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Biomedical subjects

S M Gruenewald

Publications and source records attributed to S M Gruenewald.

At least 19 recordsLinked to original sources
PubMed2001

The incidence of left iliac fossa uptake of (99m)Tc-DTPA in renal scanning.

In rare cases, extrarenal uptake of technetium-99m diethylenetriamine penta-acetic acid ((99m)Tc-DTPA) has been reported, e.g. in tumours or abscesses. Although in our experience a relatively common occurrence, increased uptake in the left iliac fossa (LIF) and its incidence have not been described. This retrospective study set out to establish the incidence of this phenomenon and to exclude malignancy as the cause. All patients who had a renal (99m)Tc-DTPA scan between 1 January 1996 and 31 December 1997 had their scans reviewed. Presence and grade of increase in iliac fossa activity were determined by consensus agreement of three observers. The list of patients with increased uptake was cross-referenced against the New South Wales (Australia) Cancer Council database to exclude the possibility of a neoplastic lesion in this region. Increased LIF uptake was noted in 41 of the 231 (18%) consecutive patients (18 men, 23 women; mean age 43 years, range 20-83). Among these 41 patients, uptake was severe in 2 (5%), moderate in 12 (29%) and mild in 27 (66%). No patient had increased uptake in the right iliac fossa. Only one patient had a malignant lesion but this was excluded as being the cause of LIF uptake. No other patient developed malignancy (mean follow-up time 4.1 years; range 3.2-5.1). Increase in LIF uptake is a common, benign finding most likely due to activity within the descending colon. It occurs in approximately 18% of the population, and it is important to recognise such uptake in order to avoid misdiagnoses.

Adult↗
PubMed2001

Diagnosis of kidney transplant obstruction using Mag3 diuretic renography.

Kidney transplant obstruction (KTO) following renal transplantation remains an important reversible cause of allograft dysfunction, requiring prompt diagnosis to prevent long-term graft damage. Although ultrasound can accurately diagnose renal transplant hydronephrosis, it cannot be used to assess its functional significance. We prospectively assessed the utility of technetium-99m mercaptoacetyltriglycine (Tc99m MAG3) diuretic renography for the diagnosis of allograft KTO, using standard visual and quantitative parameters, as well as calculated renal output efficiency (OE), which has been postulated to improve diagnostic yield. From a cohort of 45 renal transplant patients, two subgroups were formed. The first group of transplant recipients (n = 21) with stable function and no obstruction was used to derive normal values for Tc99m MAG3 scans. A second group of transplant recipients with acute renal dysfunction in whom KTO was clinically suspected was used to test the diagnostic utility of these derived values (n = 43 scans). KTO was diagnosed independently of the MAG3 scans by a fall in the serum creatinine in response to renal pelvis urinary drainage. OE in 12 renal allografts with KTO was significantly reduced compared with 31 Tc99m MAG3 scans without KTO (59.6 +/- 18.9 vs. 81.6 +/- 5.4%, p < 0.001). In KTO, the mean time of isotope appearance in the bladder (time to bladder [TTB]) was extended compared with unobstructed allografts (7.9 +/- 4.1 vs. 3.6 +/- 1.5 min, p < 0.001). Measurement of OE significantly improved the accuracy of diuretic MAG3 renography in the diagnosis of renal allograft KTO, especially when supplemented by the TTB, parenchymal transit time and shape of the renogram curve. Ureteric obstruction of the kidney transplant can be diagnosed with an OE reduced to < 75% (sensitivity 92%, specificity 87%) and confirmed by isotope hold-up in the pelvicalyceal system. A normal or slowly declining renogram curve effectively excluded KTO (sensitivity of 96%, negative predictive value of 84%). A parenchymal transit time of > 5 min and a TTB of > 7 min both yielded a sensitvity of 92% and a specificity of 81%. In conclusion, MAG3 renography is a clinically useful investigation for the diagnosis of KTO.

Adult↗
PubMed1999

Mercaptoacetyltriglycine diuretic renography and output efficiency measurement in renal transplant patients.

Suspected urinary tract obstruction following renal transplantation presents a diagnostic dilemma. The purposes of this study were: (1) to establish a normal range of measurement of output efficiency (OE) in the renal transplant population, and (2) to assess prospectively the usefulness of OE in the setting of allograft obstruction. Twenty-two renal transplant patients with stable renal function and no evidence of hydronephrosis on serial ultrasound examination had a diuretic mercaptoacetyltriglycine scan with calculation of OE. Three renal transplant patients with confirmed graft obstruction were also studied. Standard qualitative and quantitative parameters as well as OE were calculated. The mean OE for the 22 normal renal transplant patients was 86.3%+/-3.7% (range: 77%-91%). OE values in the three obstructed patients were 59%, 68% and 75% respectively. It is concluded that OE should normally exceed 77% in renal graft recipients. OE is a promising means of diagnosing functional obstruction in these patients.

