CT perfusion technique for assessment of early kidney allograft dysfunction: preliminary results.

OBJECTIVES: To assess the benefit of quantitative computed tomography (CT) perfusion for differentiating acute tubular necrosis (ATN) and acute rejection (AR) in kidney allografts. METHODS: Twenty-two patients with acute kidney allograft dysfunction caused by either AR (n = 6) or ATN (n = 16) were retrospectively included in the study. All patients initially underwent a multiphase CT angiography (CTA) protocol (12 phases, one phase every 3.5 s) covering the whole graft to exclude acute postoperative complications. Multiphase CT dataset and dedicated software were used to calculate renal blood flow. Renal biopsy or clinical course of disease served as the standard of reference. Mean effective radiation dose and mean amount of contrast media were calculated. RESULTS: Renal blood flow values were significantly lower (P = 0.001) in allografts undergoing AR (48.3 ± 21 ml/100 ml/min) compared with those with ATN (77.5 ± 21 ml/100 ml/min). No significant difference (P = 0.71) was observed regarding creatinine level with 5.65 ± 3.1 mg/dl in AR and 5.3 ± 1.9 mg/dl in ATN. The mean effective radiation dose of the CT perfusion protocol was 13.6 ± 5.2 mSv; the mean amount of contrast media applied was 34.5 ± 5.1 ml. All examinations were performed without complications. CONCLUSION: CT perfusion of kidney allografts may help to differentiate between ATN and rejection. KEY POINTS: • Quantitative CT perfusion of renal transplants is feasible. • CT perfusion could help to non-invasively differentiate AR from ATN. • CT perfusion might make some renal biopsies unnecessary.

Benefit of contrast enhanced ultrasound for detection of ischaemic lesions and arterio venous fistulas in renal transplants - a feasibility study.

PURPOSE: To evaluate the benefit of CEUS (contrast enhanced ultrasound) regarding depiction of ischaemic lesions and AVFs (arterio venous fistula) in renal transplants compared to standard ultrasound (US) (grey-scale and color Doppler). MATERIALS AND METHODS: In this study 22 patients suspected of having acute vascular complication after renal transplantation were investigated using standard ultrasound (grey-scale US and color Doppler US) and CEUS, respectively. Validity of the respective US-techniques regarding depiction of ischaemic lesions and AVF was compared. Dynamic CTA (computed tomography angiography) served as the standard of reference. RESULTS: In 10 renal transplants arterial embolism associated with kidney infarctions were observed. Very good correlation to dynamic CTA was yielded using CEUS, whereas grey scale US and color Doppler US was limited in the accurate depiction of renal infarctions. Additionally CEUS was superior in displaying arteriovenous fistulas compared to standard US. CONCLUSION: CEUS as a fast and bedside available imaging modality not associated with dose exposure or renal toxicity facilitates improved detection of ischaemic lesions and AVFs compared to standard US and thus should be considered for short term follow up of renal transplants.

Optimized contrast volume for dynamic CT angiography in renal transplant patients using a multiphase CT protocol.

OBJECTIVES: To study the feasibility of an optimized multiphase renal-CT-angiography (MP-CTA) protocol in patients with history of renal transplantation compared with Doppler-ultrasound (DUS). METHODS: 36 Patients underwent both DUS and time-resolved, MP-CTA (12 phases), with a mean contrast-volume of 34.4±5.1 ml. Quality of MP-CTA was assessed quantitatively (vascular attenuation) and qualitatively (grades 1-4, 1=best). For the assessment of clinical value of MP-CTA, cases were grouped into normal, macrovascular (arterial/venous) and microvascular complications (parenchymal perfusion defect). DUS served as the standard of reference. RESULTS: Using the best of 12 phases in each patient, optimal attenuation was 353±111 HU, 337±98 HU and 164±51 HU in the iliac arteries, renal arteries, and renal veins, respectively. Mean image quality was 1.1±0.3 (n=36) and 2.1±0.6 (n=30) for the transplant renal arteries and veins, respectively. Six renal veins were non-diagnostic in MP-CTA. In 36 patients, MP-CTA showed 13 vascular complications and 10 parenchymal perfusion defects. DUS was not assessable in eight patients. Overall, MP-CTA showed 15 cases with pathology (42%) not identifiable with DUS. The mean effective radiation dose of the MP-CTA protocol was 13.5±5.2 mSv. CONCLUSION: MP-CTA can be sufficiently performed with reduced contrast volume at reasonable radiation dose in renal transplant patients, providing substantially higher diagnostic yield than DUS.

