Study guide
7.3 Post-Processing, Reconstruction & PACS
ARRT Cardiac-Interventional Radiography CI
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1 Introduction & Exam Overview
1.1 Current Exam Facts 1.2 Eligibility, Structured Education & Clinical Experience 1.3 Content Outline & Study Plan
2 Patient Communication & Assessment
2.1 Pre-, Intra-, and Postprocedure Communication 2.2 History, Allergies, Medications & Team Communication 2.3 Screening, NPO, Education & Consent
3 Positioning, Access Assessment & Labs
3.1 Positioning & Vascular Access Assessment 3.2 Chemistry & Hematology Labs 3.3 Coagulation Studies & Arterial Blood Gas
4 Monitoring, Documentation & Contrast
4.1 Physiologic Monitoring in the Cath Lab 4.2 Support Equipment & Procedure Documentation 4.3 Contrast Agents, Indications & Contraindications
5 Medications & Sterile Technique
5.1 Anticoagulants, Antiplatelets & Thrombolytics 5.2 Vasoactives, Sedation & Emergency Medications 5.3 Asepsis, Sterile Technique & Hazardous Materials
6 Emergency Care
6.1 Contrast Reactions & Contrast-Induced Nephropathy 6.2 Cardiac Emergencies (MI, CHF, Arrhythmia, Tamponade, Shock) 6.3 Access-Site & Vascular Emergencies
7 Image Acquisition & Processing
7.1 Fluoroscopy Dose Rates & Pulse Modes 7.2 Digital Acquisition, Roadmapping & Projections 7.3 Post-Processing, Reconstruction & PACS
8 Injectors, Intravascular Imaging & Radiation Protection
8.1 Automatic Pressure Injectors 8.2 Ultrasound, IVUS, OCT & ICE Equipment 8.3 Patient Radiation Protection 8.4 Personnel ALARA, Monitoring & QC
9 Diagnostic Foundations
9.1 Cardiac Anatomy & Pathophysiology 9.2 Right & Left Heart Hemodynamics 9.3 Coronary Angiography, Dominance & Projections
10 Additional Diagnostic Imaging
10.1 Graft, Pulmonary, Aortic & Ventricular Angiography 10.2 ICE, Intravascular Imaging & Endomyocardial Biopsy 10.3 Flow Reserve (FFR, iFR, RFR)
11 Access Angiography & Hemodynamic Calculations
11.1 Peripheral & Access-Site Angiography 11.2 Stroke Volume & Cardiac Output (Fick, Thermodilution, Angiographic) 11.3 Valve Area (Gorlin, Hakki) & Shunt Calculations
12 Electrophysiology
12.1 Arrhythmia Detection & Cardioversion 12.2 Ablation for AF, Atrial Flutter & VT 12.3 Permanent, Temporary, Leadless & Biventricular Pacemakers 12.4 ICD Insertion & Lead Extraction
13 Access, Equipment & Closure
13.1 Access Methods & Ultrasound Guidance 13.2 Sheaths, Catheters, Guidewires & Manifold 13.3 Closure Devices, Pressure & Dressings
14 Suite Design & Procedure Complications
14.1 Interventional Suite & Hybrid OR 14.2 Recognition & Treatment of Procedure Complications
15 Percutaneous Intervention Basics
15.1 Coronary & Peripheral Angioplasty 15.2 Coronary & Peripheral Stent Placement 15.3 Coronary & Peripheral Atherectomy
16 Adjunctive PCI & Retrieval
16.1 Mechanical, Pharmacologic & Aspiration Thrombectomy 16.2 IVC Filters & Foreign-Body Retrieval 16.3 Pericardiocentesis
17 Mechanical Support & Advanced Devices
17.1 IABP & Catheter-Based Ventricular Assist Devices 17.2 ECMO, Intravascular Lithotripsy & Distal Embolic Protection
18 Structural Heart: Septal Defects & TAVR
18.1 PFO & ASD Closure 18.2 Ventricular Septal Defect Closure 18.3 TAVI/TAVR
19 Structural Heart: Valvuloplasty, TMVR & LAA
19.1 Valvuloplasty 19.2 Transcatheter Mitral Valve Repair 19.3 Left Atrial Appendage Closure
7.3 Post-Processing, Reconstruction & PACS
Key Takeaways Explain This Topic AI
Pixel shift re-registers a DSA mask after small motion; large motion, overlap, or a bad injection need a new run, not endless shifting.
