Author: Logan Young

Summary: Fortune favors radial access, 900 µm Embozene for distal branch pruning, and micro-coil embolization positioned above the CCR to safely halt flow below the pubic ramus.

Bloody Brilliant: A strategy targeting the superior rectal artery can effectively manage hemorrhoidal bleeding while avoiding complications. And as Dr. Eric Aaltonen explained during this QuickBytes video, particle sizing and microvascular selection shape procedural success and mucosal safety alike:

• Radial or Femoral? Aaltonen prefers radial access for entering the inferior mesenteric artery to catheterize the superior rectal.
  • Next, it’s +/- internal iliac to evaluate MRA.
• Collateral Eval: Assessing internal iliac arteries IDs potential middle rectal collaterals.
  • Hybrid-suite cone-beam CT confirms direct branch supply to the CCR or hemorrhoidal plexuses.
• Angio Aim: Target branches exhibit a characteristic tortuous appearance with distal opacification extending to the CCR.
• Mechanics of It All: Microcatheters are advanced distally to prune vascular branches with micro-particles before deploying micro-coils proximal to the CCR.

Unlike onco chemoembolization, hemorrhoids don’t require administering particles all the way to stasis. Micro-particles merely prune the distal vascular bed, after which coils placed above the CCR stop flow below the pubic symphysis.

• 70%: Incidence of self-healing, small ischemic rectal ulcers observed when using 500–700 µm embolic particles.
• 900–1100 µm: Particle size range à la Embozene or Embospheres that eliminates mucosal ulceration entirely.
• Pubic Ramus: Baseline below which all angiographic opacification must cease to achieve procedural stasis.

Summary: Clocking the flow void sign on T2 or STIR offers localization early in the workup—streamlining myelography and focusing treatment right there at the tear.

Spinal Gap: IDing spinal specifics is critical for classifying the cause of SIH and guiding myelography. As Dr. Joshua Russell Fage noted in this ARRS Web Lecture, the goal here is to establish the presence, or absence, of a spinal longitudinal extradural fluid collection. Immediate reporting directs the next best step, determining how subsequent myelography should be performed:

• Extradural Fluid Collections: Caused by dural tears, leaking meningeal diverticula, or arachnoid herniation near nerve roots.
  • Fistulas won’t exhibit extradural collection.
• T2 Tips: Eval relies heavily on T2-weighted and T2 fat-saturated sequences to clearly delineate extradural fluid.
• Flow Void Sign: Seen on 2D T2-weighted or STIR images directly at the tear site.
• 3D Trade: Alas, Dr. Fage’s flow void sign is not visible on 3D acquisitions. (However, higher-res 3D sequences can sometimes visualize the dural defect directly.)

Summary: Your report dictates the decision directly: normal signal = Grade I (rest); edema + continuous nerve = Grades II–IV (monitor); discontinuous nerve trunk = Grade V (repair).

Rend a Sunder: Severity scales with Sunderland, distinguishing mild lesions which resolve with rest from structural disruptions requiring surgery. As Dr. Laura M. Fayad reminded us at the Annual Meeting, it’s a spectrum, too:

• Grade I
  • Neurapraxia—focal demyelination without axonal disruption, maintaining normal muscle signal. Resolution with 4–6 weeks of rest.
• Grades II–IV
  • Axonotmesis—progressive connective tissue breakdown, ranging from isolated axonal disruption to endoneurial and perineurial damage. Outer epineurium remains intact.
• Grade V
  • Neurotmesis—complete nerve transection or avulsion with full disruption of all surrounding connective tissue layers. Intervention required.

Injured nerves demonstrate altered caliber, loss of normal fascicular architecture, and focal or diffuse T2 hyperintensity from edema or distal Wallerian degeneration.

Muscle Denervation: Increased fluid signal appears as early as 4 days post-injury…effectively ruling out Grade I.

• High-res MRI delineates focal sites of compression and continuity, overcoming electrodiagnostic limitations in distinguishing IV versus V.

Summary: Whereas modality selection depends on patient tolerance, provider preference, and scanner availability, MR defecography provides unmatched soft-tissue resolution and functional detail to guide targeted clinical and surgical management.

Dare to Compare: A physical exam alone doesn’t always capture a pelvic floor disorder’s underlying dysfunction. Dynamic MR defecography does, though, delivering high-yield multiplanar imaging that directly informs surgical decision-making.

