Medical Imaging Images

Question 1

Answer 1

Modality: PET-CT; 18-fluorodeoxyglucose (18F-FDG) radiotracer fused image (left); non-enhanced chest CT bone window, core biopsy (right)

Region: Chest, lung

Radiologic sign: Increased 18F-FDG uptake in the right apical mass; CT-guided core biopsy from the right apical mass

Diagnosis: Pancoast tumor, thoracic core biopsy

Question 2

Answer 2

Modality: Pulmonary CT-angiography (contrast-enhanced series in pulmonary arterial phase), iv. iodine-based contrast agent

Region: Chest, axial views at the level of the pulmonary bifurcation

Radiologic sign: Large hypodense filling defects in the pulmonary arteries at both sides. Diagnosis: Bilateral pulmonary embolism

Question 3

Answer 3

Modality: Bedside chest radiograph (AP radiograph)

Region: Chest, lung

Radiologic sign: Decreased tranparency (consolidation) in the right upper lobe with radiolucent aerobronchogram (red arrow) left-sided subclavian catheter, ECG electrodes

Diagnosis: Right-sided lobar pneumonia in the upper lobe

Question 4

Answer 4

Modality: Non-enhanced CT, brain window setting

Region: Brain, axial view

Radiologic sign: Cortical-subcortical border disappeared/blurred due to oedema (blue area), Hyperdense Media-sign - acute thrombosis of the right middle cerebral artery (yellow arrow)

Diagnosis: Subacute ischaemia in the territory of the right MCA

Question 5

Answer 5

Modality: left – Non-contrast CT, right – Contast-enhanced CT, iv. iodine-based contrast agent

Region: Upper abdomen

Radiologic sign: Enlarged pancreas with indistinct margins

• yellow arrow*: Enhancing head – living tissue
• red arrow* : Non-enhancing body – necrosis

Diagnosis: Acute necrotizing pancreatitis; fatty liver

Question 6

Answer 6

Modality: Lower extremity venous ultrasound, linear probe (7,5-10 MHz), B-mode and Color-Doppler mode (right panel)

Region: V. femoral superficial and popliteal vein;

• Left image* – transverse section,
• right image* – transverse section

Radiologic sign: Veins are filled with hypoechoic thrombus, the lumen is non-compressible demonstrating no flow (lack of Doppler–signal); beneath the popliteal artery has normal flow signal (green arrow)

Diagnosis: Deep vein thrombosis (DVT)

Question 7

Answer 7

Modality: Non-enhanced CT, brain window setting (window level: 40 HU; window width: 80 HU)

Region: Brain, axial view

Radiologic sign: Large hyperdense hemorrhage (density: 60-70 HU) extending into the ventricles, slight midline shift to the right, compressed right lateral ventricle due to the edema (yellow arrow)

Diagnosis: Acute cerebral apoplexy, most commonly caused by hypertension

Question 8

Answer 8

Modality: Non-enhanced CT, brain window setting (window level: 40 HU; window width: 80 HU)

Region: Brain, axial view

Radiologic sign: Extensive hypodense (20-25 HU) brain parenchyma, concomitant dilatation of the right lateral ventricle (arrows); calcifications of the choroideal plexuses (common finding, green arrows)

Diagnosis: Chronic ischemic lesion in the territory of right MCA

Question 9

Answer 9

Modality: FAST (Focused Assessment with Sonography for Trauma) scan

Region: Abdomen, pleural sinuses, pericardium, aorta

Radiologic sign: Free abdominal fluid in the hepatorenal fossa, around the spleen, among the bowel loops and in Douglas pouch. Patient sustained blunt trauma.

Diagnosis: Free abdominal fluid after blunt trauma, suspicious for internal hemorrhage

Question 10

Answer 10

Modality: Digital subtraction angiography (DSA), intraarterial iodine-based contrast agent; noncontrast CT (inlet)

Region: Upper abdomen, liver

Radiologic sign: large hepatic mass in the righ lobe (hyperdense mass after embolization - inlet) selective catheterization of the right hepatic artery

Diagnosis: trans-catheter arterial embolization of a giant hepatic hemangioma with lipiodol; lipiodol appears hyperdense on the noncontrast CT

Question 11

Answer 11

Modality: FDG PET-CT (right panel: noncontrast CT); 18(F)-fluorodeoxyglucose

Region: upper abdomen, axial view

Sign: increased focal uptake in the liver; physiological uptake in the right kidney

