Using gastric emptying scintigraphy to evaluate antral contractions and duodenal bolus propagation.

Our aim was to investigate the feasibility of measuring antral contractions and duodenal bolus propagation (DBP) during dynamic antral contraction scintigraphy (DACS) as an assessment of antro-pyloro-duodenal coordination (APDC). Gastric emptying scintigraphy (GES) with DACS was performed with Tc-99m sulfur colloid (SC) using increasing doses of 74 MBq (2 mCi) for 10 subjects, 185 MBq (5 mCi) for 11, and 370 MBq (10 mCi) for 11. DACS was performed for 10 min after static images at 0, 30, 60, 120, 180, and 240 min in anterior and right anterior oblique (RAO) projections. Best projection and lowest dose of Tc-99m SC were assessed visually. DBP were quantified utilizing duodenal activity peaks from a region of interest in the first portion of the duodenum. DBP was better visualized in the RAO projection than anterior projection and using 185 MBq (5 mCi) and 370 MBq (10 mCi) compared with 74 MBq (2 mCi). DBP showed infrequent and irregular bolus transfers from the antrum to the duodenum. Antral activity peaks at 60 min averaged 2.91 ± 0.66 per minute and duodenum bolus peaks 0.36 ± 0.18 per minute (ratio 0.36/2.91 = 0.12). DBP activity peaks can be measured during GES with DACS but requires a 185-MBq (5 mCi) dose of Tc-99m SC radiolabeled test meal for adequate DBP signal detection and is better imaged in RAO than anterior projection. DBPs over the first 60 min postmeal ingestion are infrequent with only 12% of the antral contractions propagating into the duodenum. This methodology appears promising to assess APDC.NEW & NOTEWORTHY This study shows that duodenal bolus propagations after meal ingestion can be measured during gastric emptying scintigraphy using dynamic scintigraphy. Duodenal bolus propagation over the first 60 min postmeal ingestion are infrequent with only 12% of the antral contractions propagating into the duodenum. This methodology appears promising to assess antropyloroduodenal coordination in patients with unexplained symptoms of upper gastrointestinal dysmotility.

False-Positive 123I-Uptake Mimics Metastatic Lung Disease in a Patient With Interstitial Lung Disease Secondary to Scleroderma.

ABSTRACT: A 59-year-old woman with a history of papillary thyroid cancer status post total thyroidectomy and 131I ablation therapy presented with lower back pain and leg weakness. MRI of the lumbar spine revealed homogenously enhancing lesions at L1-L2 and L3-L4. Subsequent whole-body 123I-Na scan demonstrated significant 123I retention in the mid to distal esophagus, as well as diffuse uptake in basal segments of the lungs bilaterally. SPECT/CT of the lumbar vertebra was unremarkable. Although 123I-Na uptake often indicates metastatic recurrence, these findings were better explained by nonspecific radioiodine uptake secondary to systemic complications of the patient's underlying scleroderma.

An unusual presentation of non-IBD related colorectal primary extranodal diffuse large B cell lymphoma with a colo-colonic fistula.

Diffuse large B cell lymphoma of the sigmoid colon and rectum is relatively uncommon and aggressive. Due to its nonspecific symptomatology, patients are often diagnosed late into the disease and present with life-threatening complications, such as hemorrhage, obstruction, or perforation, requiring emergent surgical intervention. Patients with colorectal lymphoma typically have inflammatory bowel disease or immunosuppression. We present a case of a 79-year-old male with no known inflammatory bowel disease or immunosuppression, who had significant weight loss, diarrhea, and abdominal fullness, found by CT to have irregular wall thickening of the recto-sigmoid colon along with a colo-colonic fistula, concerning for bowel perforation. Endoscopic evaluation and biopsy confirmed the diagnosis of recto-sigmoid Diffuse large B cell lymphoma, with a PET/CT scan revealing stage IV disease. He had a partial response to six cycles of palliative reduced dose R-CHOP and is currently receiving palliative radiation to the sigmoid colon and rectum. Surgery and/or chemoradiation remain the mainstay therapy for this condition. Clinicians, however, must consider patient's functional, nutritional, and clinical status prior to choosing an optimal therapeutic regimen. This case illustrates a unique clinical presentation of this condition and the associated diagnostic and therapeutic challenges that arise in order to prevent life-threatening complications.

The Utility of Adding a Liquid-Nutrient Meal to Aid Interpretation of Small-Bowel Transit Scintigraphy.