Window/level and edge enhancement change how a stored run looks; extreme settings can hide a flap or mimic dissection.
Stenosis-quantification software is an adjunct, not gospel — foreshortening, calibration error, and a single plane can lie.
Diagnostic cine/DSA series archived to PACS or a cardiovascular information system (CVIS) in DICOM are the legal image record; fluoro-store is not automatically equivalent.
Radiation dose structured reports (RDSR) document air kerma, KAP, and fluoro time; disks, media, and outbound images carry HIPAA-protected health information.
Last updated: August 2026
Post-Processing, Reconstruction & PACS
ARRT CI A.5 post processing (e.g., reconstruction) is what you do to a run after the beam is off. A.6 archiving/PACS is what becomes the legal image record , how it travels, and how dose is documented. Pretty pixels that never reach the archive do not help the next operator, the quality committee, or a later lawsuit. Ugly pixels that are the only stored coronary still count.
Quick Answer: Pixel shift fixes small DSA misregistration. Window/level and edge enhancement change display, not photons. Stenosis software is an adjunct, not gospel. 3D reconstruction comes from a rotational run. Cine/DSA is what you archive as the diagnostic series; fluoro-store is a lower-dose extra. PACS and CVIS hold DICOM images. RDSR holds dose. HIPAA still applies when you burn a disk or send a case.
Pixel shift and landmarking
Pixel shift translates (and sometimes rotates) the DSA mask relative to the filled frames so bone edges cancel again after a small breath or table nudge. It is the first rescue for mild misregistration . Limits:
It cannot create contrast that was never injected.
It cannot un-overlap two vessels that truly overlie in that projection.
Large motion, a cough, or a different cardiac phase than the mask usually need a repeat run , not twenty shifts.
Landmarking drops annotations on anatomy — a stenosis, a side branch, a calcium nodule, a sternal-wire reference. Landmarks help the operator and the later reader. They are not a substitute for an unforeshortened projection. A labeled “90%” on a foreshortened RAO does not become true because the text is burned in.
Window/level and edge enhancement
Window and level (contrast and brightness of the display) change how stored pixels look on the monitor. A narrow window can make a faint dissection flap pop; it can also clip contrast stain or a perforated blush into black. A wide window can hide a subtle lumen. Windowing does not add dose and does not change the pixels that were acquired — it changes the lookup table. Document and export a clinically honest window, not a cosmetic one that erases the complication.
Edge enhancement (spatial sharpening, unsharp masking) accentuates vessel borders. Helpful for a fine dissection line or a stent strut. The trap is noise amplification : sharpened quantum mottle and residual motion can mimic dissection or thrombus. If the flap is real, it should survive a less-enhanced window and an orthogonal projection. Do not stent a sharpening artifact.
Stenosis quantification software: adjunct, not gospel
Quantitative coronary angiography ( QCA ) and similar percent-stenosis tools calibrate from the catheter, draw a lumen, and output a number. Used well, they reduce “looks like 70% to me” variation. They do not replace angiographic judgment or physiology ( FFR/iFR/RFR , covered later in procedures).
Why the number lies:
Foreshortening shrinks apparent length and can understate or distort diameter stenosis.
Single-plane views miss eccentric plaque; orthogonal runs still matter.
Calibration off the wrong catheter French size, a foreshortened shaft, or a contrast-filled versus empty lumen error scales every measurement.
Branch overlap and poor filling confuse edge detection.
Treat the software as an adjunct . If QCA says 40% and the patient has a pressure-wire-positive, unforeshortened 80% in another view, believe the physiology and the better projection. If QCA says 90% in a spider that is still overlapped, acquire a better angle before you commit a left-main strategy to a cartoon diameter.
3D reconstruction from rotational runs
The A.3 spin is the acquisition; A.5 is the reconstruction . The workstation builds a volume you can window as a CT-like angiogram, cut as MPRs, and measure (annulus area and perimeter for TAVR , ostial diameter and depth for LAA ). Centerlines and implant-angle predictions are only as good as contrast timing, motion suspension, and completeness of the rotation. Re-window the volume the same way you re-window cine: to see anatomy, not to invent a size the operator wishes the annulus had. Store the volume and the key measurements with the case if they drove a device choice — that reconstruction is then part of the record.
Storing fluoro versus storing cine
Cine / digital acquisition / DSA series are the diagnostic pictures: high dose per frame, intended for interpretation, almost always archived . Fluoro-store (last-image-hold sequences, fluoro capture) is a lower-dose, noisier loop. Useful to document a wire perforation, a spasm that resolved, or the live roadmap. It is not automatically the complete legal angiogram.
