Focal bacterial nephritis without pyuria in a boy presenting with high urinary ß2-MG and NAG levels.

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidney presenting as an inflammatory mass without frank abscess formation. We report a case of acute focal bacterial nephritis without pyuria in a five-month-old boy presenting with high urinary ß2-microglobulin (ß2-MG) and N-Acetyl-ß-(D)-Glucosaminidase (NAG) levels. The infant initially presented with high-grade fever, and plain computed tomography (CT) showed a nearly isodense mass, and contrast-enhanced abdominal CT showed a wedge-shaped hypodense lesion. Enterococcus was detected in the subsequent urine culture. A diagnosis of AFBN was made on the basis of his high inflammatory reaction, contrast-enhanced abdominal CT findings and high urinary ß2-MG and NAG levels. He was treated with Ceftriaxone and subsequent improvement in inflammatory reaction and contrast-enhanced CT findings were observed. Voiding cystourethrogram (VCUG) showed a grade V right VUR. This case suggests that urinary ß2-MG and NAG levels may be useful additional markers for the diagnosis of AFBN without pyuria.

Imaging of a localized bacterial infection with endogenous thymidine kinase using radioisotope-labeled nucleosides.

The importance of noninvasive imaging methods to bacterial infections is widely recognized. To obtain bacterial infection imaging with radioisotope-labeled nucleosides, bacterial thymidine kinase (tk) activities of Salmonella typhimurium with [(125)I]5-iodo-1-(2'-fluoro-2'-deoxy-ß-d-arabinofuranosyl)uracil ([(125)I]FIAU) or 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) were measured. The infection model in BALB/c mice was imaged with [(125)I]FIAU or [(18)F]FLT using small-animal Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET), respectively. The accumulated radioactivity of [(125)I]FIAU or [(18)F]FLT in the two strains showed a linearly increased pattern with increasing incubation time or bacterial numbers. The image clearly demonstrated a high uptake of [(125)I]FIAU and [(18)F]FLT in the bacterial infection site. [(18)F]FLT uptake in the infection site of was 7.286±2.405, whereas that in the uninfected site was 0.519±0.561. The relative activity ratio of the infected region in relation to the uninfected region was 2.98 at 4h after an injection with [(125)I]FIAU determined by biodistribution data. In conclusion, the bacterial tk activity was confirmed by the cellular uptake and imaging with [(125)I]FIAU or [(18)F]FLT. Therefore, a localized bacterial infection in living mice can be monitored using radioisotope-labeled nucleosides with a nuclear medicine imaging modality.

Multidetector CT features of pulmonary focal ground-glass opacity: differences between benign and malignant.

OBJECTIVE: To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT). METHODS: 82 pathologically or clinically confirmed fGGOs were retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ(2) test, Fisher's exact test or Mann-Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy. RESULTS: There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively. CONCLUSION: An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant.

Focal bacterial nephritis masquerading as renal cell carcinoma: case report.

Focal bacterial nephritis is a symptom associated with inflammation of the kidneys. It may occur in children, usually indicating abnormal urinary tract development. In adults, urinary tract infection is generally caused by gram-negative bacteria, with Escherichia (E.) coli accounting for 80% of all infections. This case report describes a female patient in whom E. coli urinary infection caused, via ascending route, focal bacterial nephritis masquerading as renal cell carcinoma.

Acute focal nephritis: its true sonographic face.

BACKGROUND: Acute focal nephritis is an inflammatory process of the renal parenchyma affecting principally the cortex of the kidney. It is considered a midpoint in the spectrum of upper urinary tract infections, ranging from uncomplicated pyelonephritis to intrarenal abscesses. Until recently the hyperechoic sonographic appearance of this lesion was considered uncommon. OBJECTIVES: To determine the relative prevalence of hyperechoic and hypoechoic sonographic appearance of focal renal lesions in patients with the clinical diagnosis of acute pyelonephritis and to correlate the findings with those of the color Doppler examinations. METHODS: We reviewed the sonograms of 367 patients hospitalized with the clinical diagnosis of acute pyelonephritis. The sonograms were reviewed for acute renal inflammatory changes. When a focal lesion was detected, we noted the echogenicity, side, form, location and color Doppler characteristics. RESULTS: Abnormal sonographic findings related to the infection were found in 78 cases. In 52 patients a focal lesion was diagnosed. Forty-seven focal lesions appeared hyperechoic related to the adjacent parenchyma. These lesions were more frequently located at the upper pole and were wedge-shaped in most of the cases. The areas appeared hypo/avascular on the color Doppler examination. CONCLUSIONS: Our data suggest that the most common appearance of acute focal nephritis is an area of increased echogenicity in the parenchyma of the affected kidney.

