Radioimmunoscintigraphy of colorectal carcinoma using technetium-99m-labeled, totally human monoclonal antibody 88BV59H21-2.

Radioimmunoscintigraphy (RIS) using human monoclonal antibodies offers the important clinical advantage of repeated imaging over murine monoclonal antibodies by eliminating the cross-species antibody response. This article reports a Phase I-II clinical trial with Tc-99m-labeled, totally human monoclonal antibody 88BV59H21-2 in patients with colorectal carcinoma. The study population consisted of 34 patients with colorectal cancer (20 men and 14 women; age range, 44-81 years). Patients were administered 5-10 mg antibody labeled with 21-41 mCi Tc-99m by the i.v. route and imaged at 3-10 and 16-24 h after infusion using planar and single-photon emission computed tomographic (CT) techniques. Pathological confirmation was obtained in 25 patients who underwent surgery. Human antihuman antibody (HAHA) titers were checked prior to and 1 and 3 months after the infusion. RIS with Tc-99m-labeled 88BV59H21-2 revealed a better detection rate in the abdomen-pelvis region compared with axial CT. The combined use of both modalities increased the sensitivity in both the liver and abdomen-pelvis regions. Ten patients developed mild adverse reactions (chills and fever). No HAHA response was detected in this series. Tc-99m-labeled human monoclonal antibody 88BV59H21-2 RIS shows promise as a useful diagnostic modality in patients with colorectal cancer. RIS alone or in combination with CT is more sensitive than CT in detecting tumor within the abdomen and pelvis. Repeated RIS studies may be possible, due to the lack of a HAHA response.

Diagnostic studies in patients with sickle cell anemia and acute abdominal pain.

Twenty-eight patients with sickle cell disease who presented with acute abdominal pain were evaluated with clinical laboratory, ultrasound, and biliary scintigraphic studies to determine their predictive capabilities for differentiating veno-occlusive disease (sickle cell crisis) from acute biliary disease. Eleven patients were treated surgically and 17 medically. Gallstones were demonstrated in 25 (90%) of the patients studied by ultrasound, and biliary scans were abnormal in nine patients (32%). Abnormal laboratory and radiological studies (ultrasound, biliary scintigraphy) were not significantly different in the two groups and had a low positive predictive value for detection of acute biliary disease. Nevertheless, normal biliary scintigraphy had high negative predictive value in that, if normal, it gave assurance that the cystic duct was patent and unnecessary surgery could be obviated in this high-risk category of patients.

Radionuclide cerebral perfusion scintigraphy in determination of brain death in children.

We evaluated a radionuclide scintigraphic technique for imaging relative cerebral perfusion in 18 children who had no evidence of cortical and brainstem function. Patients without scintigraphic evidence of cerebral perfusion all later met criteria for diagnosis of brain death. Patients who failed to satisfy brain-death criteria had persistent scintigraphic evidence of cerebral perfusion. Seven patients with normal scintigraphic studies were being treated with barbiturates and hypothermia at levels that attenuated or completely suppressed EEG activity. Four patients without scintigraphic evidence of cerebral perfusion had mean arterial pressures (MAP) higher than (54.8 +/- 7.6 torr) intracranial pressures (ICP) at the time of scintigraphic study, suggesting that ICP in excess of MAP is not the sole explanation for the absence of cerebral perfusion. Radionuclide cerebral perfusion scintigraphy (RCPS) is a rapid, portable, accurate test that appears to be useful in the diagnosis of brain death in the pediatric population.

Interaction of cyclosporine A and nonsteroidal anti-inflammatory drugs on renal function in patients with rheumatoid arthritis.

PURPOSE: To determine the additive renal effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclosporine A (CYA) in patients with rheumatoid arthritis (RA) and to determine the effects of CYA on active RA. PATIENTS AND METHODS: Eleven patients with RA refractory to other agents were treated separately for 2-week periods with an NSAID (sulindac or naproxen), CYA (5 mg/kg/d), and NSAID plus CYA in combination (NSAID/CYA). The NSAID/CYA combination was continued for an additional 20 weeks. Clinical parameters of RA, electrolytes, renal function, and the renin-aldosterone system were evaluated at each interval to determine the potential interaction of these two agents. RESULTS: Combined therapy was effective in suppressing many measures of active RA in 9 of the 11 patients. Adverse drug reactions were common, but withdrawals were limited to hirsutism (one) and peripheral neuropathy (one). In about half of the patients, CYA or NSAID resulted in a decrease in the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), with a mild reduction in the filtration fraction. With NSAID or CYA, early morning renin-aldosterone system values were mildly suppressed, and their response to ambulation/intravenous (IV) furosemide was not blunted. When combined, NSAID/CYA caused more marked reductions of GFR and ERPF at 2 weeks, and this persisted at 20 weeks. The morning renin-aldosterone system values during administration of NSAID/CYA were suppressed, with an added blunted response to ambulation/IV furosemide. CONCLUSION: As previously suspected, the impairment of renal function when CYA and NSAID are combined is greater than that obtained with either agent alone. This hemodynamic effect was reversible and appeared to be, at least in part, due to renal vasoconstriction.