Diagnosis: Malignant tumor (colorectal cc. metastasis) in the liver

Question 12

Answer 12

Modality: left - DWI MRI; middle - CE T1W SE with fat saturation MRI after iv. gadolinium administration; right - T2W fatsat MRI (axial view)

Region: Brain, axial views

Radiologic sign: bilateral enhancing intrabulbar masses, restricted diffusion

Diagnosis: bilateral retinoblastoma

Question 13

Answer 13

Modality: Digital subtraction angiography (DSA), Catheter angiography, intraarterial iodine-based contrast agent

Region: Neck, carotid bifurcation

Radiologic sign:

• left image* – Significant internal carotid artery stenosis,
• center image* – balloon dilatation and stenting,
• right image* – Control angiography, normal flow

Diagnosis: Carotid angioplasty and stenting of a significant carotid stenosis

Question 14

Answer 14

Modality: fluoroscopy, iv. iodine-based contrast agent

Region: upper abdomen, liver

Radiologic sign: Stent (yellow arrow) placement between the portal (red arrow) and hepatic vein (blue arrow) to create a lasting connection for the purpose of decreasing the portal pressure.

Diagnosis: TIPS (transjugular intrahepatic porto-systemic shunt) in liver fibrosis, proper contrast filling of the stent

Question 15

Answer 15

Modality: Mammography of the right and left breast, mediolateral oblique view, soft-beam technique (30 kV)

Region: Craniocaudal (CC) views of the right and left breasts

Radiologic sign: Soft tissue mass with spiculated contour and microcalcifications in the right breast

Diagnosis: Right-sided breast cancer, Normal left breast

Question 16

Answer 16

Modality: HRCT of the lung (noncontrast study), lung window

Region: Chest, lung, axial view

Radiologic sign: Bilateral dorsobasal honeycombing pattern (yellow arrow), traction bronchiectasis (green arrow)

Diagnosis: Pulmonary fibrosis

Question 17

Answer 17

Modality: PET-CT, 18-fluorodeoxyglucose (18F-FDG) radiotracer; Hybrid imaging method: PET - Metabolic activity, CT - Morphology

Region: Whole-body, coronal view

Radiologic sign: Increased fluorodeoxyglucose (18F-FDG) uptake in liver and pubic bone, normal physiologic activity is shown in the bladder

Diagnosis: Multiple metastases (liver, pubic bone)

Question 18

Answer 18

Modality: DWI MRI (left) and 3D TOF (time-of-flight) angiography, noncontrast sequences

Region: brain, axial view

Radiologic sign: significant hyperintensity (representing restricted diffusion) in the right parietal lobe with concomitant abrupt filling defect at the right middle cerebral artery

Diagnosis: large acute infarction, acute thrombosis of the right middle cerebral artery

Question 19

Answer 19

Modailty: upper left: Non-enhanced CT, upper right and lower panels:
Multiphase contrast-enhanced CT (early arterial, portal and venous phase), iv. iodine- based contrast agent

Region: Abdomen, retroperitoneum

Radiologic sign: Aortic aneurysm with wall calcifications (yellow arrow), hyperdense retroperitoneal fluid collection (red arrow), aortic aneurysm leakage.

Diagnosis: Abdominal aortic aneurysm rupture

Question 20

Answer 20

Modality: X-ray of the left knee in two projections (left), PD FS (proton density fatsat) and T1W postcontrast MRI (middle and right respectively)

Region: Left knee, lateral view (radiograph), coronal views (MRI)

Radiologic sign: Inhomogeneous destructive metaphyseal lesion of the left femur. Periosteal reaction, Codman triangle (red area) and invasion to the surrounding soft tissue is also present (radiograph). Inhomogenously enhancing metaphyseal mass infliltrating the surrounding soft tissue.

Diagnosis: Osteosarcoma of the femur

Question 21

Answer 21

Modality: left image – PA chest radiograph (upright); right image – postcontrast chest CT; lung window setting, iodine-based contrast agent

Region: Chest, lung

Radiologic sign: Multiple soft tissue lesions showing different size and rounded shape (yellow arrows).

History: Kidney cancer.

