NP-59 SPECT/CT imaging in stage 1 hypertensive and atypical primary aldosteronism: a 5-year retrospective analysis of clinicolaboratory and imaging features.

OBJECTIVE: We retrospectively analyzed all primary aldosteronism (PA) patients undergoing NP-59 SPECT/CT imaging with regard to their clinicolaboratory and imaging features, investigation, and outcomes. MATERIAL AND METHODS: 11 PA patients who presented to our hospital for NP-59 SPECT/CT imaging between April 2007 and March 2012 and managed here were analyzed. RESULTS: Among 11 PA patients, eight (73%) had stage 1 hypertension, three (27%) stage 2 hypertension, four (36%) normal plasma aldosterone concentration, nine (82%) nonsuppressed plasma renin activity (PRA), six (55%) normal aldosterone-renin-ratio (ARR), eight (73%) serum potassium ≧3 mEq/L, seven (64%) subclinical presentation, seven (64%) negative confirmatory testing, and four (36%) inconclusive results on CT scan and seven (64%) on planar NP-59 scan. All 11 (100%) patients had positive results on NP-59 SPECT/CT scan. Two (18%) met typical triad and nine (82%) atypical triad. Among nine atypical PA patients, three (33%) had clinical presentation, six (67%) subclinical presentation, six (67%) negative confirmatory testing, and four (44%) inconclusive results on CT scan and six (67%) on planar NP-59 scan. All patients had improved outcomes. Significant differences between typical and atypical PA existed in PRA and ARR. CONCLUSIONS: NP-59 SPECT/CT may provide diagnostic potential in stage 1 hypertensive and atypical PA.

Use of laxative-augmented contrast medium in the evaluation of colorectal foci at FDG PET.

PURPOSE: To compare the diagnostic accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in the detection of colon lesions with that of delayed PET/computed tomography (CT) performed after the administration of a laxative-augmented contrast medium. MATERIALS AND METHODS: All patients gave written informed consent according to the guidelines issued by the institutional review board. In a prospective study performed from November 2005 to December 2006, images obtained in 847 patients were reviewed by two physicians in consensus. Colorectal FDG uptake on initial PET images that exceeded background FDG accumulation was graded as minimal, equivocal, or positive. When the initial PET scan revealed a colorectal region of increased uptake, either oral or anal laxative-augmented contrast medium was administered on the basis of the site of colorectal FDG focus and delayed PET/CT was performed. Initial PET findings were reevaluated and revised when necessary. Comparison was performed on a per-patient basis. Findings at histopathologic analysis and clinical follow-up served as the reference standard. The accuracy of PET was compared with that of PET/CT by using the McNemar test. RESULTS: Colorectal FDG foci were seen on initial images in 137 patients. Uptake on the initial images was reported as minimal in 14 patients, equivocal in 68, and positive in 55. With use of a laxative-augmented contrast medium and delayed PET/CT, the proportions of equivocal and positive results decreased by 84% (57 of 68 patients) and 58% (18 of 31 patients), respectively. The accuracy of delayed PET/CT in the depiction of colorectal cancer was greater than that of initial PET (93.4% [128 of 137 patients] vs 71.5% [98 of 137 patients], respectively; P < .01). CONCLUSION: Delayed PET/CT with laxative-augmented contrast medium is more accurate than initial PET alone in the detection of colorectal cancer. This approach has promise as a tool for guiding decisions about how to treat patients with colorectal FDG foci. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101193/-/DC1.

Diagnostic value of I-131 NP-59 SPECT/CT scintigraphy in patients with subclinical or atypical features of primary aldosteronism.

Accumulating evidence has shown the adverse effect of long-term hyperaldosteronism on cardiovascular morbidity that is independent of blood pressure. However, the diagnosis of primary aldosteronism (PA) remains a challenge for patients who present with subtle or atypical features or have chronic kidney disease (CKD). SPECT/CT has proven valuable in the diagnosis of a number of conditions. The aim of this study was to determine the usefulness of I-131 NP-59 SPECT/CT in patients with atypical presentations of PA and in those with CKD. The records of 15 patients with PA were retrospectively analyzed. NP-59 SPECT/CT was able to identify adrenal lesion(s) in CKD patients with suspected PA. Patients using NP-59 SPECT/CT imaging, compared with those not performing this procedure, significantly featured nearly normal serum potassium levels, normal aldosterone-renin ratio, and smaller adrenal size on CT and pathological examination and tended to feature stage 1 hypertension and non-suppressed plasma renin activity. These findings show that noninvasive NP-59 SPECT/CT is a useful tool for diagnosis in patients with subclinical or atypical features of PA and those with CKD.

