why would course of ureters be hard to follow on ct scan

Nonopacification can also be a problem in patients with urinary tract obstruction. When obstruction is present, excretion into the renal collecting systems and ureters may be delayed, and there may be minimal or no contrast material in the renal collecting systems, ureters, or bladder at the time of excretory-phase image acquisition.

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Does a deviated ureter appear on a CT scan?

Mar 27, 2015 · In cases of ureteral transection due to iatrogenic injury, blunt trauma, or penetrating trauma, the excreted contrast material does not follow the expected course of the ureter. Instead, there is active leaking of contrast material into the peritoneal cavity or retroperitoneum at the site of injury . In such cases, the ureter may still have a normal anatomic …

What are the pathologic ureteral conditions identified by CT urography?

Apr 03, 2016 · Reasons for anterior deviation of the ureter in this study included morbid obesity with prominent retroperitoneal fat, congenital renal abnormality, and post-traumatic renal/retroperitoneal hematoma. We determined that the optimal level on abdominal CT to detect the displaced ureter was the mid-body of the L4 vertebra. Conclusion

Can CT urography detect ureteral filling defects?

5 public playlist include this case. ureters by Emmanuel M Limos. Annotated CT/MR Teaching by Matt Wong . URO by Medico General Jairo Barreto. Annotated anatomy by Dr Sachintha Hapugoda . URO by Medico General Jairo Barreto. ×.

When is nonenhanced CT indicated in the diagnosis of ureteral calculi?

Mar 28, 2017 · CT Scan of the Kidneys and Ureters Most of the renal abnormalities are best seen on CT after intravenous contrast media administration. Plain CT scan is generally reserved to demonstrate calcification and calculi that may be obscured by contrast agent or it is used as a baseline of attenuation measurement when contrast enhancement is calculated as a feature of …

Can ureters be seen on CT scan?

How do you know if you have a ureter problem?

What causes ureter problems?

What causes the ureter too narrow?

What does ureter pain feel like?

What is inflammation of the ureter called?

What happens when a ureter is blocked?

What is the medical term for narrowing of the ureter?

What does Opacified ureter mean?

How do you fix a narrowing of the ureter?

Can you get an infection in your ureter?

What are the relations between the ureter and the pelvic cavity?

The relations of the ureter are somewhat complex due to the differences between the left and right sides of the abdominal cavity and differences between male and female pelvic viscera.

How many constrictions are there in the ureter?

The ureter has a diameter of 3 mm 1 but there are three constrictions, which are the most common sites of renal calculus obstruction:

How long is the ureter?

The ureter is 25-30 cm long and has three parts: abdominal ureter: from the renal pelvis to the pelvic brim. pelvic ureter: from the pelvic brim to the bladder. intravesical or intramural ureter : within the bladder wall.

Where does the ureter begin to descend?

The ureter begins its descent to the bladder by running along the medial aspect of the psoas muscle. Here, the ureter lies anteriorly and slightly medial to the tips of the L2-L5 transverse processes.

What is the diameter of the ureter?

The ureter has a diameter of 3 mm 1 but there are three constrictions, which are the most common sites of renal calculus obstruction: at the pelviureteric junction (PUJ) of the renal pelvis and the ureter. as the ureter enters the pelvis and crosses over the common iliac artery bifurcation.

How many layers are there in the ureteric wall?

The ureteric wall is composed of three layers (from outside to inside):

Which structures pass over the pelvic ureter?

anteriorly. male: ductus deferens. female: uterine artery (in the broad ligament) medially. female: cervix. It should be noted that the only structures to anteriorly pass over the pelvic ureter is the ductus deferens in males and the uterine artery in females.

How long does it take for a CT urography to show excretory phase?

Excretory phase imaging for CT urography study methods can range from 3 to 16 minutes after injection. Longer delays are beneficial for opacification of the distal ureters.

How long after contrast bolus is a renal scan?

The conticomedullary phase typically occurs approximately 30 to 70 seconds after the contrast bolus; the nephrogram phase is seen 80 to 120 seconds after the contrast bolus; the excretory phase begins about 3 minutes after injection and can last 15 minutes or longer. 2-dimentional and 3-dimentional reformations may be useful in defining certain types of renal abnormalities, such as renal cell carcinoma and ureteropelvic junction UPJ obstruction.

