Registered Diagnostic Medical Sonographer (RDMS) Study Guide

Apply it

A patient referred for right upper quadrant imaging reports gallbladder removal. Confirm the history and requested assessment, then evaluate the relevant postoperative anatomy rather than repeatedly searching for an absent organ.

Apply it

When scanning requires an elevated shoulder and a long reach, bring the patient closer and adjust bed and chair height before continuing the same imaging task.

Apply it

A deep kidney is incompletely penetrated at a high-frequency setting. Reduce frequency and reassess the posterior margin, accepting a detail tradeoff if the complete organ becomes visible.

Apply it

A volume contains a shadowed region behind a strong reflector. Acquire another acoustic window rather than assuming that rotating the reconstruction will reveal anatomy absent from the original data.

Apply it

Increase deeper TGC when the superficial liver is satisfactory but deeper parenchyma progressively darkens. Recheck vascular lumens to ensure that excessive amplification has not filled them with noise.

Apply it

A small stationary lesion lies at 4 cm while the focus is at 9 cm. Move the focus to the lesion level and compare its margins before changing unrelated controls.

Apply it

A spectral peak wraps across the baseline. Increase PRF within the depth-imposed limit and reassess whether the waveform becomes continuous before interpreting the pattern as reversed flow.

Apply it

A straight-flow segment displays approximately 141 cm/s using a 60-degree correction, although the true angle is 45 degrees. Correcting the assumption yields approximately 100 cm/s.

Apply it

A small vessel lacks diastolic signal with a high filter. Lower the filter and repeat a stable acquisition; use power Doppler cautiously to evaluate subtle vascularity without equating brightness with velocity.

Apply it

After an endocavitary examination, remove the apparently intact cover safely, clean the probe, and complete compatible high-level disinfection before preparing it for another patient.

Apply it

A vertical dark band appears in several patients. Inspect the transducer and obtain a uniform phantom image under matched settings to determine whether the defect follows that probe.

Apply it

A test detects 72 of 80 diseased patients and correctly excludes disease in 108 of 120 nondiseased patients. Sensitivity and specificity are both 90%, despite their different denominators.

Apply it

When two vessels appear anterior to the spine, trace the suspected aorta through its branches and toward the bifurcation before selecting measurement sites.

Apply it

For branching renal hilar spaces, optimize color sensitivity and trace their course. Determine whether they connect as vessels or through the pelvis and calyces before describing collecting-system dilation.

Apply it

A patient with generalized edema has wall thickening without stones or focal tenderness. Describe the finding and associated observations rather than assigning acute cholecystitis from thickness alone.

Apply it

The patent channel measures 2.2 cm, but the perpendicular outer-wall diameter is 4.8 cm. Record 4.8 cm as the aortic diameter and describe the mural thrombus.

Apply it

A lump appears only while standing and straining. Reproduce those conditions safely and observe whether tissue traverses a fascial defect, avoiding pressure that reduces the protrusion before it can be assessed.

Apply it

For an echogenic gallbladder focus, assess its attachment, mobility, and posterior behavior. Compare conventional imaging if compounding has reduced a potentially useful shadow.

Apply it

The body is visible but the tail is obscured. Reposition the patient and seek another acoustic path, then identify any pancreatic portion that remains inadequately assessed.

Apply it

Before interpreting a newly smaller kidney or larger duct, reacquire the appropriate plane and verify the caliper convention. Preserve images showing the relevant anatomical boundaries.

Apply it

A recently fed adult has a contracted gallbladder during an elective assessment. Document intake and arrange reassessment after at least 4 hours of fasting when clinically appropriate. For a child, use age-appropriate preparation; for urgent symptoms, proceed with assessment and document the limitation.

Apply it

An acutely painful enlarged ovary has peripheral follicles but retains arterial signal. Document the concerning morphology and communicate possible torsion rather than reassuring solely from arterial flow.

Apply it

Two fetuses share an apparently single placental mass, but a triangular chorionic projection enters the membrane base. Evaluate the lambda sign and membrane rather than assuming monochorionicity from placental appearance alone.

Apply it

An unusual cerebellar shape accompanies frontal scalloping. Reassess the posterior fossa and systematically trace the spine rather than treating the head findings as isolated shape variants.

Apply it

A vessel is seen near the internal os. Trace it through the membranes toward the placenta and cord insertion, use targeted transvaginal color imaging when indicated, and distinguish fetal from maternal pulsation when needed. Determine whether it is an unprotected membranous vessel rather than a cord loop, and communicate suspected vasa previa promptly.

Apply it

The anterior layer measures 2 mm and the posterior layer 3 mm around intracavitary fluid. Report a summed tissue thickness of 5 mm, with the fluid and any focal abnormality described separately.

Apply it

A fetus is tightly flexed on the initial image. Wait for a neutral position and reacquire a true sagittal view before recording the length used for dating.

Apply it

An abdominal image includes elongated ribs and both kidneys prominently. Adjust to the standard transverse level before tracing the outer skin rather than correcting only the ellipse shape.

Apply it

Confirm that CRL is within 45–84 mm. If the neck is extended, reacquire a neutral mid-sagittal view with skin separated from amnion. Obtain three separate suitable images and select the largest technically satisfactory measurement.

Apply it

Cardiac motion is clearly visible in an early pregnancy. Save suitable cine or obtain the necessary brief M-mode tracing, check that TI is preferably at or below 0.7, and end the recording once adequate documentation is obtained.

Apply it

Apparent absent end-diastolic flow is recorded with a high wall filter. Lower the filter and repeat a stable acquisition before assigning that hemodynamic finding.

