# CathSource vs Lung CT Field Guide

The clearest difference is review sentiment: Lung CT Field Guide at 100% against CathSource's 43%. Lung CT Field Guide also leads on rating (5.0 vs 1.6) and monetization model (free vs paid). CathSource's advantage is update cadence (every 2 months vs every 6 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Lung CT Field Guide holds the better App Store score, 5.0 against 1.6. Both are backed by a comparable volume of ratings — 23 and 11 respectively. Written reviews point the same way: 43% of CathSource's written reviews are positive against 100% of Lung CT Field Guide's.

CathSource ships an update every 2 months, Lung CT Field Guide every 6 months. The most recent releases landed on September 18, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | CathSource | Lung CT Field Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.6 (23 ratings)](https://appshunter.io/ios/app/cathsource/id420847275/reviews) | **[5.0 (11 ratings)](https://appshunter.io/ios/app/lung-ct-field-guide/id895302733/reviews)** |
| Number of ratings | **23** | 11 |
| Positive reviews | 42.9% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 6 months |
| Monetization | Paid | **Free** |
| Size | 79 MB | 58 MB |
| Requires iOS | 18.5 | **8.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 12+ | 12+ |
| Developer | [ECGsource LLC](https://appshunter.io/developer/377139096) | [RADIOLOGiQ, LLC](https://appshunter.io/developer/519524135) |

## What reviewers say

### CathSource

[App page](https://appshunter.io/ios/app/cathsource/id420847275)

A comprehensive medical reference focused on cardiac catheterization and angiography. It offers a searchable index of specialized topics, a database of videos of common and rare findings, and a collection of images including hemodynamic formulas and tables.

**Highlights:** Searchable index of cardiac catheterization topics, Database of coronary angiogram, ventriculogram, and aortogram videos, Image database with hemodynamic formulas and tables, Covers common and rare cardiovascular pathologies, Developed by practicing Interventional Cardiologists

**Features:** macOS Compatibility

**In-app purchases:** none


### Lung CT Field Guide

[App page](https://appshunter.io/ios/app/lung-ct-field-guide/id895302733)

This app helps physicians, especially radiologists and pulmonologists, interpret lung CT scans. It features a library of CT images and illustrations of lung diseases, along with an experimental engine to suggest differential diagnoses based on observed findings.

**Highlights:** Lung CT image library, Color graphic illustrations of lung disease patterns, Experimental differential diagnosis engine, Organized by CT findings and distribution, Over 100 curated images and illustrations

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CathSource free?

CathSource is free to download, with no in-app purchases.

### Is Lung CT Field Guide free?

Lung CT Field Guide is free to download, with no in-app purchases.

### Which has better reviews, CathSource or Lung CT Field Guide?

Lung CT Field Guide is rated higher. CathSource averages 1.6 out of 5 from 23 ratings, while Lung CT Field Guide averages 5.0 from 11 ratings.

### Do CathSource or Lung CT Field Guide have ads?

Neither CathSource nor Lung CT Field Guide shows ads.

### Which is updated more often, CathSource or Lung CT Field Guide?

CathSource ships an update every 2 months, and Lung CT Field Guide every 6 months. Most recently, CathSource was updated on September 18, 2026 and Lung CT Field Guide on June 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*