Diagnosis: Multiple lung metastases

Question 22

Answer 22

Modality: left panels - Non-enhanced CT, right panels - CE T1WI MRI (upper - Sagittal view, lower - Axial view) after iv. gadolinium administration

Region: Brain, axial and sagittal views

Radiologic sign: Intraaxial parenchymal mass with rim-enhancement, which compresses the right lateral ventricle (arrow)

Diagnosis: Glioblastoma multiforme (GBM)

Question 23

Answer 23

Modality: left image – Abdominal plain radiograph, standing posture; right image – Contrast-enhanced CT scan, iv. iodine-based contrast agent

Region: Abdomen and pelvis

Radiologic sign: Distended colon with air–fluid levels (yellow arrows). In the sigmoid colon an obstructing contrast-enhancing mass is shown (red arrow).

Diagnosis: Large-bowel obstruction caused by sigmoid cancer

Question 24

Answer 24

Question 25

Answer 25

**Modality**: Non-enhanced CT **Region**: Brain, axial view **Radiologic sign**: Hyperdense, spider-web-like hyperdensity in the basal cisterns and sulci **Diagnosis**: Acute subarachnoid hemorrhage, most commonly due to aneurysm rupture

Question 26

Answer 26

**Modality**: bone scintigraphy with 99mTc with methylene diphosphonate (MDP) radiotracer **Region**: whole body, AP and PA views **Sign**: multiple foci of increased radiopharmaceutical uptake in the bones **Diagnosis**: multiplex osseal metastases, scoliosis

Question 27

Answer 27

**Modality**: *left* - T1W fatsat postcontrast MRI after iv. gadolinium administration; right - T2W fatsat MRI (sagittal view) **Region**: thoracic spine **Radiologic sign**: epidural enhancing mass at the level of Th 9-12th vertebras, no signal loss on fatsat image; non-enhancing fluid inside of the mass **Diagnosis**: epidural abscess

Question 28

Answer 28

**Modality**: DWI MR (left), dynamic mDIXON contrast-enhanced MR (*middle*) after iv. gadolinium, T2W MRI (*right*) **Region**: pelvic MR study, axial view (*left*) and sagittal view (*right*) **Radiologic sign**: thickened rectal wall/intraluminal mass with intensive contrast enhancement and concomitant restricted diffusion (red arrow) **Diagnosis**: rectal adenocarcinoma

Question 29

Answer 29

**Modality**: Contrast-enhanced chest CT, lung window setting (right panel); mediastinal window setting (left panel), iodine-based contrast agent **Region**: Chest, axial views **Radiologic sign**: Air-containing *(red arrow)* fluid collection with thick enhancing rim (*yellow arrow*) **Diagnosis**: Left-sided lung abscess

Question 30

Answer 30

**Modality**: aortic CT angiography; **Region**: chest; *left* – coronal view, *right* – sagittal view, iv. iodine-based contrast agent **Radiologic sign**: intima flap (yellow arrow), crescent-shaped false lumen (green arrow), oval true lumen (blue arrow) **Diagnosis**: Stanford A aortic dissection, affecting the left subclavian artery (red arrow)

Question 31

Answer 31

**Modality**: ankle X-ray – lateral view (l*eft image*), CT 3D reconstruction (*right image*) **Region**: Left ankle **Radiologic sign**: abrupt discontinuity of the cortex of the calcaneus, lucent fracture lines **Diagnosis**: Comminuted fracture of the calcaneus.

Question 32

Answer 32

**Modality**: T2W MRI and dynamic contrast-enhanced MRI of the prostate after iv. gadolinium contrast agent administration **Region**: Pelvis, axial views **Radiologic sign**: T2 hypointensity in the peripheral zone (left panel); intensive contrast-enhencing mass in the same area (*signed with red*); normal central zone (*signed with blue*) **Diagnosis**: prostate adenocarcinoma

Question 33

Answer 33

**Modality**: Low-dose non-enhanced CT scan **Region**: abdomen, coronal view **Radiologic sign**: Juxtavesical hyperdensity on the left side **Diagnosis**: Juxtavesical stone

Question 34

Answer 34

**Modality**: mDIXON dynamic contrast-enhanced MR after iv. gadolinium (noncontrast, arterial phase, portal phase, venous phase) **Region**: upper abdominal MR study, axial view **Radiologic sign**: large hepatic mass, intensive arterial enhancement, no „wash-out”, non-enhancing/hypointense central scar (red arrow) **Diagnosis**: hepatic focal nodular hyperplasia (FNH)