Adult↗
PubMed1999

Acute renal failure in critically ill patients: evaluation of an ultrasound contrast agent.

The purpose of the present paper was to evaluate an ultrasound contrast agent (Levovist) in patients with oliguric acute renal failure (ARF) in order to assess renal vascularity, differentiate acute tubular from cortical necrosis and predict prognosis. Ten intensive care unit (ICU) patients with oliguric ARF were prospectively investigated by ultrasound including colour, power and pulsed Doppler before and after injection of Levovist. Doppler signals were graded as absent, equivocal or present from the inner and outer portions of the renal parenchyma, and these findings were correlated with clinical parameters and outcome. Only one patient had findings in keeping with acute cortical necrosis. All patients who survived had parenchymal vascularity while only three of six (50%) who died had parenchymal vascularity after Levovist. The ultrasound contrast caused no side effects and additional information was provided which improved diagnostic confidence, enabled appropriate classification of patients as having tubular or cortical necrosis and therefore added prognostic information.

APACHE↗
PubMed1998

The role of the gallium scan in primary extranodal lymphoma.

UNLABELLED: The purpose of this study was to examine the factors influencing gallium scan positivity for patients with primary extranodal lymphoma and to examine the role of the gallium scan in staging the disease and assessing response to initial treatment. METHODS: Ninety-two patients with extranodal lymphoma who had a gallium scan were reviewed. The influences of tumor site, size, grade and the presence of clinically detectable disease after biopsy on the rate of gallium scan positivity were analyzed. The role of the gallium scan in staging and selecting treatment was assessed. Nineteen patients had a gallium scan to assess their response to treatment, and its predictive value was reviewed. RESULTS: The overall gallium scan positivity (sensitivity) rate was 70%. This rate was low in patients whose extranodal lymphoma occurred in skin, intestine and testis, or was low grade (0%-25%). When these patients were excluded, the rate rose to 88%. Gallium scan positivity was not related to the presence of clinically detectable disease after biopsy and there was insufficient data about tumor size to determine a relationship. The gallium scan increased the disease stage in six patients (7%) and changed the initial treatment in six patients (7%). The gallium scan became negative in 15 (79%) of those patients who had a gallium scan to assess their response to treatment. All but two of these patients remain alive with a median follow-up of 3.75 yr. CONCLUSION: The gallium scan was rarely positive for patients with skin, intestinal, testicular and low-grade lymphomas, but was otherwise comparable to lymphoma arising in lymph nodes. The result affected staging or treatment in seven patients (8%). After treatment, an initially-positive gallium scan usually became negative, a conversion associated with a favorable outcome.

Citrates↗
PubMed1997

Assessment of pediatric hydronephrosis using output efficiency.

UNLABELLED: Diagnosing obstruction in pediatric patients with hydronephrosis, and renal impairment is often difficult. Renal output efficiency (OE) is a parameter that may improve diagnostic accuracy by allowing normalization of washout according to renal function. The aims of this study were to define a normal range for OE in infants and children and to evaluate its diagnostic accuracy in cases with hydronephrosis. METHODS: Seventy-four children (91 hydronephrotic kidneys; median age, 4 mo; 22 girls and 52 boys) underwent 99mTc-labeled mercaptoacetyl-triglycine scintigraphy using intravenous volume expansion (15 ml/kg normal saline), furosemide diuresis and urethral catheterization, if vesicoureteric reflux was present. Images were interpreted by consensus of two or more experienced observers using visual assessment of the images, differential function and clearance half-time after furosemide (T(1/2)), as well as OE. The final diagnosis was based on surgical findings (n = 23 kidneys) or follow-up for >12 mo (n = 68). RESULTS: Final diagnosis in 22 of the 91 hydronephrotic kidneys was obstruction at the pelviureteric (n = 21) or vesicoureteric (n = 1) junction and no obstruction in the remaining 69. The overall diagnostic accuracy of OE was 89%. Using exhaustive search multivariate logistic regression analysis, only reduced OE (p < 0.001) and decreased renal uptake by visual assessment (p = 0.058) were independently predictive of obstruction (R2 = 0.726). In dilated but unobstructed kidneys, mean OE was 93% +/- 7.1%. In the normal kidneys, mean OE was 96% +/- 3.1%. CONCLUSION: OE improves the diagnostic accuracy of diuretic renography in children and neonates with hydronephrosis and suspected obstruction. Output efficiency should exceed 89% in normal kidneys and 79% in unobstructed, hydronephrotic kidneys.

