Renal duplication artifact in US imaging

To determine the appearance of artifactual renal duplication in ultrasound (US) imaging, the authors analyzed 22 examples of such duplication in 20 patients. The artifact appeared as a duplication of the collecting system in 18, as a suprarenal mass in three, and as upper-pole cortical thickening in one. It occurred in the left kidney in 15 patients, in the right kidney in three, and bilaterally in two. To determine the frequency of the artifact, 50 additional patients were scanned. It was identified in eight of these patients. Imaging characteristics and the results of in vitro modeling proved the artifact was due to sound beam refraction between the lower pole of the spleen or liver and adjacent fat. This artifact is much more common in the left kidney and occurs more frequently in obese patients. Knowledge of the appearance and cause of this artifact should help radiologists avoid diagnostic errors.     

Variable kidney position mimicking renal artery branch stenosis in a Tc-99m-DTPA captopril scintigraphy

Tc-99m-DTPA captopril scintigraphy was performed in a patient with suspected renovascular hypertension. Markedly impaired right renal function (Glomerular filtration rate (GFR) values for the right kidney = 14 ml/min, left kidney = 79 ml/min) was detected in the initial captopril study. Only lower pole activity of the right kidney was observed during the whole study. Since prior ultrasonographic examinations have shown bilateral normal kidney parenchyma, branch stenosis of the right upper pole was suspected. Besides significant function improvement in the following baseline study (GFR values for the right kidney = 59 ml/min, left kidney = 79 ml/min), the right kidney, this time normally shaped, was visibly higher positioned. Because of the possibility of mobile kidney and/or branch stenosis, the patient underwent selective renal angiography. A long pediculed right kidney without renal artery stenosis was found. The final diagnosis was essential hypertension. Kidney position anomalies could influence the reliability of the captopril scintigraphy, particularly when a theoretical kidney depth formula is employed for the attenuation correction.     

Renal duplication with associated complications in adults: CT findings in 26 cases

AIM: To review the computed tomography (CT) findings in 26 adult patients with complicated renal duplication, and to assess whether the complications were anomaly-related or superimposed by acquired disease. MATERIALS AND METHODS: Fifteen women and 11 men, aged 17-83 years took part in the study. All CT studies were reviewed to define the moieties affected. RESULTS: The duplication was unilateral in 18 cases and bilateral in six, one patient had a single left kidney and the remaining one a horseshoe kidney. In 14 patients the pathology was related only to the anomaly. Upper pole abnormalities were seen in 13 patients (seven related to the anomaly) and lower pole abnormalities in five (all related to duplication). Both systems were affected in eight cases, six of them by pathological processes unrelated to duplication. Hydronephrosis of the affected collecting system was the most common imaging finding. CONCLUSION: Computed tomography is often used to evaluate abdominal conditions in adults and may therefore be the first imaging modality to reveal a duplex kidney complicated by a pathological process. Involvement of only one moiety was frequently related to the duplication, with a predilection for the upper moiety, while involvement of both systems was used unrelated to the duplication. Zissin, R. (2001). Clinical Radiology, 56, 58-63.     

Use of liposoluble contrast material to separate left renal and splenic parenchyma on computed tomography

A lobulated or accessory spleen lying against the upper pole of the left kidney may simulate renal tumor on computed tomograms. Water soluble contrast material is usually of little help in the differential diagnosis, since it increases the attenuation of both the kidney and the spleen. Intravenous liposoluble contrast material preferentially increases the attenuation of the liver and spleen and thus permits clear separation of the enhanced lobulated or accessory spleen from the unopacified renal parenchyma.     

Serendipitous finding of transitional cell carcinoma of the kidney on bone and gallium imaging

A 50-year-old woman presented with low back pain. Bone scintigraphy showed a focus of increased activity in the upper pole of the left kidney. Subsequent Ga-67 citrate scintigraphy demonstrated this same abnormal focus as a region of increased activity. Ultrasonography showed a renal mass in the upper pole of the left kidney. At surgery a transitional cell carcinoma of the upper pole of the left kidney was found.     