Pelvic prolapse, relaxation, dyssynergic defecation—all stem from chronic elevations in intra-abdominal pressure or structural disruptions, Dr. Christine Boatright noted during the Annual Meeting.

Percent Points: Whoppingly, 94% of MR defecography exams indicate posterior compartment complaints, à la chronic constipation and obstructive defecation.

• 92%—Correlation between MR defecography findings and suspect pelvic floor pathologies.
• 86%—Proportion of surgical cases where MR defecography provides added operational value.

MR Defecography: Performed with the patient supine using rectal gel to simulate defecation, it requires no oral small-bowel, vaginal, or bladder contrast.

• MRI offers superior soft-tissue contrast, allowing direct visualization of the levator ani muscle complex, pelvic ligaments, pubic symphysis, bladder, uterus, and rectum.

Fluoroscopic Defecography: Performed upright on a specialized chair (providing a more physiological posture), it requires oral barium swallowed an hour prior for small-bowel opacification, rectal contrast, and an optional contrast-soaked vaginal tampon, but provides limited soft-tissue detail.

Evacuation Dynamics: Patient movement during evacuation helps categorize the underlying etiology. Prominent pelvic movement suggests pelvic floor relaxation, whereas minimal pelvic movement or an inability to evacuate rectum content points toward dyssynergic defecation.

• MRI can uniquely reveal levator ani muscle atrophy and structural disruptions that remain invisible on fluoroscopy.

Summary: Sans clear, permanent payment pathways, right now, health care providers cannot sustain long-term investments in AI—no matter how clinically compelling.

Soft Serve: You know the deal. Most health care reimbursement relies on fee-for-service models that reward volume over outcomes. But AI is built different. And as Dr. Melissa A. Davis pointed out during our online course AI in Radiology: Evidence, Workflow, and Ethical Practice, the vast majority of the House of Radiology’s AI tools lack standard billing codes, clear ROI pathways, or permanent reimbursement mechanisms.

Numbers Game:

• 3: The number of AI applications that have successfully transitioned from temporary to permanent CPT Category I codes (diabetic retinopathy, FFRCT, and cardiac CT risk).
• Category III: The temporary code status where most radiology AI tools reside, offering no guaranteed payment rate and often timing out without becoming permanent.
• 2027: The proposed start year for CMS’s new software as a medical service (SaMS) payment pathway aimed at algorithmic diagnostic tools.

Subscription Friction: AI vendors frequently use subscription pricing models, but health system business offices struggle when temporary codes or NTAP payments get absorbed into low-yield inpatient DRGs.

• Commercial payers lag behind CMS payment policies, making Medicare’s evolving stance the primary catalyst for long-term financial viability.

Health Tech Investment Act: Pending legislation from the feds aims to extend temporary payment windows from three to five years, giving CMS more time to gather data and stabilize reimbursement.

Summary: Effective evaluation requires reliance on structured imaging that’s razor-focused on cyst size, count, location, and calcification.

Nothing But PNET: Diversity is on full display with cystic pancreatic neuroendocrine tumors (PNETs), requiring a structured approach to calcification and enhancement, as well as clinical presentations. Detailing these distinctions during our online course Radiology Case Review–Abdominal Imaging, Mark Sugi, MD, noted that, typically, functioning tumors present early vis à vis clinical symptoms. Meanwhile, non-functioning tumors show up later and larger and undergo necrotic degeneration.

• Intratumoral: Punctate, mural, or non-mural calcifications should serve as signs for PNETs.
• Obstructionist: Even if a lesion obstructs the pancreatic duct, the presence of intratumoral calcification should arouse suspicion for PNET.
• Pattern Profile: PNETs characteristically demonstrate post-contrast enhancement, frequently exhibiting eccentric or rim-enhancing patterns.

Beware of Imitations: A circumscribed rim-enhancing lesion with subtle punctate calcification can closely mimic duodenal diverticulitis. Alternatively, ductal adenocarcinoma developing in the setting of pancreatitis with calcifications presents a similar kind of overlap.

• Insulinomas? In patients with multiple endocrine neoplasia type 1, insulinomas display as rim-enhancing, low-attenuation masses in the pancreatic body or tail with high uptake on ⁶⁸Ga-DOTATATE PET.

