Detector view · drag to rotate

Decompressing CT volume…

Coronary CT atlas

An ECG-gated coronary CT angiogram, rendered as a volume, with each coronary segment labelled by expert annotators. Drag to swing the C-arm, scroll to zoom, click a vessel to name it, double-click to reset.

Rendering

C-arm projection

Pick a standard projection. The camera sits at the image intensifier, so the patient's left is on screen right in AP.

Radiation at this angle (teaching model)

Field of view

Pulse rate

Detector raised 15 cm off the patient

Opacity

Contrast lumen (chambers, aorta)

Myocardium & soft tissue

Epicardial fat

Lumen threshold

Spine, ribs & sternum

Diaphragm & liver

Contrast density (angiogram)

Cut plane

Plane position

Sweep the C-arm (LAO ↔ RAO) Orientation marker C-arm schematic

Load another CT

Open a de-identified .nii, .nii.gz or .nrrd volume. It is read in this browser and never uploaded. Loaded files show the CT only; segment labels come with the built-in case.

Cardiac cath views

Spine, ribs & diaphragm

The standard angiographic projections, each rendered from the gated CT in this atlas (ImageCAS case 11, a right-dominant heart). Every image is a projection of this patient's segmented coronary lumen at that C-arm angle, so overlap and foreshortening are real for this heart. Optimal angles differ from patient to patient.

Reading a projection

LAO / RAONamed for where the image intensifier sits. In LAO it is over the patient's left anterior chest, in RAO over the right.

CRA / CAUCranial tilts the intensifier toward the head, caudal toward the feet.

Find the diaphragmCranial angulation lifts the diaphragm (whose domes lie behind and below the heart) up into the field toward the heart; caudal angulation leaves it low, clear of the heart. A diaphragm rising into the field suggests a cranial view.

Find the spineThe spine moves toward the right of the image as the LAO angle increases, and toward the left with RAO. In AP it lies behind the heart. Ribs run obliquely across the field in every view.

LAO: RCA is a "C"The RCA curves around the right AV groove as a C, and the LAD runs down the centre with the LCx to the right.

RAO: RCA is an "L"The RCA runs down the AV groove and turns along the inferior wall, showing the PDA's length.

Two views minimumImage every segment in at least two roughly orthogonal projections, so a lesion hidden by overlap or foreshortening in one appears in the other.

Name that view

Unlabelled coronary angiogram rendered from the CT at a standard projection

Which projection is this? Find the spine (LAO or RAO) and the diaphragm (higher in cranial views), then read the shape of the vessels.

Left coronary views

Right coronary views

Rendering views from the CT…

Angiograms here are projections of the CT-segmented lumen (ImageCAS-X labels), not recorded cine. They show anatomy and overlap only: no flow, catheter or diaphragm shadow. The spine, ribs, sternum and diaphragm come from the same CT; the diaphragm is drawn as the soft tissue beneath the lung bases, so there is no edge under the heart itself. The CT was reconstructed on a cardiac field of view of about 17 cm, so only structures close to the heart appear. Optimal angles, and how far the diaphragm rises, vary with each patient and with breath-hold depth. "Length shown" is approximate: it uses each segment's main axis and is given only for fairly straight segments.

JL 4

Judkins Left · 6 Fr · drag to rotate

Loading 3D engine…

Catheter selection for fellows

What the trials and expert reviews say about access, catheter choice and catheter-related complications, followed by cases to test yourself. Each statement carries its evidence type.

Randomised trialMeta-analysisGuidelineExpert review / practiceCase series / registry

1 · Radial or femoral access

RIVALRCTJolly et al., Lancet 2011 [1]

7,021 patients with ACS, 158 hospitals in 32 countries.
30-day death, MI, stroke or non-CABG major bleeding: 3.7% radial vs 4.0% femoral (HR 0.92, 95% CI 0.72–1.17; p=0.50).
Major vascular complications fell with radial access: 1.4% vs 3.7%.

