Key Points PET false-negativity was seen in 11% of MM patients. PET false-negativity was associated with low hexokinase-2 expression.

The iliac crest is the sampling site for minimal residual disease (MRD) monitoring in Multiple Myeloma (MM). However, the disease distribution is often heterogeneous, and imaging can be used to complement MRD detection at a single site. We have investigated patients in complete remission (CR) during first-line or salvage therapy, for whom MRD flow-cytometry and the two imaging modalities positron-emission-tomography (PET) and diffusion-weighted magnetic resonance imaging (DW-MRI) were performed at the onset of CR. Residual focal lesions (FLs), detectable in 24% of first-line patients, were associated with short progression-free survival (PFS), with DW-MRI detecting disease in more patients. In some patients, FLs were only PET-positive, indicating that the two approaches are complementary. Combining MRD and imaging improved prediction of outcome, with double-negative and double-positive features defining groups with excellent and dismal PFS, respectively. FLs were a rare event (12%) in first-line MRD-negative CR patients. In contrast, patients achieving an MRD-negative CR during salvage therapy frequently had FLs (50%). Multi-region sequencing and imaging in an MRD-negative patient showed persistence of spatially separated clones. In conclusion, we show that DW-MRI is a promising tool for monitoring residual disease that complements PET and should be combined with MRD.

Spatial intratumor heterogeneity is frequently seen in multiple myeloma (MM) and poses a significant challenge for risk classifiers, which rely on tumor samples from the iliac crest. Because biopsy-based assessment of multiple skeletal sites is difficult, alternative strategies for risk stratification are required. Recently, the size of focal lesions (FLs) was shown to be a surrogate marker for spatial heterogeneity, suggesting that data from medical imaging could be used to improve risk stratification approaches. Here, we investigated the prognostic value of FL size in 404 transplant-eligible, newly diagnosed MM patients. Using diffusion-weighted magnetic resonance imaging with background suppression, we identified the presence of multiple large FLs as a strong prognostic factor. Patients with at least 3 large FLs with a product of the perpendicular diameters >5 cm were associated with poor progression-free survival (PFS) and overall survival (OS; median, 2.3 and 3.6 years, respectively). This pattern, seen in 13.8% of patients, was independent of the Revised International Staging System (RISS), gene expression profiling (GEP)-based risk score, gain(1q), or extramedullary disease (hazard ratio, 2.7 and 2.2 for PFS and OS in multivariate analysis, respectively). The number of FLs lost its negative impact on outcome after adjusting for FL size. In conclusion, the presence of at least 3 large FL is a feature of high risk, which can be used to refine the diagnosis of this type of disease behavior and as an entry criterion for risk-stratified trials.

Spontaneous Intracranial Hypotension typically occurs from spontaneous CSF leak. CSF volume depletion rather than decrease in CSF pressure is thought to be the main causative feature for intracranial hypotension. More and more cases of intracranial hypotension are getting diagnosed with the advances in the imaging. The advances in the imaging have also led to the better understanding of the dynamic changes that occur with intracranial hypotension. The old theories of CSF overproduction or CSF underproduction have not been substantially associated with intracranial hypotension. It has also led to the fore different atypical clinical features and presentations. Although, it has been known for a long time, the diagnosis is still challenging and dilemma persists over one diagnostic modality over other and the subsequent management. Spontaneous CSF leaks occur at the spinal level and the skull base and other locations are rare. The anatomy of spontaneous intracranial hypotension is a very complex process with significant overlap in connective tissue disorders, previous dural weakness or meningeal diverticula. To localize the location of the CSF leak-CT myelography is the modality of choice. CSF cysternography may provide additional confirmation in uncertain cases and also MRI spine imaging may be of significant help in some cases. Spontaneous intracranial hypotension continues to be a diagnostic dilemma and our effort was to consolidate available information on the clinical features, diagnostics, and management for a practicing neurologist for a "15-20 min quick update of the topic".

Patient with prior Warfarin use and IVHs are at risk of hematoma expansion. Aggressive measures to prevent hematoma growth are important in these patients.

Pneumonia was the most common infection among patients with intracerebral hemorrhage.

A 36-year-old female patient presented to our stroke neurology clinic for progressively worsening intractable, sharp, shooting interscapular pain radiating to the right shoulder and neck, which she had experienced for 4 years. She had previously seen an orthopedist and was referred to a neurosurgeon for surgical intervention after an MRI of the cervical spine showed the C3–C4 right vertebral artery loop protruding into the right C3–C4 neural foramen and compressing the exiting C4 nerve root. MR neurography showed a stable tortuous right vertebral artery loop, causing a mass effect on the dorsal root ganglion. A neuroforaminal decompression surgery was planned. However, the patient visited our stroke neurology clinic for a second opinion before surgery. An MRI of the thoracic spine showed an enhancing soft tissue mass at the right T4–T5 pedicles and adjacent body. A chest CT with contrast showed a 1 cm radiolucent lesion in the superior articular facet of T5, which represented a nidus. A technetium bone scan showed focal increased uptake within the right T5 pedicle, which is indicative of osteoid osteoma. The patient underwent laminectomy/resection and was pain-free at a 6-month follow-up; biopsy confirmed osteoid osteoma. This case illustrates the importance of neurolocalization during diagnostic testing.

The clinical presentation of contrast-induced encephalopathy (CIE) varies widely, including altered mental status, focal motor and sensory deficit, visual disturbance, ophthalmoplegia, global aphasia, and seizures.Radiologically, CIE can mimic subarachnoid hemorrhage (SAH) on CT head with hyperdensity in the subarachnoid space due to iodinated contrast extravasation.CIE is a diagnosis of exclusion that requires comprehensive workup and close monitoring of neurologic examination. Case reportA 72-year-old woman with history of hypertension and hyperlipidemia presented with chest pain, lightheadedness, and diaphoresis. ECG revealed acute inferior myocardial injury and she was loaded with clopidogrel 600 mg and aspirin 81 mg and underwent emergent percutaneous coronary angioplasty for 100% occlusion of the right coronary artery with placement for 3 drugeluting stents. A total of 210 mL of iodinated contrast with low osmolarity (884 mOsm/kg) was used. There was no complication during the procedure. Immediately after the procedure, the patient was found to be confused. Head CT without contrast revealed hyperdensity (70 Hounsfield units [HU]) along right hemispheric gyri with mild cerebral edema, concerning for subarachnoid hemorrhage (SAH) (figure 1A). The patient was transferred to the intensive care unit at our institution for suspected hemorrhagic stroke. There was no report of seizure activity or acute or chronic renal dysfunction.