Seham A. Ali

CD4 lymphocytes in the blood of HIV+ individuals migrate rapidly to lymph nodes and bone marrow: support for homing theory of CD4 cell depletion

The mechanism(s) by which human immunodeficiency virus (HIV) causes depletion of CD4 lymphocytes remains unknown. Evidence has been reported for a mechanism involving HIV binding to (and signaling) resting CD4 lymphocytes in lymphoid tissues, resulting in up‐regulation of lymph node homing receptors and enhanced homing after these cells enter the blood, and induction of apoptosis in many of these cells during the homing process, caused by secondary signaling through homing receptors. Supportive evidence for this as a major pathogenic mechanism requires demonstration that CD4 lymphocytes in HIV+ individuals do migrate to lymph nodes at enhanced rates. Studies herein show that freshly isolated CD4 lymphocytes labeled with 111Indium and intravenously reinfused back into HIV+ human donors do home to peripheral lymph nodes at rates two times faster than normal. They also home at enhanced rates to iliac and vertebral bone marrow. In contrast, two hepatitis B virus‐infected subjects displayed less than normal rates of blood CD4 lymphocyte migration to peripheral lymph nodes and bone marrow. Furthermore, the increased CD4 lymphocyte homing rates in HIV+ subjects returned to normal levels after effective, highly active antiretroviral therapy treatment, showing that the enhanced homing correlated with active HIV replication. This is the first direct demonstration of where and how fast CD4 lymphocytes in the blood traffic to tissues in normal and HIV‐infected humans. The results support the theory that the disappearance of CD4 lymphocytes from the blood of HIV+ patients is a result of their enhanced migration out of the blood (homing) and dying in extravascular tissues.

Spinal-cerebrospinal fluid leak demonstrated by radiopharmaceutical cisternography

Cerebrospinal fluid (CSF) leaks are known to occur under several conditions: lumbar puncture performed for contrast myelography, spinal surgery, spinal stab wounds, fracture of the thoracic spine, inadvertent spinal puncture during epidural anesthesia, traumatic lumbar meningocele, and bronchopleural subarachnoid fistula due to bronchogenic carcinoma. Spontaneous spinal leaks are uncommonly encountered in neurosurgical practice, but they are increasingly recognized as a cause of spontaneous intracranial hypotension. Most CSF leaks are located at the cervicothoracic junction or in the thoracic spine. The disease is often self-limiting. A CSF leak can be detected directly by accumulation of radioactivity outside the subarachnoid space or suggested indirectly by the rapid disappearance of tracer from the subarachnoid space and early appearance in the urinary bladder. In this paper we present two unusual cases of CSF leak identified by radiopharmaceutical cisternogram.

Sarcoid: An unusual mimicker of classic pulmonary embolus

A patient had both the clinical presentations and the ventilation-perfusion scan that simulated pulmonary embolism so closely that anticoagulant therapy was administered. Computed tomography of the chest and Ga-67 citrate scintigraphy identified hilar adenopathy due to sarcoidosis as the cause of a ventilation-perfusion mismatch.

Three-phase Tc-99m labeled RBC scintigraphy of a splenic hemangioma

A 46-year-old man presented with right upper quadrant pain with a clinical suspicion of cholelithiasis and was referred for an abdominal ultrasound (US). On US evaluation, the liver and gallbladder were normal. Incidentally noted a homogeneous, well demarcated, hyperechoic, 5-cm mass in the inferior portion of the spleen. A subsequent Tc-99m labeled RBC scan showed a 5-cm photopenic area in the inferior portion of the spleen on perfusion and early blood pool images. Subsequent filling in on delayed images with slightly increased uptake relative to surrounding splenic tissue was seen on the final images (85 min). Splenic hemangiomas are rare neoplasms, although they still represent the most common primary neoplasm of the spleen. The incidence of splenic hemangiomas ranges from 0.03-14% in autopsy studies.

