Name a medical scan or imaging test (pictures of the body, not readouts like an EKG)

The rarest possible answer — almost no player finds it.

• Pneumoencephalogram— Walter Dandy replaced spinal fluid with air to image the brain, 1919.

Genuinely obscure. Most players never think of it.

• 3D echocardiogram
• 3D ultrasound
• 4D CT
• 4D flow MRI
• AAA screening scan
• Acoustic angiography
• Adaptive optics retinal imaging
• Adrenal CT
• Adrenal scan
• Air enema
• Amniography
• Amplified MRI
• Amyloid PET
• Antegrade pyelogram
• Aortogram
• Appendix ultrasound
• Arthrogram
• Babygram
• Biophysical profile
• Bitewing X-ray
• Bladder scan
• Bone age X-ray
• Bone marrow scan
• Brain death scan
• Bronchial angiography
• Bronchogram
• Bubble study
• Bursogram
• Cardiac amyloid scan
• Cartilage MRI
• Cavernosogram
• Cephalometric X-ray
• Cerebral angiogram
• Cervical length scan
• CEST MRI
• Cherenkov imaging
• Chest MRI
• Cholangiogram
• Choline PET
• Cisternogram
• Colonic transit study
• Cone-beam CT
• Confocal microscopy of the cornea
• Contrast echocardiogram
• Contrast-enhanced mammography
• Contrast-enhanced ultrasound
• Corneal topography
• Cranial ultrasound
• CSF flow MRI
• CT chest, abdomen and pelvis
• CT coronary angiogram
• CT enterography
• CT fluoroscopy
• CT gastrography
• CT KUB
• CT perfusion
• CT pulmonary angiogram
• CT urogram
• Current density imaging
• Cystogram
• Dacryocystogram
• Dacryoscintigraphy
• Dating scan
• DaTscan
• Defecography
• Dental transillumination
• Dermatologic OCT
• Diffuse optical imaging
• Diffusion tensor imaging
• Digital X-ray radiogrammetry
• Discogram
• DMSA scan
• Dopamine receptor PET
• Dotatate PET
• Dual-energy CT
• Dual-energy radiography
• Elastography
• Electrical impedance tomography
• Endoanal ultrasound
• Endoscopic OCT
• Endoscopic ultrasound
• Enteroclysis
• EOS imaging
• Epidurogram
• ERCP
• Esophageal transit study
• Event-related optical signal
• External eye photography
• Extremity CT
• Facial CT
• FAPI PET
• FAST scan
• FDS PET
• FES PET
• FET PET
• Fetal echocardiogram
• Fetal MRI
• Fetography
• Fistulogram
• FLT PET
• Fluciclovine PET
• Fluorescein angiography
• Fluorescence-guided imaging
• Fluorodopa PET
• FMISO PET
• fNIRS
• Follicle tracking scan
• Full-mouth series
• Functional ultrasound imaging
• Fundus autofluorescence
• Galactogram
• Gallium scan
• Gastric emptying study
• Gastrointestinal protein-loss scintigraphy
• Genitogram
• Growth scan
• Gynography
• Handheld vital microscopy
• Heidelberg retinal tomography
• Herniogram
• HIDA scan
• High-frequency skin ultrasound
• Hip ultrasound
• HR-pQCT
• HRCT
• HyCoSy
• Hyperpolarized carbon-13 MRI
• Hyperpolarized gas MRI
• Hyperspectral imaging
• Hysterosalpingogram
• ICG angiography
• Immuno-PET
• Immunoscintigraphy
• Infarct-avid scan
• Inner ear MRI
• Intracardiac echocardiogram
• Intraoperative MRI
• Intravascular OCT
• Intravascular ultrasound
• Intravenous pyelogram
• Iodobenzamide SPECT
• Laryngeal ultrasound
• Laryngography
• Laser Doppler imaging
• Laser speckle contrast imaging
• Left ventriculography
• Linear tomography
• Liver CT
• Liver iron MRI
• Liver-spleen scan
• Loopogram
• Low-dose CT lung screening
• Lung shunt study
• Lung ultrasound
• Lymphangiogram
• Lymphoscintigraphy
• Magnetic induction tomography
• Magnetic particle imaging
• Magnetic resonance fingerprinting
• Mass miniature radiography
• Meckel's scan
• MEG
• Meibography
• Mesenteric angiogram
• Methionine PET
• MIBG scan
• Microangiography
• Microwave imaging
• Milk scan
• Modified barium swallow
• MR angiogram
• MR elastography
• MR enterography
• MR neurography
• MR spectroscopy
• MR urography
• MRCP
• MRI-PDFF
• MUGA scan
• Multiphoton tomography
• Musculoskeletal ultrasound
• Myelogram
• Neck CT
• Nuchal scan
• Obstetric Doppler ultrasound
• Occlusal X-ray
• OCT angiography
• Octreotide scan
• Ocular ultrasound
• Optical coherence tomography
• Oral cholecystogram
• Orbit CT
• Orbit MRI
• Orbit X-ray
• Orbital color Doppler imaging
• Oxygen-15 water PET
• Pancreas CT
• Parathyroid 4D CT
• Parathyroid scan
• Pelvimetry
• Penile Doppler ultrasound
• Perfusion MRI
• Periapical X-ray
• Peripheral angiogram
• PET-MRI
• Phase-contrast X-ray imaging
• Photoacoustic imaging
• Pituitary MRI
• Placentography
• Portography
• Positron emission mammography
• Pouchogram
• Proton radiography
• PSMA PET
• Pulmonary angiogram
• Pyloric ultrasound
• Quantitative CT
• Quantitative MRI
• Radionuclide venography
• Real-time MRI
• Reflectance confocal microscopy
• Renal angiogram
• Renal artery Doppler
• Retinal vessel analysis
• Retrograde pyelogram
• Right ventriculography
• Salivagram
• Salivary gland scan
• SAP scan
• Scanning laser polarimetry
• Scanogram
• Scintimammography
• Scrotal scintigraphy
• Shunt series
• Shuntogram
• Sialogram
• Siascopy
• Sinus MRI
• Skeletal survey
• Small bowel follow-through
• Small bowel transit study
• Sniff test
• Sodium fluoride PET
• Sodium MRI
• Sonohysterogram
• Spatial frequency domain imaging
• SPECT
• Specular microscopy
• Spinal angiogram
• Spinal ultrasound
• Stereoradiography
• Sternum X-ray
• Stress CT perfusion
• Stress radiographs
• Super-resolution ultrasound
• Synaptic density PET
• Tagged red blood cell scan
• Tau PET
• Temporal bone CT
• Tenogram
• Terahertz imaging
• Thermoacoustic imaging
• TMJ MRI
• Total body photography
• Transcranial Doppler
• Transesophageal echocardiogram
• Transperineal ultrasound
• Transrectal ultrasound
• Tubogram
• Ultrasound computed tomography
• Ultrasound-modulated optical tomography
• Urethrogram
• V/Q scan
• Vaginogram
• Vasogram
• Venogram
• Vertebral fracture assessment
• Videourodynamics
• Virtual autopsy
• Voiding urosonography
• Weight-bearing CT
• Weight-bearing X-ray
• White blood cell scan
• Whole-body iodine scan
• Whole-body MIBI scan
• Wound imaging
• X-ray kymography
• X-ray motion analysis
• Xenon CT
• Xeroradiography

