Index terms: Ultrasound (US), contrast media, Ultrasound (US), Doppler studies, Hypertension, renovascular, Renal arteries, stenosis or obstruction
Renal artery stenosis can be treated with either angioplasty or surgery. Physicians use variety of imaging techniques for evaluating suspected cases of renovascular hypertension. Some prefer angiography as the initial choice of their investigation when stenosis is clinically suspected. Angiography is still the gold standard diagnostic method, but it is invasive procedure with risks and expensive. Angiography with iodinated contrast cannot be performed for patients with renal failure, instead carbon dioxide angiography is performed. Because of these, a non-invasive alternative method is a necessity need to be found. Sonography is non-invasive and does not need iodinated contrast for scanning suspected cases with renal artery stenosis. Duplex sonography has been successful in diagnosing some cases with this condition, but it is still not a reliable method to determine the condition.
This study has investigated whether the use of contrast agents improve the outcome of Doppler sonographic scans of the renal artery stenosis.
Ultrasound scan focuses on the change (increase) in velocity of blood circulation at the suspected site for stenosis, and the changes of waveform. Site of stenosis make the scan difficult because it is covered with abdominal soft tissues and bowel gas also obstructs visualising. This study revealed that US contrast agents can obtain new vascular information such as greater lengths of vessels, visualise vessels that were not seen without contrast and vessels seen as occluded now proven to be patent. In general contrast agent has improved visualising stenosis.
Renal lesions
Renal cell carcinomas almost 50% are detected incidentally and nearly 85% of suspicious renal lesions are malignant. Solid renal mass consists of oncocytoma, angiomyolipoma, hemangioma, leiomyma and focal xanthogranulomatous pyelonephritis. Among these conditions only angiomyolipomas and cysts can be diagnosed as benign lesions (Nikken & Krestin, 2007).
CT and US are first choice modalities in renal tract imaging. When a lesion has been detected by CT or US scan and was not determined, usually MRI scan is performed for further study of its characterisations. MRI scan needs the use of gadolinium contrast so that distinguish a malignant lesion from a benign one or a cyst (Nikken & Krestin, 2007).
A study for the ability of contrast enhance second-harmonic US to diagnose a pseudocapsule in renal masses compared with conventional gray-scale US returns positive results. Imaging with a second-harmonic contrast improves the contrast of the image which improves the visualisation of tumoral pseudocapsule. This image improvement can benefit the US imaging for renal cell carcinoma. The study also recommends the need for a larger investigation in this regard (Ascenti, Gaeta, Carlo Magno, Mazziotti, Blandino, Melloni. Zimbaro,2004).
Fat-containing renal cell carcinomas
Lesion with calcification and macroscopic fat is often an indicator to carcinoma. MRI is not very sensitive in detecting calcifications, therefore, earlier US and CT scans needs to be taken as a valuable tool for evaluation (Nikken & Krestin, 2007).
Currently TNM staging system is used in renal cell carcinoma, to determine the staging CT or MRI scan is performed and both provide similar accuracy (Nikken & Krestin, 2007).
Transitional cell carcinoma
Transitional cell carcinoma of the kidney is assessed by intravenous urography (IVU), CT and endoscopy, if CT and endoscopy has contraindications then MRI scan can be considered.
KHORSANDI, FOY, WUI CHONG, HOENIG, COHEN, RUKSTALIS (2002) state that almost 97% of masses less than 3 cm in diameter in kidney are diagnosed accidentally and 77% were initially discovered by Ultrasound or CT scan. However, the widespread use of imaging examinations has contributed in more diagnosis in smaller renal lesions.
Renal Mass Biopsy
Keywords: core biopsy, kidney, renal disease, renal mass
Despite the advances in US, CT and MRI imaging for differentiating between solid and cystic lesions, but still limited to distinguish between benign and malignant renal masses. Lesion diagnosis is important for patient management which can alter clinical decision making or avoid unnecessary nephrectomies. For accurate tissue diagnosis a biopsy from the lesion may be needed. This procedure requires guiding images so that the needle can be directed to the lesion. Most common imaging modality used for this purpose is a CT or US depending on operator preference and lesion characteristics. Imaging guided biopsy of renal masses is safe and accurate in majority of cases (Maturen, Nghiem, Caoili, Higgin, Wolf, Wood, 2007)
Renal obstruction
Keywords. Abnormal urinary flow, silent hydronephrosis, transabdominal ultrasound, urninary obstruction.