Role of Nurses in Daily Nuclear Medicine

The aim of this study is to demonstrate the role of nurses during daily nuclear medicine procedures and to discuss the influence of nurses in quality of patient care, patient preparation and radiation safety in nuclear medicine. Methods: Data was collected from the day to day involvement of nurses during daily nuclear medicine procedures. There are several nuclear medicine procedures identified where the nurses are involved in various tasks. Those imaging studies include many procedures in Oncology, Renal, hepatobiliary, cardiac, thyroid and gastrointestinal Scintigraphy. Results: Nurses spend a significant amount of time during cardiac imaging starting from taking history, review of patient preparation, medications, and laboratory data to ultimately performing clinical examination. For Renal Scintigraphy nurses have an important function, especially in children, starting from placing a Foley catheter, to hydrating after inserting an intravenous line, administering Ace inhibitor medication, if needed, and monitoring vital signs. For thyroid imaging, the role of nurses includes administering thyrogen injections. For gastrointestinal imaging, nurses play a key role in administering drugs like morphine sulfate, cholecystokinin and taking care of various tubes including Gastric, Jejunostomy, Nasogastric tubes and suctioning as needed. Nurses also have an important role taking care of patients during other unexpected emergencies like seizures and cardiac arrest. More important task of nurses includes assisting the technologists how to use and inject radiopharmaceuticals through the central lines, Porta catheter and Hickman catheters. During PET/CT imaging nurses monitor blood glucose and adverse reactions to iodine contrast. Nurses with special training in radiation safety discuss with the patients and other personnel the potential side effects of ionizing radiation. Conclusion: Nurses have an important role in various tasks in assisting the technologists, physicians and patients to carry out daily nuclear medicine procedures. Nurses are essential in providing quality patient care and are crucial in saving patients lives in emergencies during nuclear medicine imaging procedures.

Localization of a bronchopleural fistula in a postpneumonectomy patient using ventilation scintigraphy

A 55-year-old man underwent a right pneumonectomy for squamous cell carcinoma. Three weeks later, he was seen in the emergency room for recurrent episodes of shortness of breath. A right open bronchial stump developed. A ventilation study was performed to identify a bronchopleural fistula. it revealed an immediate accumulation of the radiotracer in the right thoracic cavity.

Agenesis of the right lobe of the liver.

A 70-year-old man had hepatobiliary scintigraphy, which showed agenesis of the right lobe of the liver and hypertrophy of the left lobe. There was no scintigraphic evidence of emptying of the radiotracer into the small bowel. Agenesis of the right lobe of the liver is an extremely rare congenital an

Interventional Radiology Strategies in the Treatment of Pseudomyxoma Peritonei

PurposeTo describe percutaneous maneuvers to treat the unusual entity symptomatic pseudomyxoma peritonei (PMP).MethodsFour patients with PMP were treated by interventional radiology techniques that included large catheters (20–30 Fr) alone (n = 3), multiple catheters (n = 4), and dextran sulfate as a catalytic agent through smaller catheters (n = 1). The causes of the PMP were tumors in the ovary (2 patients), appendix (1 patient), and colon (1 patient). Each patient previously had undergone at least two operations to remove the PMP, and all patients had symptomatic recurrence. An in vitro analysis of catalytic agents also was performed.ResultsAll four patients improved symptomatically. Follow-up CT scans demonstrated marked reduction of PMP material in all cases. One patient underwent another interventional radiology session 5 months after the first; the other three patients had no recurrence of symptoms. One patient had reversible hypotension 2 hr after the procedure. The amount of material removed varied from 3 to 6 L.ConclusionThese interventional radiology techniques were effective and safe for PMP and suggest options for this difficult medical and surgical problem.

Renal scintigraphy of an infarction in an en bloc transplantation of a horseshoe kidney

A 30-year-old woman with end stage renal disease received a cadaveric horseshoe kidney transplant. The horseshoe kidney embryologically represents the fusion of the lower poles of the kidneys in 95% of occasions. Another characteristic is the abnormal blood supply thought to be persistent from the embryonic period. Because each renal artery supplies its own area, there is no collateral circulation between the areas ― an artery ligated by accident will always cause an infarction. This often happens in the fusion bridge, which receives its separate blood vessels from the distal aorta, or even the iliac artery

Incidental massive Ga-67 uptake in the thorax and abdomen for the diagnosis of lumbar osteomyelitis

Ga-67 uptake in lung carcinoma was first described by Edwards and Hayes in their original reports on Ga-67 uptake in tumors. Ga-67 scintigraphy has subsequently become a widely used method of defining the extent of tumoral disease. Uptake of Ga-67 in the primary lesion is reported to occur in 64%-100% of patients. The authors report a case of a 59-year-old man with low back pain who had an MRI with a lesion in L3-L4. Delayed images on the three-phase bone scan showed uptake in L3-L4 consistent with diskitis. Ga-67 scintigraphy showed multiple diffuse foci of increased uptake throughout the chest and abdomen. The biopsy results of one of the lymph nodes confirmed the diagnosis of metastatic adenosquamous carcinoma of the lung. This case confirms the importance of considering malignancy in the differential diagnosis of Ga-67 scintigraphy.