Summary: Take that extra second to inspect the entire stomach and gastric pouch on CT and MRI, leverage DWI sequences, and correlate manometry with fluoroscopy to detangle complex dysmotility.

Hard to Digest: Upper GI motility disorders and subtle gastric lesions don’t fit into neat tracts. Misidentifying esophageal patterns, or overlooking the excluded stomach after bariatric surgery, too often cause diagnostic delays, persistent symptoms, as well as missed malignancies.

As Dr. Kristina Flicek directed during ARRS26, look beyond the narrows to differentiate primary disorders from secondary postoperative changes. And keep an eye out for the nuances of gastric pathology on cross-sectional CT and MRI:

• Achalasia: Characterized by aperistalsis of the distal two-thirds of the esophagus and failure of the lower esophageal sphincter (LES) to relax, you get that classic bird beak sign.
  • Giving adequate contrast during a timed esophagram uses hydrostatic pressure to force open the LES, helping rule out a fixed obstruction or pseudoachalasia from GE junction adenocarcinoma.
• EGJOO: Impaired transit across the EGJ with elevated LES relaxation pressure on manometry, albeit normal esophageal body peristalsis on fluoro? That’s esophagogastric junction outflow obstruction.
  • Stems from structural—strictures, hiatal hernias, epiphrenic diverticula, fundoplication wraps—or non-structural causes (e.g., chronic opioid use, which disrupts nitric oxide releasing neurons, leading to unopposed excitatory cholinergic input and spastic LES contraction).
• POSED: A secondary achalasia developing after Roux-en-Y gastric bypass or sleeve gastrectomy, post-obesity surgery esophageal dysfunction is driven by elevated pressure or decreased compliance of the proximal pouch.
  • Fluoro demonstrates disruption of the primary stripping wave, proximal escape, and distal motor incoordination (manometry frequently confirms type II achalasia pattern).

More Roux-en-Y Complications:

• GJ Fistula: An abnormal tract communicating between the gastric pouch and the excluded remnant stomach, usually, patients present with weight regain or reduced satiety.
• Marginal Ulcers: Outpouchings or small air foci right at the gastrojejunal anastomosis caused by gastric acid irritating vulnerable jejunal mucosa that’s readily identifiable on fluoro and targeted cross-sectional CT.

Exclusions Apply! Pathology in the bypassed remnant stomach (including large bleeding masses or mucosal lesions) can be completely missed on standard upper endoscopy, if cross-sectional imaging is not performed.

• Persistent antral thickening should not be dismissed as benign simply because it appears static over consecutive months; signet cell adenocarcinoma can masquerade as stable wall thickening.
  • DWI is crucial for highlighting wall restriction, effectively distinguishing true gastric adenocarcinoma from poor stomach distension.

Summary: Focusing on contrast compartmentalization helps pinpoint full-thickness ligamentous and TFCC tears, pivoting away from small-joint pitfalls.

Small Joint, Big Problem: It’s a two-part question in single-joint wrist arthrography: where is contrast supposed to be, versus where is it not? As Dr. Joseph A. Delic reminded us during ARRS26, fluoroscopy doesn’t merely confirm needle placement; it directly aids decision-making for subsequent MRI sequences.

Strict Boundaries: In a normal single-joint radiocarpal injection, contrast remains entirely confined within the radiocarpal joint.

• Normality in sequence shows zero contrast extension through the scapholunate or lunotriquetral intervals, and no contrast leaking into the distal radioulnar joint (DRUJ).

Interval Training: Linear contrast extending through the scapholunate interval indicates a full-thickness ligament tear. When tears involve the dorsal band, volar band, and membranous segment, contrast insinuates throughout the proximal and distal carpal rows.

• Contrast extending into the DRUJ during injection would suggest a full-thickness TFCC central disc tear.

Summary: Rushing to definitives on imperfect studies leads to cognitive errors, overcalling, and inappropriate assignment (e.g., BI-RADS 3 should never be assigned at screening; baseline findings with incomplete evaluation require BI-RADS 0 for additional workup).

