Log in
Diagnostic Radiology · Diagnostic Radiology of the Abdominal Organs

Plain radiography

Plain radiography

Plain radiography is a fundamental diagnostic imaging method that provides an initial assessment of internal organs without the use of contrast agents. It remains relevant for examining patients with acute abdominal conditions, renal disorders, and for the initial characterization of musculoskeletal mass lesions.

Test your knowledge on this topicAsk the AI
Soft tissuesThe method provides the initial, basic characterization of identified mass lesions.
NephrocalcinosisDemonstrates areas of high density in the kidneys, but may fail to detect mild forms of the disease.
IntussusceptionOccasionally reveals the "meniscus sign", though its routine use remains controversial.
ConstipationHas low specificity and is ordered strictly when organic pathology is suspected.
3 min readFor medical studentsUpdated 10.10.2026
Material prepared by WhiteCoat Pro editorial team based on platform study guidesPending instructor review

Assessment of the urinary system and soft tissues

In musculoskeletal diagnostics, conventional radiography serves as the first step to obtain initial imaging characteristics of various soft-tissue lesions prior to more definitive studies.

In urinephrology, the method has several specific clinical applications:

  • Autosomal recessive polycystic kidney disease (ARPKD): In this condition, the kidneys are significantly enlarged, forming large retroperitoneal masses. On a plain abdominal radiograph, this manifests as a pronounced mass effect—bowel loops are displaced centrally into the mid-abdomen.
  • Nephrocalcinosis (nephrocalcinosis): The study visualizes areas of abnormally high density within the renal parenchyma. However, it is important to consider the limitation of the method: in milder cases of the disease, changes may not be visible on the images at all.
  • Urolithiasis: When evaluating patients with acute renal colic, a conventional abdominal radiograph is frequently compared in efficacy to non-contrast computed tomography.

Radiodiagnosis of intestinal pathologies

When evaluating the gastrointestinal tract, especially in pediatric patients, radiography is used with caution due to the availability of more accurate and safer alternatives.

  • Intestinal intussusception (intussusception): A plain radiograph may occasionally reveal the classic “meniscus sign” (meniscus sign). It appears as a soft-tissue mass clearly outlined against an air-filled bowel loop. Despite this finding, the role of the method in this pathology remains controversial, as ultrasound is the primary diagnostic modality.
  • Functional constipation (constipation): The radiograph may demonstrate colonic dilation and fecal impaction. Nevertheless, the method has extremely low sensitivity and specificity. The presence of visible stool does not always confirm clinical constipation. Therefore, routine use of radiographs is not recommended; the study is reserved for carefully selected patients in whom an organic cause of the disease is suspected.
Test your knowledge on the topicTasks from the "Diagnostic Radiology" course bank — instant answers and explanations.

Gastrointestinal motility disorders

The term "motility disorders" refers to reduced bowel peristalsis in the complete absence of organic luminal occlusion. Conventional radiography aids in the differential diagnosis of such conditions.

  1. Acute disorders (acute dysmotility): Paralytic ileus is clinically very similar to mechanical obstruction. For example, acute gastroenteritis can trigger localized paralytic ileus. On an upright plain radiograph, this appears as dilation of the affected bowel segment and multiple fluid levels.
  2. Chronic disorders: In primary anomalies such as neuronal dysplasia (neuronal dysplasia), plain radiography may demonstrate significant colonic dilation. This finding warrants further investigation, including contrast studies and biopsy.
How to memorize

To recognize intussusception on a radiograph, look for the "meniscus sign"—the shadow of the soft-tissue intussusceptum projecting into the lumen of the air-filled bowel loop, resembling a crescent moon.

Class and exam questions

Does plain radiography replace ultrasound in intestinal intussusception?

No, it does not replace it. Ultrasound is the primary and most accurate diagnostic method, whereas the role of radiography remains controversial despite its ability to detect the "meniscus sign".

Are changes always visible on radiographs in nephrocalcinosis?

No, not always. In milder cases of the disease, high-density pathological changes in the renal parenchyma may not be visualized on conventional radiographs.

Can a diagnosis of constipation be made based on a plain radiograph alone?

No. The visualization of stool accumulation has low specificity and does not always indicate clinically significant constipation. The method is prescribed only when an organic cause is suspected.

Have a question? Ask the AIThe AI tutor has reviewed the material on "Plain radiography" and will explain it in simple terms.

What else to study on this topic

  • The role of ultrasound in the triage of soft-tissue masses
  • Advantages of non-contrast CT over radiography in acute renal colic
  • Imaging and MRI semiotics of Hoffa's fat pad pathologies
  • Methods of pneumatic and contrast reduction of intussusception under fluoroscopic guidance
  • Significance of the barium enema in Hirschsprung's disease

Master the entire topic in the "Diagnostic Radiology" course

This is a summary. The course covers everything tested in classes and exams.

  • Complete study guide on "Plain radiography" and 2,199 other subject pages
  • Assignments and quizzes after every topic — just like in a colloquium
  • AI tutor answers questions on the topic anytime
  • 10 video lessons on the subject
Open full reviewSubject curriculumfrom 599 ₽ per month

Other topics in the section "Diagnostic Radiology of the Abdominal Organs"

Diagnostic imaging of soft tissue tumorsAdipocytic soft tissue tumorsNodular fasciitisDesmoid fibromatosisPigmented villonodular synovitisSoft tissue vascular malformationsTumors and pseudotumors of peripheral nervesMyxoid soft tissue tumorsSynovial sarcomaInfectious and inflammatory soft tissue diseasesDiagnostic radiology in medicineDiagnostic imaging of the handSciatic nerve MRI
Entire section "Diagnostic Radiology of the Abdominal Organs"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.