MATRIX (access)RCTValgimigli et al., Lancet 2015 [2]

8,404 patients with ACS, with or without ST elevation; two-sided α 0.025.
MACE: 8.8% radial vs 10.3% femoral (RR 0.85; p=0.031, not significant at α 0.025).
Net adverse clinical events: 9.8% vs 11.7% (RR 0.83; p=0.009).
Driven by less BARC major bleeding (1.6% vs 2.3%) and lower all-cause mortality (1.6% vs 2.2%; p=0.045).

2021 ACC/AHA/SCAI revascularization guidelineGuidelineLawton et al., JACC 2022 [3]

Radial access is a Class 1, Level A recommendation for PCI in both ACS and stable ischemic heart disease, to reduce bleeding and vascular complications, and in ACS, death.

2 · Left or right radial, conventional or distal

TALENTRCTSciahbasi et al., Am Heart J 2011 [4]

1,540 patients randomised to left or right radial; primary endpoint fluoroscopy time.
Diagnostic procedures: 149 vs 168 s fluoroscopy, favouring the left radial, with lower dose-area product.
From the left radial the catheter course resembles the femoral one, so conventional curves usually work (Pavei 2010 [9]).

Left vs right radial meta-analysisMeta-analysisGuo et al., PLoS One 2013 [5]

22 randomised trials and 10,287 patients. Left radial access reduced fluoroscopy time and contrast use, with strong between-trial heterogeneity and no significant difference in failure rate.

DISCO RADIALRCTAminian et al., JACC Cardiovasc Interv 2022 [6]

Distal (snuffbox) radial access did not reduce forearm radial artery occlusion compared with conventional radial access; occlusion was under 1% in both arms.
Distal access had more crossover and more radial spasm, but a shorter time to haemostasis.

3 · One catheter or two

JUDGERCTXanthopoulou et al., EuroIntervention 2018 [7]

640 patients undergoing non-urgent right radial angiography: Tiger II versus Judkins left and right.
Tiger II used less contrast (the primary endpoint) and less fluoroscopy time.
Catheter or access changes did not differ significantly (17.8% vs 21.3%).

A universal catheter saves an exchange and some contrast in routine diagnostic work. Keep Judkins shapes ready, because about one in five cases changes catheter either way.

4 · Choosing a guiding catheter

Read the diagnostic angiogram for four things before choosing: aortic root size, left main length, take-off of the target vessel, and lesion location. Then match the guide's lumen and support to the devices you may need. Expert review Pavei et al., EuroIntervention 2010 [9]

Situation	Suggested shapes	Why
Left coronary, femoral, normal aorta and left main	EBU 4 or JL 4	Downsize to 3.5 or upsize to 4.5 as the root requires.
Left coronary, large aorta	EBU 4–4.5 or JL 5; AL 2–3	The larger curve reaches the ostium; Amplatz shapes add support.
Complex LCx lesion	AL	Deep, coaxial engagement and strong backup, but aggressive: handle very gently.
RCA, superior take-off	AL, AR or hockey stick	The hooked tip aligns with an upward-pointing ostium.
RCA, inferior take-off	JR, JR short tip, MP, bypass right	The tip points down along the vessel's course.
Internal mammary graft	IMA catheter	Sits coaxially in the IMA ostium with support from the subclavian.
SVG to OM, hard to cross with a filter	AL 1–2, preferably 7 Fr	Better backup force.
SVG to RCA	MP; hockey stick as an alternative	Matches the inferior course of right-sided grafts.
Left coronary from the right radial	EBU 3.5 or JL 3.5	About 0.5 cm smaller than the femoral choice for the same root.
RCA from the right radial	JR (often JR 5)	About 1 cm larger than the femoral choice helps.
From the left radial	Conventional curves	The course resembles the femoral approach.
Inadequate support (LCx or RCA)	AL; AL 0.75 for the RCA	AL 0.75 is less aggressive than AL 1 with similar support.
Rotational atherectomy	6 Fr: 1.5 mm burr · 7 Fr: 1.75 mm · 8 Fr: ≥2 mm	Guide lumen limits burr size.