Outcome of surgical resection for protein-losing enteropathy in systemic lupus erythematosus.

Protein-losing enteropathy (PLE) is an uncommon manifestation associated with systemic lupus erythematosus (SLE). Here, a case with SLE and concomitant hypoalbuminemia is reported. Technetium-99m albumin scintigraphy demonstrated a localized lesion in the ascending colon, and the diagnosis of SLE-related PLE was established. Due to a poor response to medical treatment, this patient received surgical resection, but relapse still developed later on. Recurrent protein-lose from the remaining of the colon was documented by repeated images. This report discusses the management of SLE-related PLE and the role of nuclear medicine scintigraphy in the investigation of PLE.

Atypical angioma serpiginosum.

Angioma serpiginosum is an uncommon, acquired vascular nevoid disorder with capillary dilation and proliferation in the papillary dermis. The eruptions are asymptomatic and characterized by grouped, erythematous to violaceous, serpiginous and punctate macules. The condition usually appears in females during adolescence on unilateral lower extremities and the buttocks. We report a rare case with a late onset and atypical distribution of lesions in a 48-year-old female patient who had groups of punctate lesions on her left foot for four to five years. Histopathological examination showed hyperkeratosis and multiple dilated and proliferated capillaries in the papillary dermis. Inflammation and extravasation of red blood cells were not found. According to the clinical and pathological findings, we established a diagnosis of angioma serpiginosum. She was treated with a pulsed dye laser, and the angiomatous lesions subsequently improved.

Predicting hypotensive episodes during spinal anesthesia with the application of artificial neural networks.

Hypotension is one of the most frequent adverse effects of spinal anesthesia. Several factors might be related to the occurrence of hypotension. Predictions of the hypotensive event, however, had been addressed by only a few authors using logistic regression (LR) models. Artificial neural networks (ANN) are pattern-recognition tools that can be used to detect complex patterns within data sets. The purpose of this study was to develop the ANN-based predictive model to identify patients with high risk of hypotension during spinal anesthesia. From September 2004 to December 2006, the anesthesia records of 1501 patients receiving surgery under spinal anesthesia were used to develop the ANN and LR models. By random selection 75% of data were used for training and the remaining 25% of data were used as test set for validating the predictive performance. Five senior anesthesiologists were asked to review the data of test set and to make predictions of hypotensive event during spinal anesthesia by clinical experience. The ANN model had a sensitivity of 75.9% and specificity of 76.0%. The LR model had a sensitivity of 68.1% and specificity of 73.5%. The area under receiver operating characteristic curves were 0.796 and 0.748. The ANN model performed significantly better than the LR model. The prediction of clinicians had the lowest sensitivity of 28.7%, 22.2%, 21.3%, 16.1%, and 36.1%, and specificity of 76.8%, 84.3%, 83.1%, 87.0%, and 64.0%. The computer-based predictive model should be useful in increasing vigilance in those patients most at risk for hypotension during spinal anesthesia, in allowing for patient-specific therapeutic intervention, or even in suggesting the use of alternative methods of anesthesia.

Fingerprint verification on medical image reporting system.

The healthcare industry is recently going through extensive changes, through adoption of robust, interoperable healthcare information technology by means of electronic medical records (EMR). However, a major concern of EMR is adequate confidentiality of the individual records being managed electronically. Multiple access points over an open network like the Internet increases possible patient data interception. The obligation is on healthcare providers to procure information security solutions that do not hamper patient care while still providing the confidentiality of patient information. Medical images are also part of the EMR which need to be protected from unauthorized users. This study integrates the techniques of fingerprint verification, DICOM object, digital signature and digital envelope in order to ensure that access to the hospital Picture Archiving and Communication System (PACS) or radiology information system (RIS) is only by certified parties.

Diagnostic trinity: Graves' disease on F-18 FDG PET.

A 31-year-old man underwent a whole-body F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scan for cancer screening. There was no history of diabetes, thyroid disease, or noticeable exercise before imaging. The results demonstrated diffusely increased uptake of F-18 FDG in the thyroid and thymus. In addition, there was symmetrically increased uptake of F-18 FDG in skeletal muscles, especially in the psoas and limb muscles. The concurrent appearance of these characteristics led to a diagnosis of Graves' disease.

