Acute Medical Take · diagnostic imaging

Imaging Atlas

Four separate clinical navigators for X-rays, CT, MRI and special imaging—each beginning with normal studies, systematic interpretation and real-life abnormalities linked to specialist management.

◎XR · CT · MR · USNORMAL → FINDING → ACTION

DEDICATED IMAGING NAVIGATOR

Normal first. Then interpret and act.

NAVIGATOR · REAL CLINICAL IMAGING

Normal first, then common abnormalities

Four separate modality atlases with systematic interpretation, labelled real-life images and treatment-linked management.

SEPARATE IMAGING CATEGORY

X-rays

Chest, abdomen, bones and devices—begin with projection and image quality.

1Confirm patient/date, side marker, projection and body part2RIPE: rotation, inspiration, projection/position and exposure3Chest A–E: airway, breathing/pleura, circulation, diaphragm, everything else4Abdomen: gas pattern, bowel calibre, walls, soft tissues, calcification and bones5Compare priors; describe location, severity, complications and action

Normal chest radiograph

Interpretation

Use this as the baseline: adequate inspiration/exposure, no focal air-space opacity, pleural line, effusion or acute device complication. A normal CXR does not exclude PE, early infection or ACS.

Specialist management

No image-directed treatment. Correlate with physiology and the clinical question; obtain further imaging only when indicated.

Treatment and adult doses

1Do not prescribe from a normal image alone.

2If symptoms remain unexplained, reassess and follow the relevant clinical pathway.

Right upper-lobe pneumonia

Interpretation

Consolidation is an air-space pattern, not an organism. Check for air bronchograms, lobar boundaries, cavitation, effusion and alternative diagnoses.

Specialist management

Assess NEWS2, oxygenation, sepsis, aspiration and complications. Use local CAP/HAP guidance and obtain microbiology when severity or epidemiology warrants it.

Treatment and adult doses

1A common adult low-severity CAP regimen is amoxicillin 500 mg orally three times daily for 5 days; higher severity, allergy and atypical cover follow local/NICE antimicrobial guidance.

2Oxygen to the prescribed target; IV fluids only for assessed hypovolaemia. Drain complicated parapneumonic effusion/empyema with respiratory/radiology input.

Large pneumothorax

Interpretation

Identify the pleural line and absent peripheral vascular markings. Tension is a clinical diagnosis; supine films may show a deep sulcus rather than an apical line.

Specialist management

Unstable suspected tension pneumothorax requires immediate decompression without waiting for imaging. Stable management depends on symptoms, size, cause and current pleural-disease guidance.

Treatment and adult doses

1Give titrated analgesia; oxygen only to the clinically prescribed target.

2Needle decompression, aspiration or intercostal drainage is procedural and site/protocol specific—obtain respiratory/critical-care support.

Small-bowel obstruction

Interpretation

Look for central valvulae conniventes crossing the full lumen, calibre and multiple air–fluid levels. AXR cannot reliably define the cause or exclude ischaemia; CT is often required.

Specialist management

Nil by mouth, IV access, fluid/electrolyte correction, analgesia/antiemetic and early surgical review. Peritonism, closed loop, ischaemia or perforation needs emergency escalation.

Treatment and adult doses

1Balanced crystalloid boluses should be guided by haemodynamics, losses and comorbidity—not a fixed volume.

2Nasogastric decompression when vomiting/distended or directed by surgery; antibiotics are indicated for suspected ischaemia, perforation or sepsis using the local intra-abdominal protocol.

SEPARATE IMAGING CATEGORY

CT scans

Always identify the protocol, contrast phase, plane and window before interpreting.

1Confirm non-contrast versus contrast and exact phase2Review all slices—not a single screenshot3Use brain, lung, mediastinal, abdominal and bone windows as appropriate4Search vessels, solid organs, bowel, free fluid/gas, nodes and bones5State time-critical findings directly to the responsible team

Normal non-contrast CT brain

Interpretation

Follow blood–brain–CSF–bone: inspect sulci, grey–white differentiation, ventricles/cisterns, midline, posterior fossa, skull and sinuses.

Specialist management

A normal early CT does not exclude acute ischaemia, meningitis or some causes of headache. Continue the clinical pathway and obtain CTA/MRI/LP only when indicated.