Mastering Mystery: An unknown diagnosis does not equal an unknown process; you needn’t know the precise pathology to determine your safest next step. Introduced by ARRS Distinguished Educator Dr. Tanya Moseley during our Mystery to Mastery longitudinal course, here’s how her C-L-E-A-R acrostic’s stepwise methodology transforms clinical uncertainty into structured reasoning:

• C—Context: Anchor in Facts
  • Gather patient age, symptoms, indication, modality, technique, priors, etc.
• L—Localize: Boundaries, First
  • Pinpoint an abnormality’s region, compartment, and epicenter, before attempting to characterize it.
• E—Examine: Objective Descriptions
  • Systematically evaluate morphology, density, echogenicity, or enhancement, then document key negatives.
• A—Alternatives: Defensible DDX
  • Avoiding the too obscure, rank 2–3 reasonable possibilities (summation artifact vs. focal asymmetry vs. obscured mass).
• R—Resolve: Execute Safely
  • Determine whether the patient needs FFDM, DBT, targeted US, prior comparison, or even reassuring observation.

Case in Point: Single-View Asymmetry

• Scenario: In Moseley’s case, a baseline screening mammogram in an asymptomatic patient revealed a focal density in the middle posterior left breast, visible on only one view.
• Reasoning: Persistence, morphology, and second-view correlate couldn’t be confirmed.
• Action: Incomplete exam assigned BI-RADS 0 and recommended mammo, DBT, and US—rather than guessing or misapplying BI-RADS 3.

Summary: Before diagnosing a calcified right paratracheal lymph node or metastasis, verify whether that heavy brightness is simply transient contrast pooling inside an azygos arch venous valve.

Trapper John, MD: Got high attenuation in the right paratracheal space on contrast-enhanced chest CT? Careful. As Dr. Brent P. Little explained during ARRS26, contrast material often becomes trapped behind a normal venous valve in the azygos arch—creating a bright focal density that mimics pathology:

• Anatomy of Venous: A normal valve with two leaflets sits in the region of the azygos arch.
• Delayed Clearance: Whereas contrast washes out from the rest of the thoracic vasculature, stagnant contrast trapped behind the valve leaflets can remain for several minutes.
• It’s Not Unusual: Trapped contrast presents in the right paratracheal space with a distinct gestalt (sometimes demonstrating a subtle fluid/contrast level).
• The Pit: In patients with calcifying malignancies, this high-density contrast retention can be wrongly suspected as a calcified metastatic node.

Summary: Pairing artifact-reduced imaging with consistent, rad-forward language helps hone reportage that can effectively guide surgical decision-making.

Particle Problem: All functional joint arthroplasties create wear particles that can trigger a host immune response, leading to inflammatory tissue damage around hardware. Because terminology describing these soft-tissue abnormalities is used inconsistently across literature and practice alike, as Dr. Jeremiah R. Long reminded us during ARRS26, clarity is critical:

• Quality Control: Implement metal artifact reduction techniques across both CT and MRI to better detect and characterize lesions.
• A Priori Advantage: Track lesion size and progression over time to assist surgeons in determining whether/when to revise.
• Clinical Context: Query the EMR for history, labs, operative details, etc.
• Imaging-Centric Language: Utilize “umbrella terms” appropriate for the specialty—pseudotumor and adverse local tissue reaction (ALTR), specifically.

Jettison the Jargon: Dr. Long suggested that we refrain from using gross, intraoperative, or pathological terminology, à la metallosis or trunnionosis.

RadFYI: Portal venous gas is one of the most critical catastrophes that can develop as a result of pneumatosis, so do call on the classics here: branching lucencies within the liver.

Not Nothing: Reading neonatal abdominal radiographs straddles that line between the overly sensitive “call me, maybe” and the specific and definitive. As Dr. Andrew T. Trout reminded us during the ARRS Online Course Radiology Case Review – Pediatric Imaging, calling pneumatosis is not a benign diagnostic event.

• Usually, a positive read prompts clinicians to rest the baby’s gut, make them nothing by mouth, and initiate total parenteral nutrition.
• Since such interventions carry their own risks, prioritize specificity over hypersensitivity.

Clear-cut cases present with obvious intramural collections of linear or curvilinear gas across multiple loops…or the presence of portal venous gas!

• Trout’s Tip: Do not call pneumatosis unless you see clear, indisputable intramural lucencies (either linear or curvilinear) in the context of other concerning clinical findings.

Grey Zone: When faced with subtle, bubbly lucencies in the hemi-abdomen, obtaining a delayed, follow-up radiograph is a highly reasonable and helpful strategy. Over time, true pneumatosis will progress to show more convincing, clearly intramural curvilinear lucencies on a delayed radiograph.