Uncommon — only a minority of players land here.

• Abdominal CT
• Abdominal MRI
• Abdominal ultrasound
• Abdominal X-ray
• Ankle X-ray
• Anomaly scan
• Arm X-ray
• Barium enema
• Barium meal
• Barium swallow
• Breast MRI
• Breast ultrasound
• Cardiac CT
• Cardiac MRI
• Carotid ultrasound
• Chest CT
• Clavicle X-ray
• Contrast X-ray
• Coronary angiogram
• Coronary calcium scan
• Cranial MRI
• CT angiogram
• CT colonography
• Doppler ultrasound
• Early pregnancy scan
• Elbow X-ray
• Facial bones X-ray
• Femur X-ray
• Fluoroscopy
• fMRI
• Foot X-ray
• Full-body scan
• Fundus photography
• Gallbladder ultrasound
• Gender scan
• Hand X-ray
• Head CT
• Hip MRI
• Hip X-ray
• Knee MRI
• Knee X-ray
• Leg X-ray
• Mandible X-ray
• Musculoskeletal MRI
• Nasal bone X-ray
• Neck MRI
• Nuclear medicine scan
• Nuclear stress test
• Panoramic X-ray
• Pelvic MRI
• Pelvic ultrasound
• Pelvic X-ray
• Pregnancy scan
• Prostate MRI
• Renal CT
• Renal scan
• Renal ultrasound
• Rib X-ray
• Scrotal ultrasound
• Shoulder MRI
• Shoulder X-ray
• Sinus CT
• Sinus X-ray
• Skull X-ray
• Soft-tissue neck X-ray
• Spine CT
• Spine MRI
• Spine X-ray
• Stress echocardiogram
• Thermography
• Thyroid scan
• Thyroid ultrasound
• Tomosynthesis
• Transvaginal ultrasound
• Whole-body MRI
• Wrist X-ray

A solid, middling pick shared with plenty of other players.

• Angiogram
• Bone scan
• Chest X-ray
• Dental X-ray
• DEXA scan
• Echocardiogram
• Mammogram
• PET scan

The most common answer on the board.

• CT scan
• MRI
• Ultrasound
• X-ray