyelonephritis (APN) are different. This study aimed to clarify the sonographic findings used to differentiate AFBN from APN during diagnosis and to compare these findings with those obtained using computed tomography (CT). METHODS: Eleven children with urinary tract infection who underwent contrast-enhanced CT and ultrasound examinations within a 24-h period were included. Diagnoses of AFBN and APN were established using CT data as the gold standard; viz., a focal area of poor enhancement is observed in AFBN but not in APN. The following ultrasound findings were evaluated: focal loss of corticomedullary differentiation (one/multiple), focal hyperechogenicity, abscess formation, and diffuse nephromegaly. Fisher's exact test was used for statistical analysis. RESULTS: Of the 11 patients, 8 had AFBN and 3 had APN. The two groups differed significantly in the incidence of a focal loss of corticomedullary differentiation (present/absent, 8/8 vs. 0/3; p = 0.01) but not in the incidence of focal hyperechogenicity, abscess formation, and diffuse nephromegaly (present/absent, 2/8 vs. 0/3, p > 0.99; 1/8 vs. 0/3, p > 0.99; and 5/8 vs. 3/3, p = 0.49, respectively). The poorly enhanced area used to diagnose AFBN on CT images appeared as a focal loss of corticomedullary differentiation in ultrasound examinations. CT revealed multiple lesions in two cases in which ultrasound revealed only single lesions. CONCLUSION: In our small cohort, ultrasound could be adequately used to diagnose AFBN based on the presence of a focal loss of corticomedullary differentiation. CT may not be required to differentiate AFBN from APN.

Can contrast-enhanced ultrasound and acoustic radiation force impulse imaging characterize CT-indeterminate renal masses? A prospective evaluation with histological confirmation.

PURPOSE: To prospectively characterize computed tomography (CT)-indeterminate renal masses (CTIRM) using acoustic radiation force impulse (ARFI) elastography and contrast-enhanced ultrasound (CEUS) and to correlate quantitative imaging findings with histopathology or interim follow-up (FU). METHODS: 123 patients with CTIRM (longest diameter < 4 cm) underwent ARFI and CEUS with CT image fusion (IF). Exclusion criteria included all contraindications for CEUS and IF. Shear wave velocity (SWV), shear wave ratio (SWR), peak intensity (PE), time to peak (TTP) and wash-in rate (Wi) were quantified. In case of a cystic lesion classified as ≤ Bosniak 2F, follow-up imaging was performed. RESULTS: 77 out of 123 patients underwent surgical resection of a lesion due to suspect imaging findings, whereas 46 patients underwent FU, which did not show upgrading in Bosniak category. Histopathology revealed 58 renal cell carcinomas [five chromophobe (chRCC), 18 papillary (pRCC) and 35 clear cell (ccRCC)], ten oncocytomas and nine non-malignant renal lesions (one minimal fat AML, three focal nephritis and five infected cysts). SWV and SWR differed significantly between ccRCC, pRCC, chRCC (p = 0.0024, F = 13.94) and in SWR also for oncocytoma (p < 0.0001, F = 14.35). In CEUS, oncocytoma and ccRCC showed significant higher PE values (p < 0.0001, F = 77.31) as well as higher Wi and lower TTP compared to all other solid lesions. CONCLUSIONS: Quantitative CEUS and ARFI imaging can provide relevant information to further characterize CT-indeterminate renal masses to guide urological decision making and offer the possibility of differentiation between ccRCC from less malignant RCC subtypes and from oncocytoma.

Renal structural image processing techniques: a systematic review.