The junctional parenchymal defect: a sonographic variant of renal anatomy

A triangular echogenic area in the upper pole renal parenchyma can be identified at times during routine sonography of the right kidney. Thirty such cases are presented. Occasionally similar echogenic defects in the parenchyma can be seen posteriorly in the lower pole and in the left kidney. These defects in the parenchyma result from normal extensions of the renal sinus of kidneys that have a distinct division of their upper and lower poles. This is due to partial fusion of two embryonic parenchymatous masses called renunculi. The defects in the parenchyma occur at the junction of the renunculi; hence we have termed them junctional parenchymal defects. In order to differentiate them from pathologic conditions, one must identify their characteristic location and demonstrate continuity with the renal sinus.     

Pseudotumor of the left epigastrium

The authors describe the case of a patient with an accessory spleen located between the spleen and upper pole of the left kidney. A repeated sonographic examination suggested a suspicion for a kidney tumour, shape anomaly of the spleen, accessory spleen or kidney, but did not exclude even benign tumour in retroperitoneum. Computer tomography proved a formation between the upper pole of the kidney and the spleen, whose density characteristic after a rapid intravenous injection of 60% Verografin at the amount of 1 ml per kg body weight was the same as that of the spleen. Only angiographic examination revealed that the case is an accessory spleen and not a tumour.     

Assessment of renal function following irradiation of the intact spleen for Hodgkin disease.

Twenty-three patients with clinical Stage IA-IIIB Hodgkin disease underwent extended-field radiotherapy, including the intact spleen. In 17 of those patients, there was little evidence of renal dysfunction resulting from partial irradiation of the left kidney, which is inherent in such treatment. While isotopic images revealed an anatomic defect in the upper pole of the left kidney in one-third of the patients, dynamic studies showed that this anatomic alteration was not accompanied by any demonstrable dysfunction. Consistently normal serum BUN and creatinine levels in all patients tended to affirm that conclusion.     

An early rim sign in neonatal adrenal hemorrhage.

Neonatal adrenal hemorrhage can usually be diagnosed on excretory urography without resorting to surgical exploration or invasive diagnostic procedures. In the typical case an avascular mass is seen between the liver and kidney. A case is presented in which a vascular rim surrounded the avascular mass, giving an appearance similar to that of an obstructed upper pole renal duplication. This early vascular rim, not as well known as the calcified rim which develops days to weeks after the acute hemorrhage, is probably created by compression and displacement of adrenal tissue by the central hemorrhage.     

成人正常肾脏体素内不相干运动扩散加权成像

目的：定量分析成人正常肾脏体素内不相干运动扩散加权成像(IVIM-DWI)参数特征,评估不同部位、性别和年龄对IVIM-DWI 参数的影响。方法招募30例健康成人志愿者行肾脏 IVIM-DWI 检查,2名影像医师分别测量双肾上极、中部和下极肾实质的 D 值、D?值和 f 值。结果成人正常肾脏中部的 D 值、D?值和 f 值分别为(1.61±0.16)×10-3 mm2/s、(17.45±3.78)×10-3 mm2/s和(26.88±5.19)%。右肾的 D 值高于左肾(P <0.05)。男性志愿者肾脏的 f 值高于女性(t=3.321,P =0.001)。正常肾脏>50岁组的 D 值低于≤50岁组(t=3.548,P =0.001),年龄和 D 值呈负相关(r =-0.406)。2位观察者测量的 D 值、D?值和 f 值的组内相关系数分别为0.881,0.56和0.741,肾脏中部 IVIM-DWI 各参数的一致性高于肾脏上极和下极。结论成人正常肾脏 IVIM-DWI 参数受不同部位、性别和年龄的影响。     

The "two-tone" testis: spectrum of ultrasound appearances

AIM: To determine the prevalence and variation in appearance of the "two-tone" testes artefact. METHODS AND MATERIALS: Patients attending for a testicular ultrasound, without an intra-testicular lesion, were included. A single operator performed examinations using a 15L8w linear array transducer. When an artefact resembling the "two-tone" testes appearance was seen, the images were recorded prospectively. Two independent observers reviewed the images and identified patterns of the two-tone testis as: partial posterior shadowing from an incompletely identified trans-testicular artery; partial posterior shadowing from a completely identified trans-testicular artery; total posterior shadowing from a completely identified trans-testicular artery. RESULTS: Over a 44-month period 1038 patients were examined. The median age of patients was 32.5 years (range 19-46 years). A total of 17 two-tone testes artefacts of varying appearances were identified in 16 patients, occurring in 1.6% of the selected population. There were six partial posterior shadowing from an incompletely identified trans-testicular artery (0.6%); five partial posterior shadowing from a completely identified trans-testicular artery (0.5%); and five total posterior shadowing from a completely identified trans-testicular artery (0.5%) artefacts present. There was no relationship between the two-tone artefact and clinical symptoms or other ultrasound findings. CONCLUSION: The two-tone testis artefact is a rare finding and has a variable appearance according to the extent of acoustic shadowing produced. Careful examination of the testis and operator experience is required when the artefact is identified in order that underlying pathological disease is not overlooked.     