5 · Catheter-induced dissection

Iatrogenic left main dissectionRegistryEshtehardi et al., Am Heart J 2010 [10]

Incidence 0.07% (38 of 51,452 patients), almost twice as common during PCI as during diagnostic angiography.
82% were treated with stenting or CABG; early outcome was favourable when recognised and managed promptly.

Right-sided aortocoronary dissectionSystematic review of casesSanchez-Jimenez et al., JSCAI 2022 [11]

142 reported cases (1973–2021). Catheters in use: Judkins right 42.0%, Amplatz left 25.4%. These are shares of published reports, not per-catheter risks.
56% occurred during PCI; 54% were high grade (Dunning class III).
Ostial RCA stenting was used in 62%, conservative care in 18% and surgery in 28%.

Keep the catheter coaxial, watch the pressure trace before every injection, and stop injecting through the catheter once a dissection is seen, because more contrast can extend it. IVUS helps locate the entry point and guide ostial stent coverage.

6 · Cases

Choose an answer to see the explanation and its source.

References

Jolly SS, et al. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL). Lancet 2011;377:1409–20. doi:10.1016/S0140-6736(11)60404-2
Valgimigli M, et al. Radial versus femoral access in patients with acute coronary syndromes undergoing invasive management (MATRIX). Lancet 2015;385:2465–76. doi:10.1016/S0140-6736(15)60292-6
Lawton JS, et al. 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization. J Am Coll Cardiol 2022;79:e21–e129. doi:10.1016/j.jacc.2021.09.006
Sciahbasi A, et al. Transradial approach (left vs right) and procedural times during percutaneous coronary procedures: TALENT study. Am Heart J 2011;161:172–9. doi:10.1016/j.ahj.2010.10.003
Guo X, et al. Left radial access is preferable to right radial access for the diagnostic or interventional coronary procedures: a meta-analysis. PLoS One 2013;8:e78499. doi:10.1371/journal.pone.0078499
Aminian A, et al. Distal versus conventional radial access for coronary angiography and intervention: the DISCO RADIAL trial. JACC Cardiovasc Interv 2022;15:1191–201. doi:10.1016/j.jcin.2022.04.032
Xanthopoulou I, et al. Randomised comparison of JUDkins vs. tiGEr catheter in coronary angiography via the right radial artery: the JUDGE study. EuroIntervention 2018;13:1950–8. doi:10.4244/EIJ-D-17-00699
Kim SM, et al. Novel diagnostic catheter specifically designed for both coronary arteries via the right transradial approach. Int J Cardiovasc Imaging 2006;22:295–303. doi:10.1007/s10554-005-9029-8
Pavei A, et al. Tools & Techniques: choice and use of guiding catheters. EuroIntervention 2010;6:543–4. doi:10.4244/EIJV6I4A89
Eshtehardi P, et al. Iatrogenic left main coronary artery dissection: incidence, classification, management, and long-term follow-up. Am Heart J 2010;159:1147–53. doi:10.1016/j.ahj.2010.03.012
Sanchez-Jimenez E, et al. Iatrogenic aortocoronary dissection during right coronary artery procedures: a systematic review of the published literature. J Soc Cardiovasc Angiogr Interv 2022;1:100443. doi:10.1016/j.jscai.2022.100443
Radial catheter selection. Cardiac Interventions Today, March/April 2011 (practice review). citoday.com

Teaching material summarising published evidence. It does not replace institutional protocols, current guidelines or supervised training. Practice statements without trial data are labelled as expert review or practice.

SAPIEN 3 Ultra RESILIA

Aortic · balloon-expandable · drag to rotate

Expansion100%

Anatomy35%

View

Labels

Loading 3D engine…

Intravascular imaging: IVUS and OCT

Scroll through simulated pullbacks, switch between IVUS and OCT on the same vessel, measure what you see, and test yourself against the criteria the trials used. The criteria, cut-offs and trial results below are taken from the cited papers.

◇ Simulated images: a teaching model of backscatter and attenuation, not patient recordings

Pullback lab

Case

At this frame

Frame

Contours Labels Cut angle

LumenEEM (vessel border)Stent Click two points on the cross-section to measure a distance. Keys: ← → step a frame.