What is a CTU?

The CT urography (CTU) is a relatively new imaging examination designed to provide a comprehensive evaluation of the upper and lower urinary tract. Many different CT urography protocols are currently being used. CT urography is defined as a diagnostic examination optimized for imaging the kidneys, ureters and bladder. The examination involved the use of MDCT with thin slice imaging, intravenous administration of contrast media, and imaging in the excretory phase.

How much contrast media is given in a bolus?

A single bolus injection administers 100 to 150 mL of Low Osmolality Contrast Media injected at rate of 2 to 3 mL/s, scans are typically obtained in the nephrographic phase to assess the renal parenchyma and in the excretory phase to assess the urinary tract mucosa.

Why is split bolus used in urography?

The split bolus technique has been gaining in popularity because by combining 2 phases, the radiation dosed is reduced.

Can you see renal abnormalities on CT?

Most of the renal abnormalities are best seen on CT after intravenous contrast media administration. Plain CT scan is generally reserved to demonstrate calcification and calculi that may be obscured by contrast agent or it is used as a baseline of attenuation measurement when contrast enhancement is calculated as a feature of renal mass characterization. MDCT is the current modality of choice for renal evaluation.

Which is the first line imaging for urography?

abdomen and pelvis. CT urography is currently the first-line imaging

What is hematuria in medical terms?

hematuria, defined as three or more red blood cells per high-power field in . the absence of a benign cause (eg, infection, menstruation, vigorous exercise, . glomerular disease, trauma) First-line imaging modality in adult patients with gross hematuria.

Is there a universally accepted imaging protocol?

but there is no universally accepted imaging protocol (3,4). In the . most general sense, complete CT urography includes a nonenhanced . phase, a contrast-enhanced phase, and an excretory phase (Fig 1). Several imaging protocols are currently used in clinical practice, some .

How long does it take for a catheter to irritate the urethra?

Tests involving a catheter in the urethra. You might feel some mild discomfort from an irritated urethra for a few hours after the procedure.

Why is it important to have a urinary tract imaging?

That’s important because different urinary tract problems may share the same symptoms. For example, a urinary blockage can be caused by a kidney stone or an enlarged prostate.

What are the symptoms of urinary retention?

Imaging could be required for symptoms such as. difficulty initiating or maintaining urination. difficulty in emptying the bladder, known as urinary retention. accidental leakage of urine, known as bladder control problems or urinary incontinence. urinary frequency and urgency (day or night)

What is the system of the urinary system?

The urinary tract is your body’s drainage system for removing wastes and extra fluids. The urinary tract includes two kidneys, two ureters, a bladder, and a urethra. The kidneys filter wastes and fluids to produce urine. The urine travels from the kidneys down two narrow tubes called the ureters.

What is the meaning of urgency and urgency in the urinary tract?

urinary frequency and urgency (day or night) recurrent urinary tract infections (UTIs) a single UTI in a susceptible or high-risk person, such as an infant. pain in the abdomen, upper or lower back, or groin. abdominal pain or mass, such as swelling in a specific part of the abdomen. evidence of kidney failure.

What parts of the urinary system work together?

All parts of the urinary tract—the kidneys, ureters, bladder, and urethra— must work together to urinate normally.

How to prepare for an imaging test?

How you prepare for an imaging test will depend on the test’s purpose and type. Your health care professional will give you instructions. Listen carefully and ask questions if you don’t understand. You might be asked to

What is a CT scan for urinary tract?

CT Scans. A CT scan can provide a better view of the urinary tract. This test uses X-rays and a computer to create cross-sectional, three-dimensional images. The doctor may give you a contrast agent, or dye, by injection. This enhances the image.

Why do doctors use CT scans?

This enhances the image. The information provided by a CT scan helps the doctor decide the cause, location, and extent of the stricture. It can also help the doctor to decide on the best approach to treatment.

What is a UPJ obstruction?

