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Biomedical subjects

T M Maling

Publications and source records attributed to T M Maling.

At least 19 recordsLinked to original sources

Computed tomography versus intravenous urography in diagnosis of acute flank pain from urolithiasis: a randomized study comparing imaging costs and radiation dose.

The equivalent sensitivity of non-contrast computed tomography (NCCT) and intravenous urography (IVU) in the diagnosis of suspected ureteric colic has been established. Approximately 50% of patients with suspected ureteric colic do not have a nephro-urological cause for pain. Because many such patients require further imaging studies, NCCT may obviate the need for these studies and, in so doing, be more cost effective and involve less overall radiation exposure. The present study compares the total imaging cost and radiation dose of NCCT versus IVU in the diagnosis of acute flank pain. Two hundred and twenty-four patients (157 men; mean age 45 years; age range 19-79 years) with suspected renal colic were randomized either to NCCT or IVU. The number of additional diagnostic imaging studies, cost (IVU A$136; CTU A$173), radiation exposure and imaging times were compared. Of 119 (53%) patients with renal obstruction, 105 had no nephro-urological causes of pain. For 21 (20%) of these patients an alternative diagnosis was made at the initial imaging, 10 of which were significant. Of 118 IVU patients, 28 (24%) required 32 additional imaging tests to reach a diagnosis, whereas seven of 106 (6%) NCCT patients required seven additional imaging studies. The average total diagnostic imaging cost for the NCCT group was A$181.94 and A$175.46 for the IVU group (P < 0.43). Mean radiation dose to diagnosis was 5.00 mSv (NCCT) versus 3.50 mSv (IVU) (P < 0.001). Mean imaging time was 30 min (NCCT) versus 75 min (IVU) (P < 0.001). Diagnostic imaging costs were remarkably similar. Although NCCT involves a higher radiation dose than IVU, its advantages of faster diagnosis, the avoidance of additional diagnostic imaging tests and its ability to diagnose other causes makes it the study of choice for acute flank pain at Christchurch Hospital.

Adult↗

Vesicoureteric reflux in the newborn: relationship to fetal renal pelvic diameter.

There has been a low yield of primary vesicoureteric reflux (VUR) from screening the fetal urinary tract during obstetric sonography. We sought to determine whether changing the cut-off level of fetal renal pelvic diameter from 10 mm to 4 mm would improve the yield of VUR. In a prospective community-based study, a fetal renal pelvic diameter of 4 mm or more on a transverse view of the fetal renal hilum at obstetric sonography after 16 weeks' gestation was found in 426 fetuses from 9,800 consecutive pregnancies. After birth, renal sonography was performed on 386 of the 426 babies. Of the 386 babies, 264 (187 boys) had a voiding cystourethrogram (VCUG) at a mean age of 9 weeks. Primary VUR was detected in 33 (16 boys) of the 264 infants (13%), and secondary VUR in another 5 (2%). Only 5 of the 33 (15%) babies with primary VUR would have been detected if a cut-off point of 10 mm for fetal renal pelvic diameter had been used. The prevalence of reflux was similar at each cut-off level of antenatal renal pelvic diameter from 4 to 10 mm. Neither calyceal nor ureteric dilatation was helpful in differentiating those with from those without VUR. The postnatal renal sonogram did not distinguish whether reflux was present or not. More infants with primary VUR, particularly girls, were found by changing the cut-off point for fetal renal pelvic diameter from 10 mm to 4 mm, and performing a VCUG on all such infants even if the postnatal renal sonogram was normal. Of the 33 infants with primary VUR, 9 (27%, 5 boys) had an abnormal dimercaptosuccinic acid scan. Our findings support the screening of the obstetric population for a fetal renal pelvic diameter of 4 mm or more, and then investigating the infants for VUR after birth.

Female↗

DMSA renal scans in adults with acute pyelonephritis.