Treatment and adult doses

1No treatment is based on a normal CT alone.

2Thrombolysis/thrombectomy decisions require the full stroke imaging and clinical pathway.

Intracerebral haemorrhage

Interpretation

Define site, size, intraventricular extension, mass effect, hydrocephalus and potential underlying lesion. Review anticoagulants and compare CTA/venography indications.

Specialist management

Immediate stroke/neurosurgical and critical-care pathway. Control physiology, reverse anticoagulation when indicated and repeat imaging for deterioration.

Treatment and adult doses

1Warfarin-associated major ICH: 4-factor PCC is commonly 25–50 units/kg by INR/product protocol plus IV vitamin K 5–10 mg; follow the local reversal guideline.

2Dabigatran: idarucizumab 5 g IV when urgent reversal is indicated. Factor-Xa inhibitor reversal is agent/time/severity specific; use the current local/haematology protocol.

CTPA—pulmonary embolus

Interpretation

Follow the pulmonary arteries from main to segmental branches, then assess RV strain and alternative diagnoses. Motion/poor opacification can create false defects.

Specialist management

Risk-stratify with haemodynamics, biomarkers and RV findings. Shock or deterioration requires immediate PE response, cardiology/respiratory and critical-care escalation.

Treatment and adult doses

1Stable confirmed PE: apixaban 10 mg orally twice daily for 7 days then 5 mg twice daily, or rivaroxaban 15 mg twice daily for 21 days then 20 mg daily, when appropriate after renal, weight, interaction, pregnancy and bleeding checks.

2Haemodynamic instability may require unfractionated heparin and reperfusion therapy; thrombolysis dosing is specialist/protocol led.

Normal contrast CT abdomen/pelvis

Interpretation

Identify contrast phase, then review lung bases, solid organs, biliary tract, pancreas, adrenals, kidneys/ureters, bowel/mesentery, vessels, nodes, pelvis and bones.

Specialist management

Normal anatomy is a reference, not proof that symptoms are benign. Check the full series/report and pursue endoscopy, ultrasound, MRI or repeat assessment when indicated.

Treatment and adult doses

1No image-directed medication.

2Contrast reactions and extravasation require the local radiology emergency protocol.

SEPARATE IMAGING CATEGORY

MRI

Sequence determines meaning: never call a lesion bright or dark without naming the sequence.

1Confirm body part, plane, field strength and contrast2Identify T1, T2, FLAIR, DWI/ADC and susceptibility sequences3DWI bright plus ADC low supports restricted diffusion4Inspect cord/cauda equina, marrow and soft tissues on spinal studies5Check implants, monitoring compatibility and motion artefact

Normal axial T2 brain MRI

Interpretation

Use a normal study to learn symmetry and expected CSF, grey-matter and white-matter signal. Then compare every abnormality across sequences.

Specialist management

A normal selected sequence does not equal a normal complete MRI. Use the formal report and clinical context.

Treatment and adult doses

1No image-directed treatment.

2MRI safety screening is mandatory before scanning; unstable patients require an MRI-compatible monitoring plan.

Cerebellar haemorrhage

Interpretation

Blood signal varies with age and sequence. Inspect susceptibility, mass effect, hydrocephalus and the brainstem; correlate with CT and onset.

Specialist management

Urgent stroke/neurosurgical review because posterior-fossa deterioration can be rapid. Manage anticoagulation, BP and airway through the haemorrhage pathway.

Treatment and adult doses

1Use the same agent-specific anticoagulant reversal principles as for CT-confirmed ICH.

2Hyperosmolar therapy and surgical decompression are specialist decisions based on examination, mass effect and hydrocephalus—not the image alone.

Brain metastasis

Interpretation

Review T1 pre/post contrast, T2/FLAIR oedema, DWI and susceptibility. Consider abscess, primary tumour, demyelination and treatment effect.

Specialist management

Discuss urgently with oncology/neurosurgery when symptomatic, haemorrhagic or causing mass effect. Stage systemically and obtain tissue when it changes management.

Treatment and adult doses

1For symptomatic tumour-related cerebral oedema, dexamethasone is commonly started at 4–8 mg/day; severe raised-pressure symptoms may require 16 mg/day under oncology/neurosurgical guidance, with glucose, infection, GI and taper planning.