BACKGROUND AND OBJECTIVE: Renal disease, such as nephritis and nephropathy, is very harmful to human health. Accordingly, how to achieve early diagnosis and enhance treatment for kidney disorders would be the important lesion. Nevertheless, the clues from the clinical data, such as biochemistry examination, serological examination, and radiological studies are quite indirect and limited. It is no doubt that pathological examination of kidney will supply the direct evidence. There is a requirement for greater understanding of image processing techniques for renal diagnosis to optimize treatment and patient care. METHODS: This study aims to systematically review the literature on publications that has been used image processing methods on pathological microscopic image for renal diagnosis. RESULTS: Nine included studies revealed image analysis techniques for the diagnosis of renal abnormalities on pathological microscopic image, renal image studies are clustered as follows: Glomeruli Segmentation and analysis of the Glomerular basement membrane (55/55%), Blood vessels and tubules classification and detection (22/22%) and The Grading of renal cell carcinomas (22/22%). CONCLUSIONS: A medical image analysis method should provide an auto-adaptive and no external-human action dependency. In addition, since medical systems should have special characteristics such as high accuracy and reliability then clinical validation is highly recommended. New high-quality studies based on Moore neighborhood contour tracking method for glomeruli segmentation and using powerful texture analysis techniques such as the local binary pattern are recommended.

Acute focal bacterial nephritis characterized by acute encephalopathy with biphasic seizures and late reduced diffusion.

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidney presenting as an inflammatory mass, and some patients show deterioration of clinical condition with neurological symptoms. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a syndrome that is characterized by biphasic seizures and impaired consciousness with reduced diffusion in the subcortical white matter on magnetic resonance imaging, typically observed between days 3 and 9 after clinical onset. Although AFBN sometimes causes neurological symptoms, no cases of AFBN with AESD have been reported, and no studies have presented the cytokine profiles of patients with a severe form of acute encephalopathy with AFBN. We report here a very rare case involving a 6-month-old boy who developed AFBN due to Enterococcus faecalis with both the clinical and radiological features of AESD. In our patient, serum interleukin (IL)-6, IL-10, and interferon (IFN)-γ levels markedly increased on admission, and on day 4, only IL-6 levels significantly increased in the cerebrospinal fluid (CSF). These results suggest that high serum cytokines are produced locally in response to AFBN and elevated IL-6 levels in CSF may have neuroprotective roles.

Onset of Hemophagocytic Lymphohistiocytosis during Piperacillin-Tazobactam Therapy in Three Children with Acute Focal Bacterial Nephritis.

Hemophagoytic lymphohistiocytosis (HLH) is a rare life-threatening disorder caused by overactivation of the immune system, associated with infections, autoimmune disorders, and malignancies. The pathological hallmark of HLH is phagocytosis of blood cells and platelets by activated macrophages and histiocytes. In this report, we describe the onset of HLH in three children, aged 2, 5 and 7 years old, during the treatment of acute focal bacterial nephritis (AFBN) with an antibiotic, piperacillin-tazobactam (PIPC-TAZ). AFBN is acute localized bacterial infection of the kidney without abscess formation. PIPC-TAZ was chosen for the treatment of AFBN, because it not only has indications for complicated urinary tract infections, but also covers most of the causative bacteria of urinary tract infections, including ß-lactamase-producing Escherichia coli. The clinical courses of the three patients were similar, and they were treated with PIPC-TAZ and amikacin (AMK) for AFBN. Fever went down 2 to 5 days later, and AMK was discontinued by day 6. However, fever recurred on 13 to 15 days after introduction of PIPC-TAZ therapy, even though all of the patients had no signs of recurrence of AFBN. The clinical features and laboratory tests of two patients fulfilled the criteria of HLH, whereas the other patient had initiated therapy before fulfilling the criteria. Cessation of PIPC-TAZ combined with corticosteroid therapy improved clinical symptoms. HLH of our patients was probably induced by PIPC-TAZ, as judged by the timing of the onset of HLH and the positivity of the drug-lymphocyte stimulation test. In conclusion, prolonged antibiotic therapy with PIPC-TAZ could be a cause of HLH.

Acute focal bacterial nephritis is associated with invasive diagnostic procedures - a cohort of 138 cases extracted through a systematic review.

