Gross hematuria: Renal cell carcinoma mimicking a renal arteriovenous malformation.

The differential diagnosis between renal arteriovenous malformations (AVM) and cancer may be a challenge, due to the similar clinical and imaging findings. Herein, we report the case of an 80-year-old male patient presenting gross hematuria, initially diagnosed and treated with embolization for a renal AVM. Due to the recurrence of hematuria and rapid progression and changes of the vascular lesion with detection also of an intralesional solid nodule, a radical nephrectomy was performed revealing the presence of a renal cell carcinoma (RCC). Renal cell carcinoma and renal AVM can be difficult to differentiate from one another, for this reason a short-term follow-up should be carried out in patients diagnosed and treated for renal AVM to confirm the resolution of AVM or to assess any changes, such as atypical neovascularization or intralesional renal masses, which may increase the suspect of a hidden renal tumor.

Left side jejunal diverticulitis: US and CT imaging findings.

Small bowel jejunoileal diverticulosis is an uncommon and usually asymptomatic condition. Complications may occur such as acute diverticulitis including infection or perforation, bleeding, small bowel obstruction and volvulus. Herein we report a case of a 76 years-old woman with acute left side abdominal pain and tenderness. A clinical suspected diagnosis of colonic diverticulitis was formulated. She underwent Ultrasound that revealed a collapsed small bowel loop with a large sac-like out-pouching lesion with mixed content (fluid and pockets of air) associated to hyperechogenicity of perilesional fat. Because of the atypical US findings, the patient underwent abdominopelvic CT that confirmed that the large sac-like out-pouching was a jejunal inflamed diverticulum. The patient underwent emergency surgery. Radiologist should be aware of imaging findings of jejunoileal diverticulitis in order to achieve a prompt diagnosis.

Can neutrophil gelatinase-associated lipocalin help depict early contrast material-induced nephropathy?

PURPOSE: To evaluate the utility of serum and urinary neutrophil gelatinase-associated lipocalin (NGAL) in depicting an event of contrast material-induced nephropathy (CIN) in patients who received iodinated contrast media, gadoterate meglumine, or radiopharmaceutical technetium-99m ((99m)Tc) and to evaluate the protective effect exerted by isotonic saline infusion, sodium bicarbonate administration, or N-acetylcysteine administration. MATERIALS AND METHODS: Institutional ethics committee approval was given, and informed consent was obtained. One hundred twenty patients were enrolled in a prospective study and divided into three groups: iomeprol group, magnetic resonance (MR) imaging group (gadoterate meglumine), and renal scintigraphy group ((99m)Tc). They randomly received N-acetylcysteine, physiologic saline, or sodium bicarbonate. Receiver operating characteristic (ROC) analysis, Kaplan-Meier curves, and Cox proportional hazard regression analysis were used. RESULTS: In the MR imaging and renal scintigraphy groups, there were significant changes in serum creatinine and NGAL levels, and there were no cases of CIN. In the iomeprol group, an early rise in NGAL was found, while serum creatinine level changes occurred 24 hours after contrast material administration. At ROC analysis, NGAL showed high sensitivity and specificity (serum NGAL: area under the curve, 0.995; 95% confidence interval [CI]: 0.868, 0.992; urinary NGAL: area under the curve, 0.992; 95% CI: 0.925, 1.000) in identifying CIN 8 hours after iomeprol administration. Regression analysis showed that NGAL independently predicted CIN. Administration of N-acetylcysteine, sodium bicarbonate, or physiologic saline did not influence NGAL level. CONCLUSION: NGAL depicted CIN in patients who received iodinated contrast material within 8 hours of contrast material administration. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120578/-/DC1.

Hepatic Portal Venous Gas (HPVG) after Ingestion of Chlorine Bleach: A Transient Phenomenon.