Question 35

Answer 35

**Modality**: Non-enhanced CT ; *left -* brain window setting (window level : 40 HU; window width: 80 HU), *right -* bone window setting (window level: 600 HU; window width: 2800 HU) **Region**: Brain, axial views **Radiologic sign**: Lens-shaped hyperdense bleeding and skull vault fracture (*yellow arrow*) **Diagnosis**: Right-sided epidural hematoma

Question 36

Answer 36

**Modality**: Radiograph of the left hallux in two projections **Region**: Left foot, hallux **Radiologic sign**: Marked ill-defined bone resorption in distal tuberosity (= ungual process). Ulcerous lesion is also shown. **Diagnosis**: Acute osteomyelitis

Question 37

Answer 37

**Modality**: Contrast-enhanced head-and-neck CT, * left image* – axial view; * right image* – coronal view, iv. iodine-based contrast agent **Region**: Head and neck, axial (left) and coronal (right) view **Radiologic sign**: Right-sided submandibular fluid collection with thick enhancing wall *(red arrow)*. Fluid inside the abscess ha a density of 0-10 HU, and shows no enhancement. Patient had prior wisdom tooth extraction. **Diagnosis**: Neck abscess

Question 38

Answer 38

**Modality**: PA (left) and lateral (right) chest radiograph; hard-beam technique (120–140 kV) **Region**: chest, pleura **Radiologic sign**: Decreased transparency at the right lung base showing a meniscus-shaped contour on the right side. Diaphragm and lateral sinuses cannot be differentiated on the right. Left side is normal. **Diagnosis**: Right-sided pleural effusion

Question 39

Answer 39

Question 40

Answer 40

**Modality**: Non-enhanced MRI (*left*: T1WI sagittal, *center*: T2WI sagittal, *right*: T2WI axial) **Region**: Lumbar spine **Radiologic sign**: Hypointense (dehydrated) discus protruding into the spinal canal *(yellow arrow)* **Diagnosis**: Disc herniation between L2 and L3 level

Question 41

Answer 41

**Modality**: Ultrasound of gallbladder with convex probe (3.5–5 MHz), B-mode **Region**: Gallbladder, right subcostal view **Radiologic sign**: Echodense structure in the lumen (*yellow arrow*) with acoustic shadowing; Thick, stratified, oedematous wall (*red arrow*) **Diagnosis**: Acute cholecystitis with gallstone

Question 42

Answer 42

**Modality**: Noncontrast CT **Region**: Upper abdomen, axial views **Radiologic sign**: Diffusely, homogenously decreased density (cca. - 20 HU) of the liver. The vessels (*blue arrows*) are more dense in comparison to the liver parenchyma **Diagnosis**: Steatosis hepatis (Fatty liver)

Question 43

Answer 43

**Modality**: Sonogram of the appendix (left: linear 7,5–10 MHz probe; right: convex 3,5-5 MHz probe), B-mode (*inlet*: power Doppler) **Region**: Appendix, longitudinal and cross-sectional views **Radiologic sign**: *left image –* Thickened (more than 6 mm), non-compressible tubular structure (green arrow) showing signs of edema and hypervascularisation (*red arrow*). Small amount of free abdominal fluid is also present (*yellow arrow*). **Diagnosis**: Acute appendicitis

Question 44

Answer 44

**Modality**: *left -* SWI axial MRI (magnitude image); *middle -* T2WI axial MRI; right - T1W sagittal MRI, noncontrast sequences **Region**: Brain, axial and sagittal views **Radiologic sign**: crescent-shaped hyperintense area on all sequences in the subdural space **Diagnosis**: left-sided subdural hematoma, most commonly caused by the rupture of the bridge veins

Question 45

Answer 45

**Modality**: Thyroid gland scintigram, Technetium-99m (99m Tc)-pertechnetate scintigraphy **Region**: Thyroid **Radiologic sign**: Enlarged right lobe with focal lesion showing decreased tracer activity (*yellow arrow*) **Diagnosis**: Cold nodule

Question 46

Answer 46

**Modality**: *left* - Barium enema study, double-contrast method (barium and air); *right* – contrast-enhanced CT, venous phase, iv. iodine-based contrast agent **Region**: Abdomen, axial view **Radiologic sign**: Annular irregular stenosis (apple-core sign), tumorous infiltration of the surrounding fat (increased density) **Diagnosis**: Colon adenocarcinoma