Reading the image: IVUS and OCT side by side

IVUS uses ultrasound, so it sees through blood and deep into the wall but blurs detail. OCT uses near-infrared light, so it needs a contrast flush to clear blood and penetrates only a millimetre or two, but resolves structures about ten times finer. Most of the differences below follow from that.

Feature	IVUS	OCT
Resolution and depth (approximate)	Axial resolution roughly 100–200 µm; sees the whole vessel wall and beyond	Axial resolution roughly 10–20 µm; penetration about 1–2 mm, so the vessel border can be lost behind lipid
Blood in the lumen	Sparkling speckle that moves frame to frame	Must be flushed with contrast; residual blood blurs and shadows the image
Normal wall	Bright intima, dark (echolucent) media, bright adventitia	Three layers: signal-rich intima, signal-poor media, heterogeneous adventitia
Fibrous plaque	Homogeneous, intermediate brightness	Signal-rich and homogeneous, low attenuation
Lipid / necrotic core	Attenuated plaque: deep signal loss without bright calcium	Signal-poor region with diffuse borders and high attenuation under a fibrous cap; cap thickness can be measured
Calcium	Very bright leading edge with an acoustic shadow behind it; thickness cannot be measured	Signal-poor with sharp borders; light passes through, so arc and thickness can be measured
Thin-cap fibroatheroma	Not resolvable (cap below IVUS resolution)	Lipid with a fibrous cap < 65 µm
Thrombus	Low-echo, layered or lobulated intraluminal mass	Red thrombus: high backscatter with strong shadowing. White thrombus: high backscatter, low attenuation
Stent struts	Bright arcs with shadows	Bright lines with sharp, complete shadows; apposition can be measured strut by strut
Guidewire	Bright dot with a shadow, in every frame	Bright dot with a wedge-shaped shadow

Measurements and decision criteria

Before stenting: is the left main significant?

IVUS MLA ≤ 4.5 mm² best predicted FFR ≤ 0.80 in isolated ostial and shaft left main lesions (77% sensitivity, 82% specificity) [Park 2014].
Deferring revascularisation with an MLA ≥ 6 mm² was safe at 2 years in the prospective LITRO study [LITRO].
Between the two, physiology helps decide. In non-left-main vessels, IVUS MLA alone predicts FFR only modestly (MLA < 2.79 mm²: 76% sensitivity, 78% specificity) [Kang 2016].

Planning: sizing, landing zones and calcium

OCT sizing in ILUMIEN IV: the distal reference mean EEL diameter, rounded down to the nearest 0.25 mm. If the EEL is not visible, the mean lumen diameter, rounded up [ILUMIEN IV analysis].
Land the stent edges where plaque burden is < 50% (an ULTIMATE optimisation criterion) [ULTIMATE].
OCT calcium score: 2 points for a maximum arc > 180°, 1 for maximum thickness > 0.5 mm, 1 for length > 5 mm. A score of 4 predicted poor expansion (78% vs 96%) [Fujino 2018].
IVUS calcium score: 1 point each for superficial calcium > 270° over ≥ 5 mm, 360° superficial calcium, a calcified nodule, and vessel diameter < 3.5 mm. A score ≥ 2 favours upfront calcium modification [Zhang 2021].

After stenting: is the result optimal?

ULTIMATE: in-stent MLA > 5.0 mm² or ≥ 90% of the distal reference lumen; edge plaque burden < 50%; no edge dissection involving the media longer than 3 mm [ULTIMATE].
EAPCI consensus: expansion > 80% (minimum stent area / mean reference lumen area); MSA > 5.5 mm² by IVUS and > 4.5 mm² by OCT outside the left main. Malapposition matters when > 0.4 mm over > 1 mm [EAPCI 2018].
Left main MSA targets used in RENOVATE-COMPLEX-PCI: > 7 mm² distal and > 8 mm² proximal left main [RENOVATE].
Major edge dissection in ILUMIEN IV: ≥ 60° of the circumference and ≥ 3 mm long, treated with an additional stent [ILUMIEN IV analysis].