The 99mTc-DMSA scan is accepted as the most sensitive imaging modality for detecting areas of renal parenchymal scarring. More recently the DMSA scan has also been shown to be of value in imaging areas of renal parenchymal involvement in both children and adults with acute pyelonephritis. We assessed the acute DMSA scan findings in a consecutive series of 81 patients hospitalized with acute pyelonephritis. Acute pyelonephritis was diagnosed if the patient had a fever of > 37.8 degrees C, loin pain or tenderness and infected urine (99% Escherichia coli). Patients had a blood culture taken (8 positive), as well as a hematological (leukocytosis 75%) and biochemical screen, C-reactive protein (CRP) (increased in 57 of 66 [86%]) and urinary tract ultrasonography. If the initial DMSA scan was abnormal it was repeated after three months and in some instances again at six months. If persisting defects were noted an intravenous urogram was then undertaken. Of the 81 patients, 37 (46%) had an abnormality on the DMSA scan. Nineteen had a single defect, 12 multifocal defects, five features suggestive of pre-existing renal parenchymal scarring (all later shown to have reflux nephropathy) and one a shrunken kidney. Those patients with an abnormal scan had a higher CRP concentration than those with a normal scan. Of the 31 patients who had either a focal or multifocal defect on their initial DMSA scan there was adequate follow-up on 24 patients. In 18 of these the defects had resolved by six months (usually within three months), while of the remainder, three were shown to have reflux nephropathy, one had a large single renal cyst and another an area of parenchymal calcification. Fifty-three of 76 patients (70%) had normal ultrasonography. In adults with acute pyelonephritis, the DMSA scan may prove to be the most useful renal imaging procedure.

Acute Disease↗

A comparison of different doses of non-ionic contrast media in i.v. urography.

This study attempts to find out what is the appropriate dose of non-ionic contrast media to provide an acceptable study at the lowest possible cost. 139 adults with normal renal function were studied. Four different dose regimes were employed and a standardised set of I.V.U. films were obtained. These were reviewed by two independent assessors who were unaware of the dose regime used. Each I.V.U. was scored on a modified Fry regime. This survey showed a clear relationship between quality and dosage.

Body Weight↗

A protocol for the investigation of infants and children with urinary tract infection.

An investigation protocol, designed to reduce invasive procedures to a minimum, is described for the detection of reflux nephropathy in infants and children. Intravenous urography and voiding cysto-urethrography is necessary in patients up to the age of 2 years presenting with urinary tract infection, but in children over 2 years of age the protocol limits the investigation to an intravenous urogram unless this is abnormal. A review of this policy after 5 years has indicated that it is appropriate provided that children who continue to have infections have further evaluation including a voiding cysto-urethrogram.

Child↗

Radiological abnormalities in infants with urinary tract infections.

An intravenous urogram and micturating cystourethrogram were carried out in 100 infants presenting with documented urinary tract infections. Ninety three cases were identified by suprapubic aspiration and 7 by culture of two voided urine samples containing greater than 100 X 10(6) organisms per litre. The urinary tract abnormalities were analysed in respect of their clinical importance, patient's age, sex, and prematurity (in the 10 preterm infants). Radiological abnormalities were found in 47% of the infants (40% of boys; 63% of girls). Twenty nine per cent of the infants had a urinary tract abnormality regarded as clinically important--namely grade 3 or 4 vesicoureteric reflux, reflux nephropathy, or obstructive lesions requiring surgery. Six of the 10 preterm infants had radiological abnormalities. Spontaneous resolution or improvement occurred within 6 months of birth in three of the four preterm infants with severe vesicoureteric reflux.

Female↗

Percutaneous transluminal angioplasty: successful cure of malignant hypertension.

The technique of percutaneous transluminal angioplasty has been shown to be an alternative to vascular surgery in some cases of renovascular hypertension. A 40-year-old woman presented with malignant hypertension on the basis of fibromuscular hyperplasia involving her dominant right renal artery. The stenosis was successfully dilated and her blood pressure returned to normal.

Adult↗

A renal lesion in a woman with Reiter's disease.