We present a case involving a 32-year-old man who ingested chlorine bleach with self-defeating intent. The ingestion of bleach can lead to a wide range of consequences, from mild mucosal burns to severe complications, rarely resulting in death. This case highlights the association between chlorine bleach ingestion and the development of hepatic portal venous gas (HPVG), a radiological finding traditionally thought to carry poor prognoses. The HPVG in this case resolved spontaneously within 24 h with conservative management, indicating its transient nature. The exact pathophysiological mechanisms responsible for HPVG after the ingestion of toxic substances .remain only partially understood. One hypothesis suggests that extensive damage to the gastrointestinal wall caused by caustic agent may allow enteric gas to enter the portal system. While HPVG after toxic ingestion is often transient, its consequences and potential risks should be carefully considered. Hyperbaric oxygen therapy is suggested in cases with neurological symptoms. In conclusion, HPVG is not a specific disease but rather a manifestation of various underlying factors, and its development in the context of chlorine bleach ingestion represents an additional insight to its understanding. It can be associated with severe medical conditions, but it is also found in less severe cases that can be managed conservatively.

Pancreatic dual-source dual-energy CT: is it time to discard unenhanced imaging?

AIM: To compare pancreatic virtual unenhanced (VUE) and true unenhanced (TUE) images and to calculate the potential dose reduction by omitting the conventional unenhanced scan. MATERIALS AND METHODS: Fifty-one patients with known or suspected pancreatic masses underwent contrast-enhanced computed-tomography (CT) during unenhanced and portal venous phases acquired in single-energy (SE) mode, and pancreatic parenchymal phase acquired in dual-energy (DE) mode. The image quality (IQ) and image noise (IN) of TUE and VUE images were evaluated. The effective dose of a combined DE/SE dual-phase protocol was compared with that of a theoretical standard SE triple-phase protocol. The results were tested for statistical significance using the Cohen's k, the Wilcoxon's signed rank test, and the paired t-test; p-values of less than 0.05 were considered significant. RESULTS: Mean TUE and VUE IQ were 1.5 ± 0.6 and 1.6 ± 0.6 (k = 0.891), with no significant difference (p > 0.05). Mean TUE and VUE IN were 12.3 ± 1.6 and 10.3 ± 1.5 HU, and resulted significantly different (p < 0.001). Mean effective doses for a combined DE/SE dual-phase protocol and SE triple-phase protocol were 8.9 ± 2.4 mSv (range 4.8-16.2 mSv) and 12.1 ± 3.1 mSv (range 6.4-21.1 mSv). The calculated mean dose reduction achievable by omitting the unenhanced scan was 26.7 ± 9.7% (range 10-46.1; p < 0.001). CONCLUSION: VUE images are feasible for pancreatic abdominal CT. A combined DE/SE dual-phase protocol permits a significant reduction in dose exposure to patients.

First case of 18F-choline uptake in acoustic schwannoma after stereotactic radiotherapy.

A 69-year-old male patient, with bilateral hypoacusia and tinnitus, had a diagnosis of left vestibular schwannoma with synchronous meningioma on the left frontal lobe. After partial surgical resection of the acoustic schwannoma, this was followed by stereotactic radiosurgery on the residual lesion. The patient had a metachronous prostate cancer treated with conformal radiotherapy associated to 6 months of hormone therapy with luteinizing hormone/releasing hormone analog. During follow-up, prostate-specific antigen value increased to 0.27 ng/mL and the patient underwent 18F-methylcholine positron emission tomography/computed tomography (18F-choline PET/CT). The whole-body scan demonstrated a focus of increased uptake at level of the left cerebellopontine angle and at the left frontal lobe, corresponding to the known vestibular schwannoma and meningioma. A subsequent brain contrast-enhanced magnetic resonance imaging (MRI) showed an increased dimension of the left cerebellopontine neuroma and dimensional stability of the left frontal meningioma compared with previous MRI of 6 months earlier. To the best of our knowledge, we describe the first case of a 18F-choline PET/CT demonstrating a relapse of a vestibular schwannoma after stereotactic radiotherapy.