Furosemide-131I-hippuran renography after angiotensin-converting enzyme inhibition for the diagnosis of renovascular hypertension.

PURPOSE: We have previously demonstrated the greater sensitivity of 131I-hippuran renography than 99mTC-DTPA scintigraphy to diagnose renovascular hypertension (RVH). This study assesses the predictive diagnostic value of furosemide-131I-hippuran renography after angiotensin-converting enzyme (ACE) inhibition in patients with and without RVH. PATIENTS AND METHODS: All patients were investigated at the University of Miami/Jackson Memorial Medical Center. Twenty-eight patients had RVH and 22 did not. Twenty-eight patients had normal or minimally decreased renal function (serum creatinine level 1.5 mg/dL or less) and 22 had renal insufficiency (serum creatinine level 1.8 mg/dL or more). Renography was performed 60 minutes after oral administration of 50 mg captopril or 10 minutes after intravenous injection of 40 micrograms/kg enalaprilat. Forty milligrams of furosemide were administered intravenously 2 minutes after injection of 131I-hippuran. The residual cortical activity (RCA) of 131I-hippuran was measured at 20 minutes. RESULTS: RVH was unlikely when RCA after ACE inhibition was less than 30% of peak cortical activity. Conversely, RVH was present when 131I-hippuran cortical activity steadily increased throughout the test to reach 100% at 20 minutes. In azotemic patients with RCA between 31% and 100%, RVH was differentiated from intrinsic renal disease by obtaining a baseline renogram without ACE inhibition and comparing RCA in that study and RCA after ACE inhibition. If RCA increased (indicating worsening renal function) after ACE inhibition, RVH was likely; whereas, intrinsic renal disease was more likely if RCA remained unchanged or decreased (indicating improved renal function) with ACE inhibition. The test had a specificity of 95% and a sensitivity of 96% in this population. There was a direct correlation between the results of angioplasty or surgery on high blood pressure and the changes in RCA before and after intervention (n = 20). CONCLUSION: Furosemide-131I-hippuran renography with ACE inhibition is highly predictive in identifying patients with RVH.

MAG3 SPECT: a rapid procedure to evaluate the renal parenchyma.

UNLABELLED: Renal parenchymal (cortical) scintigraphy (planar or SPECT) is indicated for the diagnosis and follow-up of focal functional disorders, such as acute pyelonephritis, and for accurate quantitation of split renal function, especially in cases of atypical location of the kidney(s). This static imaging procedure is currently performed 3-5 hr after the injection of a cortical fixation agent, 99mTc-DMSA or 99mTc-GH, and requires effective immobilization of the patient for 30 min. METHODS: In five healthy adult volunteers and five children with various clinical indications, SPECT renal parenchymal scintigraphy was performed with a three-detector camera in 1-min per revolution sequential intervals for a total acquisition time of 4 min, beginning immediately after an intravenous injection of a graduated dose of 20 mCi (minimum 2 mCi) of the dynamic renal agent 99mTc-MAG3. RESULTS: Tomograms of the renal parenchyma reconstructed in three projections and volume-rendered reprojection of the SPECT-volume data indicated normal or abnormal renal parenchyma. Comparisons were made with planar MAG3 and SPECT-GH and favored MAG3-SPECT. However, comparisons with DMSA indicated certain disadvantages of MAG3 SPECT. For most organs, the radiation dose estimates from 20 mCi MAG3 were lower than those from DMSA (6 mCi) or GH (20 mCi). Simultaneous injection of MAG3 and a diuretic (2-40 mg furosemide) resulted in lower than usually reported radiation dose estimates for the urinary bladder (target organ) and the gonads, and allowed subsequent evaluation of the drainage system. CONCLUSION: MAG3 SPECT is feasible, clinically useful and may be offered as a rapid (4 min) renal parenchymal imaging procedure, or it may precede planar dynamic (dluretic) MAG3 scintigraphy.

