Renal manifestations of AIDS

Diffuse Renal Cortical Echogenic Foci in a Patient With AIDS

Pneumocystis jirovecii is ubiquitous in the environment and is best known as the cause of Pneumocystis pneumonia (PCP) in immune-suppressed hosts. Extrapulmonary P. jirovecii is a rare complication of this opportunistic infection primarily seen in patients with immune-deficient states. Nephritis due to P. jirovecii was first described by Bargman in 1991 in a patient with atypical nephrocalcinosis found on conventional radiography. This case report presents a patient with Pneumocystis nephritis and describes the sonographic appearance as well as the advantages of sonography in the early detection of this uncommon condition.

Tuberculosis of the genitourinary system-Urinary tract tuberculosis: Renal tuberculosis-Part II

This article reviews the computed tomography and magnetic resonance imaging (MRI) features of renal tuberculosis (TB), including TB in transplant recipients and immunocompromised patients. Multi detector computed tomography (MDCT) forms the mainstay of cross-sectional imaging in renal TB. It can easily identify calcification, renal scars, mass lesions, and urothelial thickening. The combination of uneven caliectasis, with urothelial thickening and lack of pelvic dilatation, can also be demonstrated on MDCT. MRI is a sensitive modality for demonstration of features of renal TB, including tissue edema, asymmetric perinephric fat stranding, and thickening of Gerota's fascia, all of which may be clues to focal pyelonephritis of tuberculous origin. Diffusion-weighted MR imaging with apparent diffusion coefficient (ADC) values may help in differentiating hydronephrosis from pyonephrosis. ADC values also have the potential to serve as a sensitive non-invasive biomarker of renal fibrosis. Immunocompromised patients are at increased risk of renal TB. In transplant patients, renal TB, including tuberculous interstitial nephritis, is an important cause of graft dysfunction. Renal TB in patients with HIV more often shows greater parenchymal affection, with poorly formed granulomas and relatively less frequent findings of caseation and stenosis. Atypical mycobacterial infections are also more common in immunocompromised patients.

Imaging features of renal pathology in the human immunodeficiency virus-infected patient

Renal disease in patients with acquired immunodeficiency syndrome was described before even human immunodeficiency virus was demonstrated to be the causative agent, when the now known human immunodeficiency virus associated nephropathy was first described. Several other pathologic processes mostly relating to the immunodeficiency caused by the virus, such as atypical infections, malignancies, as well as highly active antiretroviral therapy related side affects, have been shown to affect the kidneys. The mortality and morbidity burden is high; therefore, it is paramount the radiologist be familiar with the imaging features of this wide range of diseases processes.

Abdominal ultrasonography in HIV/AIDS patients in southwestern Nigeria

BACKGROUND

Though the major target of the HIV-virus is the immune system, the frequency of abdominal disorders in HIV/AIDS patients has been reported to be second only to pulmonary disease. These abdominal manifestations may be on the increase as the use of antiretroviral therapy has increased life expectancy and improved quality of life. Ultrasonography is an easy to perform, non invasive, inexpensive and safe imaging technique that is invaluable in Africa where AIDS is most prevalent and where sophisticated diagnostic tools are not readily available.

PURPOSE

To describe the findings and evaluate the clinical utility of abdominal ultrasonography in HIV/AIDS patients in Ibadan, Nigeria

METHODS

A Prospective evaluation of the abdominal ultrasonography of 391 HIV-positive patients as well as 391 age and sex-matched HIV-negative patients were carried out at the University College Hospital, Ibadan.

RESULTS

Of the 391 cases studied, 260 (66.5%) were females; the mean age was 38.02 years, (range 15-66 years). The disease was most prevalent in the 4th decade with an incidence of 40.4%. Compared with the HIV-negative individuals, the HIV+ group of patients had a significantly higher proportion of splenomegaly (13.5% vs. 7.7%; p < 0.01), lymphadenopathy (2.0% vs. 1.3%; p < 0.70), and renal abnormalities (8.4% vs. 3.8%; p < 0.02). There were no differences in hepatic and pancreatic abnormalities between the HIV+ and HIV- groups. There were significantly fewer gallstones in the HIV+ group (1.4% vs. 5.1%; p < 0.01).

CONCLUSION

AIDS is a multi-systemic disease and its demographic and clinical pattern remains the same globally. Ultrasonography is optimally suited for its clinical management especially in Africa. Its accuracy and sensitivity may be much improved with clinico-pathologic correlation which may not be readily available in developing countries; further studies may provide this much needed diagnostic algorithms.

Cross-sectional imaging of extranodal involvement in abdominopelvic lymphoproliferative malignancies

Extranodal lymphoproliferative diseases are common, and their prevalence is increasing. Non-Hodgkin lymphomas and Hodgkin disease, in particular, frequently involve extranodal structures in the abdomen and pelvis, including both the solid organs (liver, spleen, kidneys, and pancreas) and the hollow organs of the gastrointestinal tract. Because virtually any abdominopelvic tissue may be involved, many different imaging manifestations are possible, and lymphoproliferative diseases may mimic other disorders. Familiarity with the imaging manifestations that are diagnostically specific for extranodal lymphoproliferative diseases is important because imaging plays an important role in the noninvasive management of disease. However, a definitive diagnosis requires a biopsy (of bone marrow, a lymph node, or a mass), a peripheral blood analysis, and other laboratory tests. In patients with known disease, the goals of imaging are staging, evaluation of response to therapy, and identification of new or recurrent disease or of complications of therapy. In patients without known disease, imaging permits a provisional diagnosis.

