Kidney Stone Detection on Ultrasound

Purpose

To detect kidney, ureteral, or bladder stones on US

Tag(s)

 

Panel

Abdominal

Define-AI ID

20020007

Originator

Luther B. Adair, II
Lead Luther B. Adair, II

Panel Chair

Arun Krishnaraj

Panel Reviewers

Abdominal Panel

License

Creative Commons 4.0 
Status Public Comment
RadElement Set  RDES158 
                               

Clinical Implementation


Value Proposition


Distinguishing between hydronephrosis due to mass effect on the distal ureter in pregnancy versus urolithiasis as a cause is a common reason renal ultrasound is ordered as an alternative to CT. Additionally, renal ultrasound is often ordered in an outpatient setting to ascertain a cause for abnormal renal function, specifically to exclude hydronephrosis. AI meeting this use case would help in detecting, quantitating, comparing, and alerting both nonspecialists and radiologists to these abnormalities. In clinical settings where a radiologist is not readily available, such detection would be of value to non-radiologists such as technologists who would perform an ultrasound for this disease entity. In clinical settings where radiologists are available, such detection could be used to alert the radiologist and prioritize its reporting and notification to the treating physicians.

Narrative(s)


A 35-year old pregnant patient presents to an emergency room with abdominal pain at which time ultrasound is ordered.

A 65-year old patient presents to an outpatient office with abnormal renal function and abdominal pain and ultrasound is ordered.

Workflow Description


The relevant images are obtained from the modality and sent to PACS and the AI engine based on anatomic landmarks. The images are analyzed by the engine. The system then detects the relevant outputs providing associated categorical data or measurements. An alert message is sent back to the engine with information, identification, and graphics highlighting the presence of a renal calculus, ureteral calculus, urinary bladder calculus, or hydronephrosis. Calculus on ultrasound is defined as a hyperechoic focus with posterior shadowing or “twinkle” artifact.

An algorithm evaluates the ultrasound images and assesses whether a renal calculus(s) is present, absent, or undetermined. If present, it then counts the number of calculi in each kidney and measures the largest on each side. It will also assess whether a ureteral calculus is present, absent, or indeterminate. If present, it then measures the calculus. Assesses whether a bladder calculus is present, absent, or undetermined. If present, it then measures the calculus.Assesses whether hydronephrosis is see comment below regarding laterality and quantifying degree of hydronephrosis. For cases where the algorithm returns any degree of hydronephrosis is present, the exam is prioritized in the radiologist’s worklist for urgent interpretation and reporting.


Considerations for Dataset Development



Procedures

{retroperitoneal ultrasound, renal ultrasound, renal ultrasound limited}

View(s)

{transverse, longitudinal}

Age

[0,90]

Sex at Birth

{Male, Female}

Abdominal pain

{left flank pain, right flank pain, abdominal pain}

Other

{hydronephrosis}

Confounding variables

{percutaneous nephrostomy, ureteral catheter, vascular calculus [calcified atherosclerosis in renal arteries], echogenic renal sinus fat, emphysematous pyelonephritis or cystitis, air within the collecting system, Foley catheter}


Technical Specifications


Inputs

DICOM Study

Procedure

Renal ultrasound

Views

Transverse, longitudinal

Data Type

DICOM

Modality

ultrasound

Body Region

Abdomen and pelvis

Anatomic Focus

Kidneys, ureters, urinary bladder



Primary Outputs


Renal Calculus Detection

RadElement ID

RDE1107

Definition

Detection of renal calculus

Data Type

Categorical

Value Set

  • Absent

  • Present

  • Indeterminate

Units

N/A


Number of Renal Calculus 

RadElement ID

RDE1103

Definition

If renal calculus present, note the number of calculi

Data Type

Numeric

Value Set

N/A

Units

N/A


Renal Calculus Kidney Laterality

RadElement ID

RDE1108

Definition

If renal calculus present, note which kidney involved

Data Type

Categorical

Value Set

  • Left

  • Right

  • Indeterminate

Units

N/A


Renal Calculus Measurement

RadElement ID

RDE1104

Definition

Measurement of renal calculus

Data Type

Numeric

Value Set

N/A

Units

millimeters


Ureteral Calculus Detection

RadElement ID

RDE1109

Definition

Detection of ureteral calculus

Data Type

Categorical

Value Set

  • Absent

  • Present

  • Indeterminate

Units

N/A



Ureteral Calculus Kidney Laterality

RadElement ID

RDE1110

Definition

If ureteral calculus present, specify which kidney involved

Data Type

Categorical

Value Set

  • Left

  • Right

  • Indeterminate

Units

N/A


Ureteral Calculus Measurement

RadElement ID

RDE1105

Definition

Measurement of ureteral calculus

Data Type

Numeric

Value Set

N/A

Units

millimeters


Bladder Calculus Detection

RadElement ID

RDE1111

Definition

Detection of bladder calculus

Data Type

Categorical

Value Set

  • Absent

  • Present

  • Unknown

Units

N/A


Bladder Calculus Measurement

RadElement ID

RDE1106

Definition

Measurement of bladder calculus

Data Type

Numeric

Value Set

N/A

Units

millimeters




Secondary Outputs


Hydronephrosis Detection


RadElement ID

RDE1112

Definition

Detection of hydronephrosis

Data Type

Categorical

Value Set

  • Absent

  • Present

  • Indeterminate


Units

N/A



Hydronephrosis Kidney Laterality


RadElement ID

RDE1113

Definition

If Hydronephrosis present, note which kidney involved

Data Type

Categorical

Value Set

  • Left

  • Right

  • Indeterminate


Units

N/A

Future Development Ideas


  • Possible extension to this use case is to detect nephrolithiasis and hydronephrosis on ultrasound and assess the need for further imaging based on the absence or presence of hydronephrosis.