Nuclear medicine in pediatric urology and nephrology.

Renal scintigraphy is a diagnostic procedure of choice or a complementary imaging modality in the work up of infants and children with urologic or nephrologic problems. New radiopharmaceuticals and techniques and expert interpretation provide unique renal parenchymal and collecting system functional and anatomical information, which helps in the diagnosis and follow up of congenital or acquired kidney disorders and the quantitation of renal function. Education of the user and the referring physician, further clinical experience, and comparative studies should help increase utilization of renal scintigraphy in the neonatal and pediatric age for the benefit of the patient and the better understanding of urologic and nephrologic disorders.

Detection of ectopic gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: I. Pathophysiology and 10-year clinical experience.

Ten years of clinical experience with pertechnetate (Tc-99m) scintigraphy has proven its validity for the diagnosis of ectopic gastric mucosa in bleeding Meckel's diverticulum and other congenital anomalies. Careful patient preparation and a standardized technique based on sequential gamma imaging has resulted in an overall sensitivity of 85%. Experience in differentiating "nonspecific" accumulations of pertechnetate from true ectopic gastric mucosa had increased the specificity to 95%. When we consider all the studies reported (954) with a surgical or clinical diagnosis, the accuracy of the method is calculated at 98%. When only surgically proven cases are analyzed, the calculated accuracy is 90%. Pertechnetate excretion by the mucoid cells of gastric mucosa is the basis of this test. The effect of drugs and hormones on the test has been studied in animals and in patients. The findings suggest that an improvement can be achieved by the use of cimetidine, pentagastrin, or glucagon.

Detection of ectopic gastric mucosa in Meckel's diverticulum and in other aberrations by scintigraphy: ii. indications and methods--a 10-year experience.

Ten years' experience with pertechnetate (Tc-99m) abdominal scintigraphy has shown that the method is specifically indicated for the diagnosis and location of ectopic gastric mucosa in a Meckel's diverticulum, in enteric or gastric duplications and cysts, and in Barrett's esophagus. Careful patient preparation is essential, and sequential gamma camera imaging for 1 hr in the anterior projection is advisable, with complementary lateral, upright, and postvoiding views. Nonspecific accumulations of the tracer within tumours, intestinal obstructions, arteriovenous malformations, and the urinary tract can be recognized with the help of the clinical history and can be investigated by other tests. This approach has raised the accuracy of the method above 90%.

Endotoxin testing with limulus amoebocyte lysate in a radiopharmaceutical containing chelated metallic radionuclides and chelating agents.

The gel formation by endotoxin with limulus amoebocyte lysate (LAL) solution requires the presence of free calcium ions. The chelating agents and radiopharmaceuticals prepared from the chelating agents always reduce the available free calcium levels present in the kits used for the testing of apyrogenicity and thus inhibit gel formation of LAL with E. Coli endotoxin (ET). This inhibition of gel formation could be reversed by the addition of excess free calcium ions or the excessive dilution of radiopharmaceuticals and chelating agents. The tests of positive control (0.2 ml ET units and LAL), inhibition control (0.1 ml sample, 0.1 ml ET and LAL), and negative control (0.1 ml sterile saline and LAL) were carried out with the fresh preparation (0.1 ml) of samples (triplicate), tropolone, ACD anticoagulant, and 99mTc-labeled radiopharmaceuticals. In the Ca-supplemented tests, 0.1 ml of 60 mM sterile calcium chloride solution was added to the test solutions and incubated for 60 min at 37 degrees centigrade. The results of gel formation (+ve and -ve) and normalization of inhibition control tests with Ca-supplement indicate that commercial LAL kits need extra calcium ions for the correct testing of the apyrogenicity of chelate-containing radiopharmaceuticals and chelating agents.

Clinical comparison of technetium-99m-teboroxime and thallium-201 utilizing a continuous SPECT imaging protocol.