2Do not give prophylactic antiseizure medication routinely to a seizure-naïve patient unless the specialist pathway indicates it.

Normal midline sagittal brain MRI

Interpretation

Use sagittal anatomy to assess corpus callosum, pituitary/sella, aqueduct/ventricles, brainstem, craniocervical junction and cerebellar tonsils.

Specialist management

Correlate with axial/coronal sequences and the reported indication. A single normal slice cannot exclude pathology.

Treatment and adult doses

1No image-directed medication.

2Contrast use depends on the clinical question, renal context and local gadolinium policy.

SEPARATE IMAGING CATEGORY

Special imaging

Ultrasound, echocardiography, PET/CT and nuclear medicine require modality-specific interpretation.

1State the focused clinical question and modality limitations2Ultrasound: probe, plane, compression, Doppler and dynamic signs3Echo: LV/RV, valves, pericardium and haemodynamics4PET: uptake pattern plus anatomical CT correlate5Nuclear imaging: tracer distribution, matched/mismatched defects and artefact

Normal gallbladder ultrasound

Interpretation

Confirm fasting/context and scan dynamically in multiple planes. A still frame cannot demonstrate a sonographic Murphy sign or exclude intermittent obstruction.

Specialist management

No image-directed treatment. Correlate with LFTs, inflammatory markers and the formal report.

Treatment and adult doses

1No medicine is indicated for normal imaging.

2Persistent biliary symptoms may need repeat ultrasound, MRCP, HIDA or surgical review depending on the syndrome.

Abdominal aortic aneurysm on ultrasound

Interpretation

Measure maximum anteroposterior diameter outer wall to outer wall in a true transverse plane and confirm in longitudinal view. Pain/shock raises concern for leak or rupture regardless of screening size.

Specialist management

Symptomatic or ruptured AAA requires immediate vascular surgery, major-haemorrhage and CT/operative pathway if physiology allows. Do not delay transfer for repeated bedside measurements.

Treatment and adult doses

1Use cautious blood-product-led resuscitation and permissive hypotension according to the major-haemorrhage/vascular protocol until control; avoid indiscriminate crystalloid.

2Give analgesia and activate definitive endovascular/open repair—no drug repairs an aneurysm.

Pericardial effusion with tamponade physiology

Interpretation

Tamponade is clinical and haemodynamic, supported by right-atrial/right-ventricular collapse, respiratory Doppler variation and IVC findings. Loculated/postoperative effusions may behave differently.

Specialist management

Immediate cardiology/critical-care review. Shock requires urgent drainage by the safest expert route; do not delay for a complete elective study.

Treatment and adult doses

1Give cautious small crystalloid boluses only as a temporary bridge when preload depleted; reassess after each bolus.

2Avoid vasodilators and unnecessary diuresis in obstructive shock. Pericardiocentesis/surgical drainage is definitive; antibiotics or anti-inflammatory therapy depend on cause.

V/Q lung scan

Interpretation

A segmental perfusion defect without matched ventilation abnormality raises PE probability. Interpret using the report, CXR, clinical probability and the study’s diagnostic category.

Specialist management

Use when the PE pathway selects V/Q imaging, including appropriate patients where CTPA is unsuitable. Non-diagnostic studies require further testing rather than reassurance.

Treatment and adult doses

1Confirmed stable PE uses patient-specific anticoagulation; apixaban 10 mg twice daily for 7 days then 5 mg twice daily is one option when appropriate.

2Pregnancy, renal failure, cancer, antiphospholipid syndrome and extremes of weight require pathway-specific agent selection.

FDG PET/CT—nodal metastasis

Interpretation

FDG uptake is not synonymous with cancer: infection, inflammation and normal tissues can be avid. Review glucose, timing, prior treatment and CT morphology.

Specialist management

Use the study for the defined staging/response question and discuss in the relevant MDT. Biopsy remains necessary when histology changes treatment.

Treatment and adult doses

1No medication is selected from FDG avidity alone.

2Steroids, antimicrobials, chemotherapy, immunotherapy or radiotherapy require diagnosis- and MDT-specific protocols.