Adolescent↗
PubMed1995

Predicting glomerular filtration rate after kidney transplantation.

Serum creatinine is an important clinical measure of impairment of glomerular filtration rate (GFR) after kidney transplantation. The use of formulas that predict GFR (such as the Cockcroft-Gault) derived from patients with chronic renal failure and standardized against measured creatinine clearance may not be accurate when applied to kidney transplant recipients. The purpose of this study, was to investigate the level of inaccuracy and its causes and then to derive predictive GFR formulas that are appropriate to renal transplantation. Determinants of isotopic GFR, serum creatinine, and muscle mass were evaluated in consecutive kidney recipients (n = 146) using 99mTc DTPA GFR (n = 751) as a reference method. Factors that predicted GFR apart from serum creatinine included sex, height, body weight, serum urea, years on dialysis, numbers of rejections and infective episodes, and prednisolone dose. The relationship between serum creatinine and GFR was highly variable and dependent on factors that alter muscle mass and muscle catabolic rate. The relationship was further altered by ATN and chronic rejection when tubular secretion of creatinine was reduced. Three alternative GFR formulas (which can be applied to renal transplant patients according to the availability of clinical parameters) were derived and tested against six published methods of GFR estimation. Our derived formulas had the highest correlation, no overall bias, least scatter of sum of squares, and least error at low levels of GFR. They represent a better estimation of GFR in kidney transplantation than published formulas, and would allow a standardized approach to the study of long-term renal dysfunction.

Adult↗
PubMed1995

Ultrasound screening of families with abdominal aortic aneurysm.

Recent observations suggest that first degree relatives of patients with an abdominal aortic aneurysm (AAA) are also at risk for the development of this disorder. The first degree relatives of 130 adults with known AAA were invited to attend for an ultrasound examination. Fifty-two eligible relatives (mean age 53 years, range 41-73) from 38 families underwent sonographic screening. Using standard ultrasound criteria no participants were identified with an asymptomatic AAA. Thus, ultrasound of families of patients with AAA has a low yield and may not be useful for screening purposes.

Adult↗
PubMed1995

Adenosine thallium-201 scans in patients undergoing elective non-cardiac surgery.

Dipyridamole Thallium-201 (201Tl) scintigraphy has been used widely for assessment of patients prior to vascular surgery. Recently, Adenosine has been reported to be a safe and useful alternative to Dipyridamole. The purposes of this study were to evaluate the safety and feasibility of the use of Adenosine, to evaluate the correlation of Adenosine 201Tl scans with coronary angiograms (when available) and to evaluate the effect of scan results on clinician management style. Fifty adults with abdominal aortic aneurysm or other vascular disease underwent an intravenous infusion of Adenosine in conjunction with initial and delayed planar 201Tl scans. Images were interpreted qualitatively and quantitatively by the consensus of two or more experienced observers with patients showing transient left ventricular dilatation or redistribution in one or more myocardial segments reported as being at high risk of peri-operative cardiac events. Of the 50 subjects studied, 49 tolerated the maximum infusion dose with 60% experiencing minor transient symptoms. Low (n = 30) and high risk (n = 20) patients were defined according to Adenosine 201Tl scans. Age, gender and clinical characteristics were similar in both groups. Thirteen (65%) high risk subjects had coronary angiography compared with only three (10%) low risk patients. Patients with high-risk 201Tl scans were also more likely to proceed to coronary revascularization prior to non-cardiac surgery [5/20 (25%) vs 1/30 (3%)]. The positive predictive value of high risk 201Tl scans for coronary artery disease was 85%. Thus, Adenosine is considered a useful and safe alternative to Dipyridamole.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1994

Postnatal diagnosis and outcome of urinary tract abnormalities detected by antenatal ultrasound.