Prediction of target range of intact parathyroid hormone in hemodialysis patients with artificial neural network.

The application of artificial neural network (ANN) to predict outcome and explore potential relationships among clinical data is increasing being used in many clinical scenarios. The aim of this study was to validate whether an ANN is a useful tool for predicting the target range of plasma intact parathyroid hormone (iPTH) concentration in hemodialysis patients. An ANN was constructed with input variables collected retrospectively from an internal validation group (n = 129) of hemodialysis patients. Plasma iPTH was the dichotomous outcome variable, either target group (150 ng/L300 ng/L). After internal validation, the ANN was prospectively tested in an external validation group (n = 32) of hemodialysis patients. The final ANN was a multilayer perceptron network with six predictors including age, diabetes, hypertension, and blood biochemistries (hemoglobin, albumin, calcium). The externally validated ANN provided excellent discrimination as appraised by area under the receiver operating characteristic curve (0.83 +/- 0.11, p = 0.003). The Hosmer-Lemeshow statistic was 5.02 (p= 0.08 > 0.05) which represented a good-fit calibration. These results suggest that an ANN, which is based on limited clinical data, is able to accurately forecast the target range of plasma iPTH concentration in hemodialysis patients.

Application of upper extremity radionuclide venography as a diagnostic approach for Port-A catheter thrombosis.

BACKGROUND: To investigate the role of upper extremity radionuclide venography as a potential diagnostic modality in the assessment of venous thrombosis associated with a Port-A catheter. METHODS: Fourteen symptomatic patients who had received Port-A catheter implantation were enrolled. A dynamic nuclear medicine flow study was performed with intravenous administration of Technetium-99m macroaggregated albumin to both upper extremities. Imaging patterns of the venous system were categorized as patency, partial obstruction, and total occlusion. RESULTS: The findings of the dynamic images clearly demonstrated clinical problems. Three patients were free of a definite venous flow change. Three patients had partial obstruction of venous return. A significant cut-off of venous return was demonstrated in 8 patients, and total occlusions were hence diagnosed. All patients underwent this procedure smoothly without any complication. CONCLUSION: These results suggest that upper extremity radionuclide venography is an easily performed and effective method for diagnosing Port-A catheter thrombosis in clinical practice.

Applying an artificial neural network to predict osteoporosis in the elderly.

Osteoporosis is an essential index of health and economics in every country. Recognizing asymptomatic elderly population with high risks of osteoporosis remains a difficult challenge. For this purpose, we developed and validated an artificial neural network (ANN) to identify the osteoporotic subjects in the elderly. The study population consisted of 1403 elderly adults (mean age 63.50 +/- 0.24 years ranged from 50 to 91 years old, 157 male and 1246 female) randomly selected into 3 sets, 703 participants in training set, 350 participants in selection set, and the remaining 350 participants in test set. The input variables included demographic characteristics, anthropometric measurements, and clinical data. The outcome variable was dichotomous, either non-osteoporotic (T-score of greater than -2.5) or osteoporotic (T-score of -2.5 or less) groups classified by the measurement from dual energy X-ray absorptiometry. ANN was constructed with data from training and selection sets and validated in test set whose outcome variable was unknown to the network. The performance of ANN was evaluated by discrimination and calibration simultaneously. After training processes, the final best ANN was a multilayer perceptron network which determined seven input variables (gender, age, weight, height, body mass index, postmenopausal status, and coffee consumption) as significant features. The discriminatory power of ANN for test set was excellent (area under receiver operating characteristics curve = 0.82 +/- 0.03). ANN also had statistically good fit represented by statistically insignificant Hosmer-Lemeshow statistic (p = 0.24). These results suggested that our final ANN concurrently had good discriminatory power and good-fit calibration. ANN can be used as a promising tool for the elderly to stratify high risk subjects into osteoporotic group.

Acute hyperkalemic paralysis in a uremic patient.