To examine the advantages of a 99mTc-labeled cardiac perfusion agent, teboroxime or SQ30,217 (Squibb Diagnostics), a prospective study was undertaken comparing it to 201Tl stress testing in 17 patients suspected or known of having coronary artery disease (CAD). All patients were studied utilizing a single-detector SPECT camera with a continuous acquisition imaging protocol. Testing was performed on a treadmill to comparable levels with both agents within a 2-wk period. Concordance between the two studies on a patient by patient basis was seen in 16/17 (94%) patients, and discordance was seen in 1/17 (6%) patients. Comparison of findings between 201Tl and 99mTc-teboroxime on a segment by segment basis showed concordance in 107/119 (90%) segments, and 12/119 (10%) were discordant. Both examinations independently detected an equal number of normal (77) and abnormal (42) segments. There was no significant difference between the two agents in classifying lesions as ischemic, although there were significant differences between thallium and teboroxime in classifying infarct and infarct/ischemia. Technetium-99m-teboroxime SPECT imaging is a clinically useful method for detecting CAD, with a major advantage being the shorter examination time per individual patient study. The mean total examination time for completion of the 99mTc-teboroxime study was 2.5 hr versus 4.0 hr for 201Tl.

Comparisons of scintigraphy with In-111 leukocytes and Ga-67 in the diagnosis of occult sepsis.

In a prospective study involving 32 patients with clinical suspicion of focal infection, the sensitivity and specificity of In-111-labeled leukocyte (In-WBC) scintigraphy were compared with those of Ga-67 scintigraphy performed 24-48 hr later. Of a total of 192 body sites studied, 26 foci of infection were diagnosed by aspiration, cultures, or chest radiographs. Indium-WBC indicated 19 (73%) true-positive (TP) and four (2.5%) false-positive (FP) foci of abnormal accretion; Ga-67 had 21 (81%) TP and 15 (9%) FP. The 7/26 (27%) false-negative (FN) In-WBC scintigrams involved infection foci of more than 2-wk duration; the 5/26 (19%) FN Ga-67 studies were in patients with infections manifested for less than 1 wk. The results of this study are useful in considering the indications of the two tracers.

Single-dose captopril scintigraphy in the diagnosis of renovascular hypertension.

Renal scintigraphy with [99mTc]diethylenetriaminepentaacetic acid (DTPA) and/or sodium-iodine-131-o-iodohippurate (HIP) was performed before and after an oral dose of captopril (50 mg) in 18 patients with renovascular hypertension (RVH) due to renal artery stenosis (RAS) and 18 controls. In every patient with RVH, captopril induced, enhanced or sustained abnormal findings on HIP scintigraphy depending on the degree of RAS. With DTPA scintigraphy, renal function decreased after captopril in ten kidneys with RVH-related RAS and adequate baseline renal function, but this phenomenon was not evident in 11 kidneys with RVH and poor renal function. Captopril did not influence HIP or DTPA studies of kidneys with patent renal arteries (patients after successful renal angioplasty, patients with essential hypertension, contralateral kidneys of patients with unilateral RVH) or ipsilateral kidneys with mild and subcritical (less than 60%) RAS in patients without hypertension and/or normal renal vein renin activity. When HIP and DTPA scintigraphy were compared in the same patients, HIP demonstrated greater sensitivity and specificity than DTPA, particularly in patients with poor renal function. HIP scintigraphy before and after a single dose of captopril may provide a rapid sensitive and minimally invasive test for screening patients with hypertension.

Pertechnetate scintigraphy in primary congenital hypothyroidism.

UNLABELLED: Primary congenital hypothyroidism (PCH) is currently detected effectively by heel-stick screening. When elevated thyrotropin (TSH) and/or decreased T4 are found in the blood of neonates, they are recalled, values are confirmed in venous blood and thyroxine replacement therapy (TRT) is immediately instituted, thus cretinism or severe retardation is prevented. However, in a significant percentage of neonates with abnormal blood levels of T4 or TSH, the disorder is transient. To help determine the exact cause of PCH and the possibility of transient PCH, pinhole thyroid imaging is performed 30 min after an intravenous injection of 18.5 MBq (500 microCi) 99mTc-pertechnetate (TcPT). Patients with a nonvisualized gland or patients with images suggesting dyshormonogenesis are reevaluated at age 3-4 y to exclude transient PCH. METHODS: To define the role of TcPT imaging in determining the exact etiology of PCH and the possibility of its being transient, we reviewed data from 103 neonates with PCH who had scintigraphy in our laboratory between 1970 and 1996 and we correlated the results with clinical outcome. RESULTS: Four patterns of thyroid scintigrams were recognized and these determined patient classification: (a) normal in 7 patients with false-positive heel-stick screening but normal venous blood hormone levels; (b) hypoplasia-ectopia in 32 patients requiring lifelong TRT; (c) nonvisualization in 35 patients-32 with agenesis requiring lifelong TRT and 3 with fetal thyroid suppression by maternal antibodies whose TRT was discontinued at a later age; and (d) dyshormonogenesis (markedly increased TcPT concentration) in 29 patients-25 with permanent PCH requiring lifelong TRT and 4 with transient PCH in whom TRT was discontinued. Of the 25 patients with dyshormonogenesis, 12 belonged to five families with two or three siblings having the same disorder. CONCLUSION: TcPT thyroid scintigraphy in the neonate with PCH provides a more specific diagnosis, is useful for selecting patients for re-evaluation to uncover transient PCH and discontinue TRT and defines dyshormonogenesis, which is familial and requires genetic counseling. It is also cost-effective.