Acute focal bacterial nephritis in an 8-year-old .

Acute focal bacterial nephritis or acute lobar nephronia is an acute localized non-liquefactive bacterial kidney infection. Clinically, it may develop as an abscess and present as acute pyelonephritis but is distinguishable by the presence of a focal mass on imaging studies. The authors report the case of an 8-year-old girl with fever up to 39 degrees C and left flank pain of 6 days duration. On physical examination, she had nothing remarkable except tenderness and knocking pain over the left costovertebral angle. Post-contrast abdominal computed tomography revealed several wedge-shaped hypodense lesions in the left kidney. Urine culture grew Escherichia coli. Acute focal bacterial nephritis was diagnosed. The patient was treated with antibiotics and discharged on the 12th day of hospitalization.

Determining optimum management of descending necrotizing mediastinitis with CT; experience with 32 cases.

To determine the value of helical computed tomography (CT) in the diagnosis, management and outcome of patients suspected of having descending necrotizing mediastinitis (DNM). Thirty-two patients with suspected DNM were submitted to contrast-enhanced single detector-row helical CT, four detector-row CT and 16 detector-row CT of the neck and chest. In 10/32 patients (group 1) no abnormality was observed in the neck or in the chest spaces on CT scan. These patients were all treated non-operatively. In 12/32 patients (group 2) CT showed the presence in the neck spaces of fluid collections, fasciitis, cellulitis, myositis, jugular vein thrombosis and lymphadenopathy; in all these patients the chest was unaffected. A cervical drainage was performed in ten patients. In the remaining ten patients (group 3), the neck infection involved the mediastinal spaces in all the cases and the pleural and pericardial spaces; CT findings included mediastinal cellulitis and fluid collections, pleural and pericardial effusions, venous thrombosis and lymphadenopathy. In these patients, a cervico-mediastinal drainage was performed and antibiotics were administered. The CT provides a highly accurate depiction of the presence and the spread of DNM. The CT findings and the extension of disease are important factors in order to predict for patient management and outcome.

Effective ultrasonographic predictor for the diagnosis of acute lobar nephronia.

BACKGROUND: Correct identification of acute lobar nephronia (ALN) is necessary to prevent progression to renal abscess. The goal of this retrospective study was to determine whether the sonographic finding of severe nephromegaly (i.e. renal length greater than mean + 3 sd) is a preselection criterion for computed tomographic (CT) scanning in diagnosing pediatric ALN among children with an acute upper urinary tract infection. DESIGN/METHODS: We evaluated a new imaging work-up scheme to detect pediatric ALN. All patients with urinary tract infection were evaluated with ultrasonography. If a markedly enlarged kidney or focal mass was present sonographically, CT scanning was done immediately. CT scanning was also performed when the patient had borderline nephromegaly and remained febrile for 72 h after start of antibiotic treatment. ALN diagnosis was made on the basis of positive CT findings. RESULTS: Thirty patients with ALN (13 left, 7 right, 10 bilateral) and one with acute pyelonephritis were identified. ALN in all patients resolved after 3 weeks of antibiotic treatment. Thirty-nine of the 62 kidneys evaluated showed severe nephromegaly, and 10 had focal renal masses. With CT diagnosis of ALN as the reference standard, the sensitivity of severe nephromegaly was 90.0% and the specificity was 86.4%. When the focal renal mass was added as a combining predictor, the sensitivity further increased to 95%. CONCLUSIONS: Pediatric ALN was effectively predicted using sonographic findings of severe nephromegaly and/or focal mass before CT scanning.

Clinical value of FDG PET in patients with fever of unknown origin and patients suspected of focal infection or inflammation.