The unsuspected double collecting system on imaging studies and at cystoscopy

Five children (three girls and two boys) who had a duplex collecting system with an ectopic ureter or a ureterocele that was not detected with either imaging or cystoscopy were seen during a 10-year period. Four had urinary tract infection. The fifth was noted to have hydronephrosis when CT scanning of the abdomen was done for trauma. In each case, voiding cystourethrography showed reflux into what was thought to be a single (nonduplex) collecting system, but was found during surgery to be the lower pole of a duplex system. Excretory urography in four patients, sonography in two, and CT scanning in one did not show signs of duplication on the affected side. In each case cystoscopy failed to show a duplex system on the affected side. The diagnosis of duplication of the collecting system with ectopic ureter or ureterocele was made in each case only when the bladder was opened to reimplant the ureter. Direct opacification of the previously unsuspected upper pole ureter in each case showed it to be bind-ending and terminating at the level of the kidney. Radiologists and surgeons should be aware that duplex systems may not always be visible on urography and sonography.     

The retrorenal spleen. Implications for percutaneous left renal invasive procedures

An uncommon but potentially disastrous situation for invasive percutaneous renal procedures is the presence of the spleen behind the upper left kidney. We have termed this anatomic variant "retrorenal spleen." In a computed tomographic (CT) review of 73 patients aged 16 to 86, we found a frequency of retrorenal spleen of 21.1% in the supine and 15.4% in the prone patient. In most individuals with this variant, the spleen was behind the lateral fifth and the superior fourth of the left kidney. The majority (80.0%) of these patients were age 50 or over. However, in only 7.6% would the posterior splenic position pose a risk to posterolateral percutaneous approaches of less than 30 degrees into the upper left collecting system. No patient had retrorenal spleen at the mid-hilar level in either the supine or prone position. Posterolateral approaches up to 40 degrees into the renal hilus are 100% safe from intervening spleen.     

The diagnostic relevance of colour Doppler artefacts in carotid artery examinations

PURPOSE: Physical and technical artefacts of the colour Doppler method are examined with regard to their diagnostic relevance for the carotid artery. MATERIALS AND METHODS: After recording all diagnostic problems arising from physical and technical artefacts in 30,000 consecutively carotid arteries, the quantitative significance of relevant artefacts was determined in minor subgroups of the collective. RESULTS: Acoustic shadowing causes diagnostic problems in morphological and haemodynamic evaluation of stenoses. Mirror image artefacts simulate flow in cases of actual vessel occlusion or mimic vessel wall ulceration in carotid plaques and stenoses. Insonation angle artefacts inhibit detection of flow or mimic flow reversal. Problems of spatial resolution lead to incorrect demonstration of the vessel lumen in stenotic findings. Aliasing, perivascular colour artefacts, and ghosting do not cause any diagnostic problems. Relevant shadowing artefacts occurred in 14.7%, and relevant mirror image artefacts in 2.5% of the pathological cases. Insonation angle artefacts occurred in 17.3% of the cases (when using standard apparatus setting). However, with an exact knowledge of the artefact phenomena, insonation angle artefacts could be eliminated and mirror image artefacts were recognized in all cases. Resolution artefacts resulted in underestimation of carotid stenoses by on average 13.3% of the degree of stenosis. CONCLUSION: In principle, four artefact phenomena give rise to diagnostic problems; however, with a good knowledge of the phenomena, only artefacts due to acoustic shadowing and limited spatial resolution are of diagnostic significance.     