Question 47

Answer 47

**Modality**: Digital subtraction angiography (DSA), Catheter angiography, intraarterial iodine-based contrast agent **Region**: Lower extremity, popliteal artery **Radiologic sign**: * left image* – Significant right popliteal artery stenosis (*yellow arrow*), collateral circulation; * right image* – Control angiography after balloon dilatation (NO stents were used), collateral circulation is diminished **Diagnosis**: Chronic popliteal artery stenosis, balloon angioplasty (PTA)

Question 48

Answer 48

**Modality**: FLAIR (*left*) and DWI (*right*) MRI, noncontrast sequences **Region**: brain, axial view **Radiologic sign**: hypertensive lesion representing edema and restricted diffusion in the territory of the right basal ganglions **Diagnosis**: small acute infarction

Question 49

Answer 49

**Modality**: *left* – PA chest radiograph, frontal projection (upright position); *right* – noncontrast CT, axial view **Region**: Chest, upper abdomen **Radiologic sign**: Crescents of radiolucency under the hemidiaphragms (*red arrow*), free air accumulation at the convexity of the liver and at the liver hilum (*yellow arows*) **Diagnosis**: Free abdominal air (due to perforation of luminal abdominal organ)

Question 50

Answer 50

**Modality**: Barium swallow test, fluoroscopy **Region**: Esophagus **Radiologic sign**: Outpouching (*red arrow*) filled with contrast material near the pharyngo-esophageal junction. An air-fluid level is also seen (*yellow arrow*). Dilated, sclerotic aorta (*blue arrow*) **Diagnosis**: Zenker diverticulum

Question 51

Answer 51

**Modality**: Breast sonography with linear probe (7.5–10 MHz), B-mode **Region**: Breast, axilla **Radiologic sign**: * left image* – well-defined anechoic lesion with posterior acoustic enhancement (btw yellow lines); * right image* – ill-defined hypoechogenic lesion with partial acoustic shadowing (btw red olines): solid structure, suspicious of cancer **Diagnosis**: cyst (left) and breast carcinoma (right)

Question 52

Answer 52

**Modality**: T2W MRI and 3D TOF angiography (non-contrast) **Region**: brain, axial view **Radiologic sign**: circumscribed dilatation of the right internal carotid artery **Diagnosis**: aneurysm of the right internal carotid artery (cavernous part)

Question 53

Answer 53

**Modality**: * left image* – X-ray of the sinuses; * right image* – noncontrast CT of the sinuses, low-dose, bone window **Region**: Maxillary region, paranasal sinuses **Radiologic sign**: Right maxillary sinus shows homogenous decreased transparency, the left one has rounded mucous thickening **Diagnosis**: Bilateral sinusitis

Question 54

Answer 54

**Modality**: T2W MRI, axial plane (*left*); 3D MRCP, coronal plane (heavily T2-weighted sequence) (*right*), noncontrast study **Region**: upper abdominal MR study, axial (*left*) and coronal (*right*) views **Radiologic sign**: filling defect in the common bile duct **Diagnosis**: choledocholithiasis

Question 55

Answer 55

**Modality**: Expiratory chest radiograph in frontal projection **Region**: Chest, pleura **Radiologic sign**: Peripheral space is radiolucent with no lung markings (yellow *arrow*), visible visceral pleural line (*blue arrow*), partially collapsed left lung, slight mediastinal shift to the right. **Diagnosis**: Left-sided pneumothorax (PTX)

Question 56

Answer 56

**Modality**: *left* - contrast-enhanced ultrasonography (CEUS) after iv. microbubble administration, arterial phase; *right* - CEUS, late phase **Region**: liver, right subcostal view **Radiologic sign**: hepatic mass showing peripheral nodular enhancement in the arterial phase and complete filling in the late phase **Diagnosis**: hepatic hemangioma

Question 57

Answer 57

**Modality**: linear probe (7,5–10 MHz), * left* - B-mode US, * middle* – Color Doppler US, right – B-mode US **Region**: neck, thyroid gland **Radiologic sign**: well-circumscribed Isoechoic vascularized nodule, *right* - FNAB (fine-needle aspiration biopsy) (yellow arrow) **Diagnosis**: Suspicious thyroid nodule, cytology proves benignity

Question 58

Answer 58

**Modality**: thyroid scintigraphy; Technetium-99m (99m Tc)-pertechnetate radiotracer **Region**: thyroid gland **Sign**: Increased uptake in the left lobe of the thyroid, low uptake in the other parts of the gland. **Diagnosis**: Hot nodule in the thyroid (toxic nodule), other parts of the thyroid are supressed.