Mucus clears from the trachea in a helix: a new twist to understanding airway diseases.

BACKGROUND: Mucociliary clearance (MCC) is critical to lung health and is impaired in many diseases. The path of MCC may have an important impact on clearance but has never been rigorously studied. The objective of this study is to assess the three-dimensional path of human tracheal MCC in disease and health. METHODS: Tracheal MCC was imaged in 12 ex-smokers, 3 non-smokers (1 opportunistically imaged during acute influenza and repeated after recovery) and 5 individuals with primary ciliary dyskinesia (PCD). Radiolabelled macroaggregated albumin droplets were injected into the trachea via the cricothyroid membrane. Droplet movement was tracked via scintigraphy, the path of movement mapped and helical and axial models of tracheal MCC were compared. MEASUREMENTS AND MAIN RESULTS: In 5/5 participants with PCD and 1 healthy participant with acute influenza, radiolabelled albumin coated the trachea and did not move. In all others (15/15), mucus coalesced into globules. Globule movement was negligible in 3 ex-smokers, but in all others (12/15) ascended the trachea in a helical path. Median cephalad tracheal MCC was 2.7 mm/min ex-smokers vs 8.4 mm/min non-smokers (p=0.02) and correlated strongly to helical angle (r=0.92 (p=0.00002); median 18o ex-smokers, 47o non-smokers (p=0.036)), but not to actual speed on helical path (r=0.26 (p=0.46); median 13.6 mm/min ex-smokers vs 13.9 mm/min non-smokers (p=1.0)). CONCLUSION: For the first time, we show that human tracheal MCC is helical, and impairment in ex-smokers is often caused by flattened helical transit, not slower movement. Our methodology provides a simple method to map tracheal MCC and speed in vivo.

False positive metastatic disease due to combined thoracic and subcutaneous splenosis.

A 56-year-old man presented with dyspnea secondary to pulmonary emboli and dilated cardiomyopathy. His past medical history included a history of emergency laparotomy, splenectomy, and splenic flexure resection following a gunshot injury 30 years ago. CT and MRI imaging demonstrated multiple homogeneously enhancing lobulated lesions at the left-sided pleura and chest wall with an irregular calcified spleen. The aforementioned lesions demonstrated a similar level of tracer uptake to the splenic activity with no evidence of other FDG avid malignancy on the follow-up 18F-FDG PET study. All the above-mentioned pleural and chest wall lesions demonstrated intense tracer accumulation on technetium-99m labeled heat-damaged red cell scintigraphy, consistent with combined thoracic and subcutaneous splenosis.

Accessory Thyroid Tissue Detected Using 131 I SPECT/CT Imaging.

ABSTRACT: Thyroid ectopia has been described as a rare congenital anomaly, characterized by the presence of a thyroid gland in locations other than the orthotopic pretracheal location. The prevalence of accessory thyroid tissue in patients undergoing postablative radioiodine therapy in a 12-month period at a tertiary hospital nuclear medicine department was assessed. Fifty-seven patients were treated between September 2020 and September 2021. Retrospective analysis identified the presence and location of all accessory thyroid tissue separate from the orthotopic pretracheal thyroid gland. Accessory thyroid tissue was present in 21.1% (12/57) of the patients. Accessory thyroid tissue was most commonly located in the lingual region.

Reflux scintigraphy in gastro-esophageal reflux disease: a comparison study with 24 hour pH-impedance monitoring.

OBJECTIVE: Reflux scintigraphy is often used to diagnose gastro-esophageal reflux disease (GERD). However, the efficacy of this study remains controversial. Our aim was to determine the role of reflux scintigraphy in diagnosing GERD by comparing it to 24 h combined pH-impedance study as the gold standard. MATERIALS AND METHODS: Adult patients who presented for investigations of reflux symptoms were prospectively recruited into the study. All patients underwent high resolution esophageal manometry and those with major motor disorders of the esophagus were excluded. Eligible patients immediately underwent reflux scintigraphy following insertion of the pH-impedance catheter. RESULTS: Thirty patients were included in the study. Using a total acid exposure time (AET) of >4.2% as the reference for abnormal acid reflux, reflux scintigraphy had a sensitivity and specificity of 62.5 and 68.2%, respectively, in detecting acid reflux. When compared to AET >6%, reflux scintigraphy had a sensitivity and specificity of 66.7 and 62.5%, respectively, and a positive predictive value of 30.8% and a negative predictive value of 88.2%. There were no associations between outcomes of reflux scintigraphy and total AET (p = .46), total (acid or non-acid) reflux events (p = 0.11), proximal AET (p = .33) or the number of proximal reflux episodes (p = .75) on 24 h pH-impedance study. CONCLUSIONS: Reflux scintigraphy has limited role in diagnosing GERD when compared to 24 h combined pH-impedance monitoring.

Dissecting Mycotic RCA Aneurysm Detected on 67Ga Scintigraphy.