Acute renal failure by ingestion of Cortinarius species confounded with psychoactive mushrooms: a case series and literature survey.

Mushrooms of the Cortinarius species are nephrotoxic and can cause severe acute renal failure. The toxic effect is due to orellanine. It is suspected that the cytotoxic damage is caused by the production of oxygen-free radicals. Renal pathology shows tubular necrosis with interstitial nephritis. In addition to accidental intoxications as a consequence of mushroom meals, recent cases are often due to voluntary abuse of natural drugs like magic mushrooms. We report 4 current cases of acute renal failure from intoxication by Cortinarius species by confusing it with psychoactive fungi. Typical for the Cortinarius poisoning is the long latency period from ingestion until the onset of clinical symptoms (3 - 20 days). Diagnosis is based on microscopical identification of the mushroom spores, and detection of the orellanine toxin in leftover mushrooms. In renal biopsy tissue, orellanine is detectable by thin-layer chromaography technique up to 6 months after poisoning. There is no causative therapy, and treatment is symptomatic with adequate hemodialysis. In cases of otherwise unexplained acute renal failure, intoxication with nephrotoxic mushrooms should be considered.

Bone marrow edema: pathophysiology, differential diagnosis, and imaging.

Bone marrow edema (BME) has been a topic of increasing interest in the literature in recent years. BME is associated with numerous pathologies and is becoming recognized not only as a considerable pain generator, but also as an entity which is, in some cases, significantly linked to the worsening of patient prognosis. To date, no thorough imaging review of BME has been published. An electronic literature search was conducted through PubMed with a time parameter of January 1975 through December 2007. The primary search parameter was "bone marrow edema." Over 800 papers were listed as written in English and involving humans. Other refining parameters included "AND syndrome," "AND transient," "AND arthritis," "AND infection," "AND tumor," "AND neoplasm," "AND iatrogenic," "AND radiation therapy," and "AND inflammation." More current articles were favored over dated articles on the same topic. A total of 106 journal articles were collected concerning BME and multiple pathologic processes. The data contained therein was compiled and organized into a comprehensive format. BME can be caused by, and found concurrent with, a broad spectrum of pathologies which exhibit a variety of imaging findings. BME is also associated with the deterioration of certain pathologies. This presentation is a comprehensive discussion of different pathological conditions inducing or associated with BME. Differential diagnosis through appropriate imaging is vital to case management and could contribute to the prevention or decreased progression of certain pathologies. Continued investigation into the imaging of BME and its associated diseases, as well as the effect of BME on prognosis, is warranted.

[Orellanus syndrome: a rare cause of acute renal failure]. / Orellanus-Syndrom--seltene Ursache eines akuten Nierenversagens.

HISTORY AND CLINICAL FINDINGS: A 26-year-old woman with no contributory medical history became anuric after several days of nausea and vomiting. She was admitted to our hospital with suspected acute renal failure. INVESTIGATIONS: Laboratory tests revealed greatly elevated BUN and creatinine. There was no evidence of postrenal obstruction, infection or systemic disease. Kidney biopsy showed interstitial nephritis. DIAGNOSIS, THERAPY AND CLINICAL COURSE: Further questioning revealed poisoning with a nephrotoxic mushroom of the genus Cortinarius, which the patient had eaten together with her husband nine days before admission. The patient's husband developed anuric renal failure, too, and was admitted to our hospital. Hemodialysis was instituted on day 1. More than one year later, both patients remain on chronic dialysis. CONCLUSIONS: Intoxication with mushrooms of the genus Cortinarius should be considered in the differential diagnosis of otherwise unexplained acute renal failure, especially in autumn and late summer. These mushrooms can cause an interstitial nephritis. Once dialysis has to be instituted the prognosis is rather poor: 50 % of these patients develop chronic renal failure. So far there is no causative therapy. In case of chronic renal failure, kidney transplantation is possible.