Clinical evaluation of a scintigraphic method for diagnosing inflammations/infections using indium-111-labeled nonspecific human IgG.

This study was undertaken as part of a Phase II study to assess the sensitivity and safety of 111In-DTPA-human IgG, an imaging agent for the detection of inflammations and/or infections. Forty patients with infection/inflammation on the basis of clinical findings, microbiologic results, and/or the basis of results from other imaging modalities were studied. For evaluation of sensitivity, whole-body images were obtained at 6-12 hr (early) and 20-28 hr (delayed) postinjection and occasionally at 48 hr. No adverse reactions were recorded in any of the 40 patients studied. Positive results were obtained in 37 of 37 evaluable subjects (100%). The test appears to be a promising method for the detection of inflammation and/or infection.

Noninvasive imaging of c-myc oncogene messenger RNA with indium-111-antisense probes in a mammary tumor-bearing mouse model.

UNLABELLED: The c-myc oncogene is amplified in leukemia and solid tumors, thus making the c-myc messenger RNA (mRNA) a suitable target for following the progression of malignancy by noninvasive imaging with radiolabeled antisense pharmaceuticals or radiolabeled antisense oligodeoxynucleotide (RASON) probes. Considering the higher stability of phosphorothioate over phosphodiester, the probe stability and tumor localization was compared with both derivatives. METHODS: The 15-mer oligonucleotide sequence was synthesized, aminolinked [sense and antisense phosphodiester (O) and monothioester (S)] and coupled with diethylenetriamine pentaacetate (DTPA)-isothiocyanate and aliquots were lyophilized to make a DTPAAHON kit. The radionuclide 111In was chelated to DTPAAHON derivatives, and free 111In was separated by gel filtration. The radiolabeled antisense and sense probes were injected intravenously in mammary tumor-bearing BALB/c mice (1 x 10(6) cells, 8 days postinoculation). RESULTS: The highest uptake was observed at 2 hr with both thio and oxo derivatives of RASON probes, and small tumors could be imaged noninvasively. Tumor uptake and tumor/blood and tumor/muscle ratios for the sense probe (control) were significantly lower (p < 0.001) than those of the antisense probe. CONCLUSION: The radiolabeled antisense probe may provide a new sensitive tool for noninvasive imaging of c-myc oncogene mRNA for a variety of malignant tumors at an earlier stage.

Somatostatin receptor expression in Hürthle cell cancer of the thyroid.

Somatostatin receptor expression, which was not a previously described marker for Hürthle cell cancer of the thyroid, was demonstrated by in vivo imaging with (111)In-pentetreotide in three patients. This phenomenon not only adds another imaging technique to the nuclear medicine armamentarium for detecting recurrent and metastatic cancer in patients with Hürthle cell cancer but also opens up an alternative therapeutic avenue with somatostatin analogs or their radiolabeled compounds.

Diuretic MAG3 scintigraphy (F0) in acute pyelonephritis: regional parenchymal dysfunction and comparison with DMSA.