ABSTRACT: A 61-year-old man presented with pneumonia and myocardial infarction on a background of diabetes and end-stage renal failure. Methicillin-resistant Staphylococcus aureus bacteremia was confirmed in the setting of ongoing pyrexia. The patient was referred for a 67Ga study, which revealed Ga-avid active disease in the pericardial effusion. This was localized further on CT/MRI and coronary angiography to a dissecting right coronary artery aneurysm, which was treated with surgical repair and long-term antibiotic treatment.

131I Ablation of an Entire Thyroid Gland in Locally Invasive Differentiated Thyroid Cancer Without Surgery.

ABSTRACT: A 79-year-old man with locally metastatic papillary thyroid cancer to left-sided cervical lymph nodes was referred for radioiodine therapy. He was considered unfit for thyroidectomy due to extensive local involvement and severe interstitial lung disease requiring continuous oxygen. The patient was treated with low doses of radioiodine (approximately 30 mCi) every 6 months with corticosteroid cover for 3 years with good effect. Sequential 131I scanning and serum thyroglobulin levels confirmed virtual complete ablation of the thyroid gland. The patient remained well on thyroid hormone replacement.

Pachymeningitis Demonstrated on Gallium SPECT/CT Scan.

A 34-year-old woman presented with a 3-month history of right-sided headaches associated with photophobia and pulsatile tinnitus. Investigations including lumbar puncture revealed elevated opening CSF pressure, increased protein, and presence of monocytosis consistent with an inflammatory/infective process. Brain MRI showed an area of thickened enhancing dura around the venous sinus posteriorly. Ga scintigraphy demonstrated focal intracranial uptake in the posterior occipital region, and biopsy confirmed a chronic inflammatory infiltrate with no granulomas.

Assessing the Risks Associated with MRI in Patients with a Pacemaker or Defibrillator.

BACKGROUND: The presence of a cardiovascular implantable electronic device has long been a contraindication for the performance of magnetic resonance imaging (MRI). We established a prospective registry to determine the risks associated with MRI at a magnetic field strength of 1.5 tesla for patients who had a pacemaker or implantable cardioverter-defibrillator (ICD) that was "non-MRI-conditional" (i.e., not approved by the Food and Drug Administration for MRI scanning). METHODS: Patients in the registry were referred for clinically indicated nonthoracic MRI at a field strength of 1.5 tesla. Devices were interrogated before and after MRI with the use of a standardized protocol and were appropriately reprogrammed before the scanning. The primary end points were death, generator or lead failure, induced arrhythmia, loss of capture, or electrical reset during the scanning. The secondary end points were changes in device settings. RESULTS: MRI was performed in 1000 cases in which patients had a pacemaker and in 500 cases in which patients had an ICD. No deaths, lead failures, losses of capture, or ventricular arrhythmias occurred during MRI. One ICD generator could not be interrogated after MRI and required immediate replacement; the device had not been appropriately programmed per protocol before the MRI. We observed six cases of self-terminating atrial fibrillation or flutter and six cases of partial electrical reset. Changes in lead impedance, pacing threshold, battery voltage, and P-wave and R-wave amplitude exceeded prespecified thresholds in a small number of cases. Repeat MRI was not associated with an increase in adverse events. CONCLUSIONS: In this study, device or lead failure did not occur in any patient with a non-MRI-conditional pacemaker or ICD who underwent clinically indicated nonthoracic MRI at 1.5 tesla, was appropriately screened, and had the device reprogrammed in accordance with the prespecified protocol. (Funded by St. Jude Medical and others; MagnaSafe ClinicalTrials.gov number, NCT00907361 .).

A Brief Nonmotor Screen Combined with Transcranial Ultrasound may Improve Diagnostic Accuracy of Parkinson's Disease.

BACKGROUND: The addition of a simple nonmotor symptom (NMS) screen and transcranial sonography (TCS) to standard clinical assessment may improve the diagnostic accuracy of Parkinson's disease (PD). METHODS: Sixty-nine subjects (23 established PD group, 23 healthy controls, and 23 possible PD) were enrolled. All completed 3 "yes-no" NMS questions (score, 0-3) and had a transcranial ultrasound assessing nigral hyperechogenicity (score, 0-1). A combined PD risk score of 0 to 4 was obtained for each subject. A PD risk score of ≥2 was used as the diagnostic cutoff for PD. RESULTS: In the established PD group, there was an average of 2 NMSs per person or a group total of 46 of 69 possible NMSs, but only 4 of 69 NMSs in the healthy control group. Of the technically satisfactory TCS, 16 of 20 (80%) of the established PD group and 2 of 16 (12.5%) of the healthy control group were TCS positive. Using ≥2 NMSs alone as the cutoff identified 17 of 23 (74%) of the established PD and 100% of the healthy controls. The PD risk score of ≥2 identified 21 of 23 (91%) of the established PD as PD and 22 of 23 (96%) of the healthy control group as non-PD. In the possible PD group, the PD risk score identified 9 of 18 (50%) of those with a final clinical diagnosis of PD and 4 of 5 (80%) of non-PD. CONCLUSIONS: The combination of a brief NMS screen and TCS discriminated well between normal healthy controls and established PD. A positive TCS and one NMS, or a negative TCS with two NMSs, indicated a likely diagnosis of PD.