Doppler echocardiographic evaluation of left ventricular relaxation in patients with coronary artery disease.

The time constant of the left ventricular isovolumic pressure decline (Tc) was determined according to the Weiss equation in 23 patients with chest pain who underwent cardiac catheterization. Out of them 15 patients had significant coronary artery stenosis (CAD). Tc was compared to 21 diastolic Doppler data derived from the transmitral inflow. We could predict the Tc from Doppler data using a stepwise multiple regression model, Tc = (0.072 x A-Vpeak)-(0.387 x A-dect)-(0.137 x E-dect) + 0.050 (r = 0.7493, p < 0.0011 SEE = 0.007 All Doppler data and the predicted Tc were examined among the CAD and the healthy groups, the predicted Tc and E/A ratio indicated the best discriminant functions.

[Examination of the diastolic function of the left ventricle by Doppler echocardiography in coronary disease]. / A bal kamra diastolés functiójának vizsgálata Doppler echocardiographiával koszorúsér betegségben.

The authors examined the left ventricular diastolic function at rest and in pain-free period in patients with chest pain but without previous myocardial infarction. Two patient group were formed according to the results of coronarography: 15 patients had significant coronary artery stenosis, while the coronarography was negative in case of 11 patients. Four Doppler echocardiographic parameters were taken and their sensitivity, specificity, positive and negative predictive values were determined on the base of the result of the coronarography. The small number of patients allows only preliminary evaluation but the results suggest that the altered diastolic function enhances the probability of the presence of significant coronary artery disease, while a normal diastolic function decreases its probability.

[Comparative study of digitalized M-mode and Doppler echocardiography in assessing left ventricular function]. / A digitalizált M-mód és Doppler echocardiographia összehasonlító vizsgálata a bal kamra funkciójának megítélésében.

The systolic and diastolic functions were examined using digitized M-mode and Doppler echocardiography in 27 patients with previous myocardial infarction and in 20 healthy subjects. Both methods separated well the patients from the control group but their difference was significantly greater when the ventricular function was assessed with Doppler parametres, digitized M-mode and Doppler echocardiographical results were controlled for possible correlations, but only time intervals showed significant correlations. The highest correlation was found between the values for isovolumic relaxation period. The authors conclude that Doppler echocardiography is to be preferred as a method for assessing the systolic and diastolic functions of the left ventricle.

[Determination of the diastolic function of the left ventricle in post-infarction patients using a complex echocardiographic index]. / A bal kamra diastolés funkciójának megítélése postinfarctusos betegeken komplex echocardiographiás index alkalmazásával.

The diastolic function of 25 patients with ischemic heart disease was studied by both digitized M-mode and Doppler echocardiography. The control groups were a group of healthy subjects and patients with hypertension, resp. There was a significant difference in the diastolic parametres of the healthy and the diseased groups. The altered diastolic function of the latter showed, however, little variation. A new complex diastolic index was formed from the parametres involved in Doppler and M-mode echocardiography. It contains early and late diastolic filling rates, the isovolumic relaxation period, and the diametric change of the left ventricle during the isovolumic relaxation period. This index allowed us to separate the altered diastolic functions of patients with ischemic heart disease from those with left ventricular hypertrophy.

Effect of irradiated haemophilus influenzae endotoxin preparations in mice.

A detoxified substance (rdLPS) was produced from Haemophilus influenzae endotoxin by ionizing radiation and its capacity to prevent attacks of dyspnoea elicited by endotoxin inhalation in mice has been studied. The rdLPS proved to be an effective stimulant of aspecific immune resistance of mice but it could only partly prevent attacks of dyspnoea.

Bacterial modulation of the cellular immune response in mice. II. Stimulation by endotoxin of the reduced cellular immune response to LCM virus infection in aged mice.