Hyperkalemia is a less-recognized life-threatening cause of paralysis. We describe a 38-year-old uremic man on regular hemodialysis (HD) without interruption who suffered from muscle weakness progressing to ascending symmetric paralysis, and inability to masticate. Physical examination revealed flaccid paralysis with areflexia of the four limbs. Computed tomography of the brain and cervical spine did not demonstrate any organic lesions. Laboratory investigations revealed serum K+ 8.1 mmol/L, urea nitrogen 32 mmol/L, creatinine 919 micromol/L. Of note, electrocardiography (ECG) did not show typical features of hyperkalemia. Emergent HD with low K+ dialysate (1.0 mmol/L) rapidly normalized serum K+ (4.7 mmol/L) and reversed all neuromuscular symptoms within one hour. Upon reviewing his food and medication history, he admitted drinking 750 ml of raw coconut juice per day (K+ concentration 44.3 mmol/L) to quench his thirst for three consecutive days. Hyperkalemia should be born in mind in the differential diagnosis of acute paralysis despite no ECG changes. Hidden sources of K+ intake, such as coconut juice, should not be overlooked, especially in patients with impaired renal function.

Biochemical and etiological characteristics of acute hyponatremia in the emergency department.

Hyponatremia can be classified as acute or chronic depending on its duration, and treatment options are tailored to this classification. However, it is sometimes difficult to differentiate acute from chronic hyponatremia in the Emergency Department (ED). The objective of this study was to identify characteristics to help diagnose and manage acute hyponatremia in the ED. Patients with acute hyponatremia in the ED were enrolled from a retrospective 2-year chart review. Eleven patients (0.8%) were identified with acute hyponatremia out of a total of 1321 hyponatremic patients. There were nine women and two men. The mean age was 48.9 years. The mean sodium (Na(+)) level was 115+/-4 mmol/L. Accompanying biochemical abnormalities included hypouricemia and hypouremia with increased fractional excretions of uric acid (UA) and urea. The estimated amount of water intake ranged from 2.5 to 10 liters (mean, 5.1+/-2.3 liters) during the day before ED presentation. All patients were treated with hypertonic saline and furosemide at a correction rate of 1.6+/-0.5 mmol/L/h. No patients had neurological sequelae after treatment. The causes of acute hyponatremia included induction of abortion with oxytocin (n=1), primary polydipsia on neuroleptic agents (n=2), polyethylene glycol (PEG) preparation for colonoscopy (n=1), diuretic therapy for hypertension (n=4), ecstasy use (n=1), and weight-reducing herbal teas (n=2). We conclude that in the right clinical setting, high free water intake and low serum urea and UA favor acute hyponatremia. A detailed drug history may be helpful in the differential diagnosis of acute hyponatremia.

Diagnosis of primary aldosteronism in chronic kidney disease by I-131 NP-59 SPECT/CT imaging.

Primary aldosteronism (PA) may be missed in patients with chronic kidney disease (CKD), because CKD may disturb the renin-angiotensin-aldosterone system. Adrenal vein sampling has increased risks in patients with CKD. We report the case of a 58-year-old man with CKD and suspected PA. Left adrenal aldosteronism was diagnosed by NP-59 SPECT/CT. Left adrenalectomy demonstrated adrenocortical nodular hyperplasia. Plasma aldosterone normalized and blood pressure stabilized after surgery. NP-59 SPECT/CT may be a helpful diagnostic tool for detecting and lateralizing PA in CKD patients.

FDG uptake in sacroiliac joint due to osteitis condensans ilii shown on PET/CT in a patient with breast cancer: the value of coregistered CT in avoiding misinterpretation.

A 56-year-old woman with breast cancer underwent FDG PET/CT at follow-up. The PET images showed increased FDG uptake along right sacroiliac joint. The coregistered CT images showed diffuse sclerosis around the sacroiliac joints, but no bony destruction, periarticular erosion, or joint space narrowing. She had been complaining of intermittent lower back pain since her last pregnancy. The radiologic pictures and history of postpartum back pain were considered as typical characteristics for osteitis condensans ilii. This case reminds us that careful inspection of the coregistered CT images is important to avoid potential misinterpretation because of osteitis condensans ilii.

Asymptomatic metastasis to the larynx detected by FDG PET/CT in a patient with recurrent rectal adenocarcinoma.

Metastasis of colorectal adenocarcinoma to the larynx is a very rare condition. Here, we report a 72-year-old woman with a history of rectal adenocarcinoma. She was referred for whole-body FDG PET/CT scanning because of an elevating serum level of carcinoembryonic antigen. PET images showed focally increased FDG accumulation in the larynx (SUVmax=12.9). Coregistered CT images showed mild wall thickening at the left subglottic area. The findings of after excisional biopsy confirmed that this FDG-avid lesion was metastatic adenocarcinoma of the colorectal origin.