Five Novel Sonographic Signs

1. Introduction

Sonographic signs are specific patterns or findings on ultrasound that have been described to aid in diagnosis, help clinicians remember key imaging features, and serve as teaching aids. Over the years, many signs have been proposed in the field of ultrasound [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]. Examples include the wall-echo-shadow (WES) Sign, which indicates that the lumen of the gallbladder is completely occupied by either a single large calculus or multiple small calculi and the “Bull’s-Eye Sign” in liver metastases [19,20], both of which have become well-established descriptors in practice.

The author has previously proposed five novel sonographic signs, the Cracked Earth Sign for subcutaneous edema, the Mushroom Cap Sign for localized gallbladder adenomyomatosis, the LTS Sign for dilated cardiomyopathy, the LTI Sign for endocardial fibroelastosis, and the Three Pipes Sign for the suprasternal long-axis view of the aortic arch, covering superficial ultrasound, abdominal ultrasound, and echocardiography, all of which have been published as preprints [21,22,23].

This paper aims to provide a consolidated review of these five signs, focusing on their naming logics, definitions, clinical implications, and teaching value, in order to facilitate a better understanding of them and to promote their use in practice.

2. Novel Sonographic Signs

This section presents five novel sonographic signs previously proposed by the author, including the Cracked Earth Sign in superficial ultrasound, the Mushroom Cap Sign in abdominal ultrasound, and the LTS Sign, the LTI Sign, and the Three Pipes Sign in echocardiography. For each sign, its naming logic, definition, clinical implications, and teaching value are described.

2.1. The Cracked Earth Sign

The author has proposed the “Cracked Earth Sign” as a novel sonographic sign for subcutaneous edema.

Naming logic: The “Cracked Earth Sign” is named for its descriptive appearance, as the irregular, reticular, or branching anechoic or hypoechoic clefts within the thickened subcutaneous tissue resemble cracks in dry, sun-baked earth.

Definition: The “Cracked Earth Sign” refers to the sonographic appearance of subcutaneous edema, characterized by thickening of the subcutaneous tissue with irregular, reticular, or branching anechoic or hypoechoic clefts interspersed among fat lobules, resembling cracks in dry, sun-baked earth.

Clinical implications: The “Cracked Earth Sign” provides a simple, intuitive pattern of irregular, reticular, or branching clefts within the subcutaneous tissue that helps sonographers identify subcutaneous edema.

Teaching value: The “Cracked Earth Sign” offers trainees a simple, intuitive pattern to help them recognize subcutaneous edema.

2.2. The Mushroom Cap Sign

The author has proposed the “Mushroom Cap Sign” as a novel sonographic sign for localized gallbladder adenomyomatosis.

Naming logic: The “Mushroom Cap Sign” is named for its descriptive appearance, as the focal fundal thickening with internal anechoic cystic spaces resembles a mushroom cap.

Definition: The “Mushroom Cap Sign” refers to the sonographic appearance of a subset of localized gallbladder adenomyomatosis that exhibits a cap-like elevation with visible Rokitansky-Aschoff sinuses, together resembling a mushroom cap. The anechoic cystic spaces correspond to the spots on a mushroom cap.

Clinical implications: The “Mushroom Cap Sign” provides a simple, intuitive pattern that helps sonographers identify a focal fundal thickening as localized adenomyomatosis when it exhibits a cap-like morphology with internal anechoic cystic spaces.

Teaching value: The “Mushroom Cap Sign” offers trainees a simple, intuitive pattern to help them recognize localized gallbladder adenomyomatosis.

2.3. The LTS Sign

The author has proposed the “LTS” as a novel sonographic sign for dilated cardiomyopathy.

Naming logic: LTS is an abbreviation for the “Large-Thin-Small” triad.

Definition: The “LTS” refers to the echocardiographic appearance of dilated cardiomyopathy characterized by three features: large ventricular cavity, thin interventricular septum, and small mitral valve orifice, the initials of which yield the “Large-Thin-Small” triad: LTS.

Clinical implications: The “LTS Sign” provides a simple mnemonic: Large, Thin, Small. This may help echocardiographers, particularly trainees, recognize the typical echocardiographic features of dilated cardiomyopathy.

Teaching value: The “LTS Sign” offers trainees a simple mnemonic to help them remember the three core echocardiographic features of dilated cardiomyopathy.

2.4. The LTI Sign

The author has proposed the “LTI” as a novel sonographic sign for endocardial fibroelastosis.

Naming logic: LTI is an abbreviation for the “Large-Thick-Impaired” triad.

Definition: The “LTI” refers to the echocardiographic appearance of endocardial fibroelastosis characterized by three features: large ventricular cavity, thick endocardium, and impaired ventricular function, the initials of which yield the “Large-Thick-Impaired” triad: LTI.