Evidence

Trial	Population	Comparison	Primary result
IVUS-XPL (JAMA 2015)	1,400 patients, stents ≥ 28 mm	IVUS vs angiography	MACE at 1 year 2.9% vs 5.8% (HR 0.48), driven by less ischaemia-driven TLR
ULTIMATE (JACC 2018)	1,448 all-comers	IVUS vs angiography	TVF at 1 year 2.9% vs 5.4% (HR 0.53); 1.6% when all IVUS optimal criteria were met vs 4.4% when not
RENOVATE-COMPLEX-PCI (NEJM 2023)	1,639 complex lesions	IVUS or OCT vs angiography (2:1)	Cardiac death, TV-MI or TVR 7.7% vs 12.3% at median 2.1 years (HR 0.64)
OCTOBER (NEJM 2023)	1,201 complex bifurcations	OCT vs angiography	MACE at 2 years 10.1% vs 14.1% (HR 0.70)
ILUMIEN IV (NEJM 2023)	2,487 diabetic or complex-lesion patients	OCT vs angiography	Larger MSA (5.72 vs 5.36 mm²); TVF at 2 years 7.4% vs 8.2% (HR 0.90, not significant); stent thrombosis 0.5% vs 1.4%
OCTIVUS (Circulation 2023)	2,008 patients	OCT vs IVUS	OCT non-inferior: 2.5% vs 3.1% at 1 year; fewer major procedural complications with OCT (2.2% vs 3.7%)
ILUMIEN III (Lancet 2016)	450 patients	OCT vs IVUS vs angiography	Median MSA 5.79, 5.89 and 5.49 mm². OCT non-inferior to IVUS, not superior to angiography
Network meta-analysis (Lancet 2024)	22 RCTs, 15,964 patients	Imaging (IVUS or OCT) vs angiography	Target lesion failure RR 0.71; cardiac death RR 0.55; stent thrombosis RR 0.52; all-cause death RR 0.75. OCT and IVUS similar

Guidelines: the 2024 ESC chronic coronary syndrome guideline recommends IVUS or OCT guidance for PCI of anatomically complex lesions, in particular left main, true bifurcations and long lesions (Class I) [ESC 2024]. The 2021 ACC/AHA/SCAI revascularisation guideline gives IVUS a Class 2a recommendation for stent guidance, especially in left main or complex stenting, and lists OCT as a reasonable alternative except in ostial left main disease [ACC/AHA/SCAI 2021].