Small-bowel transit scintigraphy (SBTS) evaluates the accumulation of a radiolabeled meal in the terminal ileal reservoir (TIR) 6 h after ingestion. The location of the TIR may be difficult to determine because anatomic information is limited; for equivocal studies, the patient is asked to return the next day to help determine the TIR location by potential transit into the colon. The purpose of this study was to evaluate whether administration of an additional liquid-nutrient meal (LNM) at 6 h can promote movement of the radiolabeled meal to aid in the interpretation of SBTS and eliminate the need for the patient to return. Methods: This retrospective study reviewed 117 SBTS studies from February 2017 to September 2019. Patients were fed a standardized mixed radiolabeled solid-liquid meal for gastric emptying with SBTS according to Society of Nuclear Medicine and Molecular Imaging practice guidelines. An additional LNM was given at 6 h, and post-LNM images were obtained at least 20 min after the LNM. Two board-certified nuclear medicine physicians independently evaluated all images as equivocal or diagnostic at 6 h. Results: Of the 117 patients (71.8% female; median age, 42.0 y) undergoing SBTS, 37 were equivocal cases at 6 h before the LNM (31.6%; 95% CI, 23.3%-40.9%), compared with 12 equivocal cases after the LNM (10.3%; 95% CI, 5.4%-17.2%). Of the equivocal cases, 25 (69.4%; 95% CI, 51.9%-83.7%) had a definitive result after the LNM, whereas 11 (30.6%; 95% CI, 16.4%-48.1%) remained equivocal and 1 showed rapid transit. Among the 23 patients with gastroparesis, only 13 (57%) responded to the LNM, and none of the 3 patients with irritable bowel syndrome responded. Conclusion: The number of equivocal SBTS cases decreased after administration of an LNM at 6 h, converting to a definitive result. This suggests that with use of an LNM, most patients can complete SBTS in 1 d without the need for repeat imaging at 24 h. Administering an LNM appears to be less effective for patients with gastric disorders. However, the clinical significance remains to be explored, and it is unclear whether such patients have both a gastric and a small-bowel disorder, hence reducing any motility-promoting effect of the LNM.

Addition of small-bowel transit scintigraphy to gastric emptying for assessment of patients with upper gastrointestinal symptoms.

BACKGROUND: Dyspeptic symptoms are not well correlated with gastric emptying (GE) results. AIMS: To determine (a) prevalence of delayed SB transit (SBT) in patients undergoing GE scintigraphy for symptoms of gastroparesis; (b) symptoms associated with delayed SBT. METHODS: Patients with symptoms of gastroparesis underwent combined GE and SBT scintigraphy (GES/SBTS). Patients ingested a mixed solid (S)-liquid (L) meal with egg whites labeled with 500 µCi Tc-99 m sulfur colloid and water with 125 µCi In-111 DTPA. Retained S and L gastric activity and percent of L In-111 activity in terminal ileum (TI) and/or cecum/colon at 6 h were determined. Patient Assessment of Gastrointestinal Symptoms (PAGI-SYM) assessed symptoms from 0 (none) to 5 (very severe). KEY RESULTS: Of 363 patients, 174 (47.9%) had delayed S GE, 141 (38.8%) delayed L GE, and 70 (19.3%) delayed SBT. Delayed SBT was seen in 24 (6.6%) with normal S GE and 46 (12.7%) with delayed S GE. Patients with isolated delayed SBT had highest symptom scores for postprandial fullness (3.5), stomach fullness (3.4), nausea (3.2), bloating (3.2), compared to isolated delayed S GE who had highest symptom scores for postprandial fullness (3.7), nausea (3.6), stomach fullness (3.4), and early satiety (3.3). CONCLUSIONS & INFERENCES: Delayed SBT occurred in 19.3% of dyspeptic patients using GES/SBTS. While postprandial and stomach fullness were common to both delayed S GE and delayed SBT, early satiety was associated with delayed S GE whereas bloating was associated with delayed SBT. Thus, SBTS can augment GES to help explain some symptoms associated with dyspepsia and suspected gastroparesis.

A Rare Case of Primary Anorectal Melanoma and a Review of the Current Landscape of Therapy.

INTRODUCTION: Anorectal mucosal melanoma (ARMM) is an uncommon and highly aggressive malignancy. Given its rarity, there is insufficient evidence on the optimal medical management which presents as a clinical challenge to its diagnosis and treatment. Treatment of ARMM typically involves a multimodal approach including surgical resection, chemotherapy, targeted therapy and/or immunotherapy. CASE PRESENTATION: Here, we present a case of a 78-year-old female who presented with a four-month history of rectal bleeding and bowel incontinence. Ultimately, colonoscopy revealed a mass at the anal verge, and biopsy of the mass showed malignant cells that stained positive for S100, Melan-A and HMB-45, consistent with the diagnosis of malignant melanoma. Molecular testing revealed no BRAF, KIT or NRAS gene mutations. PD-L1 immunohistochemistry showed tumor proportion score of 1%. She underwent abdominoperineal resection with a plan to initiate immunotherapy with an anti-PD-1 checkpoint inhibitor. This case highlights a rare aggressive malignancy and reviews its treatment option, which are mostly extrapolated from its cutaneous counterpart and some derived from a few case reports. Due to its rarity, there is no consensus guideline for the treatment of ARMM.

