Diagnostic radiology in medicine

Musculoskeletal system and soft tissues

The baseline method for evaluating masses remains plain radiography (plain radiograph), which is used for the initial visual characterization of pathologies.

Ultrasound (US) is critically important for the initial triage (triage) of suspicious masses. The use of power Doppler makes it possible to assess blood flow and helps in predicting tumor malignancy.

Magnetic resonance imaging (MRI) is essential for surgical planning. It allows for an accurate assessment of the mass size and depth of invasion, which is critical for soft tissue sarcomas of the extremities (e.g., synovial sarcoma).

Radiologists must be able to differentiate between benign lipoma and well-differentiated liposarcoma, recognize elastofibroma dorsi, vascular anomalies, and specific lesions of the infrapatellar fat pad (Hoffer's fat pad). To standardize approaches, the WHO classification and digital assistant applications (e.g., BoSTT) are used.

Gastrointestinal tract and urogenital system

In pediatric radiology, priority is given to safe methods. Indications and algorithms are strictly regulated by international societies (ESPGHAN, NASPGHAN, ESPR).

• Gastrointestinal pathologies: If hypertrophic pyloric stenosis is suspected, ultrasound is performed, with diagnostic criteria depending on the patient's age. If Crohn's disease is suspected in children, ultrasound acts as the first-line method. To visualize IBD using MR enterography, the possibility of omitting gadolinium administration in favor of diffusion-weighted imaging is evaluated.
• Congenital anomalies: Hirschsprung's disease in newborns is diagnosed using a contrast enema. For bleeding Meckel's diverticulum, radionuclide scintigraphy with pertechnetate is required.
• Neonatal resuscitation: In critically ill infants in the NICU, the diagnostic value of conventional abdominal radiography and intestinal ultrasound is actively compared.
• Urogenital pathology: If ovarian torsion is suspected in children, imaging is performed according to strict ESPR recommendations. Work is underway in pediatric uroradiology to standardize terminology.

Chest organs: lungs and mediastinum

Radiography serves as the primary method for detecting chest masses. To clarify anatomical relationships, ultrasound, contrast-enhanced CT, or MRI are prescribed, and for staging — PET/CT or bone scintigraphy.

Differential diagnosis of mediastinal masses:

1. Anterior mediastinum: Lymphomas, leukemias, thymus anomalies, and germ cell tumors are most common. The most frequent of these is mature teratoma, containing fatty tissue and calcifications.
2. Middle mediastinum: Congenital cysts (bronchogenic, duplication) and lymphadenopathy, usually of infectious etiology (especially in the setting of tuberculosis), predominate.
3. Posterior mediastinum: Neurogenic tumors, such as neuroblastoma and ganglioneuroma, are characteristic.

Lung developmental anomalies: In lung hypoplasia, the radiograph shows complete opacification (white-out) of the affected hemithorax and mediastinal shift. In scimitar syndrome (congenital venolobar syndrome), CT demonstrates hypoplasia of the right lung and a key sign — the aberrant pulmonary vein ("scimitar vein") draining blood into the inferior vena cava.

Radiation dose management

Patients requiring repeated CT scans (e.g., for IBD) are at risk of exceeding their lifetime cumulative radiation dose. This can provoke radiation-induced cancer. Big data-based software is used for control, allowing online monitoring of the dose received by the patient.

Radiation dose reduction is a multidisciplinary process. Physician responsibilities include:

• Counseling patients on the risks of ionizing radiation exposure.
• Prescribing radiological examinations only when the result is highly likely to influence management tactics (change management).
• Using alternative radiation-free methods: MRI (for acute abdominal pain, including in pregnant women) or ultrasound with graded compression (for diagnosing acute appendicitis).
• Using low-dose CT algorithms: automatic tube current modulation and iterative reconstruction algorithms (with voltage reduction, e.g., down to 100 kVp in CT enterography).

Class and exam questions

What else to study on this topic

• MRI semiotics of tumors of the infrapatellar fat pad (Hoffer's fat pad).
• Specific radiological findings in elastofibroma dorsi and fibromatoses.
• Dependence of ultrasound parameters of pyloric stenosis on the child's age and size.
• Radiological staging of hepatoblastoma in childhood.
• Use of ultrasound with graded compression as the first line of diagnosis for acute appendicitis.

Other topics in the "Additional Topics" section

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