UNLABELLED: 99mTc-DMSA late static planar imaging or SPECT is being used for the investigation of focal acute pyelonephritis (APN), especially in children with urinary tract infection (UTI). Diuretic 99mTc-mercaptoacetyltriglycine (MAG3) dynamic scintirenography has been applied in the evaluation of kidney function and structure, frequently to exclude obstruction. However, in children and adults with a clinical picture of APN, diuretic MAG3 scintigraphy with zero time injection of furosemide (MAG3-F0) was observed to display focal parenchymal abnormalities; regional dysfunction (focal parenchymal decrease in early uptake; slow filling in and prolonged late retention of activity); or, less frequently, fixed defects. This observation was further studied both retrospectively and prospectively, and its sensitivity and specificity for APN were compared with those of dimercaptosuccinic acid (DMSA). METHODS: In the retrospective study, for 36 children with UTI and regional parenchymal findings on MAG3-F(0), data were reviewed, analyzed, and compared with the results of concurrent DMSA studies. In the prospective study, for 57 children with clinical and laboratory findings suggestive of APN, the 2 radiopharmaceuticals were used for imaging sequentially and the results of the 2 studies were compared. The criteria for abnormal findings compatible with the diagnosis of APN were, for MAG3-F(0), regional parenchymal dysfunction and fixed focal defects and, for DMSA, focal defects without parenchymal loss. RESULTS: In all groups of patients, most abnormal MAG3-F(0) studies (80%) showed regional parenchymal dysfunction, but in some (20%) a fixed defect was found. Compared with DMSA and when both regional dysfunction and focal defects were considered, MAG3-F(0) was as sensitive as DMSA. Some patients had only MAG3-F(0) abnormalities, suggesting a slightly lower specificity for MAG3-F(0) compared with DMSA (86%); this finding needs further study, because it also raises questions about the sensitivity of DMSA, considering that only a small percentage of patients with clinically suggestive findings had abnormal study findings. In most patients with fixed defects on both DMSA and MAG3-F(0), follow-up studies showed no resolution, suggesting that a fixed defect on MAG3-F(0) may indicate either more severe APN or preexistent scars and that regional dysfunction may be a sign more specific for APN and prognostic of potential recovery. In addition, a pattern more specific for a scar--a fixed defect with a dilated regional calyx--was seen on follow-up MAG3-F(0). CONCLUSION: A fast (25-min) planar dynamic MAG3-F(0) study was found to be as sensitive at depicting focal parenchymal abnormalities in APN as was the 3- to 4-h DMSA routine procedure. The sensitivity and specificity of both studies need further evaluation.

Experimental increase in brain HIPDM uptake by hypercapnia.

The 30-min brain uptake of [125I]HIPDM was measured in conscious rats--normocapnic (n = 8), hypercapnic (n = 12), and hyperoxic (n = 6). A mean 41.2% higher uptake was found in the brains of hypercapnic animals (p less than 0.01). In the three groups of rats, brain HIPDM uptake had a negative correlation with body weight (p less than 0.001) and a positive correlation with arterial pCO2 (p less than 0.01), when adjusted for body weight. These results indicate that HIPDM uptake with hypercapnia may be used as a provocative test to measure cerebral blood flow reserves.

Diuretic MAG3 scintirenography in children with HIV nephropathy: diffuse parenchymal dysfunction.

UNLABELLED: HIV nephropathy (HIVN) is prevalent in 15%-56% of HIV-infected children and induces mild to severe progressive nephropathy. METHODS: A total of 33 renal diuretic scintirenographic studies with 99mTc-mercaptoacetyltriglycine (MAG3) were reviewed and analyzed from 23 HIV pediatric patients, 21 of whom had HIVN with varying degrees of renal impairment. Results were compared with 10 studies of control patients of matching ages. Visual interpretation of images and renograms as well as semiquantitative analyses were performed. Variables compared were size of kidneys, time of peak and one-half peak activities, residual (or retained) cortical activity at 20 min, ratio of cortical activity at 2.5-20 min, and ratio of kidney activity to kidney plus background activity at 2 min. The results of MAG3 renal studies were also compared with laboratory data pertaining to creatinine clearance in all patients and with sonography in 17 patients. RESULTS: In most patients with HIVN (18/21), the kidneys were larger than normal, with a diffuse parenchymal dysfunction (decreased uptake, slow processing, and increased retention of activity) and flat renograms, findings similar to those observed in other diffuse parenchymal diseases. In all patients with HIVN, semiquantitative analysis (paired t test) showed statistically significant differences from control patients for all variables. On ANOVA, a statistically significant correlation was found between most scintigraphic parameters and the severity of renal impairment. Of the 17 concurrent sonographic studies in HIVN patients, 7 showed no abnormalities, whereas the results of scintigraphy were abnormal. CONCLUSION: Diuretic MAG3 scintirenography shows nonspecific diffuse parenchymal dysfunction in pediatric patients with HIVN. Such dysfunction may provide corroborative evidence of HIVN and should be recognized when the test is performed for standard indications. Further work is necessary to prove that the test has indeed the high sensitivity and good correlation with the seventy of HIVN suggested in this population; the test may be useful to follow up the progression of disease and the effect of treatment.