Facility policy decides which fluoro loops are kept. Teaching default: archive every diagnostic cine/DSA run that answers a clinical question, including “normal” coronaries; keep fluoro-store when it uniquely documents an event; do not skip archiving the left-coronary cine because a pretty fluoro-store exists. Deleting a diagnostic run to save space is not a radiation-protection technique.
PACS, CVIS, and DICOM
PACS (picture archiving and communication system) is the enterprise image store. A cardiovascular information system (CVIS) is the cath-lab-aware cousin: images plus hemodynamics, procedure logs, inventory, and the structured report, often tightly linked to PACS. You will hear both names; the exam-relevant idea is a retrievable, identified, diagnostic archive , not a pile of unnamed MP4s on a thumb drive.
DICOM (Digital Imaging and Communications in Medicine) is the file and network standard: patient identifiers, study/series/instance UIDs, pixel data, and, when configured, dose objects. Sending “a JPEG on a chat app” strips that wrapper and is not an archive.
Legal record and radiation dose structured reports
The legal image record is the identified, time-stamped, diagnostically adequate series the facility retains under medical-record rules — typically the DICOM cine/DSA (and stored 3D volumes used for sizing), plus the report. If a later operator, a referring surgeon, or a court asks “what did the left main look like?”, the answer is the archived spider and cranial runs, not your memory of last-image-hold.
Radiation dose structured reports (RDSR) are DICOM objects that record fluoro time , cumulative reference-point air kerma , KAP/DAP , and often acquisition-frame counts and system technique. They feed PACS and dose-monitoring software. RDSR is how the lab knows a long CTO crossed a skin-dose threshold. It is not optional decoration; if the system generates RDSR, it belongs with the study. Teaching, not a claim that ARRT publishes a required RDSR vendor: know what it documents and that it is archived with the case.
HIPAA when burning disks and sending images
Exporting a case does not end privacy rules. Protected health information (PHI) rides on every DICOM header (name, medical record number, date of birth, accession). HIPAA expectations in this context:
Give patients and referring physicians encrypted or otherwise controlled media when policy requires it; treat unlabeled disks as PHI, not scrap.
Do not email unencrypted clinical images to a personal account or a vendor without a business-associate pathway.
De-identify teaching files if they leave the covered entity.
Track who received a disk; a “here’s your heart on a CD” handoff in the hallway still needs identity checks.
Vendor uploads for 3D planning or research use the same PHI rules as PACS.
Processing table
Tool Use Trap
Pixel shift Re-register a DSA mask after small motion Cannot fix overlap, empty vessels, or large motion — repeat the run
- Landmarking Annotate anatomy on a stored frame A text label does not correct a foreshortened projection
- Window/level Display contrast and brightness Extreme windows hide blush or invent empty lumen
- Edge enhancement Sharpen vessel and stent edges Noise can mimic dissection
Stenosis / QCA software Adjunct percent-stenosis estimate Foreshortening, bad calibration, single plane — not gospel
3D reconstruction Volume and measurements from a rotational run Motion or poor contrast timing yields a wrong annulus or LAA size
- Fluoro-store Low-dose loop of a moment Not automatically the diagnostic legal cine series
- PACS / CVIS + DICOM Identified diagnostic archive Informal JPEGs and unlabeled sticks are not the record
- RDSR Documents air kerma, KAP, fluoro time Ignoring RDSR hides a high-dose case
- Export / disk burn Share studies HIPAA still applies; unencrypted PHI is the failure mode
- Scenario and traps
An iliac DSA for large-bore TAVR access shows black-white bone edges after a breath. Pixel-shift once. If the iliac still ghosts, repeat the DSA on suspended respiration; do not wire a false lumen on a shifted mask. The same case’s 3D TAVR spin is reconstructed, measured, and stored with the cine aortogram. RDSR goes with the study. The valve-sizing screenshots emailed from a personal phone are a HIPAA problem even if the measurements were right.
Left-coronary QCA reads 45% in a foreshortened RAO. The LAO cranial is an unforeshortened 80% and iFR is positive. Software is an adjunct — treat the lesion, do not treat the 45%.
Traps: calling edge enhancement a diagnosis of dissection. Deleting cine because fluoro-store “looks fine.” Burning an unencrypted disk with the full DICOM header for a family member. Believing window/level reduced the patient’s dose. Filing RDSR in a trash folder because “dose is a physicist problem.”