The role of ultrasound in renal insufficiency: the essentials

Sonography is the best screening modality to evaluate patients presenting with renal insufficiency. Ultrasound findings can be normal in patients with renal disease, especially in prerenal azotemia and acute parenchymal renal disease. Echogenic kidneys indicate the presence of parenchymal renal disease; the kidneys may be of a normal size or enlarged. Small kidneys suggest advanced stage chronic kidney disease. Uncommonly, cystic disease of the kidney, especially adult type polycystic kidney disease may be the cause of the patient's renal insufficiency with bilaterally enlarged kidneys containing multiple cysts of various sizes. If hydronephrosis is present, the level and cause of the obstruction should be sought. When ultrasound cannot diagnose the level and cause of obstruction, other imaging modalities, including CT and MRI may be useful. When renovascular disease (arterial stenosis or venous thrombosis) is suspected, spectral and color Doppler can be useful in detecting abnormalities.

Renal lymphoma: CT patterns with emphasis on helical CT

Renal lymphoma is most often seen in conjunction with multisystemic, disseminated lymphoma or as tumor recurrence. Renal lymphoma may also be seen in immunocompromised patients or, rarely, as primary disease. Computed tomography (CT) is the most sensitive, efficient, and comprehensive examination for evaluation of the kidneys in patients with suspected renal lymphoma. Helical CT in particular improves detection and characterization of lymphomatous renal involvement by optimizing contrast dynamics and data acquisition and is the current modality of choice for accurate staging of lymphoma. Typical CT patterns in renal lymphoma include single and multiple masses, invasion from contiguous retroperitoneal disease, perirenal disease, and diffuse renal infiltration. Atypical CT patterns may also be encountered and provide a diagnostic challenge. These include spontaneous hemorrhage, necrosis, heterogeneous attenuation, cystic transformation, and calcification. Solid renal masses including renal cell carcinoma and metastases are the most commonly encountered entities that mimic renal lymphoma at CT and require biopsy for definitive diagnosis. CT (particularly helical CT) is useful in the evaluation of patients with suspected renal lymphoma, and familiarity with the spectrum of findings in renal lymphoma is important for accurate diagnosis.

Acquired immunodeficiency syndrome (AIDS) of the abdominal organs: imaging features

The liver, spleen, biliary tract, pancreas, and kidneys are commonly affected by opportunistic infection, malignancy, and inflammatory disorders during the course of human immunodeficiency virus (HIV) infection. Clinical manifestations of solid abdominal visceral involvement are protean and usually nonspecific, but it is important to establish a specific diagnosis promptly in these often critically ill patients. This presentation reviews the cross-sectional imaging spectrum of HIV-associated lesions of these organs.

Imaging and radiologic management of upper urinary tract infections

Most infections of the upper urinary tract respond promptly to antibiotic therapy and imaging is not necessary. Patients with urinary obstruction, diabetes, or immunocompromise are more likely to develop complicated infection, abscess, or have unusual organisms. Chronic granulomatous processes involving the kidney are usually related to recurrent bacterial infections. Again, stone disease or obstruction is often an underlying problem. In those patients who do not respond promptly to treatment or have a more complicated clinical picture, imaging can assess the severity and extent of disease. CT scan is the study of choice for diagnostic evaluation in these patients and directs percutaneous intervention when appropriate. Placement of drainage catheters is often curative but also may allow the patient to stabilize until surgical treatment is accomplished. One exception is the diagnosis of pyonephrosis, which may be accomplished more easily by ultrasound. In these cases, PCN placement is generally needed and is performed under fluoroscopic guidance. Ultimately, however, definitive surgical intervention often is needed to relieve the underlying obstruction.

Pelvocalyceal thickening in HIV-associated nephropathy

BACKGROUND

Previously reported causes of renal pelvocalyceal thickening (PCT) include infection, acute tubular necrosis and obstruction. This study was performed to evaluate the significance of PCT noted sonographically in patients with hyperechoic native kidneys.

METHODS

We evaluated sonograms of 178 consecutive patients with hyperechoic native (excluding small and hydronephrotic) kidneys for the presence of PCT, and reviewed medical charts of patients with this finding. We also reviewed sonograms of two control groups: 20 consecutive patients with nephrosis unrelated to human immunodeficiency virus (HIV) infection who underwent renal biopsy, and 30 consecutive patients with severe hypoalbuminemia unrelated to kidney disease.

RESULTS

PCT was observed in 20 study patients with hyperechoic kidneys. HIV-associated nephropathy (HIVAN) was diagnosed in 15 patients (14 with bilateral PCT) in whom previously reported causes of this appearance were excluded. PCT was not observed in control patients.

CONCLUSION

Renal PCT can occur in patients with HIVAN in the absence of HIV-related complications. PCT in HIVAN does not merely reflect nonspecific nephrosis or hypoalbuminemia. HIVAN should be considered if PCT is noted sonographically in hyperechoic kidneys, even in patients not clinically suspected of harboring HIV infection.