# CTisus CT Quick Guides vs Radiology References

The clearest difference is in-app purchases: CTisus CT Quick Guides at none against Radiology References's 4. CTisus CT Quick Guides also leads on ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Radiology References sells 4 in-app purchases, starting at $1.99 per 7 days. CTisus CT Quick Guides asks for nothing beyond the download.

CTisus CT Quick Guides ships an update every 6 months, Radiology References every 5 months. The most recent releases landed on October 25, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | CTisus CT Quick Guides | Radiology References |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (6 ratings)](https://appshunter.io/ios/app/ctisus-ct-quick-guides/id6743173540/reviews)** | — |
| Number of ratings | **6** | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Every 5 months** |
| Monetization | Free | — |
| Size | 52 MB | 19 MB |
| Requires iOS | **16.6** | 17.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 17+ | 17+ |
| Developer | [Elliot Fishman](https://appshunter.io/developer/399024444) | [HVALABS, LLC](https://appshunter.io/developer/1875666107) |

## What reviewers say

### CTisus CT Quick Guides

[App page](https://appshunter.io/ios/app/ctisus-ct-quick-guides/id6743173540)

This medical reference app provides radiologists and other healthcare professionals with curated CT images, imaging pearls, and clinical findings across 17 diverse topics. Key information is organized into critical findings, etiology, epidemiology, presentation, and prognosis for each subject.

**Highlights:** Curated CT images, Imaging pearls, Clinical findings, 17 topic sections, Critical CT findings, Etiology, epidemiology, presentation, prognosis

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Radiology References

[App page](https://appshunter.io/ios/app/radiology-references/id6744572227)

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium | $1.99 | per 7 days |
| Monthly Premium | $5.99 | per month |
| Yearly Premium | $24.99 | per year |
| Yearly Premium | $34.99 | per year |


## Frequently asked questions

### Is CTisus CT Quick Guides free?

CTisus CT Quick Guides is free to download, with no in-app purchases.

### Is Radiology References free?

Radiology References is free to download, with in-app purchases available.

### Do CTisus CT Quick Guides or Radiology References have ads?

Radiology References shows ads; CTisus CT Quick Guides does not.

### Which is updated more often, CTisus CT Quick Guides or Radiology References?

CTisus CT Quick Guides ships an update every 6 months, and Radiology References every 5 months. Most recently, CTisus CT Quick Guides was updated on October 25, 2026 and Radiology References on October 11, 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.*