Aging mice treated with radio-detoxified endotoxin and subsequently inoculated intracerebrally with lymphocytic choriomeningitis (LCM) virus died earlier and in a higher rate than the virus infected and otherwise untreated controls. Thus, in mice with insufficient T lymphocyte function due to aging, the radio-detoxified endotoxin pretreatment contributed to the outcome of LCM virus infection in the form of lethal meningitis. That indicates a stimulatory effect on the reduced cellular immunological reaction to the virus infection.

Effect of an irradiated Escherichia coli endotoxin reparation on the sensitivity to a lymphotropic cytostatic agent in germfree and conventional mice.

A 18 mg/kg dose of dianhydrodulcitol, a lymphotropic cytostatic agent produced the same death rate among germfree as a 12 mg/kg dose did in conventional mice. Pretreatment with the same dose of an irradiated immunomodulatory endotoxin preparation had increased the sensitivity to these dianhydrodulcitol doses in the same degree in germfree as in conventional mice. A study of the lymphoid organs and the intestinal wall indicate that both in germfree and conventional mice the dianhydrodulcitol sensitivity increasing effect of the endotoxin preparation was due to its stimulation of the lymphoid system. The higher resistance of germfree mice to dianhydrodulcitol is ascribed to their lack of a normal intestinal flora.

Effect of Bordetella pertussis vaccine on the sensitivity to a lymphotropic cytostatic agent in germfree mice.

A single injection of 15 mg/kg dianhydrodulcitol caused death at a higher proportion of germfree, specific pathogen free, and conventional mice with lymphocytosis and spleen hypertrophy induced by Bordetella pertussis vaccine pretreatment, than of unvaccinated controls.

The course of lymphocytic choriomeningitis virus infection in germfree mice treated with Bordetella pertussis vaccine.

A single injection of Bordetella pertussis vaccine, applied intraperitoneally one day before intracerebral lymphocytic choriomeningitis virus infection depressed the immune response both in conventional and germfree adult mice, but the rate of the immunosuppressive effect differed. In adult mice with a normal immune system the vaccine only delayed the manifestation of fatal lymphocytic choriomeningitis, while it prevented its development in germfree mice with an underdeveloped lymphoid system, i.e. it inhibited the cellular immune response to the virus infection.

Bacterial modulation of the cellular immune response in mice. I. The course of lymphocytic choriomeningitis virus infection in Bordetella pertussis vaccine pretreated mice with physiological thymus involution.

The cellular immune response to lymphocytic choriomeningitis virus infection was found to be normal in 6-month-old mice with physiological thymus involution, while it was reduced in 18-month-old mice. The Bordetella pertussis vaccine elicited immunosuppression in 6-month-old mice with normal immunological responsiveness, while it failed to affect the physiologically diminished cellular immune response in 18-month-old mice. The extent of immunosuppression elicited by the vaccine changed parallel to its concomitant spleen hypertrophy inducing effect.

Effect of endotoxin preparations on the course of lymphocytic choriomeningitis virus infection in suckling mice.

Death occurred earlier and its rate was higher in suckling mice treated with parent or radio-detoxified endotoxin and subsequently inoculated intracerebrally with lymphocytic choriomeningitis (LCM) virus than in their virus infected but untreated control littermates. Thus, in suckling mice both the parent and the radio-detoxified endotoxin pretreatment contributed to the outcome of LCM virus infection in the form of lethal meningitis indicating its increasing effect on the cellular immunological reaction to the virus infection.

Higher resistance of germfree mice to dianhydrodulcitol, a lymphotropic cytostatic agent.

The same dose of dianhydrodulcitol (DAD) produced a lower mortality rate among germfree mice than among SPF or conventional C3H mice. On the other hand, it caused graver lymphoid atrophy in germfree mice. Their higher resistance, as evidenced by the mortality rate, can be explained on the basis of a histological study of the ileum. It showed milder alterations of the intestinal wall in germfree than in SPF mice. The lymphotropic cytostatic agent had a less direct toxic effect in germfree mice, due to the lacking damaging effect of endotoxin from the normal intestinal flora.