Clinical implications: The “LTI Sign” provides a simple mnemonic: Large, Thick, Impaired. This may assist echocardiographers, especially trainees, in recognizing the characteristic echocardiographic features of endocardial fibroelastosis.

Teaching value: The “LTI Sign” provides trainees with an easy mnemonic to help them remember the three core echocardiographic features of endocardial fibroelastosis.

2.5. The Three Pipes Sign

The author has proposed the “Three Pipes Sign” as a novel sonographic sign to aid in the recognition of the suprasternal long-axis view of the aortic arch when the three major branches are adequately displayed, and to assist in the echocardiographic localization and measurement of coarctation of the descending aorta based on the relationship of the narrowing to these three branches.

Naming logic: The sign is named for its descriptive appearance, as the three major branches of the aortic arch resemble three pipes.

Definition: The “Three Pipes Sign” refers to the sonographic appearance of the suprasternal long-axis view of the aortic arch in which the three major branches, namely the brachiocephalic trunk, left common carotid artery, and left subclavian artery, may be visualized arising from the aortic arch, appearing as three parallel or slightly diverging tubular structures, together resembling three pipes.

Clinical implications: The “Three Pipes Sign” serves two purposes: First, assessment of aortic anomalies: Adequate display of the three branches provides the anatomical framework for the echocardiographic localization and measurement of coarctation of the descending aorta. The location of coarctation is defined by its relationship to the innominate artery, left common carotid artery, and left subclavian artery. Thus, the “Three Pipes Sign” provides the necessary anatomical guide for localizing coarctation of the descending aorta. Second, scanning quality control: The sign may help confirm adequate visualization of the aortic arch and its three major branches.

Teaching value: The “Three Pipes Sign” provides a simple, intuitive pattern of three tubular structures arising from the aortic arch, which may help sonographers, particularly trainees, recognize the suprasternal long-axis view of the aortic arch when the three branches are adequately displayed.

In summary, the five novel sonographic signs, namely the Cracked Earth Sign, the Mushroom Cap Sign, the LTS Sign, the LTI Sign, and the Three Pipes Sign, are concise, intuitive teaching tools designed to aid in the recognition of specific ultrasound findings across abdominal, superficial, and cardiac applications. Each sign is defined by a clear naming logic and offers practical value for both clinical identification and ultrasound teaching. The summary of the five novel sonographic signs is shown in Table 1.

3. Limitations and Future Directions

The five novel signs are proposed based on established sonographic anatomy and knowledge in the ultrasound fields, and their clinical utility will require further evaluation in routine practice.

Inspired by the educational value of sonographic signs, we also note that terminological precision in sonographic parameters may have implications for teaching. Tricuspid annular plane systolic excursion (TAPSE) is one parameter that merits consideration in echocardiography. Despite being a well-established measure of right ventricular longitudinal systolic function, its name does not explicitly indicate that the measured excursion is longitudinal. A more precise term, TAPSLE, which is the abbreviation for tricuspid annular plane systolic longitudinal excursion, may therefore better reflect the longitudinal nature of this parameter and improve clarity in teaching and clinical communication. A comparable terminological refinement may also extend to mitral annular plane systolic excursion (MAPSE), for which mitral annular plane systolic longitudinal excursion (MAPSLE) could likewise be proposed. We encourage further discussion within the echocardiography community regarding the potential adoption of TAPSLE and MAPSLE in practice. Similar considerations may also apply to global myocardial work parameters, including global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), which are all derived from longitudinal strain and could likewise benefit from a more explicit directional designation, namely global longitudinal work index (GLWI), global longitudinal constructive work (GLCW), global longitudinal wasted work (GLWW), and global longitudinal work efficiency (GLWE). We also encourage further discussion within the echocardiography community on the potential adoption of GLWI, GLCW, GLWW, and GLWE in practice.

4. Conclusion

Sonographic signs help clinicians recognize characteristic imaging patterns, assist in diagnosis, and serve as effective teaching tools. In this review, we have consolidated five novel sonographic signs previously proposed by the author, namely the Cracked Earth Sign, the Mushroom Cap Sign, the LTS Sign, the LTI Sign, and the Three Pipes Sign. For each sign, we have described its naming logic, definition, clinical implications, and teaching value, highlighting their potential utility in both clinical practice and ultrasound education. We hope this review promotes a better understanding of these signs and encourages the continued development of simple, memorable sonographic descriptors to enhance both clinical practice and ultrasound education.

AI Disclosure: The author used AI-assisted language tools solely for wording and grammar refinement. All intellectual content is the sole work of the author.