Apply it

For a palpable superficial nodule, use a high-frequency view and follow the dermal boundary across adjacent images to determine whether the finding arises within the skin or underlying breast tissue. Then document its relationship to the fibroglandular tissue and pectoral interface. When evaluating a duct-associated finding, align the transducer radially toward the nipple to follow the duct, then rotate into the antiradial plane to assess its cross-section and surrounding tissue.

Apply it

An enlarged axillary structure retains a clear fatty hilum. Document cortical uniformity, shape, and vascularity rather than labeling it malignant from enlargement alone.

Apply it

A round lesion is anechoic with a thin smooth wall and enhancement. Confirm the absence of internal tissue in a perpendicular view before assigning the simple-cyst description.

Apply it

A circumscribed enhancing collection at a recent operative bed favors seroma, while heterogeneous evolving blood products after biopsy favor hematoma. Document internal components and vascularity; a persistent suspicious solid component requires further assessment even at the surgical site.

Apply it

Mammography shows a suspicious calcification cluster, but targeted ultrasound shows no mass. Preserve the mammographic concern and document the absence of a sonographic correlate rather than downgrading the abnormality.

Apply it

A suspicious imaged lesion yields a benign result that does not explain its appearance. Verify target correspondence and procedural documentation, then communicate the unresolved imaging-pathology mismatch.

Apply it

For a lesion in the upper outer breast, record the actual clockface position and nipple distance, then retain images showing its depth and relationship to nearby tissue.

Apply it

A finding appears oval in one view. Rotate through the lesion and obtain perpendicular images, then use radial-antiradial views if its ductal relationship is relevant.

Apply it

A superficial lesion shows no flow under firm compression. Lighten pressure and repeat a stable low-flow acquisition before recording its vascular pattern.

Apply it

A tiny lesion lies immediately below the skin. Improve superficial coupling, use a suitable focal region, and reacquire a magnified view that retains the full margins and skin relationship.

Apply it

An automated study identifies a focal abnormality. Confirm its location and use targeted imaging to assess morphology and determine whether a corresponding handheld ultrasound target exists.

Apply it

Before sampling a lesion, confirm that it matches the diagnostic target and select an approach that permits continuous assessment of the tip relative to the lesion.

Apply it

For an anti-Ro/SSA-positive pregnancy, evaluate conduction as well as anatomy and ventricular performance. For a diabetes referral, distinguish disease predating pregnancy from gestational diabetes diagnosed after the second trimester and review the actual cardiac screening findings.

Apply it

With confirmed trisomy 21, assess the cardiac crux, valve arrangement, and septal components carefully. With 22q11.2 deletion, scrutinize outflow and arch relationships. In both cases, complete the remaining cardiac examination and correlate the actual anatomy.

Apply it

A chamber contains a moderator band and its atrioventricular valve inserts more apically. Identify right ventricular morphology and then determine its actual connections.

Apply it

A vessel is visible behind the left atrium. Follow it toward its entry and confirm continuity rather than assuming that proximity proves normal pulmonary venous drainage.

Apply it

An apparent ventricular septal gap appears in one view. Reassess with a more perpendicular insonation angle and additional planes before classifying the discontinuity as anatomical.

Apply it

A slow ventricular rhythm with a faster, independently timed atrial rhythm supports complete block. Rapid 1:1 timing favors reentrant SVT, while multiple atrial events per ventricular event suggest flutter. Record enough interpretable cycles and evaluate function and hydrops before characterizing severity.

Apply it

A well-aligned four-chamber view shows abnormal central junction anatomy and absent expected valve offset. Examine the crux, valve arrangement, and adjacent septa systematically.

Apply it

If the great arteries appear parallel, identify ventricular morphology and trace each artery to its origin rather than diagnosing transposition from orientation alone. If an enlarged aorta overrides a ventricular septal defect, assess the pulmonary valve and right ventricular outflow tract for obstruction supporting tetralogy of Fallot. For an abnormal arch pattern, establish each arch's relationship to the trachea, assess continuity in sagittal views, compare aortic and ductal caliber, and document flow direction.

Apply it

The posterior fossa is inadequately displayed through the anterior fontanelle. Add an appropriate supplementary window rather than increasing gain on the same limited view.

Apply it

An older infant has poorer cranial coverage than on a neonatal study. Assess the actual fontanelle window, obtain feasible supplementary views, and document inaccessible anatomy rather than assuming the apparent loss of detail represents a new brain abnormality.

Apply it

A child with episodic pain has a concentric bowel mass. Obtain longitudinal views to demonstrate the invaginated bowel configuration and communicate the finding promptly.

Apply it

A noncompressible blind-ending structure has adjacent inflamed fat. Confirm its connection and follow the entire visible course, documenting both primary and secondary inflammatory findings.

Apply it

An unstable premature infant cannot tolerate repeated repositioning. Plan the bedside cranial sequence in advance and obtain the highest-priority standard views with minimal disturbance.

Apply it

A ventricular measurement appears larger than before. Recreate the appropriate cranial plane and verify the same landmarks before attributing the difference to true ventricular enlargement.

Apply it

A superficial infant structure is poorly displayed on an adult-depth preset. Reduce unused depth, select suitable frequency and focus, and correct gain before increasing output.

Apply it

A convincing bowel-within-bowel mass is identified in a symptomatic child. Notify the responsible clinician promptly while documenting its location, appearance, and relevant associated findings.

Apply it

A processed external probe will enter a sterile procedural field. Apply the required sterile cover and sterile gel, then establish a view that permits reliable tip localization before advancement.