8 modality and system maps

Choose the right study, then search it systematically

QUESTION → PROTOCOL → QUALITY → SEARCH → COMPARE → REPORT → ACT

CXR

Chest radiograph

RIPE → A B C D E

Quality, airway, lungs/pleura, heart/mediastinum, diaphragm, bones and devices. Include oedema, collapse, consolidation, effusion, pneumothorax and mediastinal widening.

CTH

CT head / stroke

Blood → brain → CSF → bone

Non-contrast CT, CTA and perfusion: haemorrhage, early ischaemia, LVO, mass effect, hydrocephalus, venous thrombosis and stroke mimics.

CTA

Aorta & pulmonary arteries

Lumen → wall → branches → organ

CTPA RV strain and infarction; CT aorta dissection flap, intramural haematoma, penetrating ulcer, rupture and malperfusion.

ABD

Acute abdomen

Gas → bowel → organs → vessels

Obstruction, perforation, ischaemia, inflammation, bleeding, pancreatobiliary disease and urinary obstruction—confirm contrast phase.

Ultrasound & POCUS

Probe → plane → finding → limit

Lung, pleura, DVT compression, aorta, bladder, biliary and renal assessment. Record the focused question, images and limitations.

ECHO

Focused echocardiography

LV → RV → valves → fluid

Global ventricular function, RV pressure/volume pattern, pericardial fluid/tamponade, severe valve disease and volume clues; comprehensive echo follows when needed.

CMR

Cardiac CT & MRI

Anatomy + function + tissue

Coronary anatomy, structural disease, myocarditis, infarction, infiltrative disease, cardiomyopathy, masses and viability using protocol-specific interpretation.

Nuclear / PET imaging

Tracer → distribution → correlate

Perfusion SPECT/PET, infection/inflammation and oncology. Recognise physiological uptake, attenuation artefact and the need for CT/clinical correlation.

CONTRASTCheck allergy history, renal function, pregnancy possibility, metformin/local policy and the exact clinical question. Do not withhold a time-critical scan automatically—discuss risk versus delay with radiology.

COMMUNICATEState modality, site, key positive and negative findings, severity, comparison, uncertainty and required action. Confirm that time-critical findings reached the responsible clinician.

Critical findings wall

! STEMI/occlusion or malignant arrhythmia! Complete/high-grade block or pacing failure! Tension pneumothorax or major airway/device problem! Intracranial haemorrhage, LVO or herniation! Aortic catastrophe, massive PE or active bleeding! Perforation, bowel ischaemia or infected obstruction! Tamponade, severe ventricular failure or acute valve catastrophe! Cord/cauda equina compression

New enhanced section

Interpretation of medical images

Chest X-ray • CT • MRI • PET/CT • ultrasound

Use a fixed system, compare prior imaging and read the radiologist’s report. These examples teach recognition; they do not replace diagnostic image review.

1ConfirmPatient, date/time, modality, body part, projection/sequence, contrast and clinical question.

2QualityCoverage, rotation, inspiration/exposure, motion and artefact. Poor quality changes confidence.

3SearchUse the modality-specific checklist below; inspect every region, not only the obvious lesion.

4ConcludeDescribe finding, location, severity, complications, comparison and urgent action.

AP chest radiograph showing right upper lobe airspace shadowing from pneumonia

1Right upper-lobe airspace opacity2Compare both hila3Check pleural angles

Chest X-ray—right upper-lobe pneumonia

A real AP chest radiograph showing right upper-lobe shadowing. Consolidation is a pattern, not an organism.

Look for: RIPE quality, then A–E: airway, breathing/lungs/pleura, circulation/mediastinum, diaphragm, everything else. Seek air bronchograms, silhouette loss and complications.
Clinical next step: Correlate with physiology and infection syndrome. Follow-up imaging is indicated for selected patients according to local/NICE guidance.

CDC, public domain · original and licence ↗

Chest radiograph showing a large right spontaneous pneumothorax with visible pleural line

1Visceral pleural line2No peripheral lung markings3Assess mediastinal shift

Chest X-ray—large right pneumothorax

A genuine chest radiograph showing a large right pneumothorax. Tension is a clinical diagnosis supported by imaging when time permits.

Look for: Pleural line, absent peripheral markings, lung collapse, deep sulcus on supine film and mediastinal shift.
Clinical next step: Unstable suspected tension pneumothorax requires immediate decompression—do not delay for imaging.