BACKGROUND: Acute focal bacterial nephritis (AFBN) is a rare disease currently described only in case reports and small case series. In this study we summarize the clinical features of AFBN as has been documented in the literature and draw recommendations on the proper diagnosis and therapy. METHODS: A systematic literature review was undertaken in PUBMED, Web of Science and The Cochrane Library online databases for relevant literature on AFBN in adults. RESULTS: Literature review revealed a total of 38 articles according to our inclusion criteria, of which we could extract data from 138 cases of AFBN. Fever (98%) and flank pain (80%) were most commonly reported symptoms. E. coli was the most frequent pathogen. Diagnosis was set by CT and/or MRI (52%) with or without sonography or by sonography alone (20%) as well as by sonography combined with IVU. In total, sonography was applied in 83% of cases. All but one patient received antibiotic treatment. Kidney lesions were occasionally mistaken for neoplasms or renal abscesses and as a result, cases were subjected to percutaneous puncture (12.3%), surgical exploration (5.1%) and partial or radical nephrectomy (4.4%). Four cases (2.9%) developed a renal abscess. CONCLUSIONS: The diagnosis of AFBN is set by characteristic clinico-radiological findings. Differential diagnoses of this interstitial bacterial infection include renal abscess and tumor. Correct diagnosis is occasionally impeded by atypical symptoms. Invasive diagnostic and therapeutic procedures should be limited as the majority of cases respond well to conservative treatment.

Quantitative evaluation of 67Ga-citrate scintigraphy in the management of nephritis.

In 67Ga-citrate scintigraphy (Ga-S), visual assessment is used by evaluating renal-uptake comparison with liver and spine and is simple and objective. We adopted the standardized uptake value (SUV) for 67Ga-citrate and proposed two quantitative indices, active nephritis volume (ANV) and total nephritis uptake (TNU). This study clarified the utility of new Ga-S-based quantitative indices in nephritis management. Before SUV measurement, the Becquerel calibration factor of 67Ga-citrate was obtained using a phantom experiment. Seventy patients who underwent SPECT/CT imaging were studied. SUV, ANV, and TNU were calculated using a quantitative analysis software for bone SPECT. SUVmean, ANV, and TNU were analyzed using the (1) threshold method (set 40%) and constant-value method for (2) vertebral SUVmax, and (3) vertebral SUVmean. ROC analysis was used to evaluate SUV, ANV, and TNU diagnostic abilities to distinguish nephritis presence and absence as well as interstitial nephritis (IN) and non-IN. The area under the curve (AUC) for nephritis presence or absence had a good value (0.80) for SUVmean (1), ANV (3), and TNU (3). The AUC for differentiation between IN and non-IN groups had a good value (0.80) for SUVmean (1). Thus, the new Ga-S-based quantitative indices were useful to evaluate nephritis and distinguish IN and non-IN.

Post-transplantation encapsulating peritoneal sclerosis without inflammation or radiological abnormalities.

BACKGROUND: Post-transplantation encapsulating peritoneal sclerosis (EPS) causing bowel obstruction has been identified as a serious complication after kidney transplantation in patients previously treated with peritoneal dialysis. Systemic inflammation and abnormalities on an abdominal computed tomography (CT) scan are important hallmarks of EPS. To our knowledge, this is the first report of a case being diagnosed with late-onset post-transplantation EPS without systemic inflammation or abnormalities on a CT scan which could only be diagnosed by laparotomy. CASE PRESENTATION: A 59-year old female presented because of symptoms of bowel obstruction 33 months after kidney transplantation. The patient had a 26-month history of peritoneal dialysis before her first kidney transplantation and was treated with peritoneal dialysis for 4 years before undergoing a second kidney transplantation. Physical examination was unremarkable and laboratory tests showed no signs of systemic inflammation (C-reactive protein <1 mg/L). An abdominal CT scan did not reveal any abnormalities fitting the diagnosis of EPS, except a "feces sign". Given the severity of the progressive symptoms, a diagnostic laparotomy was performed, visualizing a classical EPS. Total peritonectomy and enterolysis were performed, leading to restoration of peristalsis. CONCLUSION: EPS may occur several years after kidney transplantation in the absence of inflammation and typical radiological abnormalities. Obtaining a diagnosis of post-transplantation EPS is challenging, however, a low threshold for surgical exploration in case of high clinical suspicion and negative findings on the CT scan is mandatory.

[Value of contrast-enhanced ultrasound (CEUS) in the differential diagnosis between benign and malignant renal neoplasms].