References

Hong SJ, et al. Effect of IVUS-guided vs angiography-guided everolimus-eluting stent implantation: the IVUS-XPL randomized clinical trial. JAMA 2015;314:2155–63. doi:10.1001/jama.2015.15454
Zhang J, et al. IVUS versus angiography-guided drug-eluting stent implantation: the ULTIMATE trial. J Am Coll Cardiol 2018;72:3126–37. doi:10.1016/j.jacc.2018.09.013
Lee JM, et al. Intravascular imaging-guided or angiography-guided complex PCI. N Engl J Med 2023;388:1668–79. doi:10.1056/NEJMoa2216607
Holm NR, et al. OCT or angiography guidance for PCI in complex bifurcation lesions. N Engl J Med 2023;389:1477–87. doi:10.1056/NEJMoa2307770
Ali ZA, et al. Optical coherence tomography-guided versus angiography-guided PCI. N Engl J Med 2023;389:1466–76. doi:10.1056/NEJMoa2305861
Ali ZA, et al. Optical coherence tomography predictors of clinical outcomes after stent implantation: the ILUMIEN IV trial. Eur Heart J 2024 (PMC11560276).
Kang DY, et al. OCT-guided or IVUS-guided PCI: the OCTIVUS randomized clinical trial. Circulation 2023;148:1195–206. doi:10.1161/CIRCULATIONAHA.123.066429
Ali ZA, et al. OCT compared with IVUS and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI). Lancet 2016;388:2618–28. doi:10.1016/S0140-6736(16)31922-5
Stone GW, et al. Intravascular imaging-guided coronary drug-eluting stent implantation: an updated network meta-analysis. Lancet 2024;403:824–37. doi:10.1016/S0140-6736(23)02454-6
Fujino A, et al. A new OCT-based calcium scoring system to predict stent underexpansion. EuroIntervention 2018;13:e2182–9. doi:10.4244/EIJ-D-17-00962
Zhang M, et al. IVUS-derived calcium score to predict stent expansion in severely calcified lesions. Circ Cardiovasc Interv 2021;14:e010296. doi:10.1161/CIRCINTERVENTIONS.120.010296
Park SJ, et al. IVUS-derived minimal lumen area criteria for functionally significant left main coronary artery stenosis. JACC Cardiovasc Interv 2014;7:868–74. doi:10.1016/j.jcin.2014.02.015
de la Torre Hernandez JM, et al. Prospective application of pre-defined IVUS criteria for intermediate left main lesions: the LITRO study. J Am Coll Cardiol 2011;58:351–8. doi:10.1016/j.jacc.2011.02.064
Kang SJ, et al. Mathematically derived criteria for detecting functionally significant stenoses using CCTA-based myocardial segmentation and IVUS MLA. Am J Cardiol 2016;118:170–6. doi:10.1016/j.amjcard.2016.04.049
Räber L, et al. Clinical use of intracoronary imaging. Part 1: guidance and optimization of coronary interventions. An EAPCI expert consensus document. Eur Heart J 2018;39:3281–300. doi:10.1093/eurheartj/ehy285
Tearney GJ, et al. Consensus standards for acquisition, measurement, and reporting of intravascular OCT studies. J Am Coll Cardiol 2012;59:1058–72. doi:10.1016/j.jacc.2011.09.079
Vrints C, et al. 2024 ESC Guidelines for the management of chronic coronary syndromes. Eur Heart J 2024;45:3415–537. doi:10.1093/eurheartj/ehae177
Lawton JS, et al. 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization. J Am Coll Cardiol 2022;79:e21–e129. doi:10.1016/j.jacc.2021.09.006

Trial results are quoted from the published abstracts. Criteria quoted from the EAPCI consensus, ULTIMATE and the IVUS calcium score were checked against open-access papers citing them. The simulator is a schematic tissue model: its images and measurements illustrate the criteria, they are not patient data.

Physiology and hemodynamics

Pressure wires, cath-lab waveforms and circulatory support, built as working models: move the inputs and watch the tracings and the numbers change. Thresholds and trial results come from the cited papers; the tracings are generated by a teaching model, not recorded from patients.

Lesion and circulation

Diameter stenosis

Lesion length

Vessel and territory

Microvasculature

Mean aortic pressure

Pitfalls

Guide wedged / damped aortic pressure Pressure drift (+4 mmHg on the wire) Incomplete hyperaemia (recent caffeine)

State

Pa (guide)Pd (wire)Wave-free period (iFR window)

Pullback: focal or diffuse?