Fever of unknown origin (FUO) and suspected focal infection or inflammation are challenging medical problems. The aim of this study was to assess the value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) in patients with FUO and patients with suspected focal infection or inflammation. All FDG PET scans ordered because of FUO or suspected focal infection or inflammation in the last 4 years were reviewed. These results were compared with the final diagnosis. Thirty-five FDG PET scans were performed in 35 patients with FUO. A final diagnosis was established in 19 patients (54%). Of the total number of scans, 37% were clinically helpful. The positive predictive value of FDG PET in these patients was 87% and the negative predictive value was 95%. Fifty-five FDG PET scans were performed in 48 patients with suspected focal infection or inflammation. A final diagnosis was established in 38 patients (82%). Of the total number of scans, 65% were clinically helpful. The positive predictive value of FDG PET in these 55 episodes of suspected infection or inflammation was 95% and the negative predictive value was 100%. It is concluded that FDG PET appears to be a valuable imaging technique in the evaluation of FUO and suspected focal infection or inflammation. Furthermore, FDG PET could become a useful tool for evaluating the effect of treatment of infectious and inflammatory processes that cannot reliably be visualised by conventional techniques. However, to assess the additional diagnostic value of this technique, prospective studies of FDG PET as part of a structured diagnostic protocol are warranted.

[Focal bacterial nephritis: diagnosis and treatment]. / Néphrite bactérienne focale. Difficultés diagnostiques.

Focal bacterial nephritis or lobar nephronia represents an acute localized non-liquefactive infection of the kidney caused by bacterial infection. This is an uncommon form of pyelonephritis that can affect both adults and children. Imaging techniques, particularly CT scan, are necessary for diagnosis and to distinguish it from other conditions (abscess or renal masses) that require a different treatment. The authors describe a case of acute lobar nephronia in a 24-year-old man.

[A pediatric case of acute focal bacterial nephritis; comparison with the reports in Japanese child cases].

We report an 8-year-old boy with acute focal bacterial nephritis (AFBN). At the age of 3 months, he had a history of urinary tract infection and vesicoureteral reflux. He was admitted to our hospital because of high fever and costovertebral angle pain. Although acute pyelonephritis was suspected, neither pyuria nor cultures of blood and urine were positive. An initial ultrasonogram (US) of his kidneys was normal except for bilateral hydronephrosis. Two days later, however, a computed tomography (CT) revealed a poorly enhanced mass in the upper pole of the right kidney. Similar findings were also observed by US. Under the diagnosis of AFBN, he received antibiotics for 3 weeks. Voiding cystourethrogram showed both-sided vesicoureteral reflux and he underwent an operation. At present the mass of the kidney still remains, albeit its size tends to decrease. We suggest that an early examination of US or enhanced CT is necessary in cases with fever of unknown origin, considering the possibility of AFBN even if neither pyuria nor cultures of urine are positive.

99mTc-PEG liposomes for the scintigraphic detection of infection and inflammation: clinical evaluation.

UNLABELLED: Polyethyleneglycol (PEG) liposomes have been shown to be excellent vehicles for scintigraphic imaging of infection and inflammation in various experimental models. In this article we report on a series of patients with possible infectious and inflammatory disease in whom the performance of 99mTc-PEG liposomes was evaluated. The results of 99mTc-PEG liposome scintigraphy were directly compared with those of 111In-immunoglobulin G (IgG) scintigraphy. METHODS: Thirty-five patients (22 men, 13 women; mean age, 51 y; range, 20-76 y), suspected of having infectious or inflammatory disease, received 740 MBq 99mTc-PEG liposomes intravenously. Imaging was performed at 4 and 24 h after injection. Patients received 75 MBq 111In-IgG 24 h after administration of the liposomes. The scintigraphic results were compared and verified by culture, biopsy, surgery, and follow-up of at least 6 mo. RESULTS: Of the 16 proven infections and inflammations, 15 were detected by 99mTc-PEG liposome scintigraphy: soft-tissue infection (n = 3), septic arthritis (n = 3), autoimmune polyarthritis (n = 2), infected hip prosthesis (n = 1), infected osteosynthesis (n = 1), spondylodiscitis (n = 1), infected aortic prosthesis (n = 1), colitis (n = 1), abdominal abscess (n = 1), and pneumonia (n = 1). 99mTc-PEG liposome and 111In-IgG scintigraphy both missed 1 case of endocarditis. In addition, an 111In-IgG scan of a patient with mild soft-tissue infection was false-negative. Concordantly false-positive scans were recorded from 2 patients, both with uninfected pseudarthrosis and focal signs of sterile inflammation. During liposomal administration, 1 patient experienced flushing and chest tightness, which rapidly disappeared after lowering the infusion rate. No other adverse events were observed. CONCLUSION: This clinical evaluation of 99mTc-PEG liposomes shows that focal infection and inflammation can be adequately imaged with this new agent. The performance of 99mTc-PEG liposomes is at least as effective as that of 111In-IgG. With the simple and safe preparation and the physical and logistic advantages of a 99mTc label, 99mTc-PEG liposomes could be an attractive agent for infection or inflammation imaging.