OBJECTIVES: To determine the incidence of urinary tract abnormalities detected by antenatal ultrasound; the value of fetal renal measurements in predicting significant uropathy; and the nature and clinical outcome of fetal uropathy. DESIGN AND SETTING: A retrospective analysis of babies with urinary tract abnormalities detected before birth who were born at or referred to a teaching hospital. PATIENTS: One hundred and twenty-five babies born between June 1989 and November 1992. Sixty-nine babies were born at Westmead hospital and 56 were born elsewhere and referred to Westmead Hospital for investigation. RESULTS: The incidence of uropathy detected before birth among babies born at the teaching hospital was 5.1 per 1000 births. In 60% of these babies, significant abnormalities were confirmed after birth (3.1 per 1000 births). We found a significance of 71% and a specificity of 89% for fetal measurements in predicting significant uropathy. Among all 125 babies the most common abnormalities were pelviureteric junction (PUJ) anomalies (34%), minimal hydronephrosis (26%), ureteric reflux (18%) and multicystic kidney (7%). Pyeloplasty has been performed in 23 (46%) of the 52 kidneys with PUJ anomalies. Renal parenchymal abnormality was detected in four of 22 kidneys with ureteric reflux (18%). Of these four, all were exposed to Grade IV or V ureteric reflux but none had been infected. CONCLUSIONS: Antenatal ultrasound is a sensitive, though nonspecific, tool for the non-invasive identification of congenital abnormalities of the urinary tract, which are common and frequently asymptomatic after birth. Although ureteric reflux may not be predicted from renal measurements, the degree of fetal hydronephrosis indicates the likelihood of obstructive abnormality and, thus, the extent of postnatal investigation required.

Female↗
PubMed1994

Tibial insufficiency fractures in adult renal transplant recipients.

Osteonecrosis and osteopenia are widely recognized skeletal complications of therapy in recipients of renal transplants. These conditions are often complicated by fractures, usually in the femora, pelvis or vertebrae. The authors describe two sedentary adult allograft recipients who presented with leg pain and in whom bone scintigraphy, serial radiographs, and clinical progress were suggestive of insufficiency fractures of the tibiae. Although seldom reported, insufficiency fractures should be considered in the differential diagnosis of renal allograft recipients with leg pain.

Diagnosis, Differential↗
PubMed1994

Technetium-99m DTPA renography and angiography in renal artery stenosis of varying severity.

Thirty-five hypertensive patients, consecutively studied between 1986 and 1991, were retrospectively reviewed, to compare Technetium-99m (99mTc) DTPA renal scanning for renal artery stenosis with angiography. Ten patients were on chronic angiotensin converting enzyme (ACE) inhibitor medication and 20 underwent angioplasty of their stenoses. In patients not on ACE inhibitors the renal scan specificity was 83%, sensitivity 82%, negative predictive value 89% and positive predictive value 74%. In the 10 patients on ACE inhibitors the specificity was 67% (relatively more stenoses of < 50% were reported in this group), sensitivity 100%, negative predictive value 100% and positive predictive value 60%. Low levels of function (< 10 mL/min/1.73m2) in 9 kidneys did not militate against diagnoses that correlated well with angiography. Hence, renal scanning, particularly with ACE inhibition, is efficacious in the evaluation of possible renal artery stenosis. With a mean follow-up period of 29 months after percutaneous transluminal angioplasty (PTA), four patients had clinical improvement of hypertension control. Each had pre-PTA total glomerular filtration rates (GFR) of approximately 75 mL/min/1.73m2. No improvement was detected in cases with pre-PTA total GFR of < 50 mL/min/1.73m2. This may be the level of renal function below which PTA therapy or surgery will not provide benefit.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

The role of high dose 67-gallium scintigraphy in staging untreated patients with lymphoma.

BACKGROUND: Gallium-67 (67Ga) scintigraphy has been reported to be of limited value in staging lymphoma patients. However, recent technical advances in radionuclide imaging have potentially enhanced the usefulness of this method. AIMS: The purposes of this study were to determine the current: (1) sensitivity and specificity and (2) impact on clinicians' treatment decisions of 67Ga scans performed at a teaching hospital. METHODS: There were 46 newly presenting patients with lymphoma (13 with Hodgkin's disease (HD) and 33 with non-Hodgkin's lymphoma [NHL]). Planar 67Ga scans were performed up to eight days following injection of 300 MBq (8 mCi) with images interpreted by consensus of two blinded observers; sensitivity and specificity were determined on a lesion by lesion basis in comparison to computed tomography (CT) scans, palpation of peripheral lymph nodes and abdominal lymphangiograms (n = 5). The contribution of 67Ga scans to clinicians' treatment decisions was also independently assessed by an experienced oncologist. RESULTS: Gallium-67 scan sensitivity and specificity were 80% and 96% for HD and 59% and 98% for NHL. Initial treatment plans were modified in three individuals (7%; 95% confidence intervals = 3-10%) due to lesions on the 67Ga scan not prospectively detected or considered equivocal on other tests. CONCLUSIONS: Only a small proportion of newly diagnosed lymphoma patients benefit from staging with state of the art planar high dose 67Ga imaging.