OBJECTIVE: To investigate the value of contrast enhanced ultrasound (CEUS) imaging in the differential diagnosis between benign and malignant renal neoplasms. METHODS: Two hundred and forty-five cases of renal space-occupying lesions confirmed by biopsy or surgical pathology were included in this study. The CEUS features of the renal space-occupying lesions, i.e., the enhancement degree, homogeneity of enhancement, washing-in and washing-out time and enhancement pattern, were retrospectively analyzed. RESULTS: There were 210 cases of malignant renal tumors and 35 cases of benign lesions. The CEUS modes of the malignant renal tumors included "quick in and quick out" 82 cases, "quick in and slow out" 64 cases, "slow in and quick out" 18 cases and "slow in and slow out" 46 cases; good enhancement 150 cases (71.4%) and inhomogeneous enhancement 180 cases (85.7%).Both the contrast agent filling defect area and solid component enhancement of solid-cystic tumors were important features of malignant renal tumors. In the 35 cases of benign lesions,the CEUS modes included "quick in and quick out" 4 cases, "quick in and slow out" 8 cases, "slow in and quick out" 10 cases and "slow in and slow out" 13 cases. Most of the benign tumors showed low enhancement 51.4% (18/35) and inhomogeneous enhancement 54.3% (19/35). There were significant differences between the malignant and benign renal neoplasms in CEUS mode, degree of enhancement and homogeneity of enhancement (P < 0.05), and in time of increasing, peak time, peak intensity and peak intensity ratio (P < 0.05). The accuracy rates of contrast-enhanced ultrasound for diagnosis of benign and malignant tumors were 77.1% and 83.8%, respectively, while the two-dimensional ultrasound diagnosis of benign and malignant tumors were 68.6% and 76.7%, respectively, with a significant difference (P < 0.05). CONCLUSIONS: CEUS may provide more information to improve the diagnostic accuracy for renal neoplasms, and may play important role in differential diagnosis between benign and malignant renal lesions.

Utility of MRI in diagnosis and treatment of acute focal bacterial nephritis with abscess formation in a paediatric patient.

Contrast-enhanced CT is the gold standard for the diagnosis of acute focal bacterial nephritis (AFBN). However, owing to radiation exposure and the possibility of contrast agent-induced side effects, contrast-enhanced CT is not always recommended for children. A paediatric patient presenting with a 1-week history of fever was admitted to our hospital. After a urine culture detected Escherichia coli, antimicrobials were administered; however, the fever had not resolved by the third day of hospitalisation. Renal diffusion-weighted MRI was performed and showed multiple wedge-shaped areas of high signal intensity in the right kidney. Additionally, the same site showed an area of low signal intensity in the apparent diffusion coefficient, and a diagnosis of AFBN with abscess was made. A chronic-phase technetium-99m-labelled dimercaptosuccinic acid renal scintigraphy was performed, but there was no renal scarring. MRI may be a more suitable tool for diagnosing AFBN given no radiation exposure.

Bilateral kidney pseudotumor due to sarcoidosis: a radiological study case.

OBJECTIVE: To report one case of bilateral kidney pseudotumor due to sarcoidosis in a 75 year-old man with prostatic carcinoma and hypertrophic pachymeningitis. METHODS: Renal Doppler, body CT, CT-guided renal biopsy, blood analysis including angiotensin converting enzyme (ACE), blood levels and test-treatment (corticosteroid response) were performed. RESULTS: The radiological studies performed showed bilateral kidney masses and pulmonary calcified hilar adenopathies. Blood analysis showed renal failure and increased ACE levels. Renal biopsy showed non-caseating granulomas. Neurological symptoms and renal failure improved with corticosteroid therapy. CONCLUSION: Bilateral kidney pseudotumor due to sarcoidosis is a rare pathology. Sarcoidosis must be included in the differential diagnosis work up of patients with inflammatory or autoimmune disease and bilateral kidney pseudotumors. Radiological findings of kidney sarcoidosis are quite unspecific. Histological diagnosis with CT guided biopsy or US guided biopsy of kidney masses may be performed.

Clinical features of acute focal bacterial nephritis in adults.