Waart, Boender, Beek, Wolfs, Janknegt and Knottnerus, (1998) in their study to determine the occurrence of hydronephrosis in patients due for prostatectomy performed US scans and reached to a conclusion that there is no justification for routine US scan for men patient with uncomplicated obstructive complaints.
Bladder Volume Determination
Key Words: bladder volume, three-dimensional ultrasound, transvaginal ultrasound, two-dimensional
ultrasound
Evaluating bladder function in women who had anti-incontinence surgery, urogenital prolapse repair or radical hysterectormy and other cases, often involves measurements of bladder volume. The traditional method for measurement involves placing a catheter into the urethra to empty the bladder. This invasive method causes discomfort for patient and may have a risk of infection or urethral injury. US scan including 2D and 3D imaging for measuring the volume of bladder can be beneficial. Comparing 2D with 3D imaging of bladder to determine its volume shows that 3D scan tended to under-estimate and 2D tended to over-estimate the real volume. Despite these findings, the methods are of benefit for predicting the actual bladder volume considering that they are non-invasive and reliable methods (Liang, Wei, Chang and Hsieh, 2008).
Uterus
Keywords: 3D sonography, infertility, obstetrics and
gynecology, pelvic sonography, women’s imaging
Patients referred for gynecologic sonography had initial 2D view and based on this findings the 3D coronal view scan carried out, which resulted in providing more information compared to a 2D pelvic scan, particularly in patients with infertility condition or suspected endometrial lesions. Further more the coronal view is helpful in patients with an endometrium ≥ 5 mm. Studies have also suggested that additional reconstructed views of the uterus can be helpful in patients with fibroids and those undergoing sonohysterography (Benacerraf, Shipp, Bromley, 2007).
Ovarian
Scrotum
Keywords: infection, neoplasm, sonography, testicle, torsion
Sonography is the primary diagnostic tool for diagnosing disorders in the scrotum and its contents. This study confirms the effectiveness of sonography in cases of trauma, scrotal pain without trauma, neoplastic, inflammatory, congenital, vascular abnormalities and scrotal masses (Joseph, Stengel, Erick and Remer, 2008).
Paratesticular Neoplasms
Index terms: Genitourinary system, CT, Genitourinary system, diseases, Genitourinary system, MR, Genitourinary system, neoplasms, Genitourinary system, US, Scrotum, Testis.
Extratesticular neoplasms affect all age group patients although it is a rare condition, Lipoma is the most common benign neoplasm of the spermatic cord. US imaging is the preferred modality in examining suspected lesions. However, US is not specific and do not provide clear characterisation, therefore, CT and MRI imaging is the choice for further evaluation of paratesticular neoplasm (Akbar, Sayyed, Zafar, Jafri, Hasteh, Simeon, Neill, 2003).
Urinary Tract Infection (First Febrile)
This study performed ultrasound scans for children between the age of 1-24 months three days after diagnosis of first urinary tract infection, then few more scans performed. Study concluded that ultrasound scans at the time of acute infection has only a limited value. However, a voiding cystourethrogram (x-ray imaging of full bladder with contrast during emptying) to check the reflux has advantage if antibacterial prophylaxis is useful in reducing reinfections and renal scarring (Hoberman, Charron, Robert, Hickey, Baskin, Diana, Kearney, Ellen, Wald, 2003).
Pyelonephritis
Key Words: vesicoureteral reflux, urinary antibiotic, prophylaxis, acute pyelonephritis
Garin, Olavarria, Nieto, Valenciano, Campos, Young (2005) in their study to evaluate the role of primary vesicoureteral reflux (VUR) in increasing the frequency and severity of urinary tract infection (UTI) for a group of patient between 3 months to 18 years old. Their study heavily relied on US scans for monitoring the patients and concluded that VUR does not increase the occurrence of UTI, pyelonephrites or renal scarring following acut pyelonephritis..
Autosomal Recessive Polycystic Kidney Disease
The condition is heritable, affects kidneys and other organs. When is severe may impair renal function and lead to hypertension and renal failure. US imaging reveals enlarged kidneys and produce of images of reduced density of paranchymal areas (Lonergan, Col, Rice, Suarez, 2000).