Adult↗
PubMed1994

Neonatal subependymal cysts detected by sonography: prevalence, sonographic findings, and clinical significance.

OBJECTIVE: Cranial sonography in neonates occasionally shows subependymal cysts. These cysts may be due to a variety of pathologic disorders, but they also occur as an "isolated" condition without an obvious cause in some patients. Assessment of the clinical significance of these lesions has been difficult because of the limited duration of follow-up, the informal nature of neurodevelopmental evaluation, and the heterogeneous cohort of patients previously reported. Accordingly, the purposes of this study were to provide more complete and longer neurodevelopmental followup and to describe the prevalence and sonographic characteristics of isolated subependymal cysts detected on cranial sonograms in neonates. MATERIALS AND METHODS: In a 4 1/2-year period, more than 4000 cranial sonograms were obtained at our institution. We retrospectively determined that 17 neonates (59 studies) had sonographic evidence of an isolated subependymal cyst. A high-resolution real-time mechanical sector transducer was used to obtain the sonograms. No subjects had clinical or sonographic evidence of intercurrent hemorrhage, infarct, infection, or congenital abnormalities. Neurodevelopmental outcome was independently determined. In particular, premature infants who weighed less than 1500 g at birth were longitudinally assessed by a multidisciplinary developmental team. A general quotient was derived in nine subjects by using the Griffith Mental Developmental Scales. RESULTS: Subependymal cysts were often tear shaped, 2-11 mm in size, and located either at the caudothalamic groove or along the anterior aspect of the caudate nucleus. Most subjects (n = 15) who had the cysts were born prematurely (mean gestational age, 31 weeks; range, 25-34 weeks). Results of follow-up were available in 14 infants 2-41 months old (mean, 22 months; median, 21 months). Development was considered to be normal in 13 of the 14 subjects; one term infant referred because of mild dysmorphic features had a mild global delay. The general quotient for corrected age, determined in nine subjects, had a mean of 111 (range, 103-120; normal, > 83). Fifteen neonates had at least two cranial sonographic examinations. In seven patients, serial examinations showed that cysts had resolved or diminished in size (on average 23 weeks after the initial sonographic study). In the other eight, no change in the size of the cyst was observed, but the mean interval between the first and last sonograms was only 14 days. CONCLUSION: Cranial sonograms of neonates occasionally show isolated subependymal cysts, usually in premature infants. In most cases, no serious neurodevelopmental complications occur. Many cysts resolve after a variable period.

Brain Diseases↗
PubMed1994

How useful is ultrasonography in suspected acute osteomyelitis?

Sonographically detected subperiosteal fluid and periosteal irregularity have recently been proposed as diagnostic features of osteomyelitis. The purpose of this study was to determine the diagnostic accuracy of ultrasonography for suspected osteomyelitis. Nineteen patients were investigated prospectively with high-resolution ultrasonography for the presence of subperiosteal fluid or cortical irregularity. Diagnosis was established by surgery (three cases) or by results of other tests and clinical follow-up. Sixteen patients were diagnosed as having osteomyelitis, with positive ultrasonography in ten (sensitivity = 63%). Two ultrasonographic studies were false-positive; diagnostic accuracy was 58%. Thus, ultrasonographic results may be potentially misleading, emphasizing the importance of clinical judgment and results of other tests.

Adult↗
PubMed1993

The significance of isolated gallium-67 uptake in the hilar lymph nodes of an untreated lymphoma patient.

A 69-year-old woman presented with non-Hodgkin's lymphoma of the right ilioinguinal region in whom bilateral uptake of Ga-67 in hilar lymph nodes was noted on thoracic SPECT. There were no Ga-67 abnormalities elsewhere within the thorax, and a chest CT scan was also normal. The patient received radiotherapy to the inguinal region and remained in clinical remission for 28 months following treatment. She subsequently relapsed at a number of peripheral lymph node sites, but not in the chest. The authors postulate that isolated hilar uptake of Ga-67 SPECT may not be clinically significant in some untreated patients with lymphoma. This scintigraphic finding should be interpreted cautiously, particularly when other chest imaging studies remain negative.

Aged↗