A common type of ureteral stricture is ureteropelvic junction, or UPJ, obstruction. A UPJ obstruction is often congenital, but sometimes it is a result of an injury incurred during surgery or due to surgical scarring. It can also be caused by kidney stones, upper urinary tract inflammation, or a tumor.

What is the name of the tube that carries urine from the kidney to the bladder?

NYU Langone urologists are experts in diagnosing ureteral stricture, which is a narrowing of one of the ureters—tubes that carry urine from each kidney to the bladder. This narrowing causes an obstruction in the flow of urine.

What is renal scan?

A renal scan of the urinary tract is a test used to evaluate kidney function and determine the extent of ureter obstruction. A renal scan is a nuclear imaging test that reveals how long it takes for urine to flow from the kidneys to the bladder. The test is very effective in identifying obstructions in the urinary tract, as well as measuring the function of the affected kidney.

How does a doctor inject dye into the bladder?

The doctor then inserts a small catheter through the ureteroscope into the opening of the ureter. Dye is injected through the catheter, and X-rays are taken to determine if a ureteral stricture is the cause of the blockage.

What is the best way to check if your kidneys are enlarged?

Ultrasound. Your doctor may recommend that you have an ultrasound test, which uses sound waves to produce images on a high definition monitor. The results can help to establish whether the kidneys are enlarged due to a stricture. The images may also identify blockages in the ureters leading to and from the kidneys.

When is the corticomedullary phase of a renal scan?

15.3B and C ). The corticomedullary phase is usually seen at about 30 to 50 seconds after contrast medium injection into an arm vein. This phase is of limited use for detection of renal masses because only the renal cortex is enhanced and the medullary portions of the kidney remain unenhanced. The corticomedullary phase defines the renal artery and vein better than the nephrogram phase.

Why is contrast medium used in CT?

Because the kidneys actively concentrate contrast medium within the parenchyma, most renal abnormalities are best seen on CT after intravenous contrast medium administration. Unenhanced CT is performed to demonstrate calcifications and calculi that may be obscured by contrast medium administration. Multidetector CT (MDCT) is optimal for renal evaluation and is the current technique of choice. The sensitivity for detection of renal masses differs considerably with the imaging modality: 67% for traditional excretory urography, 79% for sonography, and at least 95% for MDCT.

What is the margin of the kidneys?

The kidneys are covered by a tight fibrous capsule that produces a sharp margin defined by perirenal fat on CT. The perirenal fat extends into the renal sinus, outlining blood vessels and the renal collecting system. Connective tissue septa extend between the fibrous capsule of the kidney and the renal fascia.

What is the arrowhead on a CT of von Hippel-Lindau syndrome?

CT in a patient with von Hippel–Lindau syndrome reveals the development of two renal cell carcinomas (red arrowheads) in the right kidney. Tumor thrombus (yellow arrow) extends into the right renal vein. Both kidneys contained multiple cysts (green arrow) and angiomyolipomas. The patient had a history of partial nephrectomy on the left for renal cell carcinoma.

What are the features of a renal mass?

The features that must be evaluated to characterize a renal mass are the presence and type of calcification, attenuation of the mass before and after contrast medium administration, the margin of the mass with the kidney and with surrounding tissues, and the presence and thickness of septa and the thickness of the wall of cystic masses. Artifactual pseudoenhancement, related to a beam-hardening effect from iodinated contrast medium, may increase attenuation of lesions by up to 10 Hounsfield units (HU). Attenuation must increase by a minimum of 20 HU following bolus intravenous contrast medium administration to be considered enhancement. An increase in attenuation of less than 10 HU is not considered enhancement. An increase in attenuation of 10 to 20 HU is equivocal enhancement.

Where are the renal arteries?

The renal arteries and veins can be identified from the great vessels to the kidneys. The right renal artery courses behind the vena cava. The right renal vein extends anterior to the right renal artery directly from the right kidney to the vena cava.

What are the most common sites of late metastases?

The most common sites are the lungs (50%–60%), mediastinum, bone, liver, contralateral kidney or adrenal gland , and brain. •. Late metastases (>10 years after surgery) are most common to lung, pancreas, bone, skeletal muscle, and bowel. Surgical resection of isolated late metastases may be curative.