Pulmonary Artery Intimal Sarcoma: A Diagnostic Challenge Using a Multimodal Approach.

Pulmonary artery intimal sarcoma (PAIS) is a rare tumor without clear syndromic presentation other than nonspecific symptoms of cough, dyspnea, and weight loss. This diagnosis is difficult due to challenging radiographic interpretations of multiple imaging modalities. We present a case of a 60-year-old male, who presented to his pulmonologist and underwent a CT chest with IV contrast that initially suggested primary lung carcinoma. CT angiogram showed significant vascular filling defects suspicious of an intravascular mass, rather than vascular invasion by lung lesions. The PET/CT scans further suggested a malignant process, but indistinguishable between an extravascular or intravascular etiology. Taking these results together, they suggested an intravascular malignancy, prompting a tissue biopsy, which ultimately led to a diagnosis of PAIS with metastases. Establishing a definitive diagnosis is essential as treatment and prognosis are different for sarcoma compared to carcinoma. There is no standard treatment to date, and management often includes a multidisciplinary approach involving surgery, radiation, chemotherapy, and targeted therapy. PAIS is a rare entity that cannot be diagnosed clinically and needs a multimodality approach for its diagnosis.

Seeded Biopsy Tract Recurrence After Extirpative Surgery for Renal Cell Carcinoma.

Background: Renal mass biopsy (RMB) is an increasingly utilized modality in the work-up of patients with suspicious renal masses. Recurrence of renal cell carcinoma (RCC) from biopsy tract seeding is exceedingly rare in the literature. We report a case of such a phenomenon. Case Presentation: Our patient is a 75-year-old Caucasian man and former smoker with a functionally solitary left kidney, initially worked up for gross hematuria and left flank pain. Imaging revealed hydronephrosis and a left renal mass, which was biopsied. Pathology analysis demonstrated clear cell RCC, and a left robotic radical nephrectomy was performed with negative surgical margins. Sixteen months postoperatively, imaging revealed multiple small masses along the biopsy tract, suspicious for recurrence. These were biopsied and pathology analysis confirmed recurrent clear cell RCC. Conclusion: Despite its rarity, biopsy tract seeding is a serious complication of RMB. This warrants thorough counseling and shared decision making between providers and all patients with renal masses planning to undergo a RMB.

Incidental COVID-19 in the radiology department: Radiographic findings of COVID-19 in asymptomatic patient undergoing CT staging for breast cancer.

A 59-year-old incarcerated woman who was diagnosed with invasive ductal carcinoma in 2016 was brought in for evaluation of the breast cancer. Upon evaluation of the computed tomography chest for breast cancer restaging, diffuse bilateral ground glass opacities and a reverse halo sign in the right lower lobe concerning for atypical viral pneumonia were discovered. The patient was afebrile, had an oxygen saturation of 100%, and denied chest pain as well as shortness of breath. On physical exam, she exhibited decreased breath sounds bilaterally and expiratory wheezing. She later received a COVID-19 test, which came back positive. Infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also known as COVID-19) may remain asymptomatic in the initial phase, leading to under-recognition and incidental detection on procedures for standard clinical indications. Hospitals, in particular diagnostic imaging services, should prepare accordingly in regard to health precautions while keeping in mind the potential discrepancies between clinical presentation and resultant radiologic patterns. This awareness should be heightened in patients at higher risk (ie, prisoners). Furthermore, by acting upon the incidental detection of this virus during its early stages, subsequent steps could help prevent the spread of the virus.

Renal Metastasis From Primary Thyroid Cancer on 131I and MRI Imaging.

A 66-year-old woman with a history of papillary thyroid cancer status after total thyroidectomy underwent I radioiodine ablation therapy 3 months after surgery. Posttherapy whole body planar imaging revealed focal intense I uptake in the posterior right abdomen. SPECT/CT of this region localized the uptake to the medial lower pole of the right kidney. Further evaluation with MRI demonstrated a correlative suspicious right renal mass. The patient underwent right partial nephrectomy with pathology demonstrating that the renal mass was of thyroidal origin (papillary subtype).

Idiopathic acute renal vein thrombosis in a young healthy woman with no hypercoagulable state taking oral contraceptives.

Renal veins rarely thrombose. However, when they do, the cause is almost always obvious. The clinical circumstances underlying acute or chronic renal vein thrombosis are well defined. Interestingly, the use of oral contraceptive medications is not recognized among the risk factors for renal vein thrombosis. We report a case of spontaneous renal vein thrombosis in an otherwise healthy young woman taking an oral contraceptive. This report is intended to alert clinicians to a previously unknown and serious event associated with the use of a common medication.