Septic metastatic endophthalmitis from Klebsiella pneumoniae liver abscess: CT and MR imaging characteristics--report of three cases.

Computed tomography (CT) and magnetic resonance (MR) imaging were performed in three diabetic patients with endophthalmitis and liver abscess secondary to Klebsiella pneumoniae infection. Ocular abnormalities included early uveoscleral thickening, fulminant exudative vitreous humor, and late phthisis bulbi. Characteristic imaging findings of endophthalmitis in diabetic patients with liver abscess should raise a high index of suspicion for K pneumoniae infection.

[Radionuclide study in the diagnosis of infectious foci in heart surgery patients]. / Radionuklidnoe issledovanie v diagnostike ochagov infektsii u kardiokhirurgicheskikh bol'nykh.

The radionuclide investigation was performed 1-3 and 24 hours after injection of a radiopharm preparation and included the single photon emission computed tomography of the heart and scintigraphy of the whole body. Inflammation foci were found on the scans as hyperfixation foci of autoleukocytes labeled with 99mTc-HMPAO (hexamethylpropilene aminooxime). Four patients had abscesses with 0.8-1.5 cm diameter in projection of the aortal and mitral valves of the heart, and in 10 patients there were foci of inflammation and suppuration of extracardiac localization (in the area of the operation wound, anterior mediastinum, frontal sinuses, transverse colon, parietal pleura). The data obtained convincingly speak of high sensitivity and specificity of radionuclide diagnostic methods with the help of labeled elements of the whole blood in recognizing latent inflammatory and suppurative processes in cardiosurgical patients at the pre- and postoperative periods.

Preclinical studies of indium-111-labeled IgM: a human monoclonal antibody for infection imaging.

UNLABELLED: Indium-111-labeled plasma proteins, such as albumin, transferrin and IgG, have been proven useful to image infection. We reported previously that 111In-labeled human monoclonal antibody, IgM 16.88 (In-IgM) also would localize at the site of infection. However, the kinetics of blood clearance, distribution and infection uptake have not been investigated. We compared the kinetics of distribution and infection uptake of In-IgM 16.88 with that of in-polyclonal IgG in rats with focal infection. METHODS: Both IgM 16.88 and polyclonal IgG were labeled with 111In using a bifunctional chelating agent, LiLo. The labeling efficiency was > 95%. Focal infection was induced in rats by an intramuscular injection of E. Coli in the right thigh. In-IgM (30-40 microCi) was injected into five groups of rats (five rats/group). The rats were killed at 4, 8, 16, 24 and 36 hr. The percent injected dose (%ID) in blood, infection muscle, control muscle, liver, spleen and kidney were determined. Similar studies were performed with In-IgG. RESULTS: The In-IgM activity in blood at 4 hr postinjection was 27% which decreased to 2% by 36 hr. In contrast, the In-IgG blood activity was 40% at 4 hr and 20% at 36 hr. The infection/ muscle (I/M) ratios are higher with In-IgM at all time points postinjection compared to that of In-IgG. At 24 hr, the I/M ratio was 22 compared to 9 with In-IgG. At the same time point, the infection/ blood (I/B) ratio with In-IgM was 2.7 compared to only 0.8 with that of In-IgG. In-IgM was taken up mostly by the liver compared to diffuse abdominal uptake of IgG. CONCLUSION: These result indicate that In-IgM produces higher lesion to background ratio when compared to In-IgG and, therefore, is potentially useful to image infection in patients.