Etiology, clinical manifestations and prognosis of radiation nephritis

If the irradiation field of a megavoltage therapy extends over one kidney or a part of it, blood pressure reactions suggest in some cases an affection of the kidney. These reactions may already occur after doses of 5 to 20 Gy. After higher doses, a number of symptoms may appear which have been classified into three clinical groups by Sarre and Moser and even into five groups by Luxton and Kunkler. They show histologic manifestations in the glomeruli and tubuli and are mostly progressive. In case of radiotherapy alone, the threshold doses are 20 to 25 Gy. After a latent time of several months, these patients may present renal insufficiency and hypertonia, leading eventually to death in an acute stage, chronic development with preponderant renal insufficiency, hypertonia, or incomplete healing. These doses are considerably lower in children. It has been proved recently that these threshold doses are considerably reduced by combined chemotherapy, too even if the cytostatic drugs alone have no nephrotoxic potential. This is verified by our experimentations on animals. If only a little part of the kidney is situated within the irradiation field, e.g. the upper renal pole in case of an irradiation of the spleen, a significantly reduced activity in the upper pole of the left kidney can be proved by scintigraphy after a period of eight months. After about 18 months, tomography shows a cortical atrophia in this region. However, as far as clinical or technical examinations are concerned, no abnormal parameters could be found.     

Case report: splenic-gonadal fusion--the ultrasound appearances

We report the ultrasound appearances, with pathological correlation, of splenic-gonadal fusion in a patient who presented with an asymptomatic scrotal swelling. Ultrasound examination showed an echo-poor 2 cm diameter lesion in the upper pole of the left testicle. Histologically the lesion was normal spleen. Splenic-gonadal fusion should be considered in the differential diagnosis of scrotal swellings.     

Renal imaging with 99Tcm-labelled DMSA in the detection of acute pyelonephritis: an experimental study in the pig

Serial renal 99Tcm-labelled dimercaptosuccinic acid (DMSA) scintigrams were acquired 2-58 days after the introduction of urinary tract infection in 33 pigs with experimentally induced vesicoureteric reflux (VUR). In 29 animals VUR was unilateral and in four bilateral, a total of 37 refluxing systems. Animals were killed either at varying intervals after a scintigraphic defect was noted (24 refluxing kidneys) or after a period when sequential scintigrams were normal (13 refluxing kidneys). The appearance of the scintigram acquired on the day prior to death was compared with the renal pathology, each kidney and renal image being divided into three zones (upper, middle, lower) for separate consideration. Of the 37 refluxing systems pyelonephritic lesions were seen in 27, in a total of 61 zones. In the remaining ten kidneys no scintigraphic defect was detected and no pathological lesions were identified either macroscopically or microscopically. Where an abnormality was detected on the scintigram a lesion was always identified in the kidney (sensitivity 100%). Small pyelonephritic lesions in a total of 12 zones in six kidneys were not detected on the scintigram (specificity 82%). Of the lesions undetected by scintigraphy only one occurred in the upper pole.     

Hydronephrosis of the lower pole of the duplex kidney: another renal pseudotumor.

Obstruction and reflux occur fairly commonly in the duplex kidney. Although obstruction with attendant hydronephrosis is more frequently seen in the upper pole of a duplex system, a similar process involving the lower pole should be considered in the differential diagnosis of renal mass lesions. Four cases are described in which lower pole hydronephrosis simulated neoplasm.     

Adrenocortical oncocytoma: case report

We report the case of an adrenocortical oncocytoma of the left adrenal cortex in a young woman. Physical examination revealed a mass in the left upper quadrant of the abdomen using abdomen ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), which allowed the identification of a large and inhomogeneous mass between the left kidney and the spleen. The lesion was not endowed of any specific radiologic characteristic nor bysided by any biochemical activity that could allow a radiological presurgical diagnosis. Surgical resection led to the diagnosis of adrenocortical oncocytoma, with no aspects revealing malignant potential.     

Hemorrhagic renal angiomyolipoma: Superselective renal arterial embolization for preservation of renal function

A 35-year-old woman with tuberous sclerosis and known bilateral renal angiomyolipomas presented with shock due to massive hematuria arising from the left kidney. The cause of bleeding was diagnosed angiographically as arising from a left upper pole renal artery aneurysm within the tumor. Cessation of bleeding and clinical stabilization occurred without deterioration of renal function after superselective embolization of the dorsal segmental renal artery with a single 5-mm Gianturco coil.