MRI findings of absorbable hydrogel spacer for prostate cancer therapy: a pictorial review.

Prior studies have shown that dose-escalated radiation therapy for prostate cancer improves clinical outcomes. However, this is associated with increased rectal toxicity. Hydrogel spacer for prostate cancer therapy is an effective way of decreasing rectal toxicity in the late post-therapeutic stages. In some occasions, the gel spacer may not be placed symmetrically between the rectum and prostate. There are several forms of a malpositioned spacer, including lateral displacement, rectal wall infiltration, and prostate capsule infiltration. This manuscript is aimed at evaluating appropriately positioned and malpositioned gel spacers, primarily via magnetic resonance imaging. There are limited educational imaging guides that address what radiologists should evaluate on post-spacer placement imaging. This pictorial review will specifically evaluate post-injection pitfalls such as asymmetry, rectal wall infiltration, and subcapsular injection.

Delayed presentation of splenic rupture following colonoscopy: clinical and CT findings.

The purpose of this study is to investigate the clinical and CT findings in patients with symptomatic colonoscopy-induced splenic rupture, and to assess for common features among this cohort. Multi-center search yielded 11 adults with symptomatic splenic injury related to colonoscopy. Workup included abdominal CT in 10 (91%) cases and abdominal radiography in two patients (one patient had both). Colonoscopy findings, post-procedural course, and CT findings were systematically reviewed. Mean patient age was 62.2 years (range, 51-84 years); 8 (73%) of 11 were female. The majority (64%) of colonoscopies were for screening. No immediate complications were reported at optical colonoscopy; tortuosity/redundancy was noted in five cases. Except for a small (8 mm) polyp in one case and a large (10 mm) polyp in another, the remaining nine patients had either diminutive or no polyps. Only one patient presented with hemodynamic instability during post-colonoscopy recovery; the other ten had a delayed presentation ranging from 8 h to 8 days (mean, 2.1 days). All 11 patients presented with abdominal pain. CT was diagnostic for splenic injury with subcaspular and/or perisplenic hematoma in all ten CT cases. Hemoperitoneum was present in eight, visible splenic laceration in three cases, and splenic artery pseudoaneurysm in one case. Five patients underwent splenectomy (four emergent) and six patients were treated conservatively. Average hospital stay was 5.5 days (range, 3-10 days). Colonoscopy-induced splenic rupture characteristically presents as a delayed and often serious complication. In cases of apparent non-traumatic splenic hematoma or rupture at CT, eliciting a history of recent colonoscopy may identify the etiology.