James Heilman MD, CC BY 3.0 · original and licence ↗

Non-contrast CT brain showing intracerebral and intraventricular haemorrhage

1Hyperdense acute blood2Intraventricular extension3Assess mass effect / hydrocephalus

CT brain—intracerebral haemorrhage

On non-contrast CT, acute blood is typically hyperdense. Inspect every slice and window; this single teaching frame cannot show the full extent.

Look for: Blood, extra-axial collections, early ischaemic change, mass effect, midline shift, ventricles/cisterns, skull and sinuses.
Clinical next step: Immediate stroke/neurosurgical pathway; reverse anticoagulation when indicated and manage physiology according to current guidance.

Glitzy queen00, public domain · original and licence ↗

CT pulmonary angiography images showing saddle pulmonary embolus and bilateral thrombus burden

1Central filling defect2Saddle embolus3Assess RV strain

CT pulmonary angiography—saddle embolus

CTPA demonstrates contrast-opacified pulmonary arteries with intraluminal filling defects.

Look for: Embolus level/burden, RV:LV ratio and septal bowing, reflux into IVC/hepatic veins, infarction and alternative diagnoses.
Clinical next step: Risk-stratify using haemodynamics, biomarkers and RV findings. Shock or deterioration requires immediate senior/PERT/critical-care escalation.

Thrombosis Journal open-access case, CC BY · original and licence ↗

MRI brain showing deep cerebellar haemorrhage

1Cerebellar lesion2Posterior fossa

MRI brain—cerebellar haemorrhage

MRI signal depends on sequence and blood age. DWI/ADC is central to acute ischaemia; FLAIR, T1/T2 and susceptibility answer different questions.

Look for: Confirm sequence and plane; compare DWI with ADC, inspect FLAIR/T2, SWI/GRE for blood, vessels, mass effect and enhancement after contrast.
Clinical next step: Interpret with onset time and neurological examination. Posterior fossa lesions can deteriorate rapidly despite small size.

Andrewmeyerson derivative, CC BY-SA · original and licence ↗

PET CT images showing FDG avid cervical lymph node metastasis

1High FDG uptake2CT anatomical lesion3Review whole-body distribution

PET/CT—FDG-avid nodal metastasis

PET displays metabolism; CT supplies anatomy. Uptake is not synonymous with malignancy because inflammation and physiological activity also take up FDG.

Look for: Pattern and intensity of uptake, anatomical correlate, physiological sites, treatment timing, blood glucose and prior study.
Clinical next step: Use for the specific staging/response question and multidisciplinary interpretation; biopsy remains necessary when tissue diagnosis changes management.

Akira Kouchiyama, CC BY-SA 3.0 · original and licence ↗

Ultrasound image showing a normal gallbladder without stones or wall thickening

1Anechoic gallbladder lumen2Thin wall3No posterior shadowing stone

Abdominal ultrasound—normal gallbladder view

A genuine normal gallbladder ultrasound image. Ultrasound is dynamic and operator-dependent; a still frame never replaces the full examination.

Look for: Gallstones and shadowing, wall thickness, pericholecystic fluid, sonographic Murphy sign and common bile duct calibre.
Clinical next step: Escalate suspected biliary sepsis or obstruction; correlate with LFTs, inflammatory markers and the formal report.

Ptrump16, CC BY-SA 4.0 · original and licence ↗

Chest X-ray

RIPE quality → A–E review → compare prior. Never stop after the first abnormality.

Confirm contrast phase and windows. Scroll systematically; one screenshot cannot exclude disease.

MRI

Know the sequence. Signal meaning changes between DWI/ADC, FLAIR, T1/T2 and susceptibility imaging.

PET/CT

Metabolic uptake needs anatomical and clinical correlation; infection/inflammation can be FDG-avid.

Ultrasound

Orientation, probe position, dynamic signs and Doppler matter; static images are incomplete.

Safety: If imaging and the patient conflict, reassess the patient, verify the study and contact radiology. Act immediately on time-critical findings such as tension pneumothorax, major haemorrhage, large-vessel occlusion, aortic catastrophe, massive PE, cord compression or perforation.

ESCALATE THE PATIENT—NOT JUST THE PICTUREImmediately involve the appropriate radiology, stroke, surgical, cardiology, critical-care or tertiary service for time-critical findings.