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidneys presenting as an inflammatory mass that can develop into renal abscess. The current reports on AFBN mostly are among children and rarely described in adults. This study was aimed to analyze the clinical features of AFBN in adults and make a review for the disease to give the clinicians some clues to suspect and recognize it in adults. From January 2014 to December 2019, AFBN was diagnosed by contrast-enhanced computed tomography (CT) in 238 adults at the Department of Nephrology, the Second Hospital of Hebei Medical University, Shijiazhuang, China. We reviewed the clinical records of these patients and asked them about their post-discharge status via telephone follow-up. Of all the patients, 195 were female and 43 were male, the median age were 46.87 years. 86.13% presented with fever, 55.89% presented with lower urinary tract symptoms and 97.9% presented with pyuria. In renal ultrasonography, abdominal findings were seen only 22.69% patients. E.coli accounted for 74.73% of the isolated pathogen. After 4 weeks of treatment, the patients had no recurrence of symptoms. We recommend that when a patient presents clinically with acute pyelonephritis, but the fever persist longer after antimicrobial treatment (≥ 4 days in our study), AFBN should be suspected. For the diagnosis, contrast-enhanced CT is the "gold standard", magnetic resonance imaging (MRI) may be a good option, but the ultrasonography is probably not satisfied. 3-4 weeks of antibiotic therapy may be appropriate for AFBN in adults.

Positron emission tomography in the diagnostic pathway for intracystic infection in adpkd and "cystic" kidneys. a case series.

BACKGROUND: Intracystic infection, in Autosomal Dominant Polycystic Kidney Disease (ADPKD) and in kidneys with multiple cysts, is a diagnostic and therapeutic challenge, as conventional imaging techniques may not discriminate among "complicated" cysts (infection, bleeding, neoplasia), and as the clinical picture may be attenuated, in particular in early phases. Positron Emission Tomography with fluorodeoxyglucose (FDG-PET) was recently suggested as a tool to detect infection in ADPKD, in single cases and small series.The aim of the study was to report on the role of FDG-PET in the work-up of 10 cases of suspected cystic infections, affected by ADPKD or with multiple kidney cysts. METHODS: Observational study. Review of clinical charts and of the imaging data since the use of FDG-PET for detecting cystic infections (2008-2010). RESULTS: In 2008-2010, 6 patients with ADPKD and 4 with multiple kidney cysts were referred for suspected intracystic infections (3 males, 7 females, aged 55-83 years, in all CKD stages); in one case the imaging was done in the work-up of a complicated "uremic" cyst. The clinical picture, the usual inflammatory markers and/or the conventional imaging techniques did not allow conclusive diagnosis at referral or during follow-up (ultrasounds in all, CT in 8/10). Nine patients displayed inflammatory signs (increase in C-reactive protein and other biochemical markers) and constitutional symptoms (fever in 9/10).FDG-PET was positive in 6 cases (5 kidney and 1 liver cyst), was repeated during follow-up in 4 patients and was negative in 4 cases. In the positive cases, FDG-PET guided the therapeutic choices; in particular, the duration of therapy was supported by imaging data in the 4 cases with multiple scans. No relapse was recorded after discontinuation of antibiotic therapy in the treated patients. The negative cases did not develop clinical signs of cystic infection over follow-up. CONCLUSION: In this case series, the largest prospective one so far published and the only one including different types of renal cysts, FDG-PET is confirmed as a promising diagnostic tool for detecting intracystic infection in ADPKD and in multiple kidney cysts, and a potential guide for tailoring therapy. Further larger and multicenter studies are needed to evaluate the cost-benefit ratio and the limits of this imaging technique in the clinical setting.

Diagnosis and Treatment for Acute Focal Bacterial Nephritis With Renal Abscess Based on Magnetic Resonance Imaging Evaluation.

A 5-year-old boy was diagnosed with left acute focal bacterial nephritis (AFBN) complicated with renal abscess (RA) on magnetic resonance imaging (MRI). MRI is useful for diagnosing AFBN and RA complications. He was administered antibiotics for 3 weeks on evaluation of MRI findings. Evaluation of apparent diffusion coefficient values over time may be useful as an index of treatment of RA.