Pattern

Show the curve after stenting the larger step

Evidence

Study	Question	Result
Pijls 1996 (NEJM)	Does FFR identify ischaemia?	FFR < 0.75: 88% sensitivity, 100% specificity against non-invasive tests
DEFER, 15 years (EHJ 2015)	Defer PCI if FFR ≥ 0.75?	Death no different (33.0% deferred vs 31.1% stented); MI lower when deferred (2.2% vs 10.0%)
FAME (NEJM 2009)	FFR-guided (≤ 0.80) vs angiography-guided multivessel PCI	Death, MI or repeat revascularisation at 1 year 13.2% vs 18.3%, with fewer stents (1.9 vs 2.7)
FAME 2 (NEJM 2012)	PCI + medical therapy vs medical therapy when FFR ≤ 0.80	Primary end point 4.3% vs 12.7% (HR 0.32), driven by urgent revascularisation
DEFINE-FLAIR (NEJM 2017)	iFR vs FFR to guide revascularisation	iFR non-inferior (6.8% vs 7.0%); procedural symptoms 3.1% vs 30.8%
iFR-SWEDEHEART (NEJM 2017)	iFR vs FFR, stable angina and ACS	iFR non-inferior (6.7% vs 6.1%)
FAME 3 (NEJM 2022)	FFR-guided PCI vs CABG in three-vessel disease	PCI not non-inferior at 1 year (10.6% vs 6.9%; HR 1.5)
FLOWER-MI (NEJM 2021)	FFR vs angiography to guide non-culprit PCI in STEMI	No significant benefit of FFR (5.5% vs 4.2%; HR 1.32)
FIRE (NEJM 2023)	Physiology-guided complete vs culprit-only PCI, MI age ≥ 75	Complete revascularisation better (15.7% vs 21.0%; HR 0.73)
FAVOR III China (Lancet 2021)	Angiography-derived QFR vs angiography alone	QFR guidance better at 1 year (5.8% vs 8.8%; HR 0.65)
FAVOR III Europe (Lancet 2024)	QFR vs FFR	QFR did not meet non-inferiority (6.7% vs 4.2%; HR 1.63)
VALIDATE-RFR (EuroIntervention 2018)	Resting full-cycle ratio vs iFR	Diagnostic accuracy 97.4% against iFR
CorMicA (JACC 2018)	Stratified therapy after coronary function testing in angina without obstructive CAD	Seattle Angina summary score improved by 11.7 units at 6 months; MACE no different
Talreja 2008 (JACC)	Constriction vs restrictive myocardial disease at catheterisation	Systolic area index: 97% sensitivity, 100% predictive accuracy; conventional criteria < 75% accurate

Cut-offs used in the lab: FFR ≤ 0.80 (FAME, FAME 2) and iFR ≤ 0.89 for haemodynamic significance; CFR < 2.0 and IMR ≥ 25 for coronary microvascular dysfunction, with IMR = Pd × mean transit time at hyperaemia [Ford 2018 and related]. For constriction: end-diastolic pressure equalisation < 5 mmHg and systolic area index > 1.1.

References

Trial numbers are quoted from PubMed abstracts. Cut-offs not stated in those abstracts (iFR 0.89, CFR 2.0, IMR 25, SAI 1.1, Gorlin constants) were checked in open-access papers that use them. The waveforms are generated by a teaching model and illustrate the physiology; they are not patient data.

Lesion lab: one stenosis, four modalities

Place a stenosis in this patient's real mid LAD, just after the first diagonal, and watch the same lesion on CT, on two angiographic projections, on IVUS and OCT, and on the pressure wire. Change its severity, length or plaque type and every panel updates together.

◇ Simulated lesion inserted into a normal CT (ImageCAS case 11). The CT background and anatomy are real; the plaque, the narrowed angiographic lumen, the IVUS/OCT frames and the FFR come from teaching models.

Diameter stenosis

Lesion length

Plaque

Waiting for the CT volume…

CT: straightened reformat of this patient's LAD

CT · LAD from the left main (left) to the apex (right)

Angiogram

LAO 45 · CRA 25

AP · CRA 35

Rendered by the atlas from the CT lumen with the lesion inserted.

Reading a projection

Name that view

Left coronary views

Right coronary views

1 · Radial or femoral access

2 · Left or right radial, conventional or distal

3 · One catheter or two

4 · Choosing a guiding catheter

5 · Catheter-induced dissection

6 · Cases

References

Pullback lab

At this frame

Reading the image: IVUS and OCT side by side

Measurements and decision criteria

Before stenting: is the left main significant?

Planning: sizing, landing zones and calcium

After stenting: is the result optimal?

Evidence

References

Lesion and circulation

Pitfalls

Pullback: focal or diffuse?

Scenario

Evidence

References

Classify it

Medina classification

Imaging findings

Scores and options

J-CTO score

Hybrid strategy: the four angiographic questions

Evidence

References

CT: straightened reformat of this patient's LAD

Angiogram

IVUS and OCT at the minimum lumen area

Physiology and synthesis