A 17 year old girl with Reiter's disease had extensive involvement of the entire urinary tract in addition to arthritis, vaginitis, and ocular involvement. In addition to a severe urethritis, cystitis and ureteritis there was evidence of glomerular and tubular dysfunction and abnormalities were seen on renal biopsy. The patient was treated with a five week course of doxycycline and made a slow but complete recovery.

Adolescent↗

Urinary tract obstruction and renal failure due to uterine prolapse.

Three women are described in whom obstructive uropathy was found secondary to uterine prolapse. Two of these patients had severe renal failure. It is important to exclude this condition in any woman presenting with renal functional impairment. Potentially damaging urinary tract obstruction should be considered in every patient with a uterine prolapse.

Female↗

Renal vein renin concentration in the hypertension of unilateral reflux nephropathy.

Hypertension is a frequent complication of reflux nephropathy. The cause of this hypertension is unknown. Our study was undertaken to assess the possible role of the renin-angiotensin system in the hypertension associated with unilateral reflux nephropathy. We selected for study 17 normotensive and 12 hypertensive patients with strictly unilateral reflux nephropathy. There were 3 normotensive and 2 hypertensive patients with a renal vein renin ratio exceeding 1.5. Of these 3 normotensive patients 1 had evidence from divided renal function studies to suggest functional renal ischemia. No consistent evidence was obtained to support the concept that the renin-angiotensin system has a primary role in the non-malignant hypertension of unilateral reflux nephropathy.

Angiotensin II↗

Diagnosis of gross vesico-ureteric reflux using ultrasonography.

A simple non-invasive ultrasonic technique which identifies gross vesico-ureteric reflux (VUR) in adults is described. It is based on the time position (TP)-mode (or M-mode) of ultrasound imaging. This method warrants assessment as a possible screening procedure for gross VUR in newborn children.

Dilatation, Pathologic↗

Renal trauma and persistent hypertension.

A study has been made to assess the incidence of hypertension in patients who have suffered an episode of renal trauma sufficiently severe to cause haematuria. Sixty-three patients were studied and 63 age- and sex-matched controls were also studied. At follow-up, 6-138 months after injury, 13 of the patients who had suffered renal trauma and 12 of the control subjects had a diastolic blood pressure above 99 mm Hg. Three patients showed significant reduction in the size and volume of the previously damaged kidney. In this group, renal trauma did not appear to be associated with an increased risk of permanent hypertension.

Acute Disease↗

The pathogenesis of reflux nephropathy (chronic atrophic pyelonephritis).

The relationship between vesico-ureteric reflux and coarse renal scarring (atrophic pyelonephritis) has been studied in swine. Scars were observed to develop where reflux took place into the kidney substance via the renal papillae (intrarenal reflux). They were confined to these regions and were similar in size, distribution and other features peculiar to those found in the human from early childhood onwards. Intrarenal reflux was found to be related to the pressure within the urinary tract as well as to vesico-ureteric reflux. Infection was not an essential factor in scar-formation, but it appeared to intensify the scarring process. The histological findings were a progressive focal interstitial fibrosis confined to the zones of intrarenal reflux, extending from the capsule to the papillary tip, and varying in severity with pressure, time and the extent of intrarenal reflux. Nephron and tubular damage accompanied all grades of fibrosis, with the possible exception of the earliest. In many respects the histological changes closely resemble those due to obstruction, except they are focal in distribution. Added features are the early peripheral lymphocytic aggregations and interstitial fibrosis which appear to suggest that some "irritant"--possibly urine--reaches the interstitium and drains away via the lymphatic system. Many of the phenomena observed were strikingly similar to those present in children with the more severe grades of vesico-ureteric reflux. In some cases a mixture of generalized obstructive nephropathy and focal scarring developed; in others focal scarring took place with normal papillae elsewhere. The results are readily reproducible. The basic questions as to whether it is bladder pressure, or infection, or a mixture of the two